Pharmaceutical Sciences Notes

NTA Level 4 • Semester 1 • PST04103 Structure and Functions of Muscle Tissues Human Anatomy and Physiology • Source Session/Topic 8 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 8: Structure and Functions of Muscle Tissues Prerequisites None Total Session Time: 60 minutes Learning Tasks By the end of this session, students are expected to be able to: • Define Muscle and Cell Tissues • Mention types of Muscle Tissues • Describe Structure of Muscle Tissues • Describe Functions of Muscle Tissues Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector, Transparencies, Anatomy Atlas and Models, LCD and Computer • figure 8.1: The Muscle Fibres • figure8.2: o 8.2 a Skeletal, o 8.2 b Cardiac, o 8.2 c Smooth Muscle • Figure 8.3: The Neuron SESSION OVERVIEW |Step |Time |Activity/ | | | | |Method |Content | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |05 minutes |Presentation |Definition of Muscle and cell | | | |Brainstorming |Tissues | |3 | |Presentation |Types of Muscle Tissues | | |10minutes | | | |4 |10 minutes|Presentation |Structure of Muscle Tissues | |5 |20 minutes |Presentation |Function of Muscle Tissues | |6 |05 minutes |Presentation |Key Points | | 7 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Definition of Muscle and cell Tissues (5 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is a muscle tissue? | |What is a muscle cell? | |ALLOW few students to respond and let other pairs to add on points not | |mentioned | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | Muscle tissue: specialized to contracts when it is stimulated and thus to exert a physical force on other tissue. o When a skeletal muscle contracts pulls on a bone and enhance movement, the heart muscle contracts and expel blood. o Other processes like digestion, waste elimination, breathing speech and blood circulation depends on muscular tissue. o The muscles are also an important source of body heat o As any other tissue, o muscular tissue is made up of cells Muscle Cells • Referred to as myocytes or muscle fibres o Muscle cells are usually grouped into bundle o Muscle cells are usually elongated and spindle-shaped o They function by shortening their length, approximating the two opposite points, which are attached to connective tissue structures such as septa, trabeculae, fasciae, tendons, periosteum or bone o The shortening of the muscle cell is called contraction o The structural unit of a muscle is a muscle fibre o The muscle fibres are made up of fibrils are divisible into individual filaments o The contractile property of muscle cells is determined by the presence of the filamentous contractile proteins, actin and myosin STEP 3: Types of Muscle Tissues (10 minutes) Types of Muscle Tissues • There are three types of muscle tissues which can be distinguished basing on both structure and functions, o Skeletal muscle tissues (striated voluntary muscle) o Cardiac muscle tissues (striated involuntary muscle) o Smooth muscle tissues (smooth involuntary muscle) Figure 8.1: Muscle Fibres [pic] STEP4: Structure of Muscle Tissues (10 minutes) Cardiac Muscle Tissue • This is a unique tissue found only in the walls of the heart. • Cardiac (Heart) Muscle Tissue shows some of the characteristics of smooth muscle and some of skeletal muscle tissue. • Its fibres, like those of skeletal muscle, have cross-striations and contain numerous nuclei. • However, like smooth muscle tissue, it is involuntary. • Cardiac muscle forms the muscular wall of the heart the myocardium. • Some cardiac muscle is also present in the walls of the aorta, pulmonary vein, and Superior vena cava cardiac muscle contractions are not under voluntary control. • Heart rate is regulated intrinsically by a pacemaker, composed of special cardiac muscle fibres that are influenced by the autonomic nervous system. Figure 8.2 a. Cardiac muscle [pic] Source: Moore, K. L., &Agur, A. M. R. (2007) Smooth Muscle Tissue • This type is also called non-striated or involuntary muscle. • Each cell has many myofibrils which lie parallel to one another in the direction of the long axis of the cell. • They are not arranged in a definite striped (striated) pattern, as in skeletal muscles, hence • This muscle is mainly visceral in distribution, forming the contractile portion of the wall of the digestive tract from the mid-oesophagus to anus, including the ducts of glands associated with the system. • It is found in the respiratory, urinary and genital system; in arteries, veins and larger lymphatics, in the dermis and in the iris and ciliary body of the eye. • In these locations, it functions in moderating and maintaining lumen diameter of the hollow viscera. • Smooth muscle is composed of long spindle-like cells, which in cross- section appear as narrow circular profiles. • Each cell possesses a characteristic centrally located elongated nucleus. • In contracted cells, these nuclei are frequently folded or pleated. • At the poles of the nucleus lie numerous mitochondria, well-developed rough endoplasmic reticulum, and a large golgi apparatus. Figure 8.2 b. Smooth muscle [pic] Source: Moore, K. L., &Agur, A. M. R. (2007) Skeletal Muscle Tissue • This type is described as skeletal because it forms those muscles that form movement of the skeleton; it is also known as striated or voluntary muscles. • Striated because striations can be seen on microscopic examination, and voluntary as it is under conscious control. • It consists of bundles of very long cylindrical, multinucleated cells called muscle

NTA Level 4 • Semester 1 • PST04103 Structure and Functions of Nervous Tissues Human Anatomy and Physiology • Source Session/Topic 9 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 9: Structure and Functions of Nervous Tissues Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session, students are expected to be able to: • Define Nervous Tissue • Identify Components of Nervous Tissue • Distinguish Different Types of Neurons • Distinguish Different Types of Neuroglia and their Functions Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector, Transparencies, Anatomy Atlas and Models, LCD and Computer SESSION OVERVIEW |Step |Time |Activity/ | | | | |Method |Content | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 | |Presentation |Definition of Nervous Tissue | | |05 minutes |Brainstorming | | |3 |05minutes |Presentation |Components of Nervous Tissue | |4 |10 minutes |Presentation |Types of Neurons | |5 |25 minutes |Presentation, |Types of Neuroglia and their | | | |Buzzing |Function | |6 |05 minutes |Presentation |Key Points | | 7 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Definition of Nervous Tissue (5minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | |What is nervous tissues? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | Nervous tissue or nerve tissue: • Is the main tissue component of the two parts of the nervous system; the brain and spinal cord of the central nervous system (CNS), and the branching peripheral nerves of the peripheral nervous system (PNS), which regulates and controls bodily functions and activity. o Nervous tissue is distributed throughout the body as an integrated communications network. STEP 3: Components of Nervous Tissue (5minutes) • Structurally, nerve tissue consists of two classes of cell types. o Neurons, the nervous tissue is made up of billions of cells called neurons that are specialized to respond to stimuli and to transmit a signal to activate other cells. o Glial cells or neuroglia, non-excitable supporting cells, participate in neural activity, neural nutritional and defence processes of the central nervous system. • A Typical Neuron Consist of: o Cell body, which has many radiating processes called dendrites, which are specialized to receive signals from other neurons. o Axon, a single long process, which is capable of generating a nerve impulse and conducting it over a long distance to stimulate other neurons in the CNS, or muscular or secretory cells elsewhere in the body. o Neurons usually receive information through dendrites; the information is integrated in the cell body and transmitted onwards via axons. • STEP 4 : Types of Neuron (10 minutes) • Unipolar neurons, these neurons have single processes, the axon arising from the cell body. • Unipolar neurons have no dendrites. • Bipolar neurons, have two processes (both axons) emerging directly and oppositely from the cell body. • Bipolar neurons are found in the cochlear and vestibular ganglia as well as retina and olfactory mucosa. • Multipolar neurons, has one axon and many dozens of dendrites. • Most neurons in the CNS are multipolar. • Pseudo unipolar neurons, has a single short process (an axon) with a T- shaped branching, one branch extending towards the CNS, and the other extending to a periphery ending. • In typical pseudo unipolar neurons, both branches are axons on both structural and electrophysiological grounds. Classification of Neurons according to their Functional Roles • Motor neurons are involved in stimulating muscles or glands (effector organs) in the periphery. • Sensory neurons, sensory neurons receive sensory stimuli from the environment or from tissues and organs of the body. • Interneurons, maintain connection between neurons in the CNS, forming complex functional chains or circuits [pic] Source: Strandring, (2005) Figure 9.3: A Neuron STEP 5: Neuroglia and their Functions (25 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the question for 2 minutes | | | |What is neuroglia? | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | Neuroglia (Glial Cells) • These are supporting cells found in the central nervous system and peripheral nervous system • There are six types of supporting cells • Four are found in the CNS and two are found in the PNS • Neuroglia found in central nervous system are o Astrocytes ▪ Star-shaped, abundant, and versatile ▪ Guide the migration of developing neurons, they are found in large numbers adjacent to blood vessels They form a blood-brain barrier, i.e. the blood is separated from neurones by capillary wall and a layer of astrocytes foot process o Microglia ▪ Specialized immune cells that act as the macrophages of the CNS ▪ They derived from monocytes o Ependymal Cells ▪ These cells form the epithelial lining of the ventricles of the brain and the central canal of the spinal cord o Oligodendrocytes, ▪ These are found in clusters around cell bodies ▪ They form and maintain the myelin, having the same functions as schwann cells in peripheral nerves ▪ These cells have clinical importance as most tumours of the brain are arising from them Glia Cells Found in the Peripheral Nervous System • Satellite cells, surround clusters of neuronal cell bodies in the PNS, they are of unknown function • Schwann cells, form myelin sheaths around the larger

NTA Level 4 • Semester 1 • PST04103 Structure and Functions of the Ear Human Anatomy and Physiology • Source Session/Topic 10 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 10: Structure and Functions of the Ear Total Session Time: 120 minutes + 60 minutes assignment • None Learning Tasks By the end of this session students are expected to be able to: • Define Ear • Describe Structure and Function of the Ear • Explain Mechanism of Hearing and Balance Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer • Handout 10.2: External and Middle Ear • Handout 10.3:Position of the Middle Ear • Handout 10.4: The Inner Ear SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |05minutes |Presentation |Definition of the Ear | | | |Buzzing | | |3 |50minutes |Presentation |Structure and Functions of the Ear | | | |Small group | | | | |discussion | | |4 |50minutes |Presentation |Mechanism of Hearing and Physiology | | | |Brainstorming |of Balance | |5 |05 minutes |Presentation |Key Points | |6 |05 minutes |Presentation |Evaluation | |7 |60 minutes |Presentation |Take Home Assignment | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify STEP 2: Definition of the Ear (5minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What is the ear? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • Ears are paired sensory organs comprising of: o The auditory system, involved in the detection of sound. o The vestibular system, involved with maintaining body balance/ equilibrium. STEP 3: Structure and Functions of the Ear (50minutes) |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What are the Structure and Functions of the Ear | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • The ear divides anatomically and functionally into three regions o The external ear o The middle ear o The inner ear • All three regions are involved in hearing. • Only the inner ear functions in the vestibular system. • The external ear (or pinna, the part you can see) serves to protect the tympanic membrane • (eardrum), as well to collect and direct sound waves through the ear canal to the eardrum. • About 1¼ inches long, the canal contains modified sweat glands that secrete cerumen, or earwax. Too much cerumen can block sound transmission External Acoustic Meatus (External Ear) • The external acoustic meatus extends from the deepest part of the concha to the tympanic membrane (eardrum), a distance of approximately 1 inch (2.5 cm). • Its walls consist of cartilage and bone. • The lateral one-third is formed from cartilaginous extensions from some of the auricular cartilages and the medial two-thirds is a bony tunnel in the temporal bone. • Throughout its length the external acoustic meatus is covered with skin, some of which contains hair and modified sweat glands producing cerumen (earwax). • Its diameter varies, being wider laterally and narrow medially. • The external acoustic meatus does not follow a straight course. • From the external opening it passes upwards in an anterior direction, then turns slightly posteriorly still passing in an upwards direction, and finally, turns again in an anterior direction with a slight descent. Tympanic Membrane • The tympanic membrane separates the external acoustic meatus from the middle ear. • It is at an angle, sloping medially from top to bottom and posteriorly to anteriorly. • It consists of a connective tissue core lined with skin on the outside and mucous membrane on the inside. • Around the periphery of the tympanic membrane a fibrocartilaginous ring attaches it to the tympanic part of the temporal bone. • At its center, a concavity is produced by the attachment on its internal surface of the lower end of the handle of malleus, part of the malleus bone in the middle ear. [pic]Refer to Handout 10.2: External and Middles Ear The Middle Ear • The middle ear is an air-filled, mucous membrane-lined space in the temporal bone between the tympanic membrane laterally and the lateral wall of the internal ear medially. • It is described as consisting of two parts: o The tympanic cavity immediately adjacent to the tympanic membrane o The epitympanic recess superiorly • It connects to the throat/nasopharynx via the Eustachian tube. • This ear-throat connection makes the ear susceptible to infection (otitis media). • The eustachian tube functions to equalize air pressure on both sides of the eardrum. • Normally the walls of the tube are collapsed. • Swallowing and chewing actions open the tube to allow air in or out, as needed for equalization. • Equalizing air pressure ensures that the eardrum vibrates maximally when struck by sound waves. • The middle ear communicates with the mastoid area posteriorly. • Adjoining the eardrum are three linked, movable bones called ossicles, which convert the sound waves striking the eardrum into mechanical vibrations. • The smallest bones in the human body, the ossicles are named for their shape. o The hammer (malleus) connected to the tympanic membrane. o The anvil (incus),

NTA Level 4 • Semester 1 • PST04103 Structure and Functions of Skin Human Anatomy and Physiology • Source Session/Topic 11 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 11: Structure and Functions of Skin Total Session Time: 60 minutes • None Students Learning Tasks By the end of this session students are expected to be able to: • Define Skin • Describe the Structure of the Skin • Explain the Functions of the Skin Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer • Handout 11.1: Layers of the Skin SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |05 minutes |Presentation |Definition of the skin | | | |buzzing | | |3 |15 minutes |Presentation |Structure of the Skin | |4 |25 minutes |Presentation | Functions of the Skin | | | |Brainstorming | | |5 |05 minutes |Presentation |Key Points | |6 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP2: Definition of the Skin (05minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What is the skin? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | Skin: • Is the thin layer of tissue forming the natural outer covering of the body of a person or animal o The body's outer covering, which protects against heat and light, injury, and infection. o Skin regulates body temperature and stores water, fat, and vitamin D. o The skin, which weighs about 6 pounds, is the body's largest organ. STEP 3: Structure of the Skin (15minutes) • Integumentary means covering, it covers the outside of the body. • The integumentary system consists of the skin and the accessory structures such as hair nails and glands. • The appearance of the integumentary system can indicate physiological imbalances in the body. • Disorders of other parts of the body can be reflected there. Structure of the skin • The skin is made up of the two major tissue layers o Dermis o Epidermis Dermis • The dermis is divided into two layers o The deeper reticular layer, is dense irregular connective tissue, is the main layer of the dermis consisting of layers of interlacing collagen fibers o This layer is of elastic and collagens are oriented more in some areas than others creating tension lines (cleavage lines) and wrinkle lines in the skin o The more superficial papillary is called from projections called papillae that extend toward the epidermis o It is less dense than reticular and sometimes called loose connective tissue, it also contain large number of blood vessels o These fibers provide skin tone and account for the strength and toughness of the skin o The pattern of collagen fibers in a particular region determines the characteristic o The deep layer of the dermis contains hair follicles, with their associated smooth arrector muscles and sebaceous glands o Contraction of the arrector muscles erects the hairs (causing goose bumps), thereby compressing the sebaceous glands and helping them secrete their oily product onto the skin o The dermis composed of , nerve endings, hair follicles, smooth muscles, glands, and lymphatic vessels o Skin ligaments, consisting of numerous small fibrous bands, extend through the subcutaneous tissue and attach the deep surface of the dermis to the underlying deep fascia o The length and density of these ligaments determine the mobility of the skin over deep structures [pic]Handout 11.1: Layers of the Skin Epidermis: • A keratinized stratified (layered) epithelium with a tough outer surface composed of keratin (a fibrous protein). • The epidermis is made up of several layers (strata of cells) which extends from the deepest germinative layer to the surface stratum corneum namely: o Basal layer (stratum basale) o Spinous or prickle cell layer (stratum spinosum) o Granular layer (stratum granulosum) o Clear layer (stratum lucidum) o And cornified layer (stratum corneum) • The outer layer of the epidermis is continuously or rubbed away with replacement of new cells from the basal layer. • The cells of epidermis include: o Most of the cells are called keratinocytes because they produce protein called keratin o Melanocytes which contribute to skin colour o Langerhans’ cells which are part of immune system o Merkel’s which are specialized epidermal cells associated with nerve endings responsible for detecting light touch and superficial pressure o This process renews the epidermis of the entire body every 25 to 45 days o The epidermis is avascular (no blood vessels or lymphatics) and is nourished by the vessels in the underlying dermis o The skin is supplied by afferent nerve endings that are sensitive to touch, irritation (pain), and temperature o Most nerve terminals are in the dermis, but a few penetrate the epidermis [pic] Source: Standring, 2005 Figure 11.1: The Epidermis STEP 4: Functions of the Skin (25minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the functions of the skin? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Protection for the body from environmental effects, such as: o Abrasions o Melanin absorb ultraviolet light and protect underlying tissue o Skin prevent

NTA Level 4 • Semester 1 • PST04103 Structure, Functions and disorders of the Eye Human Anatomy and Physiology • Source Session/Topic 12 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 12: Structure, Functions and disorders of the Eye Total Session Time: 120 minutes • None Students Learning Tasks By the end of this session students are expected to be able to: • Define the Eye • Describe Structure and Function of the Eye • Mention Common Disorders of the Eyes • Explain the Common Disorders of the Eye Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |05minutes |Presentation |Definition of the Eye | | | |Buzzing | | |3 |50minutes |Presentation |Structure and Functions of the Eye | | | |Small group | | | | |discussion | | |4 |50minutes |Presentation |Common disorders of the Eye | |5 |05 minutes |Presentation |Key Points | |6 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify STEP 2: Definition of the Eye (10minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What is the eye? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • The eye is the peripheral organ of sight o Is situated in the cavity of the orbit the wall which protect it from injury o The following are the accessory structures of the eyeball: ▪ Muscles ▪ Fascie ▪ Eyebrows ▪ Conjunctiva ▪ Lacrimal apparatus STEP 3: Structure and Functions of the Eye (50minutes) |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | | | |What are the Structure and Functions of the Eye? | | | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | Structure and functions of the eye: • Iris: o Regulates the amount of light that enters your eye o It forms the coloured, visible part of your eye in front of the lens. o Light enters through a central opening called the pupil. • Pupil: o The circular opening in the centre of the iris through which light passes into the lens of the eye o The iris controls widening and narrowing (dilation and constriction) of the pupil • Cornea: o Contains no blood vessels and is extremely sensitive to pain • Lens: o A transparent structure situated behind your pupil o It is enclosed in a thin transparent capsule and helps to refract incoming light and focus it onto the retina o A cataract is when the lens becomes cloudy, • Choroid: o The middle layer of the eye between the retina and the sclera o It also contains a pigment that absorbs excess light so preventing blurring of vision • Ciliary body: o The part of the eye that connects the choroid to the iris • Retina: o A light sensitive layer that lines the interior of the eye o It is composed of light sensitive cells known as rods and cones o The human eye contains about 125 million rods, which are necessary for seeing in dim light o Cones, on the other hand, function best in bright light o There are between 6 and 7 million cones in the eye and they are essential for receiving a sharp accurate image and for distinguishing colours o The retina works much in the same way as film in a camera. • Macula: o A yellow spot on the retina at the back of the eye which surrounds the fovea. • Fovea: o Forms a small indentation at the centre of the macula and is the area with the greatest concentration of cone cells o When the eye is directed at an object, the part of the image that is focused on the fovea is the image most accurately registered by the brain • Optic disc: o The visible (when the eye is examined) portion of the optic nerve, also found on the retina o The optic disc identifies the start of the optic nerve where messages from cone and rod cells leave the eye via nerve fibres to the optic centre of the brain. This area is also known as the 'blind spot’. • Optic nerve: o Leaves the eye at the optic disc and transfers all the visual information to the brain. • Sclera: o The white part of the eye, a tough covering with which the cornea forms the external protective coat of the eye. • Rod cells o Are one of the two types of light-sensitive cells in the retina of the eye o There are about 125 million rods, which are necessary for seeing in dim light. • Cone cells o Are the second type of light sensitive cells in the retina of the eye o The human retina contains between six and seven million cones o They function best in bright light and are essential for acute vision (receiving a sharp accurate image) o It is thought that there are three types of cones, each sensitive to the wavelength of a different primary colour – red, green

NTA Level 4 • Semester 1 • PST04103 Introduction to Gastrointestinal System Human Anatomy and Physiology • Source Session/Topic 13 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 13: Introduction to Gastrointestinal System Total Session Time: 120 minutes + 60 minutes assignment Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define Gastrointestinal System • Explain Gastrointestinal System Overview • Explain Functions of the Gastrointestinal System • Describe Structure of the Oral Cavity • Describe Structure and Functions of the Tongue • Explain Constituents of Salivary Glands • Explain Mechanism of Swallowing Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer • Handout 13.1: The overview of alimentary canal • Handout 13.2: General structure of the alimentary canal • Handout 13.3: The Teeth • Handout 13.4: The Tongue • Handout 13.5: The Salivary glands SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 | |Presentation, |Definition and Overview of | | |20 minutes |Brainstorming |Gastrointestinal System | |3 |15 minutes |Presentation, |Functions of the Gastrointestinal | | | |Brainstorming |System | |4 |20minutes |Presentation |Structure of the Oral Cavity | |5 |15 minutes |Presentation |Structure and Functions of the | | | |Buzzing |Tongue | |6 |10 minutes |Presentation |Salivary Glands and its Constituents| |7 |15 minutes |Presentation |Mechanism of Swallowing | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | |10 |10 minutes |presentation |Take home assignment | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Definition and Overview of Gastrointestinal System (20 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is digestive system? | |What are the organs of digestive system? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Digestive system consists of the digestive tract(alimentary canal) which is a tube extending from the mouth, pass through the thorax, abdomen and pelvis and ends at the anus and its associated accessory organs • Organs of the digestive tract include: o The mouth or oral cavity, which has salivary glands and tonsils as accessory organs o The pharynx, or throat , with tubular mucous glands o The oesophagus, with tubular mucous glands o The stomach, which contains many tube like glands o The small intestine, consisting of the duodenum, jejunum and ileum, with the liver, Gallbladder and pancreas as major accessory organs o The large intestine, including the cecum, colon, rectum and anal canal, with mucus glands o The anus • The digestive system also consists of accessory organs which include the teeth, tongue, salivary glands, liver, gallbladder, and pancreas • Teeth aid in the physical breakdown of food, and the tongue assists in chewing and swallowing. • The other accessory digestive organs produce or store secretions that flow into the GI tract through ducts to aid in the chemical breakdown of food [pic] Figure 13.1: Alimentary Canal and Accessory Organs [pic]Refer students to Handout 13.1: The Overview of Alimentary Canal The gastrointestinal tract is made of four layers of tissues: o Mucosa is the innermost layer made up of three layers ▪ The inner epithelium ▪ Lamina propria ▪ Muscularis mucosae o Submucosa this layer is composed of connective tissue, it contains numerous small glands, blood vessels, and parasympathetic nerves that form the submucosal plexus (Meissner plexus) o Muscular is thick layer of smooth muscle tissue which consists of inner circular layerand outer longitudinal layer o Between the two layers of muscles there is a nervous plexus called myenteric plexus (Auerbach plexus) o Serosa is the outermost layer of made up loose connective tissue (visceral peritoneum) • Layers of the GI tract have various modifications to enable it to perform various functions [pic]Refer students to Handout 13.2: General Structure of the Alimentary Canal STEP 3: Functions of the Gastrointestinal System (15 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the functions of the digestive tract? | | | |ALLOW few students to respond? | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | Overall, the digestive system performs six basic processes: • Ingestion. This process involves taking foods and liquids into the mouth (eating) • Secretion. Each day, cells within the walls of the GI tract and accessory digestive organs secrete a total of about 7 litres of water, acid, buffers, and enzymes into the lumen (interior space) of the tract • Mixing and propulsion. Alternating contractions and relaxations of smooth muscle in the walls of the GI tract mix food and secretions and propel them toward the anus • This capability of the GI tract to mix and move material along its length is called motility • Digestion. Mechanical and chemical processes break down ingested food into small molecules o In mechanical digestion the teeth cut and grind food before it is swallowed, and then smooth muscles of the stomach and small intestine churn the food o As a result, food molecules become dissolved and thoroughly mixed with digestive enzymes o In chemical digestion the large carbohydrate, lipid, protein, and nucleic acid molecules in food are split into smaller molecules by hydrolysis o Digestive enzymes produced by the salivary glands, tongue, stomach, pancreas, and small intestine catalyse these catabolic reactions. A few substances

NTA Level 4 • Semester 1 • PST04103 Structure and Functions of Stomach and Intestines Human Anatomy and Physiology • Source Session/Topic 14 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 14: Structure and Functions of Stomach and Intestines Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Identify structure and Functions of Pharynx and Oesophagus • Describe Structure and Functions of the Stomach • Describe Structure and Functions of the Small Intestines • Describe Structure and Functions of the Large Intestines Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer • Handout 14.1: The Oesophagus • Handout 14.2: General Structure of Stomach • Handout 14.3: Blood Supply to the Stomach • Handout 14.4: The duodenum • Handout 14.5: Structure of Small Intestine • Handout 14.6: Large Intestine • Worksheet 14.1: Large Intestine SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |15 minutes |Presentation |Structure of the Pharynx and | | | | |Oesophagus | |3 |25 minutes |Presentation, |Structure and Functions of the | | | |Brainstorming |Stomach | |4 |30 minutes |Presentation |Structure and Functions of the Small| | | |Brainstorming |Intestines | |5 |35 minutes |Presentation |Structure and Functions of the Large| | | |Individual |Intestines | | | |Assignment | | |6 |05 minutes |Presentation |Key Points | |7 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Structure of the Pharynx and Oesophagus (15 minutes) • Pharynx: A tube through which a bolus passes when moved from the mouth to the oesophagus by the process of deglutition • The pharynx is divided into three parts namely o Nasopharynx o Oropharynx o Laryngopharynx • The Oropharynx is important for digestive system • The wall of the pharynx consists of three layers • These are the Mucosa, Middle layer (Fibrous tissue) and Outer layer consisting of Smooth muscles involved in swallowing • When food enters the pharynx swallowing is no longer under voluntary control • The oesophagus is a narrow muscular tube about 25 centimetres long diameter of 2cm, which starts at pharynx at the back of the mouth • It passes through the thoracic diaphragm, and ends at the cardiac orifice of the stomach • It lies in the median plane in the thorax in front of the vertebral column behind the trachea and the heart • The oesophagus has 4 constrictions where adjacent structure produce impression o At the beginning approximately 15cm from the incisor teeth and caused by the cricopharyngeus muscles – upper oesophageal sphincter o Where it crossed by the arch of aorta 22.5cm from the incisor teeth o Where it crossed by the left main bronchus 27.5cm from the incisor o Where it passes through the diaphragm – lower oesophageal sphincter • At the top of the oesophagus, is a flap of tissue called the epiglottis that closes during swallowing to prevent food from entering the trachea (windpipe) • It has four layers; from outside: o The adventitia o Muscular layer; the muscles are striated (voluntary) in the upper third and mixed (striated & smooth) in the middle and smooth (involuntary) in the lower third o There are two layers: ▪ The inner is circular ▪ The outer is longitudinal o Sub-mucosa layer o Mucosa layer which is made up of stratified squamous epithelium • Arterial blood supply of the oesophagus is through oesophageal arteries, branches of thoracic aorta, inferior phrenic arteries and the left gastric branch of the celiac artery • Venous drainage is through the azygos and hemiazygos veins [pic]Refer students to Handout 14.1: The Oesophagus STEP 3: Structure and Functions of the Stomach (25 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is a stomach? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • The stomach: The most dilated part of the gastrointestinal tract • Has a J-like shape • Positioned between the abdominal oesophagus and the small intestine, the stomach is in the epigastric, umbilical and left hypochondrium regions of the abdomen • Its shape and size varies from person to person; even within the same individual its size and shape change from time to time depending on its food contents and the moisture of the body and in adult capacity range from 1.0 to 1.5 litre Structure of the Stomach • The stomach is divided for descriptive purposes into four regions by arbitrary lines drawn on its external surface which are o The outlet of the stomach (pyloric orifice) is marked on the surface of the organ by the pyloric constriction and surrounded by a thickened ring of gastric circular muscle (the pyloric sphincter) • The pyloric orifice is just to the right of midline in a plane that passes through the lower border of vertebra LI (the trans pyloric plane) • Other features of the stomach include: o The greater curvature, which is a point of attachment for the gastro splenic ligament and the greater omentum o The lesser curvature, which is a point of attachment for the lesser omentum o The cardial notch, which is the superior angle created when the oesophagus enters the stomach o The angular incisure, which is a bend on the lesser curvature • The stomach is lined with simple columnar epithelium • The epithelium forms numerous tube

NTA Level 4 • Semester 1 • PST04103 Accessory Organs of Digestive System Human Anatomy and Physiology • Source Session/Topic 15 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 15: Accessory Organs of Digestive System Total Session Time: 120 minutes Learning Tasks By the end of this session, students are expected to be able to: • Describe the Accessory Organs of Digestive System • Describe the Structure and Functions of the Liver • Describe the Structure and Functions of Gallbladder • Explain Organization of the Biliary System • Explain Bile Production, Circulation and Functions • Identify Structure of Pancreas Prerequisites • None Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board ,chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer • Handout 15.1: Macroscopic Structure of the Liver • Handout 15.2: Microscopic Structure of the Liver • Handout 15.3: Blood Supply to the Liver and Gallbladder • Handout 15.4: Structure of Gallbladder • Handout 15.5: The Biliary System • Handout 15.6: The pancreas SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 | |Presentation |Accessory Organs of Digestive | | |10 minutes |Brainstorming |System | |3 |35 minutes |Presentation, |Structure and Functions of the Liver| | | |Buzzing | | |4 |15minutes |Presentation |Structure and Functions of the | | | | |Gallbladder | |5 |10 minutes |Presentation |Organization of the Biliary System | |6 |15 minutes |Presentation |Bile Production, Circulation and | | | | |Functions | |7 |20 minutes |Presentation |Structure and Functions of Pancreas | | | |Brainstorming | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Overview of Accessory Organs of Digestive System (10 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the accessory organs of the digestive system? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Accessory organs of gastrointestinal tract: The organs which are not directly part of gastrointestinal tract but their products are essential for the digestive system to accomplish its primary function • These organs include: o The liver o Gallbladder and bile duct o Pancreas • These are essential for the digestive system as they either produce or store secretions essential the digestion to take place STEP 3: Structure and Functions of the Liver (35 minutes) • Liver is the largest gland in the body, weighing between 1 and 2.3Kg • In adults the liver weighs 2% of body mass • Occupying the greater part the right hypochondriac, part of the epigastric and frequently extending into the left hypochondriac regions as far as the left lateral line • The liver is divided into right and left lobes by fossae for the gallbladder and the inferior vena cava • The right lobe of liver is the largest lobe, whereas the left lobe of liver is smaller wedge shaped • The quadrate and caudate lobes are described as arising from the right lobe of liver, but functionally are distinct these are seen on the posterior side of the liver making it to have four lobes: o The quadrate lobe ▪ It is visible on the upper part of the visceral surface of the liver ▪ It is bounded on the left by the fissure for ligamentum teres and on the right by the fossa for the gallbladder ▪ Functionally it is related to the left lobe of the lever o The caudate lobe ▪ It is visible on the lower part of the visceral surface of the liver ▪ Itis bounded on the left by the fissure for the ligamentum venosum and on the right by the groove for the inferior vena cava ▪ Functionally, it is separate from the right and the left lobes of the live • Surfaces of the liver include a diaphragmatic surface in the anterior, superior, posterior directions and a visceral surface in the inferior direction o The diaphragmatic surface of the liver, which is smooth and domed, lies against the inferior surface of the diaphragm o Associated with it are the sub phrenic and hepatorenal recesses ▪ The sub phrenic recess separates the diaphragmatic surface of the liver from the diaphragm and is divided into right and left areas by the falciform ligament, a structure derived from the ventral mesentery in the embryo ▪ The hepatorenal recess is a part of the peritoneal cavity on the right side between the liver and the right kidney and right suprarenal gland ▪ The sub phrenic and hepatorenal recesses are continuous anteriorly o The visceral surface of the liver is covered with visceral peritoneum except in the fossa for the gallbladder and at the porta hepatic (gateway to the liver) • Structures Related to Liver o The right anterior part of the stomach o The superior part of the duodenum o The lesser omentum o The gallbladder o The right colic flexure o The right transverse colon o The right kidney o The right suprarenal gland [pic]Refer students to Handout 15.1: Macroscopic Structure of the Liver Structure • The porta hepatic serves as the point of entry into the liver for the hepatic arteries and the portal vein, and the exit point for the hepatic ducts • The liver is attached to the anterior abdominal wall by the falciform ligament and, except for a small area of the liver against the diaphragm (the bare area), the liver is almost completely

NTA Level 4 • Semester 1 • PST04103 Common Disorders of Gastrointestinal System Human Anatomy and Physiology • Source Session/Topic 16 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 16: Common Disorders of Gastrointestinal System Total Session Time: 60 minutes + 60 minutes assignment Prerequisites • None Learning Tasks By the end of this session, students are expected to be able to: • List the Common Features of Gastrointestinal Pathologies • Explain Common Features of Gastrointestinal Pathologies • Explain Gastrointestinal Bleeding • Describe Disorders of Gastrointestinal Motility • Explain Functional Gastrointestinal Disorder Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Charts, OHP, Multimedia Projector, Computer, Pointer SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Presentation |Common features of Gastrointestinal | | | |Brainstorming |Pathologies | |3 | 05 minutes|presentation |Disorder of gastrointestinal | | | | |bleeding | |4 |10 minutes |Presentation |Disorders of Gastrointestinal | | | |Brain storming|Motility | |5 |10 minutes |Presentation | Functional Gastrointestinal | | | | |Disorders | |6 |05 minutes |Presentation |Key Points | | 7 |05 minutes |Presentation |Evaluation | |8 |10 minutes |presentation |Take home assignment | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Features of Gastrointestinal Pathologies (10 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are the features of gastrointestinal pathologies? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | Regardless of the cause and type of a disease Gastrointestinal (GI )pathologies have the following presenting features: • Abdominal pain • GI bleeding • Diarrhoea • Steatorrhea • Constipation • Nausea • Vomiting • Dysphagia • Odynophagia • Gastroesophageal reflux • Anorexia • Weight loss Abdominal pain • Pain originates from tissue injury, distention, contraction, inflammation, and direct chemical injury. • Visceral pain is often poorly localized and loosely corresponds to the spinal segment that innervates the involved viscus. • Examples include peptic ulcer disease in which pain is localized to the epigastrium, and early appendicitis, in which pain is localized around the periumbilical region. o Somatoparietal pain arises from noxious stimulation of the parietal peritoneum. ▪ This type of pain is more localized and intense and corresponds to the dermatomal distribution that innervates the injured portion of the peritoneum. ▪ Somatoparietal pain is aggravated by movement such as coughing or a bumpy car ride. ▪ Examples of somatoparietal pain include appendicitis, with localized right lower quadrant pain attributable to localized peritonitis, and an abscess, with localized pain over the perforated viscus and inflammatory collection. • Referred pain is perceived by the patient in areas that are remote from the diseased organ. Diarrhoea • An increased number or fluidity of stools is usually due to an excess of water in stool. • Most people have experienced loose stools for a day or two (e.g. viral gastroenteritis), but other causes, such as inflammatory bowel disease, can be chronic and cause intermittent symptoms for a patient's entire lifetime. • Diarrhoea results from o An increase in secretion o Decrease in absorption, or both • It is classified as : secretory or osmotic diarrhoea • Although there may be overlap, osmotic diarrhoea usually ceases when a patient takes nothing by mouth, whereas secretory diarrhoea continues • Large-volume diarrhoea generally originates from the small intestine • Small-volume diarrhoea generally originates from the colon • Blood in the stool always implies an underlying organic abnormality • Bloody diarrhoea occurs with mucosal inflammation or erosions or ulcerations secondary to infectious, inflammatory, or ischemic enterocolitis. Steatorrhea • Steatorrhea, or fatty stools, arises from disruption of fat solubilisation, digestion, or absorption in the small intestine. • Mal digestion, or inadequate luminal breakdown of fats, occurs with pancreatic exocrine deficiency or lack of bile. • Malabsorption, or inadequate transport of the products of digestion, occurs with mucosal diseases such as celiac sprue or during impaired lymphatic transport. Constipation • Occurs most commonly in the elderly • Often used to describe more than one symptom, including: o Infrequent stools o Difficult passage of stool o A sense of incomplete evacuation o Abdominal bloating or discomfort • The causes of constipation are as varied as the complaints and include: o Inadequate stool water or faecal material, o Decreased colonic motility o Reduced mobility o Chronic illness o Medication use o Psychological factors o Functional outlet obstruction • Treatment plans vary, but the simplest and most common starting point is to increase the patient's daily fibre and fluid intake. Nausea and Vomiting • Nausea and vomiting may be manifestations of GI diseases or primary non- GI diseases and may lead to fluid and electrolyte imbalances, nutritional deficiencies, aspiration pneumonia and oesophageal rupture • Nausea is the unpleasant sensation of the desire to vomit • Retching, or ‘dry heaves,’ is coordinated voluntary muscle activity of the abdomen and chest without discharge of stomach contents into the mouth • Vomiting, or the act of emesis, occurs as gastric contents are forcefully ejected out of the mouth • Nausea and vomiting may be acute, such as with acute obstruction, inflammation, or ischemia, other acute infections, medication, pregnancy or head trauma. • Nausea and vomiting that are chronic in nature are usually associated with pregnancy, medications, and motility disorders such as diabetic, gastroparesis, partial obstruction, intracranial disease, psychogenic disorders, or an underlying metabolic or endocrine disturbance. Dysphagia • Dysphagia, or the sensation of solids or liquids not passing from the mouth into the stomach, • It is

NTA Level 4 • Semester 1 • PST04103 Composition and Functions of Blood Human Anatomy and Physiology • Source Session/Topic 17 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 17: Composition and Functions of Blood Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session, students are expected to be able to: • List the Components of Blood • Describe Functions of Blood • Describe Blood Plasma • Describe Erythrocytes, Leucocytes and Platelets Resources Needed: • Flip charts, marker pens, and masking tape • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Overhead Projector and Transparencies or Slide Projector/LCD and Computer SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Presentation |Components of Blood | | | |Brainstorming | | |3 |10 minutes |Presentation |Functions of Blood | | | |Buzzing | | |4 |15 minutes |Presentation |Blood Plasma and Platelets | | | | | | |5 |35 minutes |Presentation |Production and Functions of Red | | | |Brainstorming |Blood Cells | |6 |35 minutes |Presentation |Production and Functions of White | | | |Small Group |Blood Cells | | | |Discussion | | |7 |05 minutes |Presentation |Key Points | |8 |05 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Components of Blood (10 minutes) |Activity: Brainstorming (5 minutes) | |Ask students to brainstorm on the following question: | | | |What are the components of blood? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Blood is the specialized bodily fluid that delivers necessary substances to the body's cells such as nutrients, oxygen and transports waste products away from those same cells • Blood accounts for 7% of the human body weight • By volume the red blood cells constitute about 45% of whole blood, the plasma constitutes about 55% • The average adult has a blood volume of roughly 5 litres, composed of: o Plasma o Formed elements • These formed elements of the blood are o Erythrocytes (red blood cells) o Adult humans have roughly 2–3 × 1013 red blood cells o Leukocytes (white blood cells) and 4,000–11,000 white blood cells o Thrombocytes (platelets). 150,000–400,000 platelets in each microliter • Women have about 4 to 5 million erythrocytes per microliter (cubic millimeter) of blood and men about 5 to 6 million; people living at high altitudes with low oxygen tension will have more STEP 3: Functions of Blood (10minutes) |Activity: Buzzing (5 minutes) | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the functions of blood? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | Functions of blood • Supply of oxygen to tissues (bound to haemoglobin which is carried in red cells) bound to plasma proteins (e.g. blood lipids) • Removal of waste such as carbon dioxide, urea and lactic acid • Immunological functions, including circulation of white cells, and detection of foreign material by antibodies • Coagulation, which is one part of the body's self-repair mechanism • Messenger functions, including the transport of hormones and the signalling of tissue damage • Regulation of body pH (the normal pH of blood is in the range of 7.35 – 7.45) • Regulation of core body temperature STEP 4: Blood Plasma and Platelets (15minutes) Blood Plasma • Is the fluid portion of the blood, • The plasma, is a remarkable solution containing an immense number of ions, inorganic molecules, and organic molecules that are in transit to various parts of the body or aid in the transport of other substances • The normal plasma volume is about 5% of body weight, or roughly 3500 mL in a 70kg man • Plasma clots on standing, remain fluid only if an anticoagulant is added • If whole blood is allowed to clot and the clot is removed, the remaining fluid is called serum • Serum has essentially the same composition as plasma except that its fibrinogen an clotting factors II, V, and VIII have been removed and it has higher serotonin content because of the breakdown of platelets during clotting • The plasma consist of protein; albumin, globulin, and fibrinogen fractions • The capillary walls are relatively impermeable to the proteins plasma, and the proteins are therefore exerting an osmotic force of about 25 mm Hg across the capillary wall (oncotic pressure) that pulls water into the blood Blood Platelets • Platelets or thrombocytes are minute fragment of cells consisting of a small amount of cytoplasm surrounded by a plasma membrane • Platelets are roughly disk-shaped and an average about 3μm in diameter. • They play an important role in controlling blood loss by forming platelets plugs which seal holes in small vessels • The life expectancy of platelets is about 5 – 9 days • Platelets arise in a unique manner by the shedding of thousands of cytoplasmic fragments from the tips of processes of megakaryocytes in the bone marrow • The first detectable cell of this line is the highly basophilic megakaryoblast, followed by a promegakaryocyte stage, in which synthesis of granules begins • Finally, the fully differentiated megakaryocyte, a giant cell with a large, dense, polyploid, multilobed nucleus, appears STEP 5: Production and Functions of Red Blood Cell (35