PST NTA Level 4

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

NTA Level 4 • Semester 1 • PST04103 The ABO Blood Grouping System and Rhesus Factors Human Anatomy and Physiology • Source Session/Topic 18 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 18: The ABO Blood Grouping System and Rhesus Factors Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Describe the ABO System of Blood Grouping • Describe Rhesus Factors in Relation to Blood Grouping • Describe Blood Clotting Mechanism • Explain the Role of Vitamin K in Clotting Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Computer • Projector SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |40 minutes | Presentation|The ABO System of Blood Grouping | | | |Brainstorming | | |3 |25 minutes |Presentation | Rhesus Factors in Relation to Blood| | | |Brainstorming |Grouping | |4 | | Presentation| Blood Clotting Mechanism and Role | | |40 minutes |Small Group |of Vitamin K in Clotting | | | |Discussion | | |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 STEP 2: The ABO System of Blood Grouping (40 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is ABO system of blood grouping? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Blood type (group) o A classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells (RBCs). o These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system, and some of these antigens are also present on the surface of other types of cells of various tissues. o Several of these red blood cell surface antigens, collectively form a blood group system o Blood types are inherited and represent contributions from both parents. • ABO system o The ABO system is the most important blood group system in human blood transfusion. o It is associated with anti- A antibodies and anti-B antibodies o Blood group AB individuals have both A and B antigen on the surface of their RBCs, and their blood serum does not contain any antibodies against either A or B antigen. o An individual with type AB blood can receive blood from any group (with AB being preferable), but can donate blood only to another group AB individual o Blood group A individuals have the A antigen on the surface of their RBCs, and blood serum containing IgM antibodies against the B antigen o A group A individual can receive blood only from individuals of groups A or O (with A being preferable), and can donate blood to individuals with type A or AB. o Blood group B individuals have the B antigen on the surface of their RBCs, and blood serum containing IgM antibodies against the A antigen o A group B individual can receive blood only from individuals of groups B or O (with B being preferable), and can donate blood to individuals with type B or AB. o Blood group O individuals do not have either A or B antigens on the surface of their RBCs, but their blood serum contain IgM anti-A antibodies and anti-B antibodies against the A and B blood group antigens. o A group O individual can receive blood only from a group O individual, but can donate blood to individuals of any ABO blood group (i.e. A, B, O or AB) if anyone needs a blood. STEP 3: Rhesus Factors in Relation to Blood Grouping (25 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Rhesus factors in relation to blood grouping? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Rhesus Blood Group System o The Rhesus system is the second most significant blood group system in human blood transfusion. o The term Rhesus (Rh) blood group system refers to the 5 main Rhesus antigens (C, c, D, E and e) as well as the many other less frequent Rhesus antigens o The most significant Rhesus antigen is the Rh D antigen because it is the most immunogenic of the five main rhesus antigens o The terms "positive" or "negative" refer to either the presence or absence of the Rh D antigen irrespective of the presence or absence of the other antigens of the Rhesus system o If an Rh-negative person receives Rh-positive blood by mistake, antibodies will be formed just as they would be to bacteria or viruses o A first mistaken transfusion often does not cause problems, because antibody production is slow upon the first exposure to Rh-positive RBCs o A second transfusion, however, when anti-Rh antibodies are already present, will bring about a transfusion reaction, with haemolysis and possible kidney damage STEP 4: Blood Clotting Mechanism (40 minutes) |Activity: Small Group Discussion ( 30 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |What is blood clotting mechanism? | | | |ALLOW students to discuss for 15 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned

NTA Level 4 • Semester 1 • PST04103 Common Disorders of Blood Cells Human Anatomy and Physiology • Source Session/Topic 19 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 19: Common Disorders of Blood Cells Total Session Time: 60 minutes + 60 minutes assignment Prerequisites • Session 14, Blood grouping and ABO system Learning Tasks By the end of this session students are expected to be able to: • Define the Term Blood Cell Disorder • Explain the Common Disorders of the Blood Cells • Explain Thrombosis and Embolism Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board, chalk and whiteboard markers • Computer • Projector SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |05 minutes |Presentation |Definition of Blood Cells Disorders | | | |Brainstorming | | |3 | |Presentation |Common Blood Disorders of Blood | | |20 minutes |Small Group |Cells | | | |Discussion | | |4 |10 minutes |Presentation |Thrombosis and Embolism | |5 |05 minutes |Presentation |Key Points | | 6 |05 minutes |Presentation |Evaluation | |7 |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 of Blood Cell Disorder (5 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is a blood cell disorder? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Blood cell disorder is a disorder which affects the red blood cells, white blood cells and smaller circulating cells called platelets STEP 3: Common Disorders of the Blood Cells (20 minutes) |Activity: Small Group Discussion ( 15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |What are the common blood cells disorders? | | | |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 | Classification of Common Disorders of the Blood Cells • Anaemia o Iron-deficiency anaemia o Sickle-cell disease (anaemia) o Aplastic anaemia o Haemolytic anaemia • Haemophilia • Leukaemia • Vitamin K deficiency Anaemia • Anaemia is a deficiency of red blood cells, or insufficient haemoglobin within the red blood cells. • There are many different types of anaemia. o Iron-deficiency anaemia ▪ It is caused by a lack of dietary iron, and there is not enough of this mineral to form sufficient haemoglobin. ▪ A person with this type of anaemia may have a normal RBC count and a normal haematocrit, but the haemoglobin level will be below normal. ▪ A deficiency of vitamin B12, which is found only in animal foods, leads to pernicious anaemia, in which the RBCs are large, misshapen, and fragile. ▪ Another cause of this form of anaemia is lack of the intrinsic factor due to autoimmune destruction of the parietal cells of the stomach lining. o Sickle-cell disease (anaemia) ▪ It is a genetic disorder of haemoglobin (Hb-S), which causes RBCs to sickle, clog capillaries, and rupture. ▪ Even though erythropoiesis is stimulated by the loss of the cells, it cannot keep pace with haemolysis. o Aplastic anaemia ▪ It is suppression of the red bone marrow, with decreased production of RBCs, WBCs, and platelets. ▪ This is a very serious disorder that may be caused by exposure to radiation, certain chemicals such as benzene, or some medications. o Haemolytic anaemia ▪ It is any disorder that causes rupture of RBCs before the end of their normal life span. ▪ Sickle-cell anaemia and Rh disease of the new-born are examples. ▪ Another example is malaria, in which a protozoan parasite reproduces in RBCs and destroys them. ▪ Haemolytic anaemias are often characterized by jaundice because of the increased production of bilirubin. Haemophilia • Haemophilia is an inherited deficiency of clotting in which bleeding may occur spontaneously or after only minor trauma. • It is the oldest known hereditary bleeding disorder • Different types of haemophilia are due to deficiencies of different blood clotting factors and exhibit varying degrees of severity, ranging from mild to severe bleeding tendencies Leukaemia • The term leukaemia refers to a group of red bone marrow cancers in which abnormal white blood cells multiply uncontrollably • The accumulation of the cancerous white blood cells in red bone marrow interferes with the production of red blood cells, white blood cells, and platelets • As a result the oxygen-carrying capacity of the blood is reduced, an individual is more susceptible to infection, and blood clotting is abnormal • The cause of most types of leukaemia is unknown Vitamin K deficiency • Vitamin K is not involved in actual clot formation but it is required for the synthesis of four clotting factors. • It is a fat-soluble vitamin that can be absorbed through the lining of the intestine and into the blood if absorption of lipids is normal • People suffering from disorders that slow absorption of lipids (for example, inadequate release of bile into the small intestine) often experience uncontrolled bleeding as a consequence of vitamin K deficiency STEP 4: Thrombosis and Embolism (10 minutes) Thrombosis • It is the formation of a clot in the blood that either blocks, or partially blocks a blood vessel. • The thrombus may lead to infarction, or death of tissue, due to a blocked blood supply. • The pathologic form of haemostasis is thrombosis. It involves blood

NTA Level 4 • Semester 1 • PST04103 Body Fluids and Electrolytes Imbalance Human Anatomy and Physiology • Source Session/Topic 20 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 20: Body Fluids and Electrolytes Imbalance Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Identify Major Body Fluid Compartment • Differentiate Between Intracellular and Extracellular Fluids • Explain Mechanism that Maintain Homeostasis of Body Fluid • Describe Body Fluid Electrolyte Levels and their Functions • Explain Electrolyte Imbalance 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 | 15 |Presentation |Major Body Fluid Compartment | | |minutes | | | |3 |35 minutes |Presentation |Mechanism that Maintain Homeostasis | | | |Buzzing |of | | | |Brainstorming |Body Fluid | |4 |30 minutes |Presentation |Body Fluid Electrolytes and their | | | |Brainstorming |Functions | |5 |25 minutes |Presentation |Electrolyte Imbalance | |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: Major Body Fluid Compartment (15 minutes) • In the human body there are several major fluid compartments each of which is subject to homeostatic regulation. • Fluid content of the human body ranges from 40% to 60% of bodyweight. • The following are the major fluid compartments found in human body. o Intracellular Fluid (ICF) water inside the cell comprises 2/3 of the body's water. o Its main function is to facilitate intracellular chemical reactions that maintain life ▪ Is the largest compartment. ▪ ICF is about 40% of the body weight. ▪ The ICF is primarily a solution of potassium and organic anions, proteins etc. ▪ The cell membranes and cellular metabolism control the constituents of this ICF. o Extracellular Fluid (ECF) is the remaining 1/3 of the body's water, any fluid not contained inside a cell therefore comprises the extracellular compartment. ▪ ECF is about 20% of the body weight, it consists mainly of plasma and lymph fluid (circulating compartment) and interstitial fluid (the spaces between the cells). • The ECF is further subdivided into three sub-compartments. o Interstitial Fluid (ISF) ▪ surrounds the cells, but does not circulate ▪ It comprises about 3/4 of the ECF. o Plasma circulates as the extracellular component of blood. ▪ It makes up about 1/4 of the ECF. o Transcellular fluid ▪ It is a set of fluids that are outside of the normal compartments. ▪ These 1-2 litres of fluid make up the Cerebrospinal Fluids (CSF), Digestive Juices, Mucus, specialized joint fluids aqueous; humour and vitreous humour the fluids in the eyeball • The ECF provide a relatively constant environment for cells and transport substances to and from the cells. • Example; A 70 kg man contains about 40-45 litres of water divided into the different compartments as follow • Out of 45 total litres of body fluid o Intracellular fluid 27litres o Extracellular 18 litres, which are further, subdivided as follows; interstitial 13 litres, plasma 3.5litres and lymph 1.5litres. STEP 3: Mechanism that Maintain Homeostasis of Body Fluid (35 minutes) |Activity: Buzzing (5 minutes) | | | |ASK students to pair up and buzz on the following question for 2 | |minutes | | | |What are the factors that cause fluid and electrolyte imbalance? | | | |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 | • Under normal conditions homeostasis of the total volume of the water in the body is maintained or restored primarily by adjusting output urine volume and secondarily by fluid intake • Regulation of fluid intake; When dehydration begins to develop, salivary secretion decreases, producing the sensation of thirst; individual increased fluid intake to offset increased output tends to restore fluid balance • Regulation of urine volume; two factors determine urine volume o Glomerular filtration rate, except under abnormal conditions remain fairly constant o Rate of tubular reabsorption of water fluctuates considerably; normally adjusts urine volume to fluid intake influenced by hormonal mechanisms • Some of the factors that alter fluid loss under abnormal conditions are increased rate of respiration and volume of sweat secreted, certain abnormal conditions such as vomiting, diarrhoea, or intestinal drainage can produce fluid and electrolyte imbalance • The volume of extracellular fluid can increase or decrease, even if the osmolality of the extracellular fluid is maintained within a narrow range of values • The following are the major mechanisms that regulate extracellular fluid volume o Neural mechanism ▪ Neural mechanism changes the frequency of action potentials carried by sympathetic neurons to the afferent arterioles of the kidney in response to change in blood pressure ▪ When baroreceptors detect an increase in arterial and venous pressure, the frequency of action potential carried by sympathetic neuron to the afferent arteriole decreases. ▪ Consequently the afferent arteriole dilates ▪ This increases glomerular capillary pressure, resulting in an increase in the glomerular filtration rate, an increase in filtrate volume and an increase in urine volume ▪ When the baroreceptors detect a decrease in arterial and venous pressure the action potential carried by sympathetic neuron causes constriction of afferent arteriole and the opposite occurs o Renin-angiotensin-aldosterone mechanism ▪ The Renin angiotensin-aldosterone mechanism responds to small changes in the blood volume