Structure and Functions of Muscle Tissues
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:
Resources Needed:
Computer
o 8.2 a Skeletal,
o 8.2 b Cardiac,
o 8.2 c Smooth Muscle
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
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
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
muscle and some of skeletal muscle tissue.
contain numerous nuclei.
vein, and
Superior vena cava cardiac muscle contractions are not under
voluntary control.
cardiac muscle fibres that are influenced by the autonomic nervous
system.
Figure 8.2 a. Cardiac muscle
[pic]
Smooth Muscle Tissue
direction of the long axis of the cell.
skeletal muscles, hence
portion of the wall of the digestive tract from the mid-oesophagus
to anus, including the ducts of glands associated with the system.
veins and larger lymphatics, in the dermis and in the iris and
ciliary body of the eye.
diameter of the hollow viscera.
section appear as narrow circular profiles.
rough endoplasmic reticulum, and a large golgi apparatus.
Figure 8.2 b. Smooth muscle
[pic]
Skeletal Muscle Tissue
form movement of the skeleton; it is also known as striated or voluntary
muscles.
voluntary as it is under conscious control.
called muscle fibres.
cell membrane.
skeletal muscle from cardiac muscle, which has centrally located
nuclei.
a group of fibres (fibre bundles) is invested by perimysium, and the
entire muscle is surrounded by epimysium.
muscle fibres it controls, is a motor unit.
impulse that causes
all the muscle fibres supplied by that motor unit to contract
simultaneously.
fibre a stripedor striated appearance (hence the name striated muscle).
sequential steps.
o An action potential travels along a motor nerve to its endings on muscle
fibres.
o At each ending, the nerve secretes a small amount of the neurotransmitter
substance acetylcholine.
o The acetylcholine acts on a local area of the muscle fibre membrane to
open multiple
"acetylcholine-gated" channels through protein molecules
floating in the membrane.
o Opening of the acetylcholine-gated channels allows large quantities of
sodium ions to diffuse to the interior of the muscle fibre membrane.
o This initiates an action potential at the membrane.
o The action potential depolarizes the muscle membrane, and much of the
action potential electricity flows through the centre of the
muscle fibre.
o Here it causes the sarcoplasmic reticulum to release large quantities of
calcium ions that have been stored within this reticulum.
o The calcium ions initiate attractive forces between the actin and myosin
filaments, causing them to slide alongside each other, which is
the contractile process.
o After a fraction of a second, the calcium ions are pumped back into the
sarcoplasmic reticulum by a Ca++ membrane pump, and they remain stored in
the reticulum until a new muscle action potential comes along;
this removal of calcium ions from the myofibrils causes the
muscle contraction to cease.
Figure 8.2 c, Skeletal Muscle
[pic]
STEP 5: Function of Muscle Tissues (20 minutes)
|Activity: Buzzing (5 minutes) |
| |
|ASK students to pair up and buzz on the following question for 2 |
|minutes |
| |
|What are the functions of skeletal muscle tissue? |
| |
|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 |
Muscles serve specific functions in moving and positioning the body.
fixator under specific conditions.
o A prime mover or agonist is the main muscle responsible for producing a
specific movement of the body (e.g. concentric contraction).
o Fixators steady the proximal parts of a limb while movements are
occurring in distal parts.
o A synergist complements the action of prime mover for example, by
preventing movement of the intervening joint when a prime
mover passes over more than one joint.
o An antagonist is a muscle that opposes the action of a prime mover.
o As a prime mover contracts, the antagonist progressively relax, producing
a smooth movement.
STEP 6: Key Points (5 minutes)
specialized for contraction. It provides motion, maintenance of posture,
heat production, and protection.
cardiac muscle tissue.
(blood vessels and viscera) and is non striated and involuntary
STEP 7: Evaluation (5 minutes)
References
Seeley, R. R., Stephens, T. D., &Tate, P. (2003). Anatomy and Physiology.
(5thed.).Boston:
McGraw-Hill.
Standring, S. (2008). Grays’s Anatomy; the anatomical basis of clinical
practice.(40th ed.).
Elservier: Churchill Livingstone.
Thibodeau, G. A., & Patton, K. T. (1999). Anatomy & Physiology. Mosby:
Hoffman
Press, Inc.
Tortora, G.J &Derrickson, B (2009). Principles of Anatomy and Physiology
12th Edition,
USA, John Wiley & Sons Inc, USA
Waugh, A., & Grant, A. (2006). Ross and Willson Anatomy and physiology in
Health and
illness. China: Churchill Livingstone Elservier.
| | |
Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP
