Question

Correlate muscle physiology to normal body function.

Answer 1

Correlate muscle physiology to normal body function

Muscle is a specialized contractile tissue of mesodermal origin. It is responsible for locomotion and motion of visceral organ. It is of three types:

Skeletal – Voluntary – Striated – Multi nucleated –T tubule is present.

Cardiac – Voluntary – Striated – Uni nucleated - encompasses the heart - T tubule is present – Intercalated disc - specialized intercellular only in cardiac cells.

Smooth – Involuntary- Unstriated – Uninucleated- Found throughout the gastrointestinal, reproductive, urinary, vascular, and respiratory systems - T tubule is absent.

Bodily organs are composed of skeletal muscle tissue, connective tissue, nerve tissue, and blood or vascular tissue.

Muscles are innervated by motor nerves and the action potential travel to the pre synaptic neuron terminal which trigger the influx of calcium. It causes the release of neurotransmitter acetylcholine which is stored in synaptic vesicles by exocytosis. Across the synapse the surface of myofibril contains receptors that can bind with the neurotransmitter resulting in muscle contraction. This muscular contraction is the basis for various bodily function.

Muscle functions:

• Locomotion – By muscle contraction.
• Vasoconstriction and vasodilatation- constriction and dilation of smooth muscle in blood vessels and respiratory pathways
• Peristalsis – wavelike motion of smooth vessel along the digestive tract.
• Cardiac function.
• Posture maintenance - skeletal muscles plays important role in maintaining body posture and muscle tone.
• Heat regulation – about 75% of ATP energy used in muscle contraction is released as heat.