Muscle tissue 1

Muscle Tissue 1

Muscle types and functional characteristicsLevels of organization and microanatomy of muscle

The basicsMuscles are attached to bonesMuscles contract (get shorter) and move bonesMuscles comprise 40-50% of body massMyology

Study of muscle anatomy and physiology

Myo- Mys- Sarco- = prefixes that reference muscle

Muscle functional characteristicsExcitable / excitability

ability to respond to stimuli

Contractile / -ilityability to shorten; initiated by nerve signal (action potential)

Extensible / -ilityability to stretch; lengthen

Elastic / -icityability to return to original length

Types of muscleSkeletal

Attached to bones, striated, voluntary

CardiacForms heart, striated, involuntary

SmoothWalls of blood vessels, stomach intestines, hair follicles, non-striated, involuntary

Muscle FunctionsMotion

contraction moves bones; bodyblood flowperistalsis (squeezing of intestines)gall and urinary bladder contraction

Posture maintenance / joint stabilization

Thermoregulationcontraction results in heat energy release

Skeletal muscle contraction(microanatomical TEM)

Skeletal muscle tissue organization

ConnectionsTendons

Dense connective tissue continuous with deep fascia, connect muscles to periosteum

AponeurosesBroad flat tendon attachment to bone, or to different muscle, or skin

Microanatomy

Muscle Contraction RequirementsNerve impulse

A nerve penetrates every muscleSynaptic bulb / neuromuscular junction = muscle connection with nerve cell

BloodSupplies energy, nutrients, oxygenRemoval of waste and heatEach muscle fiber is in contact with capillaries