Muscle Tissue

Question 1

types of muscle

Answer 1

skeletal
smooth
cardiac

Question 2

muscle contraction

Answer 2

depends on two types of myofilaments with contractile proteins that generate contractile force
actin and myosin

Question 3

functional features of muscles

Answer 3

excitability: electrical nerve impulse stimulates muscle to contract
contractility: long cells shorten and generate pulling force
extensibility: can be stretched back to its original length by contraction of an opposing muscle
elasticity: can recoil after being stretched

Question 4

smooth muscle

Answer 4

propels substances through internal hollow organs by alternating contraction and relaxation
squeezes fluids and other substances through glands
activity of smooth muscle in arterial walls influences blood pressure
involuntary control typically modulated by the autonomic nervous system

Question 5

smooth muscle: locations

Answer 5

mostly in walls of hollow viscera

eg digestive tract, urinary tract, uterus, glands, and blood vessels

Question 6

smooth muscle: cell shape and appearance

Answer 6

spindle-shaped cells with central nuclei
elongated with tapered ends
arranged closely to form sheets
no visible striations

Question 7

cardiac muscle

Answer 7

located in walls of the heart
contracts to propel blood into into circulatory system
involuntary control through the autonomic nervous system

Question 8

cardiac muscle tissue

Answer 8

branching striated cells
generally uninucleate, but sometimes binucleate
cells brain and join/interdigitate at special intercellular joints called intercalated discs

Question 9

skeletal muscle

Answer 9

attached to bones or skin (eg with some facial muscles)
typically voluntary movement
facial expression
movement of upper and lower extremities

Question 10

skeletal muscle: functions

Answer 10

maintenance of posture - enables the body to remain sitting or standing
joint stabilization
heat generation - muscle contractions produce heat, helps maintain normal body temperature

Question 11

skeletal muscle coverings

Answer 11

epimysium: dense irregular connective tissue surrounding entire muscle
perimysium: fibrous connective tissue that surrounds each fascicle
endomysium: within a fascicle, each muscle fiber is surrounded by a fine sheath of loose connective tissue consisting mainly of reticular fibers

Question 12

skeletal muscle supplied by branches of:

Answer 12

one nerve
one artery
one or more veins

Question 13

muscle attachments

Answer 13

origin - less movable bone attachment, usually the proximal end
insertion - more movable bone attachment, usually the distal end
direct vs. indirect attachments