Lecture #14 Chapter 9

Question 1

What is peristalsis?

Answer 1

The contraction of smooth muscle in a wavelike fashion pushing food through the intestine

Question 2

What is the contraction of smooth muscle in a wavelike fashion pushing food through the intestine called?

Answer 2

Peristalsis

Question 3

What is the location of each type of muscle?

Answer 3

-Skeletal muscle attached to bones
-Cardiac muscle makes up the heart
-Smooth muscle lines the wall so internal organs (blood vessels & digestive tract)

Question 4

How is each type of muscle contracted?

Answer 4

-Skeletal is voluntary
-Cardiac is involuntary
-Smooth is involuntary

Question 5

What are the organs of the muscular system?

Answer 5

An entire skeletal muscle

Question 6

What four types of tissue are skeletal muscles comprised of?

Answer 6

-Skeletal muscle tissue
-Nervous tissue
-Blood
-Connective tissue

Question 7

What causes vasodilation and vasoconstriction of blood vessels?

Answer 7

Smooth muscles

Question 8

What are the three types of connective tissue called in muscles?

Answer 8

-Fascia
-Tendon
-Aponeuroses

Question 9

What is fascia?

Answer 9

Connective tissue that encloses a muscle

Question 10

What are tendons?

Answer 10

A cordlike band of connective tissue that connects muscle to bone

Question 11

What is an aponeuroses?

Answer 11

A sheet of connective tissue that attaches a muscle to bone, skin, or other muscles

Question 12

What are the three muscle coverings?

Answer 12

-Epimysium
-Perimysium
-Endomysium

Question 13

What is the epimysium?

Answer 13

The outer layer of connective tissue that surrounds the whole muscle

Question 14

What is the perimysium?

Answer 14

The layer of connective tissue that encloses a bundle of skeletal fibers/fascicle

Question 15

What is the endomysium?

Answer 15

Layer of connective tissue that surrounds each muscle fiber

Question 16

What are myofibrils?

Answer 16

Threadlike bundles of filaments in striated muscle cells

Question 17

What are the two types of myofiliments?

Answer 17

Actin and Myosin

Question 18

What is sarcolemma?

Answer 18

Cell membrane of muscle cell

Question 19

What is sarcoplasm?

Answer 19

Cytoplasm in a muscle fiber

Question 20

What is a sarcomere?

Answer 20

Structural and functional unit of a myofibril

Question 21

What is the sarcoplasmic reticulum (SR)?

Answer 21

Membranous networks of channels and tubules in a muscle fiber that corresponds to the smooth ER of other cells

Question 22

What is a transverse (T) tubule?

Answer 22

A membranous channel that extends deep into a cell from a muscle fiber membrane

Question 23

What is the triad structure in muscles?

Answer 23

A group of three structures in a muscle which is two cisternae and a transverse tubule

Question 24

What are cisternae?

Answer 24

An enlarged portion of the sarcoplasmic reticulum near the actin and myosin filaments of a muscle fiber

Question 25

What do muscle fibers consist of?

Answer 25

Sarcomeres connected end-to-end

Question 26

What cause the striated pattern in muscles?

Answer 26

Myofilaments arranged in myofibrils

Question 27

What is the I band?

Answer 27

A light band composed of thin actin filaments

Question 28

What is the A band?

Answer 28

A dark band composed of thick myosin filaments overlapping with thin actin filaments

Question 29

What is the H zone?

Answer 29

The center of the A band composed of thick myosin filaments

Question 30

What is the Z line/ Z disc?

Answer 30

The center of the I band/thin myofilaments

Question 31

What is the M line?

Answer 31

The center of the A band and anchors the thick filaments in place

Question 32

What is the function of myosin head?

Answer 32

It forms cross-bridges

Question 33

What is actin composed of?

Answer 33

The actin protein with binding sites and troponin and tropomyosin which hide the actin binding site and prevent cross-bridge formation

Question 34

What occurs in the sarcomere as a muscle contracts?

Answer 34

Actin and myosin slide past one another

Question 35

What is the neuromuscular junction (NMJ)?

Answer 35

A type of synapse where an axon of a motor neuron and a skeletal muscle fiber interact

Question 36

What five things comprise the NMJ?

Answer 36

-Motor neuron -Motor end plate -Synaptic vesicles -Neurotransmitters -Synaptic cleft

Question 37

What is a motor neuron?

Answer 37

Neurons which conduct impulses from the CNS to an effector

Question 38

What is the motor end plate?

Answer 38

A specialized part of a muscle fiber membrane at the NMJ

Question 39

What is a neurotransmitter?

Answer 39

A chemical that an axon secretes into a synapse that stimulates or inhibits an effector of another neuron

Question 40

What is the synaptic knob?

Answer 40

Tiny enlargement at the end of an axon that secretes a neurotransmitter

Question 41

What is the synaptic cleft?

Answer 41

A narrow extracellular space between the cells at a synapse

Question 42

What are synaptic vesicles?

Answer 42

Vesicles/tiny sacs that store neurotransmitters

Question 43

What is the synaptic terminal?

Answer 43

The end of a neuron

Question 44

What type of neurotransmitter does skeletal muscle respond to?

Answer 44

Acetylcholine (ACh)

Question 45

What are the six steps that must occur in the nervous system for a muscle to contract?

Answer 45

1. Stimulus received 2. Impulse transmitted through the axon 3. Synaptic vesicles rupture releasing Acetylcholine (ACh) 4.Neurotransmitters spill into the synaptic cleft causes a change in membrane permeability to Na+ and K+ ions generating a muscle impulse/action potential 5. This impulse causes the Triad to release Ca++ ions 6. Ca++ ions bind to troponin which cause both troponin and tropomyosin to reveal the actin binding sites