Chap 10: Muscles

Question 0

Functions of skeletal muscle

Answer 0

1. Body movement
2. Maintenance of posture
3. Temperature regulation (shivering)
4. Storage and movement of materials
5. Support

Question 1

Properties of muscle tissue:

Answer 1

1. excitability
2. Contractility
3. Elasticity
4. Extensibility- extra stretch

Question 2

Gross anatomy of skeletal muscle:

Answer 2

Named muscle
Fascicle
Muscle fiber(cell)
Myofibril
Myofilaments

Question 3

Epimysium:

Answer 3

Layer of dense irregular connective tissue that surrounds the entire skeletal muscle.

Question 4

Perimysium:

Answer 4

Surrounds fascicles
Dense irregular connective tissue
Contains an array of supportive blood vessels and nerves

Question 5

Endomysium

Answer 5

Innermost connective tissue layer
Areolar connective tissue
Surrounding and electrically insulating muscle fibers

Question 6

Deep fascia:

Answer 6

Dense irregular connective tissue
Binds together muscles with similar functions

*extra layer around epimysium

Question 7

Superficial fascia:

Answer 7

Areolar & adipose
Between muscle and bone- connects to the skin.
-spiderweb like

Question 8

Tendon

Answer 8

Muscle to bone

Question 9

Aponeurosis

Answer 9

Tendon in a thin flattened sheet

Question 10

Origin

Answer 10

Less mobile attachment of the muscle

-usually more proximal, medial, and bigger area

Question 11

Insertion:

Answer 11

More mobile attachment if the muscle

- distal lighter area

Question 12

Skeletal muscles are ________ muscles

Answer 12

Voluntary

Question 13

Motor neurons

Answer 13

Nerve cells that innervate muscle cels and stimulate muscle contraction
*only one axon touched a muscle

Question 14

Neuromuscular junction

Answer 14

Connection between nerve axon and muscle fiber

- neurotransmitter released over the synapse

Question 15

Sacrolemma:

Answer 15

Plasma membrane of a skeletal muscle fiber

Question 16

Sacroplasm:

Answer 16

Cytoplasm of the muscle fiber

Contains mitochondria to meet high energy demands

Question 17

Transverse tubules: t- tubules

Answer 17

Carry nerve impulses from sacrolemma and rapidly spread it internally
*mine shafts into muscle fibers

Question 18

Sacroplasmic reticulum (SR)

Answer 18

Similar to smooth endoplasmic reticulum

• stores calcium ions needed for muscle contraction
• calcium is critical to the muscle contractions

Question 19

Terminal cisternae:

Answer 19

Blind sacs of SR located in pairs

Reservoirs for calcium ions

Question 20

Thin filaments:

Answer 20

Actin protein- twisted around each other

Twizzler like

Question 21

Tropomyosin:

Answer 21

Short thin twisted filament that covers small sections of the actin strands
-like a hair twisted around a Twizzler

Question 22

Troponin

Answer 22

Attaches to actin and tropomyosin
Provides a binding site for calcium ions
-nerd on top of hair on top of Twizzler

Question 23

Thick filaments:

Answer 23

Twice as large as thin filaments

MYOSIN - two strands, free globular heads- “gimme” hands for troponin binding sites

Question 24

Sarcomere

Answer 24

Basic contraction unit

Z disc to Z disc -accordion like movement =contraction

Question 25

Movement of filaments

Answer 25

Sliding back and forth

Question 26

A band: shortens, widen, or no change?

Answer 26

No change

Question 27

H zone: shortens, widens, no change?

Answer 27

Disappears

Question 28

Z disc: shorten lengthen or no change

Answer 28

Move closer together

Question 29

Sarcomere

Answer 29

Shortens

Question 30

I band

Answer 30

Shortens

Question 31

Neuromuscular junctions:

Answer 31

*each muscle fiber is controlled by one motor neuron

Question 32

Nerve impulse conduction:

Answer 32

Axon
Synaptic knob
Release Ach
Ach across synaptic cleft
Ach receptors bound
Impulse passes through muscle

Question 33

Ach?

Answer 33

Neurotransmitter in skeletal muscle