Chapter 7- Muscular System

Question 0

Name the four main characteristics of skeletal muscle?

Answer 0

1. Makes up 40% of body weight.
2. Named skeletal because it is attached to the bones (skeleton)
3. Many nuclei per cell (near periphery)
4. Striated

Question 1

List the main functions of the muscular system?

Answer 1

Movement, Maintain posture, Respiration, Production of body heat, Communication, Contraction of organs and vessels, and Contraction of the heart.

Question 2

The terms used to best describe skeletal muscles that respond to stimuli and recoil are?

Answer 2

Excitability- respond to stimulus

Elasticity- recoil

Question 3

What is the muscular fasica?

Answer 3

Bundle of muscle fibres.

Question 4

What are the names of the connective tissue that surrounds muscle fibres?

Answer 4

Endomysium

Question 5

The region of the muscle that contains the T-tubes is called?

Answer 5

Sarcolemma

Question 6

What is the function of Sarcoplasmic Reticulum?

Answer 6

Holds all Ca and releases it.

Question 7

Calcium binds to this region on actin?

Answer 7

Troponin

Question 8

Resemble golf clubs?

Answer 8

Myosin

Question 9

How would you best describe the following Z disk, A band, and H zone?

Answer 9

Z disk are protein fibres that form attachment site for actin.
H zone is the center of sarcomere and contains only myosin.
I band contains only actin.
A band is where actin and myosin overlap.
M line is where myosin are anchored.

Question 10

During a muscle contraction the following regions of _______ and _______ shorten but ___________ stays the same.

Answer 10

During a muscle contraction, H zone and I band shorten but A band stays the same.

Question 11

Define synaptic cleft.

Answer 11

Space between presynaptic terminal and postsynaptic membrane.

Question 12

What is the underlining cause of rigor mortis?

Answer 12

When a person dies and there is no ATP left available to release cross-bridges.

Question 13

T or F, ATP can only be made in the mitochondria under aerobic respiration?

Answer 13

False. ATP can be made under both Anaerobic and aerobic respiration.

Question 14

Define the terms threshold and twitch.

Answer 14

Threshold is the weakest stimulus needed to produce a response and Twitch is the contraction and relaxation of a muscle fibre in response to a stimulus.

Question 15

What is the difference between slow and fast twitch fibres?

Answer 15

Slow twitch fibres happen under aerobic and fast twitch fibres happen under anaerobic.

Question 16

What is the role of myoglobin in muscle?

Answer 16

Myoglobin helps O2 bind in muscle.

Question 17

Define the terms agonist and fixator?

Answer 17

Agonist- prime mover, a muscle that accomplishes a certain movement.
Fixation- a muscle or group of muscles that hold a body part in place so another one can move.

Question 18

List the muscles of the head and neck? What are their major functions?

Answer 18

Occipitofrontalis- raises eyebrows (forehead)
Orbicularis Oculi- allows blinking (eyes)
Orbicularis Oris- kissing muscle (mouth)
Zygomaticus- smiling muscle (cheek)
Masseter- chewing (mastication) muscle

Question 19

List the muscles of the abdomen originating from the skin layers?

Answer 19

Rectus abdominis, External abdominal oblique, Internal abdominal oblique, Transverse abdominis.

Question 20

What muscle flexes the elbow?

Answer 20

Biceps Brachii

Question 21

List the muscles of the hips and thighs?

Answer 21

Iliopsoas, Gluteus maximus, Gluteus medius

Question 22

What is the muscle that is responsible for flexing the foot and leg?

Answer 22

Gastrocnemius

Question 23

T or F, Cardiac muscle cells are rich in both mitochondria and nuclei?

Answer 23

False.

Question 24

What is the functional role of the intercalated disks?

Answer 24

Special cell junctions that allow cells to act as a unit.

Question 25

What muscle is responsible for allowing the eye to blink?

Answer 25

Orbicularis oculi