Lecture 11- skeletal muscle and function 1

Question 1

Smooth muscle

Answer 1

Line hollow organs (gut and blood vessels and are NOT UNDER VOLUNTARY CONTROL

Question 2

Voluntary control

Answer 2

Muscle whose actions are controlled by an individual’s’ will (airways).

Question 3

Cardiac muscle

Answer 3

Located in heart, generates force to pump blood around the body and is NOT under voluntary control. (muscular pump).

Question 4

Skeletal muscle

Answer 4

muscle applies force to bones to control posture and body movements. IT IS under voluntary control.

Question 5

Voluntary muscle is AKA..

Answer 5

striated (striped) muscle.

Question 6

Primary job of skeletal muscles is…

Answer 6

develop forces to move or resist movement of joints. Also enacts instructions from the brain to produce these movements.

Question 7

How many directions do muscles develop in?

Answer 7

1 direction. They can ‘pull’ (develop muscles by shortening) but cannot ‘push’ (develop force by lengthening as individual fibres can’t lengthen)

Question 8

Secondary jobs of skeletal muscles..

Answer 8

Provides support and protection to soft internal organs (esp muscles of abdominal wall). Controls entry/exit of substances into/out of body. Store energy and protein, and can convert energy to heat to maintain core body temp.

Question 9

Name skeletal muscle structural features…

Answer 9

Fibres are huge, multinucleate cells containing large amounts of proteins. Connective tissue encloses these fibres and connects them to bone = tendons

Question 10

Skeletal muscle is richly supplied with

Answer 10

Blood vessels and nerve fibers.

Question 11

Fascicles

Answer 11

Muscle fibres gathered into bundles, wrapped in sheet of connective tissue.

Question 12

Muscle composition..

Answer 12

Fascicles bundled together, enclosed in connective tissue.

Question 13

Myoblasts

Answer 13

Muscle precursor cells that fuse to form large multinucleated cells.

Question 14

Sarcolemma

Answer 14

Membrane around a multinucleated cell.

Question 15

Myofiber

Answer 15

Bundles of myofibrils within the muscle fiber.

Question 16

Proteins within myofilaments

Answer 16

Actin (thin) and myosin (thick)

Question 17

Sarcomere

Answer 17

Units of myofilaments in muscle fiber.

Question 18

Myofibril

Answer 18

Bundles of contractile proteins in fiber, where myofilaments fun the length of.

Question 19

Sarcoplasmic reticulum

Answer 19

Extensive membranous network surrounding myofibril, that has T-Tubules running through it. Stores calcium also.

Question 20

T-Tubule

Answer 20

Extension of surface membrane that runs through the sarcoplasmic reticulum, deep into the muscle fiber.

Question 21

Triad

Answer 21

Structure formed by a T-tubule with the sarcoplasmic reticulum.

Question 22

Terminal cisternae

Answer 22

Chambers of SR that surround the T-tubules.

Question 23

Filamentous protein (F-actin) strands are…

Answer 23

Made up of actin globular proteins, and formed in strands.

Question 24

Tropomyosin

Answer 24

Protein that also assists muscle contraction. Works with the troponin in thin muscle filaments to do this.

Question 25

Troponin

Answer 25

Globular protein complex involved in muscle contraction.

Question 26

Myelin

Answer 26

Substance that wraps around axons. It is rich in fatty acids and lipids. It insulates and protects the axon during speed nerve transmission.

Question 27

Synapse

Answer 27

Junction between two cells- related to NMJ

Question 28

Motor neuron

Answer 28

Neuron that carries nerve impulses that activate a muscle.