Muscles and Nerves

Question 1

Appendicular muscles

Answer 1

muscles found attached to just to bones of the limbs or to bones of the limbs and axial skeleton.

Question 2

Axial muscles

Answer 2

muscles just joined to the axial skeleton

Question 3

origin of a muscle

Answer 3

the proximal /superior/medial attachment of muscles

Question 4

insertion of a muscle

Answer 4

the distal/inferior/lateral attachment of muscles

Question 5

aponeurosis

Answer 5

anterior tendons of the abdominal oblique muscles, these tendons and flat, thin and broad.

Question 6

abdominal oblique muscles

Answer 6

muscles in the abdomen, there are three layers of them and they are arranged with muscle fibres at 90 degrees to each other

Question 7

Biceps Brachii attachments

Answer 7

attaches to bones at 4 places has two heads at proximal end of muscle (hence its name BI (two)-ceps(heads)) that attach to the scapula.
the two distal attachments are to the radius and ulna

Question 8

joints biceps brachii crosses

Answer 8

glenohumeral, elbow, proximal radioulnar joint

Question 9

joints brachioradialis crosses

Answer 9

just elbow joint

Question 10

joints triceps brachii crosses

Answer 10

elbow and glenohumeral

Question 11

action of biceps brachii and triceps brachii at elbow

Answer 11

biceps- flexion

triceps- extension

Question 12

what is a diaphragm

Answer 12

a muscle that crosses the median sagittal plane and has attach on either side. Largest is “the diaphragm”.

Question 13

action of the diaphragm

Answer 13

when it contracts it descends causing the thoracic volume to increase and the lungs to inflate, breath in. When it relaxes the thoracic volume decreases again and the lungs deflate, breath out.

Question 14

supporting skeletal muscles

Answer 14

are found around joints to give support eg. the rotator cuff muscles around the shoulder.
they also work against gravity. eg. the intrinsic muscles of the back

Question 15

arrangement of fibres in the deltoid

Answer 15

split into anterior, middle and posterior fibres

Question 16

function of anterior fibres in deltoid

Answer 16

contraction causes flexion of shoulder joint

Question 17

function of posterior fibres in deltoid

Answer 17

contraction extension of shoulder joint

Question 18

function of middle fibres in deltoid

Answer 18

contraction causes abduction of the shoulder joint.

Question 19

co-operative muscle action

Answer 19

• antagonistic pairs
• synergists
• fixator/stabilising muscles

Question 20

antagonistic pairs

Answer 20

a flexor will work with an extensor so that one contracts the other relaxes to allow a movement at the joint. in flexion the flexor will contract and the extensor will relax and for extension it the other way around.

Question 21

synergists

Answer 21

a muscle that carries out the same action as the agonist to stabilize muscle movements.

Question 22

Fixator/stabilising muscles

Answer 22

stabilize the joint which they are attached to, prevents dislocation.

Question 23

brachialis and brachioradialis as synergists

Answer 23

act as synergists to stabilize the action of biceps brachii, flexion.

Question 24

muscle testing

Answer 24

muscles are assessed bilaterally in pairs for comparison. This can help diagnose muscle and nerve injuries

Question 25

muscle atrophy

Answer 25

wasting away of muscle, caused by a disorder of a muscle or its innervation. Can also be caused by muscle immobilisation eg. by long period in plaster cast

Question 26

ways in which muscles can be compartmentalised

Answer 26

1. deep fascial intermuscular septa
2. nerve innervation, common nerve supply within a compartment
3. common action of muscles

Question 27

brachial plexus

Answer 27

matrix of nerves from the C5-T1 spinal nerve roots. Innervates the arm and forearm muscles

Question 28

Lumbosacral plexus

Answer 28

matrix of nerves from the L1-S4 spinal roots. Innervates the thigh and leg muscles.

Question 29

muscle nomenclature, ways in which muscles can be named

Answer 29

1. location eg. serratus anterior and posterior
2. action eg. extensor digitorum
3. direction of muscle fibres eg. oblique muscles
4. number of heads eg. biceps brachii
   5 points of attachment eg. sternocleidomastoid muscle
5. shape eg. deltoid
6. size eg. pectoralis major and minor

Question 30

observations when looking at a micrograph slide of skeletal muscle

Answer 30

1. presence of cross striations
2. normal nuclear size and shape
3. multinucleate
4. absence of branching fibres

Question 31

observations when looking at a micrograph slide of cardiac muscle

Answer 31

1. presence of cross striations
2. large round nuclei
3. mononucleate
4. presence of branching fibres

Question 32

observations when looking at a micrograph slide of smooth muscle

Answer 32

1. absence of cross striations
2. elongated nuclei
3. mononucleate
4. absence of branching fibres

Question 33

intervertebral foramen

Answer 33

hole in vertebrae through which a mixed spinal nerve exits.

Question 34

sensory dorsal root

Answer 34

structure in which somatic sensory nerves enter the spinal cord

Question 35

motor ventral root

Answer 35

structure in which somatic motor nerves exit the spinal cord.

Question 36

dorsal ramus

Answer 36

contains both sensory and motor nerve fibres that innervate the skeletal muscle, skin and bones of the posterior side of the trunk only.

Question 37

ventral ramus

Answer 37

contains both sensory and motor nerves that innervates anteriolateral muscles, skin and bone.

Question 38

cutaneous nerve

Answer 38

nerves that supply the skin over muscles but are not specific to one spinal level.

Question 39

dermatomes

Answer 39

areas of skin that are supplied by a single spinal level

Question 40

dermatome of T2

Answer 40

sternal angle

Question 41

dermatome of T4

Answer 41

nipples

Question 42

dermatome of T10

Answer 42

umbilicus

Question 43

dermatome of L1

Answer 43

inguinal region

Question 44

endoneurium

Answer 44

layer of delicate connective tissue that surrounds the myelin sheath of nerve fibres

Question 45

perineurium

Answer 45

protective sheath that surrounds a fascicle (bundle) of nerve fibres

Question 46

epineurium

Answer 46

protective sheath that surrounds the bundles of fascicles, surrounds the entire nerve.