Muscles

Question 1

Name elbow flexors

Answer 1

3 muscles:
Brachialis
Biceps Brachii
Brachioradialis

Question 2

Briefly describe position and arrangement of brachialis

Answer 2

Fusiform muscle located on the anterior surface of the shaft of the humerus, deep to the muscle belly of biceps brachii and distally to its tendon

Tendon forms part of the floor of the cubital fossa

Question 3

Give attachments of brachialis

Answer 3

Origin: Distal ½ , anterior surface shaft of humerus
Insertion: Anterior surface of Ulna tuberosity

Question 4

Give actions of brachialis

Answer 4

Main flexor of elbow (in midline of anterior elbow joint)

Question 5

Briefly describe arrangement and location of biceps brachii

Answer 5

large, thick muscle of the arm consisting of long head and short head

superficial to the brachialis and coracobrachialis muscles, and essentially forms the anterior side of the arm

Question 6

Give attachments of biceps brachii

Answer 6

Origin:
Short head- tendon from apex of coracoid process of scapula.
Long head- tendon from supraglenoid tubercle of scapula. Long head tendon passes in a synovial sheath under the transverse ligament passing through intertubercular sulcus of the humerus

Insertion:
Tendon conjoined and twists before attaching to the radial tuberosity of the Radius. From the medial borders forms bicipital aponeurosis, it runs down and medially across cubital fossa to attach to the posterior border of the upper end of the ulna

Question 7

Give actions of biceps brachii

Answer 7

Powerful Flexion at the elbow,
supination of the radio-ulnar joints (forearm)
weak flexor of the shoulder

Question 8

Briefly describe the position and arrangement of brachioradialis

Answer 8

Superficial layer of the posterior forearm muscles on the lateral aspect extending from the elbow almost to the wrist

Question 9

Give attachments of brachioradialis

Answer 9

Origin:
Lateral supracondylar ridge of humerus, Lateral intermuscular septum

Insertion:
Lateral distal radius proximal to the styloid process

Question 10

Give actions of brachioradialis

Answer 10

Flexes the elbow when forearm mid-prone

Returns forearm from full supination or full pronation to mid-range (insertion anterior to point of rotation; most powerful in neutral)

Question 11

State 1 functional activity in which brachioradialis is important

Answer 11

Hammering, pulling a pint of beer, chopping

Question 12

State nerve supply of elbow flexors

Answer 12

Brachialis & biceps brachii:
Musculocutaneous nerve C5-6

Brachioradialis:
Radial nerve C5-6

Question 13

Name elbow extensors

Answer 13

2 muscles
Triceps brachii
Anconeus

Question 14

Briefly describe location and arrangement of triceps brachii

Answer 14

only constituent of the posterior muscle group of the arm, spanning almost the entire length of the humerus

consists of a long, medial and lateral head and makes up all the muscle bulk in the posterior region of the arm

Question 15

Give the attachments of triceps brachii

Answer 15

Proximal:
Long head - infraglenoid tubercle and glenoid labrum of the scapula
Lateral head- posterior surface of the shaft of the humerus, supralateral to the spiral groove
Medial head- posterior surface of humerus, inframedial to the spiral groove.

Distal:
Three heads converge to a tendon
tendon attaches to the superior surface of the olecranon of the ulna and deep fascia of forearm.

Question 16

Give actions of triceps brachii

Answer 16

As a whole - Prime mover of Extension at elbow joint

long head - extends arm at shoulder joint, assists in adduction of humerus

Question 17

Name two functional activities in which triceps brachii has a prime action

Answer 17

Triceps extends the elevated arm to put books on a shelf. Works strong in punching
Pushing up from a chair, pushing a car etc

Question 18

Briefly describe location and arrangement of anconeus

Answer 18

triangular muscle in the posterior compartment of the forearm

Question 19

Give attachments of anconeus

Answer 19

Origin: Lateral epicondyle of humerus
Insertion: Descends to lateral olecranon, coronoid process of ulna, proximal ulna

Question 20

Give actions of anconeus

Answer 20

Assists elbow extension

Question 21

Give nerve supply of elbow extensors

Answer 21

Radial nerve

Triceps brachii - C6-8
Anconeus - C7-8

Question 22

Give names of forearm pronators

Answer 22

Pronator teres
Pronator quadratus
Brachioradialis

Question 23

Briefly describe location and arrangement of pronator teres

Answer 23

fusiform muscle found in the anterior forearm, consisting of a humeral head and ulna head
most lateral muscle of the superficial flexors of the forearm
forms the medial margin of the cubital fossa (elbow pit)

Question 24

Give attachments of pronator teres

Answer 24

Origin:
Humeral head - Medial epicondyle of humerus
Ulna head - medial part of coronoid process of ulna

Insertion:
Middle of lateral surface of radius (distal to supinator)

Question 25

Give actions of pronator teres

Answer 25

Powerful pronation of forearm (rotates radial head on radial notch of ulna)

Humeral head - assists elbow flexion

Question 26

Briefly describe location and arrangement of pronator quadratus

Answer 26

quadrangular, thin, short and flat muscle lying within the anterior compartment of forearm

deepest muscle in the anterior (flexor) compartment of forearm

located distally in the forearm, covering the interosseous membrane superficially

Question 27

Give attachments of pronator quadratus

Answer 27

Origins - Distal anterior surface of ulna

Insertion - Distal anterior surface of radius

Question 28

Give actions of pronator quadratus

Answer 28

Pronation of forearm (rotates radial head on radial notch of ulna)

Stabilises bones (inf RUJ) in weight-bearing

Question 29

Give nerve supply of the forearm pronators

Answer 29

Pronator teres -
Median nerve C6-7 (passes through gap between 2 heads)

Pronator quadratus-
Anterior Interosseous nerve C8 - T1

Brachioradialis
Radial nerve C5-6

Question 30

Name forearm supinators

Answer 30

3 muscles
Supinator
Biceps brachii
Brachioradialis

Question 31

Briefly describe location and arrangement of supinator

Answer 31

spiral muscle contained in the posterior compartment of the forearm, consisting of a humeral head and ulna head

found deep in the forearm, superficial only to the parts of the radius and ulna over which the muscle lies.

Along with the brachialis muscle, it forms the floor of the cubital fossa

Question 32

Give attachments of supinator

Answer 32

Origin:
Humeral head - Lateral epicondyle of humerus, slips to radial collateral and annular ligaments

Ulna head - supinator fossa and crest of ulna (inferior to radial notch)

Insertion:
Heads conjoin and wrap around lateral, posterior and anterior surfaces of proximal 1/3 of radius

Question 33

Give actions of supinator

Answer 33

Prime mover of supination of forearm (de-rotate radial head on radial notch)

Question 34

Give nerve supply of forearm supinators

Answer 34

Supinator-
Radial nerve (motor branch through gap of two heads) C5-6

Biceps brachii-
Musculocutaneous nerve C5-6

Brachioradialis -
Radial nerve C5-6