Anatomy of the Ulna Bone

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Questions and Answers

What is the origin of the Flexor carpi radialis muscle?

Common flexor origin

Lateral epicondyle

Medial epicondyle (correct)

Coronoid process of ulna

How many muscles are in the superficial group of the anterior or flexor muscles of the forearm?

5 (correct)

What is the insertion of the Pronator teres muscle?

Base of the 2nd and 3rd metacarpal bones

Into palmar aponeurosis

Pisiform bone, hamate, and 5th metacarpal bones

Rough impression at the middle of the lateral side of the radius (correct)

What percentage of people are born without the Palmaris longus muscle?

10% Signup and view all the answers

What is the origin of the Flexor pollicis longus muscle?

From the anterior surface of the body of radius Signup and view all the answers

What is the insertion of the Flexor digitorum profundus muscle?

Bases of the distal phalanges of medial 4 fingers Signup and view all the answers

How many muscles are in the deep group of the anterior or flexor muscles of the forearm?

3 Signup and view all the answers

What is the insertion of the Pronator quadratus muscle?

Lower 1/4 of the lateral border and anterior surface of the radius Signup and view all the answers

What is the action of the lumbricales muscles on the phalanges?

They flex the first phalanges at the metacarpo-phalangeal joints Signup and view all the answers

How many dorsal interossei muscles are there in the hand?

4 Signup and view all the answers

What is the nerve supply of the interossei muscles?

Ulnar nerve Signup and view all the answers

What is the action of the palmar interossei muscles on the fingers?

They adduct the fingers to the imaginary line Signup and view all the answers

What is the function of the pectoralis major muscle in the upper limb?

Flexes and medially rotates the arm Signup and view all the answers

Which muscle is responsible for flexing the wrist and medial 1/2 of flexor digitorum profundus?

Flexor carpi ulnaris Signup and view all the answers

How many phalanges are present in the fingers of the hand, excluding the thumb?

3 Signup and view all the answers

What is the shape of the body of the ulna in the upper 3/4?

Triangular Signup and view all the answers

What is the result of a lesion of the median nerve?

Ape hand Signup and view all the answers

How many muscles are present in the pectoral region of the shoulder?

4 Signup and view all the answers

How many muscles are supplied by the ulnar nerve in the upper limb?

15 1/2 Signup and view all the answers

What is the name of the concave surface on the lateral side of the coronoid process of the ulna?

Radial notch Signup and view all the answers

What is the result of a lesion of both the ulnar and median nerves?

Complete claw hand Signup and view all the answers

How many carpal bones are present in the proximal row of the wrist?

4 Signup and view all the answers

What is the name of the muscle that connects the clavicle to the scapula?

Subclavius Signup and view all the answers

What is the name of the process that projects medially and below the head of the ulna?

Styloid process Signup and view all the answers

Study Notes

Upper Limb Bones

Radial notch: a concave surface on the lateral side of the coronoid process that articulates with the head of the radius to form the superior radio-ulnar joint.
Ulna body: triangular in the upper ¾ and cylindrical in the lower ¼.
Lower end of ulna:
- Head: small and rounded, articulating with the medial side of the lower end of the radius to form the inferior radio-ulnar joint.
- Styloid process: projects medially and below the head.

Bones of the Hand

27 bones in total, consisting of:
- Carpal bones: 8 in number, arranged in 2 rows (proximal and distal).
- Metacarpal bones: 5 in number, one for each finger.
- Phalanges: 14 in number, with 3 in each finger (proximal, middle, and distal) except the thumb, which has only 2 (proximal and distal).

Muscles of the Upper Limb

Muscles of the Shoulder Region

15 muscles divided into 3 groups:
- Muscles of the pectoral region:
  - Pectoralis major: originates from the clavicle and sternum, inserts into the lateral lip of the bicipital groove of the humerus, and flexes and adducts the arm while medially rotating it.
  - Other muscles in this group include pectoralis minor, serratus anterior, and subclavius.

Muscles of the Hand

Interossei:
- 4 dorsal interossei muscles: occupy the intervals between the metacarpal bones and are bipenniform muscles.
- 3 or 4 palmar interossei muscles: smaller and placed on the palmar surfaces of the metacarpal bones.
- All interossei muscles are supplied by the ulnar nerve.
Action of the interossei:
- Palmar interossei: adduct the fingers to an imaginary line drawn longitudinally through the center of the middle finger.
- Dorsal interossei: abduct the fingers from that line.

Nerve Supply

Ulnar nerve (C.8 and T.1) is motor to 15 ½ muscles:
- 1 ½ muscles in the front of the forearm.
- 14 short muscles in the hand.
Median nerve (C.5, 6, 7, 8, and T.1) is motor to 12 ½ muscles:
- 6 ½ muscles in the front of the forearm.
- 6 short muscles in the hand.

Muscles of the Forearm

Anterior or flexor muscles: 8 in number, consisting of:
- Superficial group: 5 muscles, including pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis.
- Deep group: 3 muscles, including flexor digitorum profundus, flexor pollicis longus, and pronator quadratus.