Upper Limb Bones Anatomy

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Questions and Answers

What is the term for the groove that marks the location of the former epiphyseal plate on the humerus?

anatomical neck

What is the name of the sulcus that contains the tendon of the long head of the biceps brachii muscle?

intertubercular sulcus (or bicipital sulcus or bicipital groove)

What is the name of the prominent structure located lateral to the head of the humerus?

greater tubercle

What is the term for the narrowing of the bone immediately distal to the tubercles on the humerus?

surgical neck Signup and view all the answers

What is the name of the roughened area on the shaft of the humerus?

deltoid tuberosity Signup and view all the answers

How many bones are found in each upper limb?

30 Signup and view all the answers

What is the name of the cavity that the head of the humerus articulates with?

glenoid cavity of the scapula Signup and view all the answers

What is the term for the proximal end of the humerus?

hemispherical head Signup and view all the answers

What is the function of the interosseous membrane between the radius and ulna?

It helps keep the radius and ulna a fixed distance apart and provides a pivot of rotation for the forearm. Signup and view all the answers

What is the position of the palm of the hand in anatomic position?

The palm of the hand is facing anteriorly. Signup and view all the answers

What is the carrying angle of the elbow?

It is the angle at which the forearm deviates laterally from the elbow joint, allowing the forearm to clear the hips during walking. Signup and view all the answers

What are the proximal row of carpal bones, listed from lateral to medial?

Scaphoid, lunate, triquetrum, and pisiform. Signup and view all the answers

What is the function of the carpals, metacarpals, and phalanges?

They form the wrist and hand, allowing for multiple movements possible at the wrist. Signup and view all the answers

In which position is the forearm when the palm of the hand is facing posteriorly?

Pronation. Signup and view all the answers

What are some bony features that the radius and ulna share?

They both exhibit interosseous borders. Signup and view all the answers

What is the position of the distal end of the radius and ulna in relation to the fingers?

The distal end of the radius is near the thumb, and the distal end of the ulna is near the little finger. Signup and view all the answers

What are the distal row of carpal bones, listed from lateral to medial?

Trapezium, trapezoid, capitate, and hamate. Signup and view all the answers

What is the function of the metacarpals?

They support the palm of the hand and articulate with the distal carpal bones. Signup and view all the answers

What is the term used to describe the arrangement of bones in the fingers, comparing them to a line of soldiers?

phalanges Signup and view all the answers

How many phalanges are present in the thumb, also known as the pollex?

2 Signup and view all the answers

What is the consequence of a scaphoid fracture that leads to a prolonged healing time?

avascular necrosis Signup and view all the answers

What is the term used to describe the death of bone tissue due to inadequate blood supply?

avascular necrosis Signup and view all the answers

What is the name of the bone that is commonly fractured in a fall on an outstretched hand?

scaphoid Signup and view all the answers

What is the name of the bone at the base of the little finger?

metacarpal V Signup and view all the answers

What is the name of the surface on the humerus where the deltoid muscle attaches?

The deltoid tuberosity Signup and view all the answers

What is the name of the groove located adjacent to the deltoid tuberosity?

The radial groove or spiral groove Signup and view all the answers

What are the names of the two bony side projections on the distal humerus?

The medial and lateral epicondyles Signup and view all the answers

What is the name of the nerve located posterior to the medial epicondyle?

The ulnar nerve Signup and view all the answers

What are the names of the two smooth, curved surfaces on the distal end of the humerus that articulate with the bones of the forearm?

The capitulum and trochlea Signup and view all the answers

What is the name of the depression on the distal end of the humerus that accommodates the head of the radius?

The radial fossa Signup and view all the answers

What is the name of the bone that forms the lateral aspect of the forearm?

The radius Signup and view all the answers

What is the name of the bony projection on the lateral side of the wrist that can be palpated?

The styloid process of the radius Signup and view all the answers

What is the name of the notch on the distal end of the radius that articulates with the medial surface of the distal end of the ulna?

The ulnar notch Signup and view all the answers

What is the name of the prominent projection on the posterosuperior aspect of the trochlear notch of the ulna?

The olecranon Signup and view all the answers

Study Notes

Bones of the Upper Limb

The upper limb consists of the brachium (arm), antebrachium (forearm), and hand, containing a total of 30 bones.
The complex structure of the hand gives humans capabilities beyond those of most other vertebrates.

Humerus

The humerus is the longest and largest upper limb bone, located in the brachium region.
Features of the humerus include:
- Proximal end with a hemispherical head that articulates with the glenoid cavity of the scapula.
- Greater tubercle, positioned lateral to the head, that helps form the rounded contour of the shoulder.
- Lesser tubercle, smaller and located more medial to the head.
- Intertubercular sulcus (bicipital sulcus or bicipital groove), a depression that contains the tendon of the long head of the biceps brachii muscle.
- Anatomical neck, an almost indistinct groove that marks the location of the former epiphyseal plate.
- Surgical neck, a narrowing of the bone immediately distal to the tubercles, at the transition from the head to the shaft, a common fracture site.
- Shaft with a roughened area, the deltoid tuberosity, which extends along its lateral surface for about half the length of the humerus, where the deltoid muscle of the shoulder attaches.
- Radial groove (or spiral groove), located adjacent to the deltoid tuberosity, which is the location of the radial nerve and some blood vessels.
- Medial and lateral epicondyles, bony side projections on the distal humerus that provide surfaces for muscle attachment.
- Distal end with two smooth, curved surfaces for articulation with the bones of the forearm.

Radius and Ulna

The radius and ulna form the forearm.
Features of the radius include:
- Proximal end with a distinctive disc-shaped head that articulates with the capitulum of the humerus.
- Narrow neck extending from the radial head to the radial tuberosity (bicipital tuberosity).
- Radial tuberosity, an attachment site for the biceps brachii muscle.
- Shaft that curves slightly and leads to a wider distal end.
- Laterally placed styloid process on the distal end, which can be palpated on the lateral side of the wrist, just proximal to the thumb.
- Ulnar notch, on the distal medial surface, which articulates with the medial surface of the distal end of the ulna at the distal radioulnar joint.
Features of the ulna include:
- C-shaped trochlear notch at the proximal end, which interlocks with the trochlea of the humerus.
- Olecranon, a prominent projection on the posterosuperior aspect of the trochlear notch, which articulates with the olecranon fossa of the humerus and forms the posterior “bump” of the elbow.
- Coronoid process, on the inferior lip of the trochlear notch, which articulates with the humerus at the coronoid fossa.
- Radial notch, lateral to the coronoid process, which accommodates the head of the radius and helps form the proximal radioulnar joint.
- Tuberosity of ulna, where the brachialis tendon attaches.
- Distal end with a knoblike head that has a posteromedial styloid process, which can be palpated on the medial (little finger) side of the wrist.

Carpals, Metacarpals, and Phalanges

The bones that form the wrist and hand are the carpals, metacarpals, and phalanges.
The carpals are small, short bones that form the wrist, arranged in two rows (proximal and distal) of four bones each.
Features of the carpals include:
- Proximal row: scaphoid, lunate, triquetrum, and pisiform bones.
- Distal row: trapezium, trapezoid, capitate, and hamate bones.
The metacarpals are bones in the palm of the hand, with five metacarpal bones articulating with the distal carpal bones and supporting the palm.
The phalanges are bones in the digits, with 14 bones present in the fingers, including:
- Three phalanges in each of the second through fifth fingers.
- Two phalanges in the thumb (pollex).

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Description

Learn about the 30 bones that make up the human upper limb, including the brachium, antebrachium, and hand. Discover the structure and functions of each bone.