Forearm Anatomy Overview

Questions and Answers

What is the antebrachium?

The wrist

The forearm (correct)

The elbow

The upper arm

What does the interosseus membrane do?

It holds ulna and radius together.

What movements does the loose arrangement of the ulna and radius permit?

Pronation and supination of the forearm.

The wrist allows for rotation.

False Signup and view all the answers

How is the antebrachium divided?

Into a posterior and anterior compartment. Signup and view all the answers

Match the characteristics of the ulna:

Location = Medial aspect of forearm Expansion = Proximal Narrowing = Distally Signup and view all the answers

What makes up the anterior part of the antebrachium?

Superficial, intermediate, and deep muscles. Signup and view all the answers

Match the superficial muscles of the anterior compartment:

Flexor Carpi Ulnaris = Medial muscle innervated by ulnar nerve Palmaris Longus = Vestigial in some populations Flexor Carpi Radialis = Radial deviation Pronator Teres = Pronates the forearm Signup and view all the answers

What is medial epicondylitis commonly known as?

Golfer's elbow. Signup and view all the answers

Where is the origin of the Flexor Carpi Ulnaris?

Common flexor tendon attached to the medial epicondyle. Signup and view all the answers

Where does the ulnar nerve pass?

Between two muscle attachments of the Flexor Carpi Ulnaris. Signup and view all the answers

What is the function of the Flexor Carpi Ulnaris?

Wrist flexion and ulnar deviation. Signup and view all the answers

What is unique about the Palmaris Longus?

It is vestigial and absent in 14% of the population. Signup and view all the answers

What artery supplies the Palmaris Longus?

The ulnar artery. Signup and view all the answers

What is the primary function of the Flexor Pollicis Longus?

Flexion of the wrist and all joints of digit 1. Signup and view all the answers

What function do the posterior muscles of the forearm serve?

Extension Signup and view all the answers

All muscles of the posterior compartment of the forearm are innervated by the radial nerve.

True Signup and view all the answers

What condition is caused by lateral epicondylitis?

Tennis elbow. Signup and view all the answers

Study Notes

Antebrachium Overview

The antebrachium refers to the forearm, running from the elbow to the wrist.
Composed of two bones: ulna (medial aspect) and radius, connected by the interosseus membrane.

Interosseus Membrane

Tough connective tissue that stabilizes the ulna and radius, allowing mobility.

Pronation and Supination

Loose arrangement of the ulna and radius enables rotation of the forearm, termed pronation and supination.
The wrist itself does not allow for rotation.

Muscle Compartments of the Antebrachium

Divided into anterior (flexors) and posterior (extensors) compartments, with proximal muscle bellies and distal tendons.
Proximal attachment is typically higher up (nearer to the elbow), which can contribute to injuries like tendinitis.

Anatomy of the Ulna

Medial bone of the forearm, featuring a broad proximal end and narrowing distally.

Anterior Compartment Muscles

Anterior compartment consists of superficial, intermediate, and deep muscle layers.
Superficial muscles include Flexor Carpi Ulnaris, Palmaris Longus, Flexor Carpi Radialis, and Pronator Teres.
Originates primarily from the common flexor tendon at the medial epicondyle.

Flexor Carpi Ulnaris

Most medial of the anterior superficial muscles, innervated by the ulnar nerve.
Originates from the medial epicondyle and olecranon process, attaching distal to the pisiform bone and fifth metacarpal.
Function: allows wrist flexion and ulnar deviation.

Palmaris Longus

Lateral to Flexor Carpi Ulnaris, often absent in 14% of the population.
Originates from the medial epicondyle; attaches to the flexor retinaculum and palmar aponeurosis.
Innervated by the median nerve; aids in tensing the palmar aponeurosis.

Flexor Carpi Radialis

Innervated by the median nerve; responsible for wrist flexion and radial deviation.
Originates from the medial epicondyle; attaches to the base of the second metacarpal.

Intermediate and Deep Muscles

Intermediate layer: Flexor Digitorum Superficialis, which divides into four tendons reaching distal phalanges.
Deep muscles include Flexor Digitorum Profundus (runs to distal phalanges 2-5), Flexor Pollicis Longus (flexes thumb), and Pronator Quadratus (primary pronator).

Posterior Compartment Muscles

Divided into superficial, deep, and outcropping muscles.
Mainly involved in wrist and digit extension, and innervated by the radial nerve.

Brachioradialis

Unique muscle that flexes the elbow, originating from the supinator ridge, and attaches to the radius.
Supplied by the radial recurrent artery.

Extensor Muscles Overview

Superficial muscles include Extensor Carpi Radialis Longus/Brevis, Extensor Digitorum, Extensor Digiti Minimi, and Extensor Carpi Ulnaris.
Common origin is the lateral epicondyle of the humerus, with functions primarily focused on wrist extension and radial/ulnar deviation.

Clinical Conditions

Golfer's elbow refers to medial epicondylitis, while Tennis elbow refers to lateral epicondylitis.

Blood Supply and Innervation

Anterior compartment is supplied by ulnar and radial arteries and innervated mainly by the median and ulnar nerves.
Posterior compartment is supplied by the posterior interosseous artery.

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Description

Explore the anatomy of the forearm, known as the antebrachium, including its structure, bones, muscle compartments, and functional movements like pronation and supination. This quiz covers key concepts such as the ulna and radius, interosseus membrane, and common injuries related to the anterior compartment muscles.