Thoracic Cage and Upper Limb Muscles

Vocabulary practice flashcards covering thoracic cage, pelvic diaphragm, rotator cuff, and upper limb muscles from BIO 201 Lecture 14.

Diaphragm

A large, flat muscle transversing the entire abdomen directly beneath the lungs; its downward contraction creates a vacuum for inhalation, and its upward relaxation creates thoracic pressure that expels air during exhalation.

Valsalva maneuver

A technique where holding one's breath stabilizes peritoneal cavity volume and pressure while contracting the abdominal muscles, thereby increasing downward pressure on the intestinal, urinary, or reproductive tract to assist with defecation, urination, or childbirth.

Intercostal muscles

Three sets of respiratory muscles located between the ribs that assist in breathing by altering the dimensions of the rib cage to regulate inhaled and exhaled air volume.

Pelvic diaphragm

The muscular partition forming the pelvic floor, comprised of the levator ani and the coccygeus muscles.

Levator ani

The most important muscle of the pelvic floor, composed of the pubococcygeus and iliococcygeus, which functions to support the abdominal and pelvic organs.

Pubococcygeus

One of the two component muscles that together make up the levator ani in the pelvic floor.

Iliococcygeus

One of the two component muscles that together constitute the levator ani in the pelvic floor.

Coccygeus

A pelvic floor muscle that, together with the levator ani, forms the pelvic diaphragm.

Rotator cuff

A functional group of four muscles and their tendons (supraspinatus, infraspinatus, teres minor, and subscapularis) that secure the head of the humerus in the shoulder socket and help raise and rotate the arm.

Supraspinatus

A rotator cuff muscle that holds the humerus in place, maintains upper arm stability, and helps lift the arm.

Infraspinatus

A rotator cuff muscle that serves as the primary muscle responsible for rotating and extending the shoulder.

Teres minor

The smallest of the rotator cuff muscles, which assists in rotating the arm away from the body.

Subscapularis

A rotator cuff muscle that secures the humerus to the shoulder blade, rotates the arm, holds the arm straight out, and lowers it.

Rotator cuff tear

An injury commonly resulting from wear and tear from repetitive movements (such as in tennis or baseball), falling on the arm, or lifting heavy objects, often requiring surgical repair and rehabilitation.

Tendinitis

Inflammation or irritation of a tendon attaching to bone, frequently caused by overuse, which produces pain just outside the joint (e.g., tennis elbow, swimmer's shoulder).

Bursitis

Inflammation of a bursa (a small, fluid-filled sac that cushions joints and absorbs shock), commonly caused by repetitive motion or infection.

Flexor carpi ulnaris

An anterior lower arm muscle situated along the ulna.

Flexor carpi radialis

An anterior lower arm muscle situated along the radius.

Palmaris longus

An anterior forearm muscle positioned between the flexor carpi radialis and flexor carpi ulnaris.

Pronator teres

A muscle located on the anterior compartment of the forearm that aids in pronation of the lower arm.

Extensor carpi ulnaris

A muscle located on the posterior aspect of the forearm that acts along the ulnar border to extend the wrist.

Extensor digitorum

A posterior forearm muscle that extends the medial digits of the hand.