CHA101L Quiz 3

Labs 5 and 6

Superficial palmar arterial arch

* Branches from the ulnar artery
* Anastomoses with the deep palmar arterial arch for collateral circulation
* Gives rise to the palmar digital arteries

Deep palmar arterial arch

* Branches from the radial artery
* Anastomoses with the superficial palmar arterial arch for collateral circulation

Median nerve

* Deep to flexor retinaculum
* Cutaneous branches to palmar surface of digits 1-3 and lateral 1/2 of digit 4
* Recurrent branch to thenar muscles
* Branches to lumbricals 1 and 2 (on the radial side)

Ulnar nerve

* Superficial to flexor retinaculum
* Cutaneous branches to digit 5 and the medial 1/2 of digit 4
* Motor branches to all other intrinsic hand muscles

Abductor pollicis brevis

* Origin: flexor retinaculum, scaphoid, and trapezium
* Insertion: proximal phalanx of thumb
* Main actions: abducts the thumb, aids in opposition
* Innervation: median nerve

Flexor pollicis brevis

* Origin: flexor retinaculum and trapezium
* Insertion: proximal phalanx of thumb
* Main actions: flexes thumb, aids in opposition
* Innervation: median nerve

Opponens pollicis

* Origin: flexor retinaculum and trapezium
* Insertion: lateral side of 1st metacarpal
* Main actions: opposition
* Innervation: median nerve

Adductor pollicis

* Origin: 2nd and 3rd metacarpal bones
* Insertion: medial side of the proximal phalanx of thumb
* Main actions: adducts thumb, assists opposition
* Innervation: ulnar nerve

Abductor digiti minimi

* Origin: pisiform bone
* Insertion: medial side of proximal phalanx of digit 5
* Main actions: abducts digit 5
* Innervation: ulnar nerve

Flexor digiti minimi

* Origin: hamate bone and flexor retinaculum
* Insertion: medial side of proximal phalanx of digit 5
* Main actions: flexes proximal phalanx of digit 5
* Innervation: ulnar nerve

Opponens digiti minimi

* Origin: hamate and flexor retinaculum
* Insertion: medial border 5th metacarpal
* Main actions: opposes 5th digit to thumb
* Innervation: ulnar nerve

Lumbricals

* Origin: tendons of flexor digitorum profundus
* Insertion: lateral sides of extensor expansion digits 2-5
* Main actions: flex MCP joints, extend IP joints
* Innervation: 1 and 2 by median nerve, 3 and 4 by ulnar nerve

Dorsal interossei

* Origin: adjacent sides of two metacarpal bones
* Insertion: extensor expansions and base of digits 2-4
* Main actions: flex MCP joints, extend IP joints, abduct digits 2, 3, 4
* Innervation: ulnar nerve

Palmar interossei

* Origin: palmar surface of 2nd, 4th, and 5th metacarpals
* Insertion: extensor expansions of digits 2, 4, and 5
* Main actions: flex MCP joint, extend IP joints, adduct digits 2, 4, 5
* Innervation: ulnar nerve

Palmar aponeurosis

* Origin: palmaris longus tendon
* Insertion: digits 2-5
* Main actions: protects deeper structures
* Innervation: ulnar nerve

Extensor expansion

* Attached to dorsum of proximal phalanges 2-5
* Receives insertion of lumbrical and interosseous muscles
* Results in the following actions of the lumbricals and interossei
* flexion of MCP joints
* extension of IP joints

Passes through the vertebral canal

Spinal cord

Kyphosis vs. Lordosis vs. Scoliosis

* Excessive curvature posteriorly (hunchback, thoracic region)
* Excessive lumbar curvature anteriorly
* Lateral curvature (S-shape)

Primary vs. secondary curvature

* Thoracic and sacral (present during fetal development)
* Cervical and lumbar (develops after birth)

What happens when the nucleus pulposus herniates posteriorly or posterolaterally?

* Posteriorly: spinal cord at risk, compression of spinal cord
* Posterolaterally: spinal nerves at risk of damage

What structure largely prevents anterior herniation of the intervertebral discs?

* Anterior longitudinal ligament
* Prevents excessive movements and hyperextension of the spine

Why is the sternal angle an important landmark?

* It marks the point at which the costal cartilages of the second rib articulate with the sternum

What are some potential dangers of injury to the floating ribs?

* Spleen can be damaged (left side)
* Liver can be damaged (right side)
* Kidneys can also be damaged on both sides

Diaphragm

* Large skeletal muscle that attaches to, and for the most part closes off, the thoracic outlet
* Innervated by the phrenic nerve
* Upon inhalation, contracts and flattens and the chest cavity enlarges

External intercostal muscles

* Run in a superolateral to inferomedial direction
* Most active during inspiration

Internal intercostal muscles

* Run in a inferolateral to superomedial direction
* Most active during exhalation

Innermost intercostal muscles

* Incomplete and primarily represented by the transversus thoracis muscles
* Radiate out from the sternum

Neurovascular bundle

* Between the internal and innermost intercostal muscles
* Consists of the intercostal veins, arteries, and nerves

Costal groove

* A groove on the inferior surface of each rib that contains the neurovascular bundle

Posterior vs. Anterior intercostal arteries

* Posterior arise from the descending aorta
* Anterior arise from the internal thoracic arteries
* The anastomoses of these arteries are important for providing collateral circulation to the chest and other structures

Intercostal nerves

* Ventral primary rami of the thoracic spinal nerves
* Provide motor innervation to the intercostal muscles and sensory innervation to the skin of the thorax

Diaphragmatic hernia

* Birth defect where there is a hole in the central tendon of the diaphragm

Hiatal hernia

* Part of the stomach pushes up through the esophageal hiatus of the diaphragm

Accessory muscles of inspiration

* Pectoralis major
* Pectoralis minor
* Serratus anterior
* Sternocleidomastoid
* Scalene muscles

Accessory muscles of expiration

* Rectus abdominis
* Internal obliques
* External obliques
* Quadratus lumborum

Emphysema

* Air sacs in the lungs (alveoli) are damaged
* Over time, the inner walls of the alveoli weaken and rupture
* Causes shortness of breath

Pneumothorax

* Collapsed lung
* Air leaks into the space between the lungs and chest wall (pleural cavity)
* Negative pressure is messed up

Coronary (atrioventricular) sulcus

* Separates the atria and the ventricles
* Can see more posteriorly

Interventricular grooves (sulci)

* A groove that separates the ventricles

Fossa ovalis

* Remnant of the foramen ovale
* Tissue that separates the right and left atria