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