Hand and Vertebral Column

ulnar deviation

deviation of the hand toward the ulna (medially) due to radial n. damage

radial deviation

deviation of the hand toward the radius (laterally) due to ulnar n. damage

how do flexion/extension and abduction/adduction actions of the thumb differ from the same actions of the fingers?

movement of the thumb is perpendicular to the movement of the fingers. Abduction/adduction of the fingers is in the coronal plane, while that of the thumb is in the sagittal plane.

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

what is the relationship of the median nerve to the flexor retinaculum?

deep to flexor retinaculum

how does the median nerve branch?

cutaneous branches to palmar surface of digits 1-3 and lateral half of digit 4, recurrent branch to thenar muscles, and branches to lumbricals 1 and 2 on the radial side

what is the relationship of the ulnar nerve to the flexor retinaculum?

superficial to flexor retinaculum

how does the ulnar nerve branch?

cutaneous branches to digit 5 and the medial half of digit 4, motor branches to all other intrinsic hand muscles

what are the thenar muscles and first 2 lumbricals innervated by?

median nerve

what muscles make up the thenar eminence?

abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis

what is the thenar eminence innervated by?

recurrent branch of the median nerve

origin of abductor pollicis brevis

flexor retinaculum, scaphoid, trapezium

insertion of abductor pollicis brevis

proximal phalynx of the thumb

innervation of abductor pollicis brevis

recurrent branch of the median nerve

main actions of abductor pollicis brevis

abducts the thumb, aids in opposition

origin of flexor pollicis brevis

flexor retinaculum and trapezium

insertion of flexor pollicis brevis

proximal phalynx of the thumb

innervation of flexor pollicis brevis

recurrent branch of the median nerve

main actions of flexor pollicis brevis

flexes thumb, aids in opposition

origin of opponens pollicis

flexor retinaculum and trapezium

insertion of opponens pollicis

lateral side of 1st metacarpal

innervation of opponens pollicis

recurrent branch of the median nerve

main actions of opponens pollicis

opposition

origin of adductor pollicis

2nd and 3rd metacarpal bones

insertion of adductor pollicis

medial side of the proximal phalynx of the thumb

innervation of adductor pollicis

ulnar nerve

main actions of adductor pollicis

adducts the thumb, assists in opposition

origin of abductor digiti minimi

pisiform bone

insertion of abductor digiti minimi

medial side of the proximal phalynx of digit 5

innervation of abductor digiti minimi

ulnar nerve

main actions of abductor digiti minimi

abducts digit 5

origin of flexor digiti minimi

hamate bone and flexor retinaculum

insertion of flexor digiti minimi

medial side of the proximal phalynx of digit 5

innervation of flexor digiti minimi

ulnar nerve

main actions of flexor digiti minimi

flexes proximal phalynx of digit 5

origin of opponens digiti minimi

hamate and flexor retinaculum

insertion of opponens digiti minimi

medial border of 5th metacarpal

innervation of opponens digiti minimi

ulnar nerve

main actions of of opponens digiti minimi

opposes 5th digit to the thumb

how many lumbricals are there?

4

origin of the lumbricals

tendons of flexor digitorum profundus

insertion of the lumbricals

lateral sides of the extensor expansion of digits 2-5in

innervation of the lumbricals

median nerve (1 and 2), ulnar nerve (3 and 4)

main actions of the lumbricals

flex MCP joints, extend IP joints

how many dorsal interossei muscles are there?

4

origin of dorsal interossei

adjacent sides of two metacarpal bones

insertion of dorsal interossei

extensor expansions and base of digits 2-4

innervation of dorsal interossei

ulnar nerve

main actions of dorsal interossei

flex MCP joints, extend IP joints, abduct digits 2,3, and 4

how many palmar interossei muscles are there?

3

origin of palmar interossei

palmar surface of 2nd, 4th, and 5th metacarpals

insertion of palmar interossei

extensor expansions of digits 2, 4, and 5

innervation of palmar interossei

ulnar nerves

main actions of palmar interossei

flex MCP joints, extend IP joints, and adduct digits 2, 4, and 5

origin of palmar aponeurosis

palmaris longus tendon

insertion of palmar aponeurosis

digits 2-5

innervation of palmar aponeurosis

ulnar nerve

main actions of palmar aponeurosis

protects deeper structures

what does the extensor expansion do?

causes flexion of the MCP joints and extension of the IP joints in the lumbricals and interossei

what is the extensor expansion attached to?

dorsum of proximal phalanges 2-5

what does the extensor expansion receive insertion from?

lumbrical and interosseous muscles

what is absent on the atlas

body

which vertebra is the atlas?

C1

which vertebra is the axis?

C2

what is present on the axis

the dens

what are the key features of the cervical vertebrae?

transverse foramina and small bodies

what are the key features of the thoracic vertebrae?

articular (costal) facets for ribs on the transverse processes and demifacets on the bodies

what are the key features of the lumbar vertebrae?

large bodies and thick processes

what are the key features of the sacral vertebrae?

fused, sacral foramina and sacral hiatus

what are the key features of the coccygeal vertebrae?

rudimentary vertebrae, may be fused

what passes through the transverse foramina in the cervical vertebrae?

vertebral arteries, vertebral veins, and sympathetic nerves

which spinal curvatures are primary?

thoracic and sacral

which spinal curves are secondary?

cervical and lumbar

what defines a spinal curve as primary or secondary?

primary is anterior concavity, secondary is posterior concavity

what is kyphosis?

excessive thoracic spinal curvature

what is lordosis?

excessive lumbar spinal curvature

what is scoliosis?

excessive lateral and rotational spinal curvature

what structures absorb shock and bear load in the intervertebral disc?

annulus fibrosis and nucleus pulposus

what happens when the nucleus pulposus herniates posteriorly or posterolaterally?

it hits the spinal nerves, causing pain

what structure prevents anterior herniation of the intervertebral discs?

anterior longitudinal ligament

why is the sternal angle an important landmark?

it’s the level of the disc between T4 and T5 vertebrae, the 2nd rib (listening for heart sounds), trachea bifurcation, and the superior border of the heart

how many pairs of ribs are there?

12

how do the ribs articulate?

each rib articulates with the same numbered thoracic vertebra at the articular (costal) facet and superior demifacet. It also articulates with the inferior demifacet of the vertebra superior to the correspondingly numbered thoracic vertebra

what are ribs 1-7?

true ribs

what makes a rib a true rib?

it articulates with the sternum directly via a costal cartilage

what are ribs 8, 9, and 10?

false ribs

what makes a rib a false rib?

they articulate with the sternum indirectly via a common costal cartilage

what are ribs 11 and 12?

floating ribs

what makes a rib a floating rib?

it does not articulate with the sternum at all

what is the functional significance of floating ribs?

broken floating ribs can puncture organs (kidney)

what forms the superior thoracic aperture (thoracic inlet)?

the 1st ribs, manubrium of the sternum, and 1st thoracic vertebra

what is the purpose of the superior thoracic aperture?

it allows communication between the thorax, neck, and upper limbs

what forms the inferior thoracic aperture (thoracic outlet)?

the xiphoid process of the sternum, common costal cartilage, floating ribs, and 12th thoracic vertebra

what is the purpose of the inferior thoracic aperture?

it separates the thorax from the abdomen

what muscle attaches to and closes off the thoracic outlet?

diaphragm

what does the diaphragm do and what is it innervated by?

it attaches to the inferior ribs and thoracic vertebrae. During contraction, it descends and pulls the central tendon downward, increasing the volume of the superior-inferior dimension of the thoracic cavity. it is innervated by the phrenic nerve.

how are the ribs oriented?

as they pass anteriorly and laterally, they slope inferiorly

how does the thoracic volume increase anteroposteriorly?

when the upper ribs are elevated, the sternum moves anteriorly

how does the thoracic volume increase transversely?

when the lower ribs are elevated, the lateral walls move outward