Upper Limb Flashcards
sacrum
- largest bone located at terminal part of vertebral column where it forms the posterior aspect of the bony pelvis
- remarkably thick, aids in supporting and transmitting weight of the body
- composed of 5 fused sacral vertebrae
- articulates with ilium bilaterally and with L5 at its base
sacral canal
- a continuation of the vertebral canal terminating at the sacral hiatus
- protects cauda equina and filum terminale
sacral foramina
- 4 sacral foramina located lateral to fused sacral bodies on anterior and posterior surface
- foramina decease in size with most superior foramina being the largst
- anterior and posterior rami can exit through sacral foramina
sacral cornua
- 2 bony processes
- palpable as anatomical landmark when administering injections into sacral hiatus
promontory
- upper border/base of sacrum articulates with L5 vertebral body
- promontory projects forward, decreasing the anteroposterior diameter of the pelvic brim
- in females, sacral promontory is of significant obstetric importance and is used when measuring size of pelvis
coccyx
- tailbone
- composed of 4 fused rudimentary coccygeal vertebrae which articulate with the sacrum superiorly at the sacrococcygeal joint
- smaller in size compared to sacrum
- serves as attachment site for ligaments and muscles (Ex. muscles of pelvic floor)
- a small and variable amount of flexion and extension occurs at the sacrococcygeal joint (especially when sitting)
vertebral trends
- size of vertebral body increased moving superior to inferior to support the increasing weight
- size of vertebral foramen decreases to support spinal cord diameter decreasing as spinal nerves exit
- with a smaller vertebral foramen, it is more likely a blockage to the foramen could irritate nerves in lumbar region
accessory ligaments of the vertebral column
- strong, fibrous bands of tissue that stabilize the vertebral column and protect the intervertebral discs
- 3 major ligaments involved in movements of flexion and extension: ligamentum flavum, anterior longitudinal ligament, posterior longitudinal ligament
what is the function and names of the extrinsic muscles of the back
movement of upper extremities
- latissimus dorsi
- trapezius
- rhomboid minor
- levator scapulae
- rhomboid major
latissimus dorsi
origin: T7-T12, iliac crest, inferior angle of scapula
insertion: intertubercular groove of humerus
trapezius
origin: occipital bone
insertion: scapula
rhomboid minor
origin: C7 and T1
insertion: scapula
levator sacpulae
origin: C1-4
insertion: scapula
rhomboid major
origin: T2-T5
insertion: scapula
latissimus dorsi
- broad triangular shaped muscle
- covers lumbar region and inferior portion of thoracic cage
- multiple points of origin therefore varying muscle fibre directions
- one of the largest points of origin is the broad fascial sheath
- fibres share common insertion point
- thoracolumbar fascia made from multiple crosshatched layers of collage – important role in stabilization and load transfer
- all muscle fibres of latissimus dorsi insert in the tuberucular sulcus (bicipital groove) of the humerus
erector spinae muscles
- muscle group comprised of 3 deep muscles in the back organized in parallel columns on either side of vertebral column
- from lateral to medial: iliocostalis, longissimus, spinalis
- responsible for extending (straightening) the vertebral column
what are the sections of the iliocostalis muscle
- iliocostalis cervicis
- iliocostalis thoracis
- iliocostalis lumborum
axilla
- armpit
- pyramidal shaped space between upper thorax and arm
- passageway for major nerves and blood vessels to enter and leave the upper limb
anterior wall of axilla
pectoralis major
lateral wall of axilla
intertubercular sulcus of humerus
posterior wall of axilla
subscapularis, latissimus dorsi, teres major
apex of axilla
base of neck
medial wall of axilla
serratus anterior
base of axilla
skin of armpit
axillary lymph nodes
drain breast
brachial plexus
- network of nerves that supplies motor and sensory innervation to the upper limb
- begins in neck, passes through axilla, terminal branches run through entire upper limb
what are the 5 divisions of the brachial plexus
1) roots
2) trunks
3) divisions
4) cords
5) branches
roots of the brachial plexus
- formed from ventral rami of spinal nerves C5-T11
- the 5 spinal nerve roots leave the spinal cord through the intervertebral foramen of the vertebral column
trunks of the brachial plexus
- each trunk branches into an anterior and posterior division
- nerve fibres of anterior muscles sorted from those of posterior muscles of arm, forearm and hand
divisions of brachial plexus
- each trunk branches into 6 divisions (3 anterior and 3 posterior)
- divisions correspond with anterior and posterior muscle compartments of arm, forearm and hand
cords of brachial plexus
- 3 cords (medial, lateral posterior – names by position relative to axillary artery)
branches of brachial plexus
5 terminal branches
- musculocutaneous nerve
- axillary nerve
- median nerve
- radial nerve
- ulnar nerve
musculocutaneous nerve
motor innervation of anterior compartment (flexion) of arm
axillary nerve
motor innervation to the deltoid (abduction of arm) and teres minor (lateral rotation of arm)
median nerve
motor innervation to most of the muscles of the anterior compartment of the forearm, as well as 5 of the intrinsic muscles of the hand
radial nerve
motor innervation of the posterior compartment (extension) of the arm and forearm
ulnar nerve
motor innervation of 2 muscles of the anterior compartment of the forearm and most of the anterior compartment of the hand
blood supply of upper limb
- branches of subclavian artery
radial artery
preferred pulse point at the wrist due to its relatively large size and proximity to the surface of the arm
deep venous drainage of upper limb
follows same naming and general pathway as arterial supply
- consists of an interconnected pathway that eventually forms the subclavian vein
- then continues into the brachiocephalic vein, then the superior vena cava
radial vein
drains blood from deep structure of palm and lateral aspect of forearm
ulnar vein
drains blood from deep structures of the palm and medial aspect of forearm