Define and identify the anatomical position and anatomical planes.
-Anatomical position: head, eyes and toes directly anterior (forward), upper
limbs by the sides with the palms facing anteriorly, lower limbs close together
with the feet parallel and the toes directly anterior
-Anatomical planes: four imaginary plans that intersect the body at anatomical
position.
-Median: there is one median plane. It is the vertical plane passing
longitudinally through the center of the body (divides it into right and left
halves)
-Sagittal planes are vertical planes passing through the body parellel to the
median plane
-Frontal (coronal) plane- vertical planes passing through the body at right
angles to the median plane (divides the body from front and back)
-Transverse planes are planes passing through the body at right angles to the
median and frontal planes. It divides the body into upper and lower portions.
Define be able to use the terms that are used to describe relationships of
structures to each other and to the body wall (medial, lateral, superior,
inferior, anterior, posterior)
-RELATES TO ANATOMICAL POSITION
-medial- nearer to the median plane (the little finger is on the median side of the
hand)
-lateral- nearer to the outside, further from the median plane (the thumb is on
the lateral side of the hand)
-superior- nearer to the head (the heart is superior to the stomach)
-inferior- nearer to the feet (the stomach is inferior to the heart)
-anterior- nearer to the front (the sternum is anterior to the heart)
-posterior- nearer to the back (the kidneys are posterior to the intestine)
Compare and contrast the pulmonary and systemic circulation.
-in the pulmonary circulation, the right heart propels low oxygen blood returned
to it into the lungs where carbon dioxide is exchanged for oxygen (pulmonary is
under lower pressure)
-in systemic circulation, oxygen rich blood returned to the left heart is pumped
to the remained of the body, exchanging oxygen and nutrients for carbon dioxide
Describe the function of the blood circulatory system.
-The heart pumps blood through the body’s system of vessels. The blood caries
oxygen, nutrients and waste product to and from cells.
Define the parts of vertebrae.
-Vertebral body: gives strength to the vertebral column and supports body
weight
-The superior and inferior surfaces of vertebral bodies are covered with hyaline
cartilage and a rim of smooth bone= epiphysial rim
-the verterbral arch lies posterior to the vertebral body and is formed by right
and left pedicles and laminae
-Pedicles: are short, stout processes that join the vertebral arch and the
vertebral body
-Laminae: the pedicles project posteriorly to meet these two broad, flat bones
(unit the midline)
-the vertebral arch and the posterior surface of the vertebral body form the walls
of the vertebral foramen
-the succession of vertebral foramen form the vertebral canal
-the vertebral canal contains the spinal cord, meninges, fat, spinal nerve roots
and vessels
-the indentations formed by the projection of the body and articular processes
superior and inferior pedicles are vertebral notches.
-the IV foramina gives passage to spinal nerve roots and accompanying vesssels
and contain the spinal ganglia
-1 spinous process: median, projects posteriorly from the vertebral
arch at the jx of the laminae and overlaps the vertebra below
-2 transverse processes project posterolaterally from the jx of the
pedicles and the laminae
-4 articular processes also arise from the jxs of pedicles and laminae
and bear articular surface (facet)
Compare and contrast cervical, thoracic and lumbar vertebrae.
-The cervical vertebra have holes in the transverse proceses called the
transverse foramen. Arteries and veins pass through these holes. The also
have bifid spinous processes.
-The thoracic vertebrae are the only vertebrae with costal facets that
articulate with the ribs.
- The lumbar vertebrae have mammary processes and a much larger body
and can hold a lot more weight.
Compare and contrast the curvatures of the vertebral column.
-Babies are born with the thoracic and sacral curves that remain. After birth
they develop their cervical and lumbar curves.
-Sacral and thoracic curves (primary curves) are concave
-Cervical and lumbar curves (secondary curves) are convex
Describe abnormal curvatures of the vertebral column: kyphosis, lordosis and
kyphoscoliosis.
-Kyphois: “humpback”, abnormal increase in the thoracic curvature,
vertebral column curves posteriorly
-occurs in geriatrics (Dowager’s hump), loss of height
-Lordosis: “hollow back”, anterior rotation of the pelvis, abnormal increase in
lumbar curvature (more convex anteriorly)
-some women develop this in late pregnancy
-Scoliosis: “curved back”, abnormal lateral curvature that is accompanied by
rotation of the vertebrae
-common in pubertal girls, difference in length of lower limbs
Describe the composition and the function of intervertebral discs.
-the presacral vertebral column is flexible because it consists of vertebrae joined
together by semi rigid IV discs
-the IV disks are composed of fibrocartilage
-1 nucleus pulposus (from notocord) surrounded by annulus fibrosus
-the disks act as shock absorbers
Compare and contrast the three meninges.
-There are 3 meningeal covers
1) Dura- outermost, forms a sac within the canal, starts at the base of the
scull and works all the way down
-composed of tough fibrous and some elastic tisue
-seperated from the vertebrae by epidural space
2) Arachnoid: delicate, avascular membrane composed of fibrous and elastic
tissue that lines the dural sac and the dural root sheaths
-it encloses the csf filled subarachnoid space containing the spinal
cord, spinal nerve roots and spinal ganglia
-held next to dura matter via CSF pressure
3)Pia: innermost covering membrane of the spinal cord, consists of flattened
cells with equally flattened proceses that closely follow the surface of the
spinal cord
-directly covers the roots of spinal nerves and spinal blood vessels
-continues as the filum terminale
Describe the enlargements of the spinal cord.
-The cervical enlargement extends from vertebral level C3 to T2 with
maximum enlargement opposite C5 and C6 (forms a lot of the brachial
plexus)
-The lumbosacral enlargement extends from vertebral level T10 to taper
down to the conus medularis with maximal enlargement opposite T12
-They are enlarged because they have more nerves running two and from
them to give rise to the upper and lower limbs
Define and describe the function and composition of the conus medullaris,
cauda equina, ligmentum denticulatum, filum terminale internum, dorsal and
ventral roots
-Conus medullaris: the conus medullaris is the tapering end of the spinal cord
-Cauda equina: This is the termination of the spinal cord. It is a bundle of
nerve roots running from the lumbar cistern The ventral and dorsal roots of
the spinal cord segments below L1/L2 and in the center the filum terminale
is found.
-Filum terminale and ligementum denticulum: They are both made from pia
mater and help anchor the spinal cord, laterally and inferiorly to the coccyx
-A ventral root is exclusively comprised of motor fibers and connects the
ventral horn with the mixed nerve.
-ligementum denticulum: small tooth
-the filum terminale anchors the spinal dural sac inferiorly
- A dorsal root is exclusively comprised of sensory fibers and connects the
dorsal horn with the mixed nerve.
Describe the epidural, subdural and subarachnoid space.
-epidural space: the spinal dura mater is separated from the vertebrae by
this, this is a fat filled space
-subdural space: the potential space between the dura and arachnoid mater
(dura-arachnoid interface), no actual space, but rather a weak cell layer (held
together by pressure from csf)
-subarachnoid space: the arachnoid mater is seperated from the pia mater by
this space. It contains csf. There are strands of connective tissue, the
arachnoid trabeculae, spanning this space
Describe the difference between spinal cord level and vertebral level.
-Since the spinal cord is shorter than the vertebral column, the spinal cord
segments that correspond to vertebral levels are located higher in the
vertebral canal.
List the components of the central nervous system and the peripheral nervous
system.
-The CNS contains the brain and spinal cord
-the PNS consists of nerves and ganglia, together with their motor and
sensory endings
-the nervous system controls and coordinates functions of the organ systems.
Describe the organization of the peripheral nervous system.
-the PNS consists of nerve fibers and nerve cell bodies that connect the CNS
with peripheral structures
-sensory neurons running from the stimulus receptors that informs
the CNS of stimuli and motor neurons running from the CNS to
muscles and glands to take action
-the PNS is divided into sensory-somatic nervous system and the automatic
nervous system
Compare and contrast the function of the somatic vs autonomic nervous
system
-Somatic nervous system is voluntary and provides general sensory and
motor innervation to all parts of the body accept the viscera, smooth muscle
and glands
-sensory fibers transmit sensations of touch, pain, temperature and
position from sensory receptors
-the motor fibers stimulate voluntary skeletal muscle movement
-Automatic nervous system consists of visceral efferent motor fibers that
stimulate involuntary muscle, blood vessels and glands and sensory motor
fibers that conducts pain impulses from internal organs
Define and describe function of the following terms – dorsal and ventral
horns, ventral and dorsal roots, dorsal root ganglion, dorsal and ventral rami,
mixed spinal nerves
-in transverse sections of the spinal cord, the grey matter appears as an H shaped
area embedded in a matrix of white matter, these are the horns!
-posterior dorsal horns and anterior ventral horns
-A typical spinal nerve arises from the spinal cord by nerve roots:
-The ventral root (anterior) consists of motor fibers passing from nerve cell
bodies in the anterior horn of the spinal cord to effector organs located in the
periphery
-The dorsal root (posterior) consists of sensory afferent fibers that convey
neural impulses to the CNS from sensory receptors of the body. The posterior
root carries general sensory fibers to the posterior horn of the spinal cords.
-The anterior and posterior roots unite at the intervertebral foaramen to form a
sinal nerve, which immediatley divides into two rami
-posterior rami supply nerve fibers to synovial joints of the vertebral colun,
deep muscles of the back and overlying skin
-the anterior rami supply nerve fibers to a musch larger area: anterior and
lateral regions of the trunk and the upper and lower limbs
-Dorsal horn: location of synapses for sensory neurons
_________________________________________________________________________________________________
Describe clavicle, scapula and humerus and list their key bony features.
-the Clavicle (collar bone) connects the upper limb to the trunk. Its sternal
end articulates with the manubrium of the sternum. Its acromial end
articulates with the acromian of the scapula. The medial two thirds of the
shaft are convex anteriorly where as the lateral third is flattened and concave
anteriorly. These curvatures increase the resilience of the clavical (looks like
big S)
-no marrow cavity—consists of spongy bone with a shell
-the Scapula (shoulder blade) is a triangular flat bone that lies on the
posteriolateral aspect of the thorax overlying the 2nd-7th ribs. The posterior
convex surface is unevenly divided by the spinae of scapula into a small
supraspinous fossa and a much larger infraspinasous fossa. The conave
costal surface has a large subscapular fossa.
-the lateral border of the scapula is the thickest part and includes the
head of the scapula where the glenoid cavity is located, the neck of the
scapula
-the superior border of the scapula is marked by a suprascapular
notch
-the spine of the scapula continues laterally as a flat expanded
acromian (forms subcue point of shoulder
-the lateral surface has a glenoid cavity which articulates with the
head of the humerous at the shoulder joint
-there is a beak like coracoid process superior to the glenoid cavity
and project anterolaterally
-the Humerus is the largest bone in the upper limb. It articulate with the
scapula at the glenohumeral joint and the radius and ulna at the elbow joint
-the head of humerus articulates with the glenoid cavity of scapula
-the intertubercular sulcus (bicipital groove) of the proximal end of
the humerus seperates the lesser tubercle from the greater tubercle
-just distal to the humeral head is the anatomical neck of the humerus
and distal to the tubercles is the surgical neck of the humerous
-the shaft of the humerous has 2 prominent features:
-deltoid tuberosity laterally
-radial groove posteriorly for the radial nerve and deep artery
of the arm
-the inferior end of the humeral shaft widens as the lateral and medial
epicondyles form
-the condyles af the humerus are made up of the trochlea, capitulum,
olecranon, coronoid and radial fossae
-the condyles have 2 articular surfaces:
-a lateral capitulum for articulation with the head of the radius
-a medial trochlea for articulation with the trochleor notch of
the ulna
-the coronoid fossa is tneriorly and superior to the trochlea and
recieves the coronoid process of the ulna during full flexion of the
elbow
-the olecranon fossa is posterior and occomadates the olecranon of
the ulna during extension of the elbow
-superior and anterior to the capitulum, the radial fossa accomadates
the edge of the head of the radius when the elbow is fully flexed
Describe the function and innervation of the rotator cuff muscles.
-the four rotator cuff muscles are the: Supraspinatus, Infraspinatus, Teres
Minor and Subscapularis
-The subscapularis muscle is a medial rotator and pulls the humerus toward
the center of the body. It is innervated by the upper and lower subscapular
nerves.
-The supraspinatus is a lateral rotator and initiates abduction of the
shoulder. It is innervated by the suprascapular nerve
-The infraspinatus is a lateral rotator and strengthens the shoulder joint. It is
innervated by the suprascapular nerve.
-the teres minor is a lateral rotator and it is innervated by the axillary nerve.
-MEDIAL ROTATORS: subscapularis, teres minuor
-LATERAL ROTATORS: infraspinatus and supraspinatous
Describe the function and innervation of the muscles that move the
shoulder besides the rotator cuff muscles.
-the Latissimus dorsi acts directly on the shoulder join (extends, adducts and
medially rotates humerus). It is innervated by the Thoracodorsal nerve.
-the Deltoid muscle acts to abduct the arm at the shoulder joint. It is
innervated by the axilary nerve.
-the Teres major helps extend the arm from the flexed position and adducts it
and medially rotates the arm at the shoulder. It is innervated by the lower
scapular nerve.
-the Pectoralis major primarily adducts the arm at the shoulder. It also is a
medial rotator of the humerous. It is innervated by the lateral and medial
pectoral nerves.
Describe the function and innervation of the muscles that rotate the
scapula.
-the Serratus anterior protracts and stabilizes the scapula. It assists in upper
rotation. It is innervated by the long thoracic nerve.
-the Rhomboid major and minor hold the scapula in place to the rib
cage/thoracic wall. They are innervated by the dorsal scapular nerve.
-the Trapezius rotates the scapula for full abduction of the upper extemity.
The scapula can be adducted and the head drawn directly backward. It is
motorly innervated by the spinal accesory nerves and sensory innervated by
cranial nerves 3 and 4
-the Levator scapulae elevates the superior angle of the scapula and draws it
medially. It is innervated by the dorsal scapular and cervical nerves 3 and 4
Describe the location and function of bursa.
-Bursae contain capillary films of synovial fluid and are located near the joint
where tendons run against bone, ligaments or other tendons and where skin
moves over a bony prominence
-bursae acts as a cushion/grease so that joints can move easily.
Describe the clinical significance of humeral fractures in different
locations and the resulting vulnerability of different nerves.
-because nerves are in contact with the humerus, they may be injured when t
he associated part of the humerus is fractured
-surgical neck: axillary nerve
-radial groove: radial nerve
-distal humerus: median nerve
-medial epicondyle: ulnar nerve
Describe the flexor compartment of the arm with respect to its muscles,
functions and innervations.
-there are three muscles in the anterior aspect of the arm. These are the
biceps brachiae, brachialis and corraco brachialis. They are all innervated by
the musculoutaneous nerve.
-Biceps brachiae: has a long head laterally and a short head medially.
This muscle allows you to flex your elbow and supinate (as in opening
a bottle of wine). It is innervated by the musculocutaenous nerve.
-Brachialis: attaches to the ulna, is under the biceps brachae, flexor of
the forearm at the elbow. It is innervated by the musculocutaneous
nerve.
-Corraco brachialis: starts on the coricoid process and extends down
toward the brachialis. It flexes and adducts the arm at the shoulder. It
is innervated by the musculocutaneous nerve.
Describe the extensor compartment of the arm with respect to its muscles,
functions and innervations.
-there is one muscle in the posterior aspect of the forearm. This muscle is the
extensor and is called the Triceps brachiae.
-the Triceps brachiae has three heads: long, lateral and medial. This muscle
extends the forearm at the elbow. The long head of the triceps can also
extend the humerus at the shoulder joint.
-the triceps muscle is innervated by the radial nerve, which travels in the
radial groove and provides motor innervation as it travels down the
humerus.
Describe the borders of the axilla and the contents of the axilla.
-the axilla provides a passageway for vessels and nerves going two and from
the upper limb
The borders of the axilla are:
-anteriorly – pect major and pect minor
-posteriorly – latissimus dorsi and teres major
-medially – serratus anterior
-laterally the bicipital groove of the humerus
-The apex is bordered by first rib, clavicle and upper edge of the
subscapularis muscle
-the anterior axillary fold consists of the teres major and the pectoralis major
-the posterior axillary fold consists of the latissimus dorsi
Draw the brachial plexus from memory from roots to nerves.
If you look at the brachial plexus one can note that the radial nerve receives
contributions from all 5 ventral rami. The axillary nerve should also have all 5
spinal cord levels because both the radial and axillary nerves are branches of the
posterior cord, the reality is however that the axillary nerve typically has only C5
and C6 in it because the upper roots of the brachial plexus supply the proximal
portion of the upper limb and the lower roots supply the most distal parts of the
upper limb.
Draw the axillary artery and its branches.
-the axillary artery begins at the lateral border of the first rib as the continuation
of the subclavian artery and ends at the interferior border of the teres major. It
passes posterior to the pec minor into the arm and becomes the brachial artery
when it passes distal to the inferior border of the teres major. The axillary artery
has three divisions.
-the first division has 1 branch: supreme thoracic artery
-the second division has 2 branches: (just deep to the pec muscles) the
thoracoacromial artery (pass medially to muscle) and lateral thoracic
arteries (pass laterally to muscle)
-the third division has 3 branches: the subscapular artery, the anterior
humeral circumflex artery and the posterior humeral circumflex arter.
-the subscapular artery is the largest branch of the axillary artery
Describe the cutaneous innervation to the arm and forearm.
-Supraclavicular nerves (C3, C4)- supply the skin over the clavicle and the
superolateral aspect of the pec major
-Posterior cutaneous nerve of the arm: this is a branch of the radial nerve, it
supplies skin on the posterior surface of the arm
-Posterior cutaneous nerve of the forearm: also a branch of the radial nerve, it
supplies skin on the posterior surface of the forearm
-Superior lateral cutaenous nerve of the arm: this is a terminal branch of the
axillary nerve, supplies innervation to the skin over the lower part of the deltoid
and on the lateral side of the mid arm
-Inferior lateral cutaneous nerve of the arm: branch of the radial nerve, supplies
skin over the inferolateral aspect of the arm , it is frequently a branch of the
posterior cutaneous nerve of the forearm
-Lateral cutaneous nerve of the forearm: this is the terminal branch of the
musculocutaneous and supplies skin on the lateral side of the forearm
-Medial cutaneous nerve of the arm: arises from the medial cord of the brachial
plexus, often unites in the axilla with the lateral cutaneous branch of the second
intercostal nerve. It supplies skin on the medial side of the arm
-Intercostobrachial nerve: a lateral cutaneous branch of the second intercostal
nerve also contributes to innervation of the skin on the medial surface of the arm
-Medial cutaneous nerve of the forearm: arises from the medial cord of the
brachial plexus, supplies the skin on the anterior and medial surfaces of the
forearm.
Describe the symptoms that patient would present with after injury to upper
brachial plexus or lower brachial plexus
-injury to the upper part of the brachial plexus (to c5 and c6) you would have
shoulder issues
-injury to the upper brachial plexus would result in waiter’s tip
-Erb-Duchenne palsy: paralysis of the muscles of the shoulder and arm
(upper limb with adducted shoulder, medially rotated arm and extended
elbow)
-inury to the lower part of the brachial plexus (c8 and t1) you would have hand
issues
-injury to the lower part of brachial plexus would result in Klumpke’s palsy,
claw hand would result
Be able to describe the bony landmarks on the ulna, radius and distal
humerus.
ULNA-the ulna is a stabilizing bone of the forearm. It is medial and longer
than the radius. Its proximal end has 2 prominent projections:
-the olocranon posteriorly
-the coronoid process anteriorly
-the two of them together form the trochlear notch (where the ulna
articulates with the trochlea of the humerus)
-inferior to the coronoid porcess is the tuberosity of the ulna.
-on the lateral side of the coronoid process is a smooth, rounded
cavity called the radial notch which articulates with the head of the
radius.
-Distal to the radial notch is a prominent ridge, the supinator crest,
and between it and the distal part of the coronoid process is a
concavity called the supinator fossa
-proximally, the shaft of the ulna is thick, but tapers, diminishing in
diameter distally.
-at its narrow distal end is the rounded head of the ulna with a small,
conical ulnar styloid process.
-the ulnar doesn’t articulate directly with the carpal bones. It is
separated from the carpals by a fibrocartilaginous articular
disc.
RADIUS: the radius is the lateral and shorter of the two forearm bones.
-its proximal end consists of a cyndrilacal head, a short neck and a
projection from the medial surface, a radial tuberosity. The radial
tuberosity demarcates the proximal end (head and neck) from the
shaft
-proximally, the smooth aspect of the head of the radius is concave for
articulation with the capitulum of the humerus
-the head also articulates medial with the radial notch of the ulna
-the neck of the radius is the narrow part between the head and the
radial tuberosity.
-the shaft of the radius has a lateral convexity and gradually enlarges
as it passes distally.
-the medial aspect of the distal end of the radius forms a concavity, the
ulnar notch (accomodates the head of the ulna)
-its lateral aspect terminates distally as the radial styloid process. It is
larger than the ulnar styloid process and extends further distally.
-the dorsal tubercle of the radius lies between two of the shallow
grooves for passage of the tendons of the forearm muscles.
Be able to identify the eight carpal bones and phalanges.
-the wrist, or carpus, is composed of 8 carpal bones arranged in proximal and
distal rows.
-these bones give flexibility to the wrist.
-the proximal surface articulates with the artciular disk of the wrist joint
(btw ulna) and the radius. The distal surfaces of these bones articulate with
the distal row of carpals.
SO LONG TO PINKY, HERE COMES THE THUMB! (start with bottom
row, thumb side, then circle back and end on thumb side)
Scaphoid, Lunate, Triquetrum, Pisiform
Hammate, Capitate, Trapezoid, Trapezium
-the metacarpus forms the skeleton of the palm of the hand between the
carpus and phalanges. It is composed of 5 metacarpal bones. Each metacarpal
bones has a base, shaft and a head.
-the proximal bases of the metacarpals articulate with the carpal bones
-the distal heads of the metacarpals form the knucks (articulate with the
proximal phalanges) The first metacarpal is the thumb and is the thickest and
shortest of these bones.
-each digit (except for the thumb) has 3 phalanges (proximal, middle, distal)
-thumb only has proximal and distal
-each phalange has a base proximally, a body and a head distally (under the
nails)
Be able to list the muscles in the flexor forearm, their function and
innervation.
-the brachoradialis comes from the lateral side (starts in the back and comes
around the front)
-action: flexor of forearm at the elbow
-innervation: radial nerve
-there are 3 layers of flexor muscles. The flexor muscles are on the anterior
surface.
Superficial layer (starting from medial side) PFPF
-pronator teres-rotates the radius on the ulna, helps flex forearm at
elbow
-innervated by median nerve
-flexor carpis radialis- flexes the hand at the wrist joint and aids in
wrist abduction
-innervated by median nerve
-palmeris longus-flexus the hand at the wrist and tightens the palmar
aponeurosis
-innervated by the median nerve
-flexor carpi ulnaris- flexes and adducts the hand at the wrist
-innervated by the ulnar nerve
Second layer:
-Flexor digiorum superficialis: flexor of the proximal interphalangeal
joints, contributes to flexion of elbow, wrist and knuckles
-innervated by the median nerve
Third layer: right next to the bones
-Flexor Pollicis longus: flexion of the distal phalanx of the thumb
-innervated by the anterior interosseous branch of the median
nerve
-Pronator quadratus: pronates the hand.
-innervated by the anterior interosseous branch of the median
nerve
-Flexor digitorum profundus: flexes the tips of the fingers
-innervated on the medial side by the ulnar nerve, and the
lateral side by the anterior interosseous branch of the median
nerve
Be able to list the muscles in the extensor forearm, their function and
innervation.
-there are three groups of extensor muscles which all get innervation from
the radial nerve or its branches (originating off the lateral epicondyle)
-Group 1: extensors of the wrist
-Extensor carpi radialis longus- extends and abducts the hand at the
wrist joint, more superficial than the brevis
-innervated by the radial nerve
-Extensor carpis radialis brevis- extends and abducts the hand at the
wrist joint
-innervated by the deep branch of the radial nerve
-Extensor carpis ulnaris: extends and adducts the hand at the wrist
joint
-innervation: posterior interosseous branch of the radial nerve
-Group 2: all the way out to the fingers
-Extensor digitorum: extension at the metacarpophalangeal and
interphalangeal joints (also participates in wrist extension when
fingers are extended)
-innervated by the posterior interosseous branch of the radial
nerve
-Extensor digiti minimi: extends the pinky at the metacapophalangeal
and interphlangeal joints. Also participates in wrist extension when
the fingers are extended.
-innervated by the posterior interosseous branch of the radial
nerve
-Extensor digiti indices: extends all the joints of the index finger, can
help other extensors at wrist
-innervated by the posterior interossesous branch of the radial
nerve
-Group 3: form the borders of the anatomical snuff box, these wrap around
-Abductor pollicis longus: abducts the thumb at the carpometacarpal
joint and metacarpophlangeal joints
-innervated by recurrent branch of the median nerve
-Extensor pollicis brevis: extends the proximal phalanx of the thumb
the carpometacarpal and interphalangeal joint
-innervated by the posterior interosseous branch of the radial
nerve
-Extensor pollicis longus: extends the distal phalanx of the thumb at
the carpometacarpal and interphalangeal joint
-innervated by the posterior interosseous branch of the radial
nerve
Be able to list the intrinsic muscles of the hand, their function and innervation.
-these muscles start and end at the hand!
Thumb:
-Opponens pollicis brevis- pulls and rotates the first metacarpal in a
median fashion across the palm
-innervated by the recurrent branch of the median nerve
-Abductor pollicis brevis: abducts the thumb at the carpometacarpal
joint and metacarpophalangeal joints
-innervated by the recurrent branch of the median nerve
-Flexor pollicis brevis: flexes the proximal phalanx of the thumb at the
metacarpophlangeal joint and indirectly rotates the metacarpal bone
of the thumb medially at the carpometacarpal joint
-innervated by the recurrent branch of the median nerve
-Adductor pollicis: adducts the proximal phalanx of the thumb toward
the middle digit
-innervation: deep branch of the ulnar nerve
Pinky:
-Abductor digiti minimi: abducts the 5th digit
-innervated by the deep branch of the ulnar nerve
-Flexor digiti minimi:flexes the proximal phalanx of the 5th digit
-innervated by the deep branch of the ulnar nerve
-Opponens digiti minimi: abducts, flexes and laterally rotates the 5th
metacarpal, enhances cupping of the hand, increase power of grip
-innervated: deep branch of the ulnar nerve
-There are 4 lumbricals (2 on the radial side and 2 on the ulnar side)
-flex the metacarpalphalaneal joints, extend interphalange joints
(make an L with hand, wave bye bye)
-2 on radial side are innervated by the median nerve
-2 on the ulnar side are supplied by the ulnar nerve
-The interosseous muscles are responsible for adduction and abduction
-Palmar interousseous muscles Adduct
-Dorsal interosseous muscles Abduct
-both are innervated by the deep branch of the ulner nerve
Be able to describe the symptoms and account for the clinical anatomy of
scaphoid bone fracture, carpal tunnel syndrome, ulnar nerve palsy (claw
hand), median nerve palsy (Pope’s blessing), and wrist drop.
Ulnar nerve palsy: Claw hand: Loss of sensation to little finger and half of ring
finger, loss of innervation to 3rd and 4th lumbricals, adductor pollicis, all digiti
minimi muscles and all palmar intersossei and dorsal interossei.
-4th and 5th fingers cant curl to make a fist or fully extend them
-Carpal Tunnel syndrome:- Loss of sensation to thumb, index, middle and half
of ring finger, atrophy of thenar eminence due to denervation of abductor
pollicis, flexor pollicis brevis and opponens.
-Median Nerve Palsy: Pope’s blessing: the index finger and the middle can’t
make a fist towards the palm (unable to flex those two fingers) cant fully
extend them either
-Wrist drop is caused by injury to the radial nerve (inability to extend the
wrist and fingers)
-Scaphoid bone fracture: fracture of the scaphoid often results from a fall on
the palm with the hand abducted. The fracture occurs at the narrow part of
the scaphoid. You may not see the fracture on initial radiograph but may see
it 10-14 days after. This is because bone resorption has occurred (poor blood
supply causes union of fractured parts to be prolonged)
Be able to describe sensory innervation to the forearm and hand such that you
know where an injection of anesthetic should be placed in order to block a
specific spot on the forearm and hand.
-injection of an anesthetic solution into or immediatley surrounding the
axillary sheath interrupts nerve impulses and produces anesthesia supplied
by the branches of the cords of the plexus.
Sensory innervation to the hand: Thumb and fingers up to half ring finger is
median nerve on palm side and nail beds on dorsal side, little finger and half
ring finger on palm side and nail beds on dorsal side is ulnar nerve, palm of
hand on lateral side is median nerve also, dorsal side is radial nerve and
ulnar nerve.
Sensory innervation to the forearm:
-Medial cutaneous nerve of the forearm: arises from the medial cord of the
brachial plexus, supplies the skin on the anterior and medial surfaces of the
forearm.
-Lateral cutaneous nerve of the forearm: this is the terminal branch of the
musculocutaneous and supplies skin on the lateral side of the forearm
-Posterior cutaneous nerve of the forearm: also a branch of the radial nerve,
it supplies skin on the posterior surface of the forearm