Anatomy Block III- Forearm
what is the humerus an attachment for
some forearm muscles
what are two bony landmarks on the ulna
styloid process
interosseus border
what are some bony landmarks on the radius
head
styloid process
interosseus border
is the head of the radius or ulna more distal
radius
how many carpals are there
8
how many phalanges are there
14, 2 for thumb, 3 for remaining digits
what does the interosseus membrane divide
flexor (anterior) compartment from extensor (posterio) muscles
why is the interosseus of the upper limb important
pronation/supination
what fascia is in the forearm
deep fascia of the forearm
what is the deep fascia of the forearm continuous with
brachial fascia
what is another name for the deep fascia of the forearm
antebrachial fascia
what forms compartmenst along with the interosseous membrane
deep fascia of the arm
what are two thickenings in the deep fascia of the forearm
flexor retinaculum
extensor retinaculum
where is the flexor retinaculum
anterior aspect of forearm
what flexor tendons don't get covered
palmaris longus
where is the extensor retinaculum
posterior aspect of forearm
what is the point of of the retinaculum
prevents bowstringing of tendons agaisnt skin and fascia themselves, keeps their advantage
a. brachioradialis
b. pronator teres
c. flexor carpi radialis
d. palmaris longus
e. flexor carpi ulnaris
what is the action of the anterior forearm compartment
hand/wrist flexors and forearm pronators
what muscles are part of the anterior superficial layer
pronator teres
flexor carpi radialis
palmaris longus
flexor carpi ulnaris
where do all of the superficial muscles of the anterior superficial layer originate from
medial epicondyle off tendon called flexor tendon
what innervates pronator teres
median nerve
what innervates flexor carpi radialis
median nerve
what innervates palmaris longus
median nerve
what innervates flexor carpi ulnaris
ulnar nerve
what innervates flexor digitorum superficialis
median nerve
what innervates flexor digotorum profundus on digits 2-3
median nerve
what innervates flexor digitorum profundus on digits 4-5
ulnar nerve
what innervates flexor pollicis longus
anterior interosseous nerve
what innervates pronator quadratus
anterior interosseous nerve
what is innervated by the median nerve in the anterior forearm
pronator teres
flexor carpi radialis
palmaris longus
flexor digitorum superficialis
what is innervated by the ulnar nerve in the anterior forearm
flexor carpi ulnaris
flexor digitorum profundus 4-5
what is innervated by the anterior interosseous nerve in the anterior forearm
flexor pollicis longus
pronator quadratus
what is the action of the pronator teres
flex forearm, no hand/wrist flexion (only one that does not cross wrist), PRONATION mainly
what is the action of the flexor carpi radialis
flex forearm, hand wrist flexion, forearm pronator and radial deviation (hand abduction)
what is the action of the palmaris longus
wrist flexion only
what is interesting about the palmaris longus
missing in a fair number of people
what does the palmaris longus have and what does that thing attach to
long central tendon, attaches to palmar aponeuroses
a. supniator
b. flexor digitorum superficialis
a. supinator
b. flexor digitorum profundus
c. flexor pollicis longus
d. pronator quadratus
what innervates the brachioradialis
radial nerve
what innervates the extensor carpi radialis brevis
deep branch of radial nerve
what innervates the extensor carpi radialis longus
radial nerve
what innervates the extensor digitorum
posteiror interosseous nerve
what innervates the extensor digiti minimi
posteiror interosseous nerve
what innervates the extensor carpi ulnaris
posterior interosseous nerve
what innervates the supinator
deep branch of radial nerve
what innervates the abductor pollicis longus
posterior interosseous nerve
what innervates the extensor pollicis longus
posterior interosseous nerve
what innervates the extensor pollicis brevis
posterior interosseous nerve
what innervates the extensor indicis
posterior interosseous nerve
what is in the intermediate layer of anterior muscles
flexor digitorum superficialis
where does the flexor digitorum superficialis start and end
medial epicondyle and radius to fingers
what is the action of the flexor digitorum superficialis
flex wrist and fingers PIP joint 2-5
what muscles are in the deep layer of the anterior forearm compartment
flexor digitorum profundus
flexor pollicis longus
pronator quadratus
what do the flexor digitorum profundus go to
go to distal phalanges and flex DIP joint 4-5
what do flexor pollicis longus go to
more latera, flexes thumb joint
what does the pronator quadratus not do
hand/wrist flexion
what does the pronator quadratus do
helps pronation
what nerves are in the anterior compartment
median nerve
ulnar nerve
a. median nerve
b. ulnar nerve
c. ulnar artery
d. common interosseous artery
e. median nerve
f. radial artery
g. anterior interosseous artery and nerve
what vessels are in the anterior compartment
ulnar artery
radial artery
anterior interosseous artery
what does the median nerve innervate in the anterior forearm
all forearm muscles except medial 1/2 flexor digitorum profundus and flexor carpi ulnaris
(and its branch the anterior interosseous nerve innervates the flexor pollis longus and the pronator quadratus)
what does the median nerve give off
anterior interosseous nerve
where does the anterior interosseous nerve run
along top of anterior surface of interosseous membrane
what does the anterior interosseous nerve innervate
flexor pollicis longus
pronator quadratus
what does the ulnar nerve innervate
medial 1/2 of flexor digitorum profundus and flexor carpi ulnaris
where does the ulnar nerve go
intrinsic hand on medial side
where does the ulnar artery run
along medial side
where does the radial artery run
along lateral side, more superficial and better to get pulse from
where does the anterior interosseous artery run
from common interosseous artery from ulnar artery
what is the shared action of the posterior forearm compartment
wrist extensors and forearm supinators
what muscles are in the superficial layer of the posterior forearm muscles
brachioradialis
extensor carpi radialis longus
extensor carpi radialis brevis
extensor digitorum
extensor digiti minimi
extensor carpi ulnaris
a. brachioradialis
b. extensor carpi radialis longus
c. extensor carpi radialis brevis
d. extensor digitorum
e. extensor carpi ulnaris
a. supinator
b. abductor pollicis longus
c. extensor pollicis brevis
d. extensor indicis
e. extensor pollicis longus
what is the action of brachioradialis
weak flexion of forearm, holding it at 90 degrees
what innervates the brachioradialis
radial nerve
what does the extensor carpi radialis longus do
helps extend wrist, goes with flexor carpi radialis to get wrist abduction (radial deviation)
what is the role of extensor digitorum
gives rise to 4 tendons on all 4 finguers
what does the extensor digiti minimi do
pinky extension
where does the extensor carpi ulnaris go
metacarpal bones
what does the extensor carpi ulnaris do
wrist extension and wrist adduction with flexor carpi ulnaris
what are the deep posterior forearm muscles
supinator
abductor pollicis longus
extensor pollicis longus
extensor pollicis brevis
extensor indicis
what does the supinator do
only supination of the forearm with help from biceps brachii
what does the supinator wrap around
radius, it is deep
what is the action of abductor pollicis longus
thumb abduction
where does extensor pollicis longus run
off ulna, more medial on back of arm
where does extensor pollicis brevis go
more distally than extensor pollicis longus
what does extensor indicis do
extends index finger to a point
a. radial nerve
b. deep branch of radial nerve
what are the nerves in the posterior compartment
radial nerve
what are the vessels in the psoterior compartment
posterior interosseous artery
distal portion of anterior interosseous artery
a. supinator
b. posterior interosseous nerve
c. posterior interosseous artery
what does the radial nerve innervate (muscles)
brachioradialis and extensor carpi radialis longsu
what are teh branches of the radial nerve
deep branch
posterior interosseous nerve
what does the deep branch of the radial nerve innervate
supinator and extensor carpi radialis brevis
where is the posterior interosseous nerve off of
deep branch of radial nerve, innervates the remainder of the posterior compartment muscles
where is the posterior interosseous artery from
common interosseus artery in anterior compartment
what side of the forearm is the carpal tunnel on
atnerior side
what is within the carpal tunnel
tendons of flexor pollicis longus and flexor digitorum superficialis and profundus
median nerve
synovial sheaths around flexor tendons
what is carpal tunnel syndrome
overuse leading to inflammatin and swelling in a small area, can decrease space and impingue on medial nerve
where are the differentces in sensation typically with carpal tunnel syndrome
lateral 3 fingures, some thumb, but not always palm of hand
what can start wasting due to median nerve compression
intrinsic muscle of thumb
what is Phalen's test
compresses carpal tunnel space and can exacerbate things and cause issues
what can help carpal tunnel syndrome
exercising, bracing, surgery better on the medial side
what is the anatomical snuff box
triangular depression on lateral side of wrist
a. extensor pollicis longus
b. extensor pollicis brevis
c. radial artery
what forms the anatomical snuff box
tendons of abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus
a. medial cutaneous nerve of forearm
b. posterior cutaneous nerve of forearm
c. lateral cutaenous nerve of forearm
a. posterior cutaneous nerve of forearm
b. lateral cutaneous nerve of forearm
what does the cutaneous innervation of the forearm
lateral cutaneous nerve of forearm
medial cutaneous nerve of forearm
posterior cutaneous nerve of forearm