Forearm and elbow Flashcards
What are the bones in this region of elbow, forearm and wrist
What makes up the elbow joint
The Humerus
The Radius
The Ulna
The carpal bones
Elbow joint is the humerus articulating with the forearm bones…..
NOT between the forearm bones (which are the radio-ulnar joints involved in pronation and supination….. these actions do not come from the elbow)
What is the name of the two rounded regions on each side of the humerus
Medial and lateral epicondyle
What is the T/f the capitulum lies lateral to the trochlea
T
Which is more lateral, the coranoid fossa or the radial fossa.
These are present anteriorly on the humerus
Coranoid medial to the lateral epicondyle
Where does the head of the radius articulate with the humerus
Laterally, onto the capitulum/lateral epicondyle
Where does the ulna articulate with the humerus
At the trochlea, the coranoid process of the ulna articulates,
Posteriorly, the oleranon of the ulna articulates with the olecranon fossa of the humerus
What is related to the medial epicondyle anteriorly and posteriorly
Ant: flexors
Post: flexors and the ulnar nerve
What is related to the lateral epicondyle anteriorly and posterirly
Ant: extensors
Post: extensors, anconeus muscle
Which way does the radial tuberosity point
Medially
What lies between the radius and the ulna
Interosseus membane
Where is the syloid process of the ulna
inferior and medially
Where is teh styloid process of the radius
Inferior and laterally
Where does the ulna artiuclate with the radius inferiorly
articular circumference of head of ulna inserts into the ulnar notch of the radius
What is the interosseus membrane, why is it important
The interosseous membrane separates the anterior and posterior compartments, and is a site of attachment for muscles in the forearm
On the distal ends of the ulna and radius there are facets (at the radio-ulnar joint)…. state the bones that go therefrom medial to lateral
On yourself
Medial for articular disk, then for lunate then for scaphoid
Name the proximal and distal row of the carpal bones
Proximal row: scaphoid, lunate, triquetrum, pisiform
Distal row: trapezium, trapezoid, capitate, hamate
Which bone in the wrist does not articulate with the radius or ulna
Pisiform (sesamoid bone)
Which arm muscles act across elbow joint and what is their innervation
Biceps and brachialis
musculocutaeneous nerve
Where do the arm muscles attach on the forearm
Biceps –> radial tuberosity and then there is a biceps aponeurosis (merges with connective tissue)
Brachialis –> coranoid process of ulna
Biceps also a supinator due to its attachment to the radial tuberosity
Which posterior arm mucles act over the elbow + their innervation
Triceps and anconeus
radial nerve (c7, 8
Where do the arm muscles attach to the foreaem
Triceps attach onto the elecranon process of ulna
Anconeus to olecranon process of ulna and lateral epicondyle of the humerus
What to the forearm muscles do
Conrol hand and wrist muscles
Where do the forearm muscles originate generally
from the distal humerus as well as the radius and ulna
Outline the distribution of the forearm muscles
Flexors (and pronators) anteriorly
Extensors (and supinators) posteriorly
What are the muscles in the superficial compartment of the forearm
Pronator teres (PT) Flexor carpi radialis (FCR) Palmaris longus (PL) Flexor digitorum superficialis (FDS) Flexor carpi ulnaris (FCU)
What muscles are in the deep forearm
Flexor digitorum profundus (FDP)
Flexor pollicis longus (FPL)
Pronator quadratus (PQ)
Muscles in the anterior forearm generally perform which functions
Flexion and pronation
Flexor Carpi Ulnaris function and innervation
Flexion and adduction at the wrist.
Innervation: Ulnar nerve.
Where do all of the superficial flexors originate
medial epicondyle (at the common flexor tendon)
Pronator teres innervation and function
Pronation of the forearm
Median nerve.
Flexor carpi radialis function and innervation
Flexion and abduction at the wrist
Median nerve
Palmaris longus function and innervation
Flexion at the wrist
Absent in 15%
Median nerve
Where can median nerve be found
Just behind palmaris longus
Summary of the innervation of forearm muscles
All median nerve apart from flexor carpi ulnaris (ulnar)
Summary of function of forearm muscles
FCR does adduction
FCU does abduction
What is the flexor retinaculum and what combines with it
The transverse carpal ligament…..
palmaris longus tendon combines
Why is the flexor retinaculum important
forms the roof of the carpal tunnel
What is the most superficial to deepest of the deep muscles of the anterior compartment of the forearm
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What assists in teh abduction of the wrist by the flexor carpi radialis
radial extensors
Function of Flexor digitorum superficialis and innervation (also superfiial forearm)
Flexor of proximal interphalangeal joints
Median nerve (C7,8 T1)
Function and innervation of Flexor digitorum profundus (FDP)
Flexor of the distal interphalangeal joints
Medial part: ulnar nerve 9C8, T1)
Lateral part by the anterior interosseus branch of the median nerve (C8 and T1)
Function adn innervation of Flexor pollicis longus (FPL)
Function flexion of distal phalanx of the thumb and the proximal phalanx
anterior interosseus branch of the median nerve (C7,8 and T1)
Function and innervation of pronator quadratus
Pronates the hand. Assisted by pronator teres when extra power needed
Median nerve C8 T1
State the extensor muscles that move the wrist joint
Extensor carpi radialis longus (ECRL)
Extensor carpi radialis brevis (ECRB)
Extensor carpi ulnaris (ECU)
State the extensor muscles moving the digits
Extensor digitorum (ED) Extensor indicis (EI) Extensor digit minimi (EDM)
State the extensor muscles moving the thumb
Abductor pollicis longus (APL)
Extensor pollicis brevis (EPB)
Extensor pollicis longus (EPL)
State other extensor muscles in the extensor compartment of the forearm
Brachioradialis
Supinator
Carpi muscles do what
Movers of the wrist (the “carpi” muscles) act on the radial (radialis) or ulnar (ulnaris) aspects of the forearm.
Which digits do these muscles move
digitorum
pollicis
indicis
digiti minimi
on groups of digits (digitorum muscles) or on individual digits (pollicis (thumb), indicis (index finger) digiti minimi (little finger)) (these muscles also contribute to wrist movements).
Why is the anatomical snuff-box useful
Important in determining if the scaphoid might be fractured: a common injury.
Which tendons can be seen in the anatomical snuff box
EPL (superiorly)
EPB (inferiorly)
What are the joints in this region
Elbow joint
Proximal radio-ulnar joint
Distal radio-ulnar joint
Wrist joint
Function of the ligaments of the elbow joint
Ligaments at the elbow joint are arranged to stabilise the joint, but allow pronation/supination movements (BUT THESE MOVEMENTS DO NOT ORIGINATE FROM THE ELBOW!)
What are the main ligaments and their attachments
Radial collateral…. from the lateral epicondyle to blend with the anular ligament of the radius
Ulnar collateral… from the medial epicondyle to the coranoid process and the olecranon of the ulna
What is the firrence in carrying angle between men and women
men 10-15 degrees
woman greater than 15 degreees
Where does the anular ligament of the radius extend from
This is part of the proximal radio-ulnar joint
Attahes to the radial notch of the ulna anteriorly and posteriorly after wrapping around the head of the radius…..
allows radial head to slide against radial notch of ulna and pivot on the capitulum during pronation and supination
Explain the distal radial ulnar joints
The 3 carpals involved in this joint are the triquetrum (medial), lunate and scaphoid (lateral)
The articular surfaces of these 3 bones forms a convex surface, which articulates with the concave surface of the radius, and the articular disc of the ulna
Why can the hand be adducted more than abducted
Becase the radial styloid process extends further distally than the styloid process of the ulna does
Which ligaments support the wrist joint
palmar radiocarpal, palmar ulnocarpal, dorsal radiocarpal ligaments.
Radial and ulnar collateral ligaments of the wrist span distance between styloid processes of radius and ulna and the adjacent carpal bones
Which carpals does the radius and ulnar interact with
RADIUS with the scaphoid laterally and the lunate medially
ULNA does not articulate directly with the triquetrum carpal bone. An articular disc intervenes.
In resting position, where is the radius with respect to the ulna
Look at slide 31
when palm faces the trunk, radius essentially above the ulna
Outline the movements at the elbow joint and the muscles causing it
Flexion: Brachialis Biceps (Brachioradialis) (Pronator teres) C5-C6 (musclocutaneous nerve)
Extension:
Triceps
(Anconeus)
C7-8 (radial nerve)
Flexion C7 (&C6)
Extension C6 (&C7)
Outline the movements of the radioulnar joints
Supination: supinator/biceps/EPL/ECRL
Pronation: Pronator quadratus
Pronator teres
FCR, PL, brachioradialis
Outline movements at the wrist joint
FLEXION:
- FCR/FCU
- Long flexors of thumb and fingers
- PL/APL
EXTENSION:
- ECRL, ECRB, ECU
- Long extensors of thumb and fingers
RADIAL DEVIATION (abduction): APL, FCR, ECRL, ECRB
ULNAR DEVIATION (addution) ECU, FCU
LOGICAL: flexors/extensors working on the radius cause abduction
Those working on the ulnar cause adduction
Explain the arteries from the elbow
Brachial arteries give a large branch to the arm (produnda brachii) then at the elobow divides into:
ULNAR AND RADIAL ARTERIES.
Ulnar art. Has common interosseous branch which imediately branches to give the anterior and posterior interosseous atreries
Arches of the hand – anastomosis of the radial and ulnar arteries
Where is the cubital fossa
the space anterior to the elbow joint.
Borders of the cubital fossa
Lateral border – medial border of the brachioradialis muscle.
Medial border – lateral border of the pronator teres muscle.
Superior border – hypothetical line between the epicondyles of the humerus.
What are the contents of the cubital fossa
Really Need Beer To Be At My Nicest.
RN-radial nerve
BT- biceps tendon
BA- brachial artery
MN- median nerve
Venous drainage of the forearm elbow and wrist
-Cephalic vein (superficial) runs up lateral border of
arm
-Basilic vein (superficial) runs up the medial border
of arm
-Basilic veins joins venae comitantes to form the
axillary vein in the arm
-Cephalic vein joins axillary vein in the axilla
-Axillary vein becomes the subclavian vein at the
level of the first rib
Where do the cephalic and basilic veins arise
Cephalic and Basilic veins arise from the dorsal venous arch of the hand.
What are the cephalic and basilic veins connected by and where
Commonly connected at the cubital fossa by the median cubital vein (not always present or prominent).
(used in phlebotomy)
What does deep drainage of this region follow
the arteries (vanae comitantes)
Where are the lymph nodes
Superficial and deep systems, run with veins
Cubital lymph nodes
Axillary nodes are also draining nodes for the distal parts of the upper limb
What are the main nerves of the upper limb and their spinal cord levels
Musculocutaneous nerve (C5,6,7)
Ulnar nerve (C8,T1)
Median nerve (C6,7,8,T1)
Radial nerve (C5,6,7,8,T1)
Functions of the musculocutaneous nerve (C5,6)
Supplies all the anterior compartment of the upper arm
Sensory to the lateral forearm (as the lateral cutaneous nerve of the forearm)
Course and function of median nerve
Courses through the anterior compartment of the arm (no significant branches) and lies anterior to the elbow, with the brachial artery (easily damaged!)
Main nerve to the muscles of the forearm
Common sites of nerve damage
Axillary nerve posteriorly in the armpit
Radial nerve around triceps brachii
Ulnar nerve near the medial epicondle, or medial part of the distal radio-ulnar joint
Course and function of the radial nerve
Supplies all the muscles of the posterior compartments of the upper arm and forearm
Passes around the body of the humerus at its mid-shaft in the radial groove (easily damaged!)
Supplies triceps in the arm
Courses via the anterior compartment of the upper arm more distally
Divides just above the level of the elbow into;
Deep branch – the posterior interosseous nerve (motor)
Superficial branch – the superficial radial nerve (sensory)
What is a sesamoid bone
Bone forming in a tendon/muscle near a joint… e.g. pisiform and patella
Which superficial flexors cross over the wrist
Flexor carpi radialis (FCR)
Palmaris longus (PL)
Flexor carpi ulnaris (FCU)
Where does the Flexor digitorum superficialis (FDS)
attach
On the common flexor origin….
and the radial head
What muscles in the anterior forearm move the digits
Flexor digitorum superficialis (FDS) (superficial flexor of the digit)
Flexor digitorum profundus (FDP) (deep flexor of the digits)
Flexor pollicis longus (FPL) (flex thumb)
Where do most extensor muscles originate
Common origin extensor origin
T/F….. extnsor digitorum is medial to extensor digiti minimi
F… think that the small finger is medial to the other fingers so this muscle will be too
Extensorys slide 22..
…..
Extensors slide 22
…..
Functin of the extensor retunaculum
Prevents movement of tendons away from bone
What is found on the floor of the anatomical snuffbox
Scaphoid bone
What is the anular ligament important in
Pronation (because the radius has to rotate)
T/F the ulnar articulates directly with the carpal bones
F…
Which part of the radius moves in pronation
the proximal part
Which vessel pierces the interosseus membrane
The posterior interosseus artery (goes to the dorsal of the hand)
Function of brachioradialis
Can contribute to flexion or extension….. and pronation and supination (adjunct muscle) involved in cubital fossa
T/f musculocutaneous nerve supplies muscles in the forearm
F… only supplies muscles in the upper arm…. involved in moving the elbow joint tho
Radial nerve supplies both arm and forearm posteriorly
T… supplies all muscles in both posterior compartments of upper arm and forearm
Which muscles does ulnar nerve supply? What are the remaining anterior forearm muscles supplied by
The Ulnar Nerve supplies only FCU and the Ulnar half of FDP .
The Median Nerve supplies all of the remaining anterior muscles.
