Anatomy Week #3: Upper Limb II - Forearm, Wrist Joint & Hand
Which *muscles* in the *forearm* are innervated by the *median nerve*?
All muscles of the *anterior forearm* with the *exception of flexor carpi radialis and flexor digitorum profundus for digits 4 and 5*
*True or False*: The *ulnar nerve* passes through the *carpal tunnel*
False!
Describe the location of the *cephalic vein* in the *upper limb*?
Found in the *superficial fascia* between the *deltoid* and *pectoralis major muscles*
Which *muscles* in the *forearm* are *innervated* by the *radial nerve*?
Innervates all of the muscles of the *posterior forearm compartment* Recall that in the arm the radial nerve also innervates the muscles of the posterior compartment (i.e. the triceps brachii)
What is the *key dermatome testing area* for *C5*?
Over the *deltoid insertion*
What is the role of the *palmar interossei muscles*?
Produce *adduction* of *digits 2-5*
The *radius* and *ulna* articulate with one another at the ______________________ joints.
Proximal and distal radioulnar joints
The *deep group* of *muscles* in the *anterior compartment of the forearm* originate from the _________________________.
Radius, ulna and/or interosseous membrane
The *antebrachial fascia* divides the *forearm* into which *compartments*?
*Anterior* and *posterior* compartments
The *flexor retinaculum* holds the long tendons in place ______________________ (anterior or posterior) to the *wrist*.
*Anterior* to the wrist
What causes the *gap* between the *ulna* and *carpal bones*?
*Articular disc*
The *cephalic vein* dives through the *deep fascia* to *drain* into the ____________________ vein.
*Axillary vein*
In the *forearm* the *medial cutaneous nerve* travels with which other *vessel*?
*Basilic vein*
Which *blood vessel(s)* are used to *measure* a patient's *blood pressure*?
*Brachial artery*
Which *dermatome* can be *assessed* at the area *over the deltoid insertion*?
*C5*
Which *myotome* are you testing with *abduction* of the *forearm/elbow*?
*C5*
Identify the *spinal nerve contributions* of the *axillary nerve*?
*C5-C6*
Identify the *spinal nerve contributions* of the *musculocutaneous nerve*?
*C5-C7*
Identify the *spinal nerve contributions* of the *median nerve*?
*C5-T1*
Identify the *spinal nerve contributions* of the *radial nerve*?
*C5-T1*
A patient presents with *weakness against resistance* of *flexion* at the *elbow joint*. Which *myotome* is most likely affected?
*C6*
Which *dermatome* can be *assessed* at the *lateral aspect* of the *forearm* extending *to the thumb*?
*C6*
Which *myotome* are you testing with *flexion* of the *forearm/elbow*?
*C6*
Which *dermatome* can be *assessed* at the *pad* of the *ring, middle or index finger*?
*C7*
Which *myotome* are you testing with *extension* of the *forearm/elbow*?
*C7*
Identify the *spinal nerve contributions* of the *ulnar nerve*?
*C7-T1*
Which *dermatome* can be *assessed* at the *medial aspect* of the *wrist* extending *to the little finger*?
*C8*
Which *myotome* are you testing with *flexion* of the *digits*?
*C8*
The *radius* articulates with the *humerus* at the ________________________.
*Captiulum*
The *wrist bones* are called the __________________________.
*Carpal bones* (8)
Which *vein* is located in the *superficial fascia* between the *deltoid* and *pectoralis major* muscles?
*Cephalic vein*
Which *muscle(s)* produce *abduction* of *digits 2-5*?
*Dorsal interossei muscles*
The *cephalic* and *basilic veins* continue *distally to the hand* where they originate as the _______________________ veins.
*Dorsal veins of the hand*
What is the *myotome test* for *C7*?
*Extension* of the *forearm/elbow*
What is the *myotome test* for *C8*?
*Flexion* of the *digits*
What is the *myotome test* for *C6*?
*Flexion* of the *forearm/elbow*
The 4 *lumbricals* originate from the *tendons* of the ___________________________ muscle.
*Flexor digitorum profundus*
What is the *key dermatome testing area* for *C6*?
*Lateral aspect of the forearm* extending *to the thumb*
The majority of the *superficial posterior muscles* in the *forearm* originate from the __________________________.
*Lateral epicondyle* of the *humerus*
Which *area of the skin* is innervated by the *musculocutaneous nerve*>
*Lateral forearm*
In the *upper limb* the *cephalic vein* is located _______________________ (medially or laterally).
*Laterally*
Which *muscles* produce *flexion* at the *MCP joint* * *extension* at the *PIP and DIP joints*?
*Lumbricals* = formed from the tendons of the flexor digitorum profundus muscle
What is the *key dermatome testing area* for *T1*?
*Medial aspect* of the *forearm and arm*
What is the *key dermatome testing area* for *C8*?
*Medial aspect* of the *wrist* extending *to the little finger*
The *medial cutaneous nerve* of the *forearm* is a *direct branch* of the ___________________________.
*Medial cord* of the *brachial plexus*
The *superficial group* of *muscles* in the *anterior compartment of the forearm* originate from the _________________________.
*Medial epicondyle of the humerus*
Which *bony feature* does the *ulnar nerve* pass directly *posterior to*?
*Medial epicondyle of the humerus*
In the *upper limb* the *basilic vein* is located ______________________ (medially or laterally).
*Medially*
Which *blood vessel(s)* are used to conduct a *blood draw*?
*Median cubital vein* = connects the cephalic and basilic veins in the upper limb
Which *vein* in the upper limb *connects the cephalic vein* to the *basilic vein*?
*Median cubital vein* = often used for venous access
Which *nerve* innervates the *thenar muscles* in the hand?
*Median nerve*
Which *nerve* passes through the *carpal tunnel*?
*Median nerve*
What is the *key dermatome testing area* for *C7*?
*Pad* of the *ring, middle or index finger*
Which *muscle(s)* produce *adduction* of *digits 2-5*?
*Palmar interossei muscles*
The *pinky side* of the *hand* is associated with which *bone* in the *forearm*?
*Pinky side = ulnar bone*
The *hypothenar eminence* is associated with the ______________________ (thumb or pinky).
*Pinky*
*Muscles* in which *compartment* of the *forearm* are responsible for *extension* of the *wrists* and *digits*?
*Posterior compartment*
*Muscles* in which *compartment* of the *forearm* are responsible for *supination* of the forearm?
*Posterior compartment*
Which *compartment* of the *forearm* is associated with the *dorsum of the hand side*?
*Posterior compartment*
The *extensor retinaculum* holds the long tendons in place ______________________ (anterior or posterior) to the *wrist*.
*Posterior* to the wrist
Which *blood vessel* is at the most *risk of damage* if a patient has an injury involving the *distal radius*?
*Radial artery*
Which *artery* passes through the *anatomical snuffbox*?
*Radial artery* Note: the anatomical snuffbox is associated with the thumb side of the hand
Which *nerve* innervates all of the muscles in the *posterior compartment* of the *forearm*?
*Radial nerve*
Which *nerve* innervates the *muscles* which produce *wrist extension*?
*Radial nerve* = innervates the posterior forearm muscles which produce wrist extension
Which *bone* of the forearm *rotates* during *pronation and supination*?
*Radius*
Which *carpal bone* directly *articulates* with the *distal radius*?
*Scaphoid bone*
Which *dermatome* can be *assessed* at the *medial aspect* of the *forearm and arm*?
*T1*
Which *myotome* are you testing with *abduction/adduction* of the *digits*?
*T1*
The *thumb side* of the *hand* is associated with which *bone* in the *forearm*?
*Thumb side = radial bone*
The *thenar eminence* is associated with the ______________________ (thumb or pinky).
*Thumb*
The _____________________ ligament helps to *shape the carpal bones into a "C" shape*. This ligament is part of the *flexor retinaculum* and forms the *roof of the carpal tunnel*.
*Transverse carpal ligament*
Which *ligament* forms the *roof* of the *carpal tunnel*?
*Transverse carpal ligament*
The *ulna* articulates with the *humerus* at the ________________________.
*Trochlea*
Which *artery* predominantly forms the *superficial palmar arch* in the *hand*?
*Ulnar artery*
Which *nerve* innervates the *hypothenar muscles*?
*Ulnar nerve*
Which *2 veins* are *connected* by the *median cubital vein*?
- *Basilic vein* = medial - *Cephalic vein* = lateral
Name the *7 muscles* found in the *superficial group* of the *posterior compartment* of the *forearm*?
- *Brachioradialis* - *Anconeus* - *Extensor carpi radialis longus* - *Extensor carpi radialis brevis* - *Extensor digitorum* - *Extensor carpi ulnaris* - *Extensor digiti minimi*
What *movement(s)* are produced by the *lumbrical muscles* in the *hand*?
- *Flexion* at the *MCP joint* - *Extension* at the *PIP and DIP joints*
Which *muscles* in the *forearm* are innervated by the *ulnar nerve*?
- *Flexor carpi ulnaris* - *Flexor digitorum profundus for digits 4 and 5*
Identify the *3 muscles* of the *superficial group* of muscles in the *anterior compartment* of the *forearm*?
- *Flexor digitorum profundis* - *Flexor pollicis longus* - *Pronator quadratus*
Which *muscles* of the *anterior forearm compartment* have *tendons* which *travel through* the *carpal tunnel*?
- *Flexor digitorum superficialis* - *Flexor digitorum profundis* - *Flexor pollicis longus*
Which *muscles* in the *hand* are innervated by the *ulnar nerve*?
- *Hypothenar muscles* - *Lumbricals to digits 4 and 5* - *Palmar and dorsal interossei* - *Adductor pollicis*
What are the major *branches* of the *lateral cord* of the *brachial plexus*?
- *Musculocutaneous nerve* - *Lateral contribution to the median nerve*
Identify the *five main terminal branches* of the *brachial plexus* and their respective *spinal nerve contributions*?
- *Musculocutaneous nerve* (C5-C7) - *Median nerve* (C5-T1) - *Ulnar nerve* (C7-T1) - *Axillary nerve* (C5-C6) - *Radial nerve* (C5-T1)
Which *movements* are produced by the muscles in the *anterior compartment* of the *forearm*?
- *Pronation* of the *forearm* - *Flexion* of the *wrists* and *digits*
Identify the *5 muscles* of the *superficial group* of muscles in the *anterior compartment* of the *forearm*?
- *Pronator teres* - *Flexor carpi radialis* - *Palmaris longus* - *Flexor carpi ulnaris* - *Flexor digitorum superficialis* Recall: all of these muscles originate from the medial epicondyle of the humerus
*Distal to the elbow joint*, the *brachial artery* bifurcates into which 2 arteries?
- *Radial artery* = thumb side - *Ulnar artery* = pinky side
Which *bones* are most likely to be *fractured* in a *fall on an outstretched hand* (FOOSH)?
- *Radial head* - *Distal radius* - *Scaphoid bone*
The *anterior forearm* is divided into a ________________________ and _____________________ group.
- *Superficial group* - *Deep group*
Which *movements* are produced by the muscles in the *posterior compartment* of the *forearm*?
- *Supination* of the *forearm* - *Extension* of the *wrists* and *digits*
Name the *5 muscles* found in the *deep group* of the *posterior compartment* of the *forearm*?
- *Supinator* - *Abductor pollicis longus* - *Extensor pollicis brevis* - *Extensor pollicis longus* - *Extensor indicis*
Which *muscles* in the *hand* are innervated by the *median nerve*?
- *Thenar muscles* - *Lumbricals for digits 2 and 3*
What are the major *branches* of the *medial cord* of the *brachial plexus*?
- *Ulnar nerve* - *Medial contribution to the median nerve*
Which *muscles* are found in the *thenar and hypothenar muscle groups*?
- Flexor - Abductor - Opponens muscle (deep)
What is the *transverse carpal ligament*?
- Helps to *shape the carpal bones into a "C" shape* - Part of the *flexor retinaculum* - Forms the *roof of the carpal tunnel*
What are the two primary *bones* that form the *forearm*?
- Radius - Ulna
The *muscles of the posterior forearm* are divided into a _______________________ and _________________________ group.
- Superficial group - Deep group
How many *muscles* are located in the deep group* of the *posterior forearm compartment*?
*5 muscles*
How many *muscles* are located in the *superficial group* of the *posterior forearm compartment*?
*7 muscles*
What is the *myotome test* for *C5*?
*Abduction* of the arm
What is the *myotome test* for T1*?
*Abduction/adduction* of the *digits*
What is the *movement(s)* produced by the *adductor pollicis muscle*?
*Adduction* of the *first digit* (i.e. thumb)
Which *muscle* produces *adduction* of the *first digit*?
*Adductor pollicis muscle* Recall: pollicis = thumb
Which *fascia* divides the *forearm* into an *anterior and posterior compartment*?
*Antebrachial fascia*
*Muscles* in which *compartment* of the *forearm* are responsible for *flexion* of the *wrists* and *digits*?
*Anterior compartment*
*Muscles* in which *compartment* of the *forearm* are responsible for *pronation* of the forearm?
*Anterior compartment*
Which *compartment* of the *forearm* is associated with the *palm side*?
*Anterior compartment*
A patient with a *herniated interveretebral disc* between the *C7/T1 vertebrae* is *impinging the nerve that passes *below the C7 vertebrae*, which would present with a *loss of sensation* at which location(s)?
5th digit
What is the role of the *dorsal interossei muscles*?
Produce *abduction* of *digits 2-5*
