Lecture 8 - Neuroanatomy: Brachial Plexus & Cranial Nerves Flashcards
1
Q
What does Innervation mean?
A
- means nerve “in”
2
Q
What do nerves do?
A
- they supply sensory and motor nerves in the upper limb
3
Q
What are nerve roots?
A
- Paired branches that leave the spinal cord at each vertebral segment
- Exit spinal column through the intervertebral foramen
4
Q
What 2 fibres are nerve roots comprised of?
A
- Efferent (motor) fibres
- Afferent (sensory) fires
5
Q
What is the brachial plexus?
A
- Plexus = network of nerves or vessels in the body that have web-like formation
- Formed by anterior rami of nerve roots (C4-T1)
6
Q
What are the 5 terminal nerves of the brachial plexus?
A
- Musculocutaneous nerve
- axillary nerve
- radial nerve
- median nerve
- ulnar nerve
7
Q
What is the Musculocutaneous nerve?
A
- its root is the ventral rami of C5, C6, & C7
- it Innervates muscles of the anterior brachium:
- biceps brachii
- brachialis
- coracobrachialis
8
Q
What is the axillary nerve?
A
- it roots at the ventral rami of C5 & C6 & continues as the smaller branch of the posterior cord of the brachial plexus
- it Innervates the deltoid & the teres minor
9
Q
What is the radial nerve?
A
- it roots from C5, C6, C7, & C8
- it Innervates the triceps brachii, brachioradialis & muscles of the posterior forearm
10
Q
What is the median nerve?
A
- it roots from C6, C7, C8, & T1
- it Innervates most muscles of the forearm like the Pronator teres, flexor carpi radialis, palmarus longus, flexor digitorum profundus & superficialis
- also Innervates hand muscles like lumbricals (1 & 2), & the thenar group
11
Q
What is the ulnar nerve?
A
- it roots from the C7, C8, & T1
- it Innervates median muscles of the forearm like the flexor carpi ulnaris, flexor digitorum profundus (medial half), the hypothenar group, lumbricals (3 & 4), & the interossei (dorsal & palmer)
12
Q
What are the 9 peripheral nerves of the brachial plexus?
A
- long thoracic nerve
- dorsal scapular nerve
- nerve to subclavius
- suprascapular nerve
- lateral pectoral nerve
- medial pectoral nerve
- upper subscapular nerve
- lower subscapular nerve
- Thoracodorsal nerve
13
Q
What is the long thoracic nerve?
A
- originates at the anterior rami of C5, C6, & C7
- Innervates the Serratus anterior
14
Q
What is the dorsal scapular nerve?
A
- originates at the ventral rami of C4 & C5
- Innervates the rhomboids major/minor & the levator scapulae
15
Q
What is the nerve to subclavius?
A
- originates at C5 & C6
- Innervates the subclavius muscle
16
Q
What is the suprascapular nerve?
A
- originates in the nerve roots of C5 & C6
- it goes through the scapular notch
- Innervates the Supraspinatus & infraspinatus
17
Q
What is the lateral pectoral nerve?
A
- originates from the lateral cord of the brachial plexus, containing fibres from C5, C6, & C7
- Innervates the Pectoralis major
18
Q
What is the medial pectoral nerve?
A
- originates from the medial cord of the brachial plexus, containing fibres from C8 & T1
- Innervates the Pectoralis major & minor
19
Q
What is the upper subscapular nerve?
A
- originates from the ventral rami of C5 & C6
- Innervates the subscapularis muscle
20
Q
What is the lower subscapular nerve?
A
- originates from the ventral rami of C5 & C6
- Innervates the subscapularis muscle & the teres major
21
Q
What is the Thoracodorsal nerve?
A
- originates from the posterior cord of the brachial plexus, containing fibres of C6, C7, & C8
- Innervates the latissimus dorsi
22
Q
How many cranial nerves are there?
A
- 12
23
Q
What is the olfactory nerve?
A
- the 1st cranial nerve (CN I); also the shortest sensory nerve in your body
- part of your autonomic nervous system
- enables your sense of smell
24
Q
What is the optic nerve?
A
- known as the 2nd cranial nerve (CNII); optic means vision
- transmits sensory information for vision in the form of electrical impulses from the eye to the brain
25
Q
What is the oculomotor nerve?
A
- the 3rd cranial nerve (CNIII); motion of the eye
- Innervation of eye muscles for for gaze fixation and eye tracking (somatic motor)
- Innervation to the lens and pupil (autonomic parasympathetic)
- Innervation to the upper eyelid (somatic motor)
26
Q
What is the trochlear nerve?
A
- the 4th Cranial Nerve (CNIV); with the longest intracranial course, but also the thinnest
- trochlear means “pulley” (lift the eye)
- enables movement in the eye’s superior oblique muscle
- This makes it possible to look down & to move your eyes toward your nose or away from it
27
Q
What is the Trigeminal nerve?
A
- the 5th cranial nerve (CN V); the largest of the cranial nerves
- Its primary function is to provide sensory innervation to the face
28
Q
What is the abducens nerve?
A
- the 6th cranial nerve (CN VI); is purely a somatic motor nerve, It has no sensory function
- It is responsible for the abduction of the eyes on the same (ipsilateral) side
29
Q
What is the facial nerve?
A
- the 7th cranial nerve (CN VII); carries nerve fibers that control facial movement and expression
- also carries nerves that are involved in taste to the anterior 2/3 of the tongue and producing tears (lacrimal gland)
30
Q
What is the vestibulocochlear nerve?
A
Is the 8th cranial nerve (CN VIII); consists of the vestibular and cochlear nerves
- Each nerve has distinct nuclei within the brainstem
- The vestibular nerve is primarily responsible for maintaining body balance and eye movements
- the cochlear nerve is responsible for hearing
31
Q
What is the glossopharyngeal nerve?
A
- is the 9th cranial nerve (CN IX); It provides motor, parasympathetic and sensory information to your mouth and throat
- the nerve helps raise part of your throat, enabling swallowing.
32
Q
What is the vagus nerve?
A
- is the 10th cranial nerve (CN X); This system controls specific body functions such as your digestion, heart rate and immune system
- These functions are involuntary, meaning you can’t consciously control them
33
Q
What is the accessory nerve?
A
- is the 11th cranial nerve (CN XI); main functions are contracting the trapezius muscle and the sternocleidomastoid
34
Q
What is the hypoglossal nerve?
A
- is the 12th cranial nerve (CN XII); hypo’ meaning under, and ‘glossal’ meaning tongue
- The nerve has a purely somatic motor function, innervating all the extrinsic and intrinsic muscles of the tongue
