Anatomy Flashcards
what is the name for a collection of cell bodies in the CNS and the PNS?
CNS- nucleus
PNS- ganglion
nerves can be what kind of ‘modality’?
single modality
mixed modality
describe single modailty nerves?
one of:
somatic motor
somatic sensory
special sensory
sympathetic/parasympathetic/visceral afferent
decribe mixed modailty nerves?
somatic motor, somatic sensory and sympathetic all in one
how many pairs of spinal nerves are there?
31 pairs
how do spinal nerves connect with structures of the soma (body)?
via rami
spinal nerves are only found within what structure?
intervertebral foramina
describe the path of sensory axons
spinal nerve→ posterior root→ posterior rootlet→ posterior horn of spinal cord
describe the path of motor axons
anterior horn of spinal cord→ anterior rootlet→ anterior root→ spinal nerve
each spinal nerve supplies a body segment with what?
general snesory supply
somaotic motor to skeletal muscle
sympathetic nerve supply to skin/arterioles
the anterior rami of which spinal nerves make up the cervical plexus?
C1-C4
the anterior rami of which spinal nerves make up the brachial plexus?
C5-T1
the anterior rami of which spinal nerves make up the lumbar plexus?
L1-L4
the anterior rami of which spinal nerves make up the sacral plexus?
L5-S4
what are the 4 routes of sympathetic outflow within the sympathetic trunk?
- ascend then synapse
- synapase at level of entry
- descend and then synapse
- pass through sympathetic trunk without synapsing and enter abdominopelvic splanchnic nerve
presynaptic parasympathetic axons leave the CNS via which cranial nerves?
2,7,9,10
(optic, facial, glossopharyngeal, vagus)
what are the extrinsic muscles of the back?
levator scapulae
rhomboids
trapezius
latissimus dorsi
what is the function of the extrinsic back muscles?
move upper limb
what is the function of the intrinsic back muscles?
maintain back posture and move spine
what are the two groups of intrinsic back muscles?
erector spinae (superficical)
tranversospinalis (deep)
what muscles are responsible for flexion of the spine?
psoas major
rectus abdominus
contraction of erector spinae bilaterally causes what movement?
extension of spine
(unilateral contraction causes lateral flexion)
what are the supraspinous and interspinous ligaments?
supraspinous- connects tips of spinous processes (strong/fibrous)
interspinous- connects superior and inferior surfaces of adjacent spinous processes (weak/membranous)
where are intervertebral discs found?
between bodies of adjacent verebrae
(can herniate)
what are facet joints?
between articular processes of adjacent vertebrae
(can be affected by arthritis)
what are the two types of tissue in intervertebral discs?
outer fibrous ring- annulus fibrosis
inner soft pulp- nucleus pulposus
of the anterior and posterior ligaments of the spine which is stronger?
anterior- broad strong
posterior- narrow, weak
what is the first palpable spinous process in 70% of people?
C7- vertebrae prominens
where does the spinal cord begin/end?
begins at foramen magnum and ends at L1/2 (conus medullaris)
how many stages of cervical vertebrae dislocation are there?
A- stage 1, flexion sprain
B- stage 2, anterior subluxation
C- stage 3, 50% translation
D- stage 4, complete dislocation
what are somatic general sensory symptoms?
pain (neuralgia)
paraethesia
numbness
sensitivity (hyperpaesthesia)
hot or cold
ataxia
what are some motor symptoms?
muscle stiffness, tightness, spasm
muscle floppiness (reduced tone)
muscular wekaness (reduced power)
ataxia
how are spinal nerves tested clinically?
sensory function → dermatomes
motor function → mytotomes
both → spinal reflexes
how do spinal nerves differ from named nerves?
spinal nerve = axons originating from one spinal cord i.e. C5 spinal nerve
named nerve = axons originating from one or more spinal levels supplying particular area i.e. C5,6,7 musculocutaneous nerve
spinal cord reflexes depend on the integrity of which pathway?
the arc pathway
reflex muscle contractions are controlled by descending/ascending pathways?
descending pathways
how do UMN lesions affect reflexes?
spasticity
how do LMN lesions affect reflexes?
flaccidity
what are the different spinal reflexes that can be tested clinically?
biceps brachii- C5,6
brachioradialis- C7
triceps brachii C7
knee jerk L3
ankle jerk S1
what are the layers of the scalp?
skin
connective tissue
aponeurosis
loose conenctiev tissue
pericranium
what artery can be found behind the pterion?
middle meingeal artery
CSF is reabsorbed into the dural venous sinuses via what structure?
arachnoid granulations
which of the internal and external carotid arteries enters the cranial cavity?
internal carotid enters cranial cavity to supply brain
external carotid remains outisde cavity to supply neck, face and scalp
how do the vertebral arteries enter the cranial cavity?
passes trhough vertebral foramina in cervical vertebrae then through foramen magnum
subarachnoid bleeds are termed what?
berry aneurysms (ruptured circle of willis)
(can also be due to congenital aneurysms)
how does an extradural bleed occur?
ruptured middle menigial artery- trauma to pterion
how does a subdural bleed occur?
torn cerbral veins
falls in elderly/those w drinkign problems
compression of teh oculomotor nerve by an uncal herniation results inw hat clinical sign?
ipsilateral fixed dialted pupil
‘blown pupil’
