anatomy Flashcards
4 types of glial cells
astrocytes
oligodendrocytes
microglia
ependymal cells
what are astrocytes
support, maintaining the blood brain barrier
maintain homeostasis
what are oligodendrocytes
produce myelin sheet in CNS
round nucleus
what are microglial
phagocytic
what level does the spinal cord become conus medullaris.
L2 vertebral level
levels of spinal enlargement
cervical enlargement is located proximally, at the C4-T1 level
T11 and L1 is the lumbar enlargement
venous supply in cranial cavity
dura mater attached to periosteum of skull bone
venous supply of vertebral canal
space exits between dura and bone
epidural space
divisions of trigeminal nerve
opthalmic- sensory
maxillary- sensory
mandibular- sensory and motor
sensory innervation of CNV1
supplies: upper eyelid, cornea and all the conjunctiva
skin of the root/bridge of nose
deep sensory: bones and soft tissue of the orbit, upper anterior nasal cavity, paranasal sinuses, anterior and posterior cranial fossae
sensory innervation of CNV2
the skin of lower eyelid
the skin over the maxilla
the skin of the ala of the nose
the skin /mucosa of the upper lip
deep teritory: lower posterior nasal cavity, maxilla and maxillary sinus, floor of nasal cavity/palate, maxillary teeth
sensory innervation of CNV3
the skin over the mandible and temporomandibular joint (apart from the angle of the mandible)
deep territory: middle cranial fossa, the mandible, anterior 2/3rd of the tongue, the floor of the mouth, buccal mucosa, mandibular teeth
what is the great auricular nerve
C2,3 > sensory branch of cervical plexus
supplies the skin of the angle of the mandible and some of the external ear
motor innervation of trigeminal nerve
CNV3 supplies the muscles of mastication
also supplies tensor veli palatini and tensor tympani
what are the muscles of mastication
masseter
temporalis
medial pterygoid
lateral pterygoid
what nerve provides pre-synaptic parasympathetic fibres for the pterygopalatine ganglion
facial
what does the pterygopalatine ganglion innervate
lacrimal, nasal, palatine, and pharyngeal glands
what nerve provides pre-synaptic parasympathetic fibres for the submandibular ganglion
facial
what does the submandibular ganglion innervate
sublingual and submandibular glands
what nerve innervates taste on the anterior 2/3 of the tongue
lingual nerve
branch of mandibular from V3
anatomical course of the cranial portion of the facial nerve
leaves brainstem at the pontomedullary junction and enters the internal acoustic meatus in the posterior cranial fossa
anatomical course of the temporal portion of the facial nerve
after the internal acoustic meatus > nerve travels anteriorly within the temporal bone
turns and runs along the medial wall of typanic cavity
modalities of vestibulocochlear nerve
both parts are special sensory only
where does the vestibular component of the vestibulocochlear nerve arise
vestibular nuclei complex in the pons and medulla
where does the cochlear component of the vestibulocochlear nerve arise
from the ventral and dorsal cochlear nuclei, situated in the inferior cerebellar peduncle
anatomical course of the vestibulocochlear nerve
both fibres combine in the pons to form the nerve
nerve exits cranium via the internal acoustic meatus of the temporal bone
the nerve splits again
sensory modalities of the glossopharyngeal nerve
oropharynx, carotid body and sinus, posterior 1/3 of the tongue, middle ear cavity and Eustachian tube
special sensory modalities of the glossopharyngeal nerve
taste sensation to the posterior 3rd of the tongue
parasympathetic modalities of the glossopharyngeal nerve
parasympathetic innervation to the parotid gland
motor modalities of the glossopharyngeal
stylopharyngeus muscle of the pharynx
anatomical course of glossophrayngeal
leaves CNS at the upper medulla oblongata
exits cranium through jugular foramen
tympanic branch arisis- has mixed sensory and parasympathetic composition
enters the parapharyngeal space and lays on the stylopharygeus muscle to supply somatic motor
somatic sensation modalities of vagus
innervates skin external acoustic meatus and the internal surfaces of the laryngopharynx and larynx
somatic motor modalities of vagus nerve
palate, pharynx, larynx
somatic motor modalities of vagus nerve
palate, pharynx, larynx
special sensory modalities of vagus nerve
epiglottis- taste
visceral sensation of vagus nerve
thorax/abdomen
where does the vagus nerve orginiate
lateral aspect of the medulla
what nerves exit via the jugular foramen
CN IX, X, XI
(and internal jugular vein)
anatomical course of vagus nerve in the neck
travels in the carotid sheath with the jugular vein and common carotid artery
right and left nerves have differing pathways at base of neck
what muscles are innervated by the spinal accessory nerve
sternocleidomastoid and trapezius
modalities of the hypoglossal nerve
somatic motor- to all the muscles of the tongue, except palatoglossus (vagus nerve)
where are spinal nerves found
intervertebral foramina
definition of dermatome
area of skin supplied with sensory innervation from a single spinal nerve
dermatome for the nipple
T4
dermatome of umbillicus
T10
dermatome of posterior scalp, neck and shoulder
C2-4
what does the cervical plexus innervate
posterior scalp, neck and diaphragm
when do sympathetic nerve fibres leave the CNS
T1-L2
sympathetic innervation of the heart
presynaptic axons synapse in T1 or cervical paravertebral ganglia
postsynaptic axons pass in cardiopulmonary splanchnic nerves to SA and AV nodes and myocardium
when do parasympathetic fibres leave the CNS
within 4 cranial nerves (CN III, VII, IX, and X)
sacral spinal- craniosacral outflow
extrinsic back muscles
levator scapulae
trapezius
rhomboids
latissimus dorsi
intrinsic back muscles function
maintain posture and move the spine
intrinsic back muscles function
maintain posture and move the spine
two groups of intrinsic back muscles
erector spinae (superficial)
transversospinalis (deep)
ligamentum flacum
connects adjacent laminae posterior to spinal cord
posterior longitudinal ligament
narrow, weak
less support for disc
prevents over-flexion of spine
anterior longitudinal ligament
broad, strong
stronger support for disc
prevents over-extension of spine
atlanto-axial joints
3 articulations- all synovial
- 2 between the inferior articular facets of the atlas and the superior articular facets of the axis
- 1 between the anterior arch of the atlas and odontoid process of the axis
- Main movement is rotation
where is it most safe for the needle to be inserted for spinal and epidural anaethesia
region where subarachnoid space surrounds the cauda equina, NOT the spinal cord
vertebrae not fused
most commonly L3/4
biceps reflex tests what?
C5
supinator/brachioradialis reflex tests what
C6
supinator/brachioradialis reflex tests what
C6
knee reflex tests what
L4
ankle reflex tests what
S1
what does SCALP stand for
skin
connective tissue
apopneurosis
loose connective tissue
pericranium
what forms the pterion
frontal, parietal, temporal and sphenoid bones
what innervates the dura mater
CN V
what is the daiphragm sellae
tough sheet of dura mater forming a roof over the pituitary fossa
what is the tentorium cerebelli
sheet of dura mater ‘tenting’ over the cerebellum
- attaches to the ridges of the petrous temporal bones
- has a central gap to permit the brainstem to pass through
falx cerebri
midline structure made of dura mater that separates the right and left cerebral hemispheres
supratensorial herniation
cingulate
central
uncal or transtenrotial- the uncus of the tempral lobe herniates inferior to the tentorium cerebelli
transcalvarial
intratentorial herniation
upward
downward or tonsillar herniation- cerebellar tonsils herniate into the foramen magnum
function of frontal lobe
higher intellect, personality, mood, social conduct and language
motor cortex is located within frontal lobe
functions of parietal lobe
language and calculation on the dominant hemisphere side, and visuospatial function on the non-dominant hemisphere side
function of temporal lobe
memory and language
includes hearing- contains the primary auditory cortex
functions of occipital lobe
vision
function of insular lobe
important role in patients experience of pain
clinical signs of dsfunction of the frontal lobe
- Personality dysfunction
- Paraparesis
- Paratonia
- Grasp reflex
- Frontal gait dysfunction (magnetic gait)
- Cortical hand
- Seizures
- Incontinence
- Visual field defects (anterior visual pathway including optic chiasms are beneath frontal lobe)
- Expressive dysphasia (Broca’s area is in the dominant frontal lobe)
- Anosmia (olfactory pathway is beneath frontal lobes)
clinical signs of dysfunction of parietal lobe
- Visual field defect (congruous lower homonymous quadrantanopia)
- Sensory dysfunction (visual and sensory modalities in particular)
- Gerstmann’s syndrome (disease of the dominant angular gyrus, part of the inferior parietal lobe): dysgraphia, left-right disorientation, finger agnosia, acalculia
- Dyspraxia
- Inattention (non-dominant angular gyrus)
- Denial
clinical signs of dysfunction of temporal lobe
- Memory dysfunction especially episodic memory
- Agnosia (visual and sensory modalities in particular)
- Language disorders receptive dysphasia (Wernicke, dominant hemisphere)
- Visual field defects (congruous upper homonymous quadrantanopia)
- Auditory dysfunction (Heschel’s gyrus, as hearing is represented bilaterally, deafness is not a cerebral feature)
- Limbic dysfunction
- Temporal lobe epilepsy
what is the DCML pathway
carries sensory modalities of fine touch, conscious proprioception and vibration
where does DCML information travel in the brainstem
the medial lemniscus
what is the first order neurones in the DCML
carries sensory information regarding touch, proprioception or vibration from peripheral nerves to medulla oblongata
what is the second order neurones in the DCML
they begin in the cuneate nucleus or gracilis
the fibres receive the information from the preceedng neurones and deliver to the third order in thalamus
where does the DCML fibres decussate
medulla oblongata
what do the third order neurones in the DCML do
transmit sensory signals from the thalamus to the ipsilateral primary sensory cortex of the brian
anterior spinothalamic tract
carries the sensory modalities of crude touch and pressure
lateral spinothalamic tract
carries the sensory modalities of pain and temperature
first order neurones of the anterolateral system
arise from the sensory receptors in the periphery
enter the spinal cord, ascend 1-2 vertebral levels, synapse at the tip of dorsal horn (substantia gelantinose)
second order neurones of the anterolateral tract
carry information from substantia gelatinosa to the thalamus
- decussate within the spinal cord and form the two distinct tracts
third order neurones of the anterolateral spinal tract
carry sensory signals from the thalamus to the ipsilateral primary sensory cortex of the brain
the spinocerebellar tract carry?
unconscious proprioceptive information
Posterior spinocerebellar tract?
Carries proprioceptive information from the lower limbs to the ipsilateral cerebellum
Cuneocerebellar tract?
Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum
Anterior spinocerebellar tract
Carries proprioceptive information from the lower limbs. The fibres decussate twice – and so terminate in the ipsilateral cerebellum
Rostral spinocerebellar tract
Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum
pyramidal tracts
originate in the cerebral cortex
carry motor fibres to spinal cord and brainstem
responsible for voluntary control of musculature of body and face
extrapyramidal tracts
originate in the brainstem
carry motor fibres to spinal cord
responsible for involuntary and automatic control of musculature: such as tone, balance, posture and locomotion
corticospinal tract
is a pyramidal tract
responsible for fine movement
About 85% of fibres cross the caudal medulla at the decussation of the pyramids
- Crossed fibres form the lateral CST
- Uncrossed fibres form the ventral CST, which cross segmentally
brown-sequard’s syndrome
condition characterised by a lesion in the spinal cord resulting in weakness or paralysis on one side of the body and loss of sensation on the opposite
caused by lateral hemisection of spinal cord
3 lobes of the cerebellum
anterior lobe, posterior lobe and flocculondoular lobe
where does the cerebellum receive its blood supply
superior cerebellar artery- branch of basilar artery
anterior inferior cerebellar artery- branch of basilar artery
posterior inferior cerebellar artery
Descending corticospinal tracts
responsible for voluntary motor control of the body.
Descending corticobulbar tracts
responsible for voluntary motor control of face, head and neck.
Ascending medial lemniscus tracts
responsible for fine touch, vibration and proprioception.
Ascending spinothalamic tracts
responsible for pain and temperature sensation
