Week 6 - Brainstem and Venous Drainage

Question 1

What are the 3 parts of the brainstem inferior to superior?

Answer 1

1. Medulla Oblongata
2. Pons
3. Midbrain

Question 2

What are the anatomical relations of the medulla oblongata?
What cranial nerves is it associated with?
What centres does it contain?

Answer 2

• most caudal portion of brainstem and brain, and below the pons
• associated with cranial nerves IX, X, XI, XII
• contains respiratory, cardiac and vasomotor centres

Question 3

What are the anatomical relations of the pons?
What cranial nerves is it associated with?
What functions is it involved in?

Answer 3

• central portion of brainstem between midbrain and medulla oblongata (“pons” latin for: bridge)
• associated with cranial nerves V, VI, VII, VIII
• involved in control of sleep and respiration

Question 4

What are the anatomical relations of the midbrain?
What cranial nerves is it associated with?
What functions is it involved in?

Answer 4

• between diencephalon and pons
• associated with cranial nerves III and IV
• composed of white matter tracts and grey matter nuclei; coordinates movements in response to visual and auditory stimuli. Conveys motor information from cerebral cortex to pons. Conveys sensory information from spinal cord to thalamus

Question 5

What are prominent features of the midbrain?

Answer 5

superior and inferior colliculi (visual and auditory reflex centres)
cerebral peduncle/crus cerebri 
substantia nigra
red nucleus 
cerebral aqueduct 
interpeduncular fossa

Question 6

What are prominent features of the pons?

Answer 6

rhomboid fossa - forming floor of 4th ventricle
bulbopontine sulcus
basilar sulcus
middle cerebellar peduncles

Question 7

What are prominent features of the medulla oblongata?

Answer 7

olive
pyramid
decussation of pyramids 
nucleus gracilis and cuneatus 
anterior median fissure 
ventrolateral sulcus

Question 8

At the level of the rostral medulla - what is the function of the inferior cerebellar peduncle/restiform body? Where is it located?

Answer 8

• most dorsolateral part
• consists of fibres passing between the medulla and cerebellum
• includes - olivocerebellar fibres (connects vestibular nuclei and cerebellum)
• includes - dorsal spinocerebellar tract (conveys proprioceptive information from lower limb)

Question 9

At the level of the rostral medulla - what is the function of the nucleus solitarius? Where is it located?

Answer 9

• medial to inferior cerebellar peduncles and ventral to vestibular nuclei
• surrounds a small, dense fascicle of fibres called the solitary tract
• nucleus solitaris receives visceral afferent fibres entering the brainstem in the facial (CNVII), glossopharyngeal (CNIX) and vagus (CNX) nerves

Question 10

At the level of the rostral medulla - what is the function of the nucleus ambiguus? Where is it located?

Answer 10

• deep to ventricular floor and ventral to nucleus solitarius. dorsal to inferior olivary nucleus
• sends motor fibres into glossopharyngeal (CNXI) and vagus (CNX) nerves, and cranial roots of the accessory (CNXI) nerve (therefore muscles of the pharynx and larynx)

Question 11

At the level of the mid medulla - what is the function of the gracile and cuneate nuclei?

Answer 11

the termination point for ascending fibres (1st order neurons) of the dorsal columns
2nd order neurons continue on to medial lemniscus.

Question 12

At the level of the mid medulla - what is the function of the medial lemniscus?

Answer 12

runs through the brainstem (rostral medulla, pons and midbrain) to terminate on 3rd order neurons in the ventral posterior nucleus of the thalamus

Question 13

At the level of the caudal medulla - what is the function of the trigeminal sensory nucleus? Where is it located?

Answer 13

• dorsal medulla contains both nuclei and spinal tract of trigeminal. large nucleus extending the whole length of the brainstem and into the upper segments of the spinal cord
• regarded at brainstem homologue of dorsal horn
• receives primary afferent fibres conveying general sensation from head entering the brainstem as CNV
• caudal portion of the trigeminal nucleus particularly associated with modalities of pain and temperature

Question 14

At the level of the mid medulla - what is the function of the decussation of the pyramids?

Answer 14

in the ventral medulla, majority of the pyramids undergo decussation - crossing over. They pass laterally and dorsally and caudally to form the lateral corticospinal tract

Question 15

At the level of the rostral medulla - what is the function of the inferior olivary nucleus?

Answer 15

Dorsolaterally located
nucleus focus:
- control of movement
- afferent from motor and sensory cortices of cerebral hemisphere and red nucleus from midbrain
- main efferent fibres connect cerebellum via inferior cerebellar peduncle

Question 16

At the level of the pons - what is the function of the pontine nuclei?

Answer 16

give off transversely oriented fascicles of pontocerebellar fibres that pass contralaterally via middle cerebellar peduncle to opposite cerebellar hemisphere.

Question 17

At the level of the pons - what is the function of the trapezoid body?

Answer 17

consists of acoustic fibres that cross the brainstem from the cochlear nuclei
ascend into the midbrain at the lateral lemniscus, terminating in the inferior colliculus

Question 18

What nuclei are found below the floor of the 4th ventricle in the pontine tegmentum?

Answer 18

Abducens - innervates lateral rectus muscle
Facial Motor - innervates muscles of facial expression
Trigeminal Motor - innervates muscles of mastication

Question 19

Where is the superior cerebellar peduncle located?

What kind of fibres does it contain? What do they convey?

Answer 19

In the rostral half of the pons, forming the lateral walls of the 4th ventricle
ventral spinocerebellar tract - convey proprioceptive information from lower limb and efferent fibres ascending from the cerebellum which coordinate movement. They are destined for the red nucleus of the midbrain and ventral lateral nucleus of the thalamus

Question 20

At the level of the midbrain - what is the function of the superior colliculus?

Answer 20

Is part of the visual reflex centre
corticotectal fibres from the visual cortex of the occipital lobe and the frontal eye field of the frontal lobe are involved in the accommodation reflex
inputs concerned with controlling movements of the eyes, e.g. when following a moving object with eyes (smooth pursuit) or altering direction of gaze (saccadic eye movement)

Question 21

What is the function of the Edinger-Westphal Nucleus?

Answer 21

controls the smooth muscle of the eye and is part of the circuit mediating the pupillary light reflex

Question 22

At the level of the midbrain - what is the function of the inferior colliculus?

Answer 22

Is part of the auditory reflex centre

Question 23

At the level of the midbrain - what is the nuclei subdivisions of the substantia nigra? Where is it located?

Answer 23

Ventral-most part of the midbrain

2 types of subnuclei - pars compacta and pars reticulata

Question 24

What is the function of pars compacta?

What pathology is degeneration associated with?

Answer 24

pigmented, melanin-containing neurons
synthesis dopamine
project neurons to caudate nucleus and putamen of basal ganglia - nigrostriatal pathway
controls voluntary movement, posture and muscle tone
degeneration associated with Parkinson’s

Question 25

What is the function of pars reticulata?

Answer 25

non-pigmented subdivision functional homologue of internal segment of globus pallidus shares very similar connections as pars compacta

Question 26

What is the function of the medial longitudinal fasciculus in the midbrain?

Answer 26

links oculomotor and Edinger-Westphal nuclei to abducens nucleus (in pons) and vestibular nucleus (in medulla) functions to help control gaze

Question 27

What is the function of the red nucleus in the midbrain?

Answer 27

motor control major source of afferents from motor cortex in frontal lobe efferent fibres from the red nucleus cross in the ventral tegmental decussation and descend into the spinal cord via the rubrospinal tract projects to the inferior olivary nucleus of the medulla via the central tegmental tract

Question 28

What is the function of crus cerebri in the midbrain?

Answer 28

made up entirely of descending cortical efferent fibres from cerebral hemisphere by traversing the internal capsule around the middle 50% of the crus cerebri consists of corticobulbar and corticospinal fibres either side of this corticopontine fibres originating in the cerebral cortex travel to the pontine nuclei of the ventral pons

Question 29

Where is the dentate nucleus found? What is it's function?

Answer 29

The dentate nuclei are located deep within the lateral hemispheres They receive the majority of their input from the lateral hemispheres (dentate - has a tooth-like/serrated edge)

Question 30

Name the 4 deep cerebellar nuclei

Answer 30

dentate emboliform fastigial globose

Question 31

What are the inputs and outputs of the deep cerebellar nuclei?

Answer 31

They receive projections from mossy fibers and climbing fibers The nuclei receive inhibitory GABAergic input from the Purkinje cells The nuclei receive excitatory input from the mossy and climbing fibers The majority of the output from the cerebellum arises from these nuclei

Question 32

What are symptoms of cerebellar diseases?

Answer 32

* dysarthria - slurring of speech/inappropriate phrasing and/or articulating words correctly * ataxia - unsteady gait * asynergia - inability to combine motions into fluid movement * nystagmus - involuntary and rhythmic to and fro motion of eyes * dysdiadochokinesia - inability to perform rapid alternating movements * dysmetria - inability to control range of movement * hypotonia - decreased muscle tone * scanning speech - slow enunciation with tendency to hesitate at beginning of a word/syllable * tremor - oscillating movement, can be intention or postural tremor

Question 33

What is the tectum? Where is it found?

Answer 33

The posterior region of the midbrain, dorsal to the cerebral aqueduct The roof of the midbrain Contains two pairs of sensory nuclei - superior and inferior colliculi Collectively called - tectal place

Question 34

What is the tegmentum? Where is it found?

Answer 34

sandwiched between substantia nigra and periaqueductal gray matter in the midbrain contains red nuclei and reticular formation

Question 35

What causes the red colour in the red nucleus?

Answer 35

blood vessel density | iron pigmentation in neuronal cell bodies

Question 36

What is the rhomboid fossa?

Answer 36

forms the floor of the fourth ventricle of the brain | is formed by the dorsal surfaces of the pons and medulla oblongata

Question 37

What is the difference between direct and indirect descending spinal pathways?

Answer 37

``` direct = conscious skilled movements indirect = unconscious movements ```

Question 38

Name two direct descending spinal pathways | What are the functions they control? Give an example

Answer 38

Corticospinal tract - lateral and anterior movements below the head, especially of the hands lateral - neck, trunk and limbs, e.g. push-ups, moving with a hula hoop anterior - neck and upper limb extremities, e.g. typing Corticobulbar tract movements of the head and face, e.g. facial expression, chewing

Question 39

What is the origin of the direct descending spinal pathways?

Answer 39

cerebral cortex

Question 40

What is the pathway of the lateral corticospinal tract?

Answer 40

1. originates from cerebral cortex 2. crossover at inferior end of medulla oblongata 3. terminates in anterior horn of spinal cord 4. innervates contralateral side of body

Question 41

What is the pathway of the anterior corticospinal tract?

Answer 41

1. originates from cerebral cortex 2. crossover at level of lower motor neuron 3. terminates in anterior horn of spinal cord 4. innervates contralateral side of body

Question 42

What is the pathway of the corticobulbar tract?

Answer 42

1. originates from cerebral cortex 2. crossover varies depending on the cranial nerve 3. terminates in cranial nerve nuclei in brainstem (lower motor neuron) 4. innervates contralateral side of body

Question 43

Name four indirect descending spinal pathways | What are the functions they control? Give an example

Answer 43

Rubrospinal - movement coordination, e.g. positioning of digits and palm of hand when reaching out to grasp Vestibulospinal - maintenance of upright posture and balance, e.g. extension of upper limbs when falling Reticulospinal - posture adjustment, walking, e.g. maintenance of posture when standing on one foot Tectospinal - movements of head and neck in response to visual and auditory reflexes, e.g. movement of head and neck away from a sudden flash of light

Question 44

What is the pathway of the rubrospinal tract?

Answer 44

1. originates at the red nucleus 2. crossover at the midbrain 3. terminates in the anterior horn of spinal cord 4. innervates contralateral side of body

Question 45

What is the pathway of the vestibulospinal tract?

Answer 45

1. originates at the vestibular nucleus 2. doesn't cross over (uncrossed) 3. terminates in the anterior horn of spinal cord 4. innervates ipsilateral side of body

Question 46

What is the pathway of the reticulospinal tract?

Answer 46

1. originates at the reticular formation 2. some crossover at termination; others uncrossed 3. terminates in the anterior horn of spinal cord 4. innervates contralateral or ipsilateral side of body (depending if crossed over or not)

Question 47

What is the pathway of the tectospinal tract?

Answer 47

1. originates at the superior colliculus 2. crossover at the midbrain 3. terminates in the cranial nerve nucleus in medulla oblongata and anterior horn of upper levels of spinal cord (lower motor neurons that turn the head and neck) 4. innervates contralateral side of body

Question 48

What are the four types of ascending spinal pathways?

Answer 48

Anterolateral Dorsal-column medial-lemniscal (DCML) Spinocerebellar Spinoolivary

Question 49

What are the three types of anterolateral ascending spinal pathways? What are their modality (information transmitted)?

Answer 49

Spinothalamic - pain, temperature, light touch, pressure, tickle and itch Spinoreticular - pain Spinomesencephalic (including spinotectal) - pain and touch

Question 50

What is the origin, primary and secondary cell bodies of the anterolateral pathway? What side of the body does all three pathways innvervate?

Answer 50

origin - cutaneous receptors primary cell body - dorsal root ganglion secondary cell body - posterior horn of spinal cord innervates contralateral side

Question 51

Spinothalamic Tract - what is the point of crossover? - what is the tertiary body? - what is the termination point?

Answer 51

crossover - level at which the primary neuron enters the spinal cord for pain and temperature. or 8-10 segments from where the primary neuron enters spinal cord for light touch tertiary body - thalamus termination - cerebral cortex

Question 52

Spinoreticular Tract - what is the point of crossover? - what is the tertiary body? - what is the termination point?

Answer 52

crossover - reticular formation tertiary body - reticular formation termination - reticular formation and thalamus

Question 53

Spinomesencephalic Tract - what is the point of crossover? - what is the tertiary body? - what is the termination point?

Answer 53

crossover - point of origin tertiary body - superior colliculus termination - mesencephalon and superior colliculus

Question 54

Describe the Dorsal-Column Medial Lemniscal (DCML) tract | origin, primary/secondary/tertiary cell bodies, point of crossover, termination, side of body of termination

Answer 54

``` origin - joints, tendons, muscles primary body - dorsal root ganglion secondary body - medulla oblongata crossover - medulla oblongata tertiary body - thalamus termination - cerebral cortex and cerebellum side of body - contralateral side ```

Question 55

Spinocerebellar Tract What are the two divisions of this tract? Describe the tract (origin, primary/secondary/tertiary cell bodies, point of crossover, termination, side of body of termination)

Answer 55

Posterior and Anterior origin - joints and tendons primary body - dorsal root ganglion secondary body - posterior horn of spinal cord tertiary body - cerebellum crossover - uncrossed (anterior - some cross a point of entry; recross at cerebellum) termination - cerebellum side of body - ipsilateral

Question 56

Describe the Spinoolivary tract | origin, primary/secondary/tertiary cell bodies, point of crossover, termination, side of body of termination

Answer 56

origin - joints and tendons primary body - dorsal root ganglion secondary body - posterior horn of spinal cord tertiary body - accessory olivary nucleus crossover - crossed at point of entry; recross to reach cerebellum termination - accessory olivary nucleus, then cerebellum side of body - ipsilateral

Question 57

What is a discriminative ascending pathway responsible for? | Give an example?

Answer 57

sensory - fine touch, vibration, two-point discrimination, proprioception e.g. dorsal-column medial lemniscal (DCML) tract

Question 58

What is a reactive ascending pathway responsible for? | Give an example?

Answer 58

sensory - pain, temperature, crude touch | e.g. spinothalamic tract

Question 59

What is Wallenberg Syndrome? | What are the symptoms?

Answer 59

a rare condition where infarction or stroke occurs in the lateral medulla symptoms - dysphagia, dizziness, hoarseness of voice, nausea and vomiting, problems with balance and gait, uncontrollable hiccups, loss of pain/temperature sensation on one side of face/weakness in one side of body

Question 60

What are the cerebellar afferent pathways?

Answer 60

``` olivocerebellar vestibulocerebellar reticulocerebellar corticopontocerebellar trigeminocerebellar ```

Question 61

What are the cerebellar efferent pathways?

Answer 61

``` cerebellovestibular cerebelloreticular corticonuclear cerebellothalamic cerebellorubral ```

Question 62

Describe the olivocerebellar pathway

Answer 62

- climbing fibers from olivary nucleus decussate to reach the opposite Raphe nucleus - these fibers pass on as internal arcuate fibers - these go on through the inferior peduncle to the opposite cerebellar hemisphere

Question 63

Describe the trigeminocerebellar pathway

Answer 63

- ascending mossy fibers travel to the cerebellum via the inferior cerebellar peduncle - they transmit proprioceptive information from the face to the cerebellum

Question 64

Describe the cerebellothalamic pathway

Answer 64

- fibers arise from the cerebellar dentate nucleus passing through the superior cerebellar peduncle - fibers decussate to terminate in the ventral anterior nucleus of the thalamus

Question 65

What are the major arterial components of the Circle of Willis?

Answer 65

``` vertebral a. anterior spinal a. basilar aa. pontine aa. superior cerebellar a. posterior cerebral a. posterior communicating a. internal carotid a. middle cerebral a. anterior choroidal a. ophthalmic a. anterior cerebral a. anterior communicating a. ```

Question 66

Describe the arterial pathway from the arch of aorta to anterior and middle cerebral arteries

Answer 66

Arch of aorta - > right - brachiocephalic trunk - right common carotid a. - > left - left common carotid a. common carotid a. -> external and internal carotid a. lateral to optic chiasm internal carotid divides into two terminal branches: anterior and middle cerebral aa.

Question 67

Ophthalmic Artery - what path does it follow? - what structures does it supply?

Answer 67

passing into the orbit through the optic foramen supplies structures of the orbit; frontal and ethmoidal sinuses; frontal part of the scalp; and dorsum of the nose

Question 68

Anterior Choroidal Artery | - what structures does it supply?

Answer 68

optic tract choroid plexus of lateral ventricle hippocampus some deep structures of the hippocampal hemisphere including the internal capsule and globus pallidus

Question 69

Anterior Cerebral Artery - what path does it follow? - what structures does it supply?

Answer 69

courses medially above the optic nerve then passes into great longitudinal fissure between frontal lobes of the cerebral hemisphere as it does this it is joined by the anterior communicating a. within the great longitudinal fissure the artery follows the dorsal curvature of the corpus callosum supplies medial surfaces of frontal and parietal lobes, includes motor and sensory cortices of lower limb

Question 70

Middle Cerebral Artery - what path does it follow? - what structures does it supply?

Answer 70

passes laterally from its origin from internal carotid a. it branches to supply virtually the whole of the lateral surface of the frontal, parietal and temporal lobes, including the primary motor and sensory cortices for the whole body (excluding lower limb) supplies auditory cortex and the insula within the depths of the lateral fissure

Question 71

Vertebral Artery - what is its origin? - what path does it follow? - what structures does it supply? - what branches does it give off?

Answer 71

arises from subclavian artery ascends through foramina transversaria of cervical vertebrae enters cranium through foramen magnum alongside the ventrolateral aspect of the medulla two vertebral arteries converge at the junction of the medulla and pons to form basilar artery posterior inferior cerebellar artery - branches before converging and supplies the inferior aspect of the cerebellum anterior and posterior spinal arteries

Question 72

Basilar Artery - where is it located? - what branches does it give off?

Answer 72

runs the length of the pons branches: - many small pontine branches - supplies pons - anterior inferior cerebellar artery - which supplies the anterior and inferior cerebellum - labyrinthine artery - passes into internal acoustic meatus to supply internal ear

Question 73

At junction of pons and midbrain what two branches does the basilar artery divide into?

Answer 73

superior cerebellar arteries posterior cerebral arteries

Question 74

What does the superior cerebellar arteries supply?

Answer 74

superior aspect of the cerebellum

Question 75

Posterior Cerebral Arteries - what path does it follow? - what does it supply?

Answer 75

curves around the midbrain supplies the visual cortex of the occipital lobe and the inferomedial aspect of the temporal lobe

Question 76

What is the function of the posterior communicating arteries?

Answer 76

To connect the internal carotid and vertebrobasilar systems | these pass rostrocaudally between the ends of the internal carotid arteries and posterior cerebral arteries

Question 77

Why is the circle of Willis functional and clinically important?

Answer 77

the anastomotic arrangement of vessels can make allowances for compensating blood flow in the event of obstruction or narrowing of an artery via the communicating arteries circle of Willis arteries give rise to perforating arteries which supply different regions of the brain

Question 78

What do the anterior perforating arteries arise from? What do they supply?

Answer 78

arise from anterior cerebral artery, anterior communicating a. and the originating region of the middle cerebral artery enter the brain in the region between optic chiasm and termination of the olfactory tract supply large parts of the basal ganglia, optic chiasm, internal capsule and hypothalamus

Question 79

What do the posterior perforating arteries arise from? What do they supply?

Answer 79

arise from posterior cerebral and posterior communicating arteries enter the brain in the region between the two crura cerebri of midbrain supply the ventral portion of midbrain and parts of the subthalamus and hypothalamus

Question 80

What disorders can lead to neurological damage or deficits?

Answer 80

* stroke - blockage or rupture of vessels * cerebral haemorrhage - rupture of blood vessels * aneurysm - abnormal, balloon-like swelling of an artery that can rupture * angioma (arteriovenous malformation) - congenital collection of swollen blood vessels that can rupture

Question 81

What is an infarction?

Answer 81

sudden occlusion of a cerebral artery leading to death of brain tissue

Question 82

What are the three types of epidural haematoma?

Answer 82

temporal fossa haematoma - likely damage to middle meningeal artery subfrontal haematoma posterior fossa haematoma

Question 83

What are the symptoms of a subfrontal haematoma?

Answer 83

headache poor cerebration intermittent disorientation anisocoria (unequal size of pupils)

Question 84

What are the symptoms of a posterior fossa haematoma?

Answer 84

headache meningismus (symptoms similar to meningitis but not caused by) cerebellar and cranial nerve signs Cushing's triad indicate increased intracranial pressure (high systolic BP/decreased respiration/decreased puslse)

Question 85

What are the usual cause of a subdural haematoma?

Answer 85

acute venous haemorrhage of the cortical bridging veins draining cortical blood into the superior sagittal sinus

Question 86

What are the symptoms of a subdural haematoma?

Answer 86

decreased levels of consciousness ipsilateral pupillary dilation headache contralateral hemiparesis (paralysis opposite site of body)

Question 87

What is a transient ischemic attack (TIA)? What is the most common cause?

Answer 87

a temporary interruption of focal brain circulation that results in a neurologic deficit lasting less than 24 hours (usually only 15 minutes to 1 hour) common cause embolic disease from heart, carotid or cerebral vessels leading to the temporary blockage

Question 88

What are the common deficits of a TIA?

Answer 88

Hemiparesis (paralysis of one side of body) Aphasia (inability to understand or produce speech) Hemisensory loss Ataxia (full loss of control of body movements) Vertigo Hemianopia (blindness in half optic field) Confusion

Question 89

What is a stroke? What are the two types?

Answer 89

a localised brain injury caused by a vascular episode that last more than 24 hours 2 types: 1. Ischaemic - (70-80%) infarction, thrombotic or embolic. resulting from atherosclerosis (usually carotid a.) or underlying heart disease 2. Haemorrhagic - when a cerebral vessel weakens and ruptures causing an intracranial bleed affecting a larger brain area

Question 90

What is a carotid-cavernous sinus fistula? Is is more common in men or women? What are the symptoms?

Answer 90

high-pressure (arterial) low-flow lesions often resulting from trauma more common in men characterised by: orbital bruit (increased blood flow through collateral arterial supply and intracranial arterial system); exophthalmos (abnormal protrusion of eyeball); chemosis (oedema of the conjunctiva); and extraocular muscle palsy involving CN III, IV and VI

Question 91

What is vascular (multiinfarct) dementia? What are common dementia symptoms? What causes vascular dementia? What are associated conditions that can lead to multiinfarct dementia?

Answer 91

dementia is an acquired neurologic syndrome presenting with multiple cognitive deficits includes short-term memory impairment, behavioural disturbances, and/or difficulties with daily functioning vascular dementias are caused by anoxic damage (lack of oxygen) from small infarcts - accounting for 15-20% of dementia cases multiinfarct dementia associated with heart disease, diabetes mellitus, hypertension and inflammatory diseases

Question 92

What is the most common cause of subarachnoid haemorrhage?

Answer 92

rupture of a SACCULAR (localised swelling of a vessel wall) or BERRY (most common/looks like berry on a stem/often appear where vessels branch) ANEURYSM of an artery of circle of Willis

Question 93

Why is the venous drainage system of the cranial vault so important?

Answer 93

very little space to accommodate large quantities of blood and so needs an efficient system to allow blood to leave the restricted compartment.

Question 94

What are the 7 paired and 5 unpaired dural sinuses?

Answer 94

paired - 1. transverse, 2. cavernous, 3. greater petrosal, 4. lesser petrosal, 5. sphenoparietal, 6. sigmoid, 7. basilar unpaired - 1. superior sagittal, 2. inferior sagittal, 3. straight, 4. occipital, 5. intercavernous

Question 95

Describe the location of the superior sagittal sinus

Answer 95

resides in the superior border of the falx cerebri and runs between the foramen caecum and internal occipital protuberance

Question 96

Describe the location of the inferior sagittal sinus

Answer 96

midline sinus residing in the free border of the falx cerebri, dorsal to the corpus callosum joined by the great cerebral vein (of Galen)

Question 97

Describe the location of the straight sinus

Answer 97

a midline structure that lies within the posterior end of the falx cerebri and in the middle of the tentorium cerebelli terminates at level of the internal occipital protuberance formed by the inferior sagittal sinus and great cerebral vein

Question 98

Describe the location of the sphenoparietal sinus

Answer 98

located along the free (posterior) edge of the lesser wing of the sphenoid bone of the skull

Question 99

Describe the location of the cavernous sinus What venous structures/sinuses does it connect to?

Answer 99

situated between dural layers on either side of the sella turcica of the sphenoid bone of the skull connects to the superior ophthalmic veins, pterygoid plexus of veins, sphenoparietal sinuses, petrosal sinuses and basilar sinus note - also called Parasellar sinuses

Question 100

Describe the location of the superior (greater) petrosal sinus

Answer 100

runs along the petrous part of the temporal bone in the base of the tentorium cerebelli, crossing over the trunk of the trigeminal nerve (before it enters Meckel's cave) and terminates in the sigmoid sinus

Question 101

Describe the location of the inferior (lesser) petrosal sinus

Answer 101

exits the cavernous sinus and terminates in the sigmoid sinus inferior to the fibres of the facial (CNVII) and vestibulocochlear (CNVIII) nerves

Question 102

Describe the location of the occipital sinus

Answer 102

lies within the fixed part of the falx cerebelli, running from the foramen magnum towards the internal occipital protuberance to the confluence of sinuses

Question 103

Describe the location of the transverse sinus

Answer 103

travels in the base of the tentorium cerebelli, along the occipital bone, terminating at the confluence of sinuses

Question 104

Describe the location of the sigmoid sinus

Answer 104

continuation of the transverse sinus, courses along the posterior cranial fossa, passing inferomedially in an S-shaped pathway to the jugular foramen (becoming the internal jugular vein) via the jugular bulb

Question 105

What is the confluence of sinuses?

Answer 105

point where the superior and inferior sagittal sinuses, straight and occipital sinuses all meet at the level of the internal occipital protuberance

Question 106

Describe the location of the basilar sinus

Answer 106

network of venous channels on the basilar part of the occipital bone has connections to the petrosal sinuses and drains into the vertebral venous plex

Question 107

What are Emissary veins?

Answer 107

small veins that connect the dural sinuses with the diploic veins in the bony skull, which are connected to the scalp veins

Question 108

What is meningitis? What causes it? What are the symptoms? How is it diagnosed?

Answer 108

inflammation of the meninges - in particular the arachnoid and pia mater bacterial or aseptic causes aseptic includes: viral, drug reactions, systemic diseases headache, fever, seizures, painful stiff neck lumbar puncture and examining the CSF