anatomy of lobes, meninges, ventricles, CSF outflow, cerebellum

Question 1

what are the 2 major functions of the meninges?

Answer 1

1. support for brain & vasculature

2. acting with CSF to protect brain from mechanical damage

Question 2

what are the 2 layers or the dura mater?

Answer 2

1. periosteal (superficial)
2. meningeal (deep)

tough fibrous layers

Question 3

what are 2 important structures formed from dura?

Answer 3

• falx cerebri

- tentorium cerebelli

Question 4

where does the falx cerebri lie?

Answer 4

• lies between the 2 hemispheres within the longitudinal fissure

Question 5

where does the tentorium cerebelli lie?

Answer 5

• forms a roof over the posterior cranial fossa and the cerebellum

Question 6

which meninges layer contains no blood vessels or nerve?

Answer 6

the arachnoid mater

Question 7

what structures can be found within the subarachnoid space?

Answer 7

Cerebrospinal fluid CSF
blood vessels
the circle of willis - within the subarachnoid interpeduncular cistern

Question 8

describe the pia mater

Answer 8

• adherent with the gyri

- highly vascularised

Question 9

what is the choroid plexus?

Answer 9

• is a secretory tissue
• found in each of the brain ventricles,
• the main function is to produce CSF
• by ependymal cells

Question 10

within which ventricle is the majority of CSF produced?

Answer 10

the lateral ventricles

Question 11

describe the order of CSF drainage

Answer 11

1. lateral ventricles
2. Interventricular Foramen of Munroe
3. 3rd ventricle
4. drains down the Cerebral Aqueduct
5. 4th ventricle
6. goes through these 2 openings:
   
   • the medianForamen of Magendie
   • the lateralForamina of Luschka
7. into subarachnoid space
8. into dural venous sinuses via arachnoid granulations

Question 12

what are the parts of the the lateral ventricles

Answer 12

looking front on

• anterior horn
• inferior horn

at the back
- posterior horn

Question 13

what is the CSF-brain barrier

Answer 13

a barrierformed by tight junctions between neighbouring choroid plexus epithelial cells (ependymal cells)

a physical barrier to regulate the movement between ventricles and brain

Question 14

what are the arachnoid granulations?

Answer 14

• essentially valves between the subarachnoid space and dural spaces
• allows CSF to be reabsorbed
• they are aged/calcified tufts of arachnoid mater villi

Question 15

how does CSF flow in the right direction ?

Answer 15

due to pressure gradient

high pressure in ventricles, pushes CSF into subarachnoid space which has a lower pressure

Question 16

which sulcus separates the frontal lobe from the parietal lobe?

Answer 16

the central sulcus

Question 17

which sulcus separates the temporal lobe from the frontal and parietal lobes?

Answer 17

the lateral sulcus

Question 18

what are the functions carried out by the frontal lobe?

Answer 18

Motor control, problem solving,

speech production, personality

Question 19

what are the functions carried out by the parietal lobe?

Answer 19

Touch perception, sensory
discrimination and
proprioception

Question 20

what are the functions carried out by the temporal lobe?

Answer 20

Auditory processing, language comprehension, memory, emotion

Question 21

what are the functions carried out by the occipital lobe?

Answer 21

sight , visual reception and interpretation

Question 22

what are the functions carried out by the cerebellum?

Answer 22

Balance and coordination

Question 23

describe where the primary motor cortex lies?

Answer 23

frontal lobe, within pre central gyrus

Question 24

within which lobe lies the primary and secondary auditory cortices?

Answer 24

temporal

Question 25

within which lobe lies the primary somatosensory cortex?

Answer 25

parietal lobe, on post central gyrus

Question 26

within which lobe lies the primary and secondary visual cortices?

Answer 26

occipital

Question 27

what and where is the insulur cortex? what are the 3 functions its involved in?

Answer 27

- a portion of the cerebral cortex - folded deep within the lateral sulcus - involved in 1. sensory processing, 2. decision-making, 3. motor control.

Question 28

Brocas area where? function? symptoms if damaged

Answer 28

- frontal lobe - normally on left hemisphere - language production (MOTOR, control of mouth and laryngeal muscles) - Brocas aphasia (patient CAN understand but CANNOT pronounce)

Question 29

wernickes area where? function? symptoms if damaged

Answer 29

- at back of lateral sulcus, back of temporal lobe - language comprehension (speech and written) - Wernicke’s aphasia (scrambled speech, can't understand speech and writing)

Question 30

are brocas and wernickes areas paired structures?

Answer 30

no only on 1 side of brain normally on left as its dominant.

Question 31

what are the 3 sections of the brain ?

Answer 31

1. the hindbrain → rhombencephalon 2. the midbrain → mesencephalon 3. the forebrain → prosencephalon (majority of brain)

Question 32

what are the 2 subsections of the forebrain?

Answer 32

prosencephalon: - telencephalon (majority of cerebral hemispheres) - diencephalon ( contains thalamus & hypothalamus

Question 33

what are the 2 subsections of the midbrain?

Answer 33

mesencephalon: - tectum (dorsal to cerebral aquaduct) - the cerebral peduncle (ventral to cerebral aqueduct)

Question 34

what does the tectum contain?

Answer 34

tectum = part of midbrain dorsal/above the cerebral aqueduct - contains superior and inferior colliculi

Question 35

what does the cerebral peduncle contain?

Answer 35

cerebral peduncle = part of midbrain ventral/below the cerebral aqueduct 1. tegmentum - dorsal, contains red nuclei & oculomotor nerves 2. crus cerebri - ventral, sectioned off by substantia nigra, contains motor tracts

Question 36

what are the operculum?

Answer 36

the parts of the temporal, frontal and parietal lobes that overlie the insula. inside lateral sulcus look like lips can open them up to see into the insula

Question 37

what section of the brain is the cerebellum in ?

Answer 37

hindbrain inferior to occipital and temporal lobes within posterior cranial fossa

Question 38

what is the function of the cerebellum?

Answer 38

MOTOR - the coordination, precision and timing of movements - and for motor learning

Question 39

name the midline that separates the 2 ovoid hemispheres of the 'little brain'

Answer 39

the vermis

Question 40

is the cerebellum made of grey or white matter?

Answer 40

both: grey - surface, forms cerebellar cortex white - inner core, holds the 4 cerebellar nuclei

Question 41

are there more neurones in the cerebrum or cerebellum?

Answer 41

more in cerebellum (90%)

Question 42

what are the 2 main fissures in the cerebellum?

Answer 42

- primary fissure | - horizontal fissure

Question 43

what are the 3 lobes of the cerebellum ?

Answer 43

- anterior lobe - posterior lobe - flocculonodular

Question 44

what are the 3 zones of the cerebellum?

Answer 44

- the vermis - the intermediate zone - the lateral hemispheres

Question 45

what is the blood-brain barrier? what is its purpose?

Answer 45

- physical barrier - that limits the ability of molecules to pass between the blood and the CNS - in order to protect the tissue from toxic substances

Question 46

what are the 4 key features of the blood brain barrier?

Answer 46

- endothelial cell tight jucntions - lack of BM fenestrations (holes) - astroctyres end feet - perictyes

Question 47

what is another name for the floor of the IVth ventricle?

Answer 47

the rhomboid fossa because diamond shaped