Neuroanatomy 1

Question 1

explain the directions and planes of section for the brain

Answer 1

Question 2

what are the layers of meninges and spaces starting most superficial

Answer 2

epidural space
dura mater
subdural space
arachnoid mater
subarachnoid space
pia mater

Question 3

what type of tissue are the meninges made of

Answer 3

dense irregular connective tissue

Question 4

what is the epidural space and what is its function

Answer 4

a potential space between inner surface of cranial bone and outer surface of dura mater
allows passage of blood vessels such as the middle meningeal artery

Question 5

what does the middle meningeal artery do

Answer 5

supplies meninges

Question 6

explain an epidural hematoma

Answer 6

when the thin, temporal/pterous region of the skull is fractured, it can rupture vessels causing a collection of blood

Question 7

what is the dura mater, what are its two layers, and what is its function

Answer 7

thickest, most durable double layered membrane
periosteal and meningeal layers
typically both layers are fused except where they have dural sinus cavities

Question 8

what is the periosteal dura and what is its function

Answer 8

outer layer of dura that is attached to the cranial bone
has lots of blood supply

Question 9

what is the meningeal dura and what is its function

Answer 9

inner, avascular layer of the dura

Question 10

what are dural sinuses and what are their functions

Answer 10

venous channels between the superficial and deep layers of dura
drain excess CSF and deoxygenated blood from the brain

Question 11

what are dural folds

Answer 11

where the meningeal dura (deep) layer folds over itself

Question 12

what is the falx cerebri

Answer 12

dural fold between longitudinal fissure
separates left and right cerebral hemispheres

Question 13

what is the superior sagittal sinus

Answer 13

dural sinus (cavity) made by separation of the two dura mater layers

found within the longitudinal fissure

Question 14

what is the tentorium cerebelli

Answer 14

dural fold between cerebellum and occipital lobe of cerebrum

Question 15

what is the falx cerebelli

Answer 15

dural fold between left and right hemispheres of cerebellum

Question 16

what is the subdural space and what is its function

Answer 16

narrow space directly under dura mater and above arachnoid mater
has a thin layer of serous fluid and veins that drain blood from the brain

Question 17

what is a subdural hematoma

Answer 17

when cerebral veins in the subdural space tear and cause pooling of blood
much slower accumulation because they’re low pressure veins

Question 18

what is the arachnoid mater and what is its function

Answer 18

found beneath subdural space
has arachnoid mater and makes up arachnoid granulations

Question 19

what do arachnoid granulations do

Answer 19

project superficially through meningeal dura into dural sinuses
allow for return of CSF to bloodstream which helps maintain pressure

Question 20

what is the subarachnoid space and what is its function

Answer 20

found deep to the arachnoid mater
filled with CSF and major brain blood vessels
has arachnoid trabeculae which connect arachnoid matter to pia mater

Question 21

what is a subarachnoid hemorrhage

Answer 21

major brain blood vessels in the subarachnoid space can rupture
produces “worst headache of life”

Question 22

what is a berry aneurysm

Answer 22

enlargement or ballooning of an artery due to weakening of the arterial wall
can pinch optic nerve depending on where they are

Question 23

at which artery will you find 40% and 34% of berry aneurysms

Answer 23

40%: anterior communication artery (opic nerve pinching)
34%: off of the middle cerebral artery

Question 24

what is the Pia mater and what is its function

Answer 24

deepest meningeal layer that is directly adhered to brain
permeable to substances in CSF and extracellular fluid of brain
allows for substances to move between two fluid compartments

Question 25

explain a concussion

Answer 25

brain injury caused by violent blow to the head or shaking of head widespread and micoscopic

Question 26

explain a contusion

Answer 26

pia mater is stripped from brain which causes bleeding localized with macroscopic bruising

Question 27

what type of cell lines ventricles of the brain

Answer 27

ependymal cells

Question 28

what are the right and left lateral ventricles (first and second ventricles)

Answer 28

largest cavities found in the cerebral hemispheres look like ram horns

Question 29

what is the third ventricle

Answer 29

narrow cavity found between 2 lobes of diencephalon (forebrain)

Question 30

what is the interventricular foramen

Answer 30

hole that connects left + right lateral ventricles to the 3rd ventricle

Question 31

what is the fourth ventricle

Answer 31

between pons and cerebellum continuous with the central canal of spinal cord have posterior openings to allow CSF in ventricles to flow into subarachnoid space

Question 32

what is the cerebral aqueduct

Answer 32

connects third and fourth ventricles

Question 33

what is the purpose of CSF

Answer 33

cushions brain maintains constant temperature removes wastes increases buoyancy of brain

Question 34

what are the choroid plexuses and what do they do

Answer 34

tissue in ventricles made of cells that make the majority of CSF

Question 35

what are fenestrated capillaries

Answer 35

gaps between endothelial cells that allow fluid and electrolytes to exit from blood plasma to enter extracellular fluid

Question 36

what is the pathway for CSF formation, circulation, and reabsorption

Answer 36

1.) fluid leaks out of capillaries of choroid plexuses into ECF of ventricles 2.) ependymal cells take up fluid and secrete it into ventricles as CSF 3.) CSF is circulated through brain and spinal cord in subarachnoid space by the cilia on ependymal cells 4.) some CSF is reabsorbed into venous blood in arachnoid granulations

Question 37

explain hydrocephalus

Answer 37

when arachnoid granulations are blocked or too much CSF is produced, it builds up in ventricles which causes swelling of the brain

Question 38

where does the majority of the brain's blood supply come from

Answer 38

internal carotid arteries

Question 39

what does the internal carotid artery branch into

Answer 39

anterior, middle, and posterior cerebral arteries

Question 40

what does the anterior cerebral arteries do

Answer 40

supply most of medial and superior surface of cerebrum and frontal pole connected to the other anterior cerebral artery by anterior communicating artery

Question 41

what does the middle cerebral arteries do

Answer 41

supply lateral surface of cerebrum and temporal pole common site for plaque formation and strokes

Question 42

what does the basilar artery do

Answer 42

made of both vertebral arteries fused gives off small branches that supply brainstem

Question 43

what does the posterior cerebral arteries do

Answer 43

supply inferior surface and occipital lobe

Question 44

what do the posterior communicating arteries do

Answer 44

connect posterior cerebral arteries to internal carotid arteries

Question 45

explain temporal arteritis

Answer 45

aka giant cell arteritis or Horton's arteritis autoimmune disorder that causes inflammation of the blood vessels can cause headaches, vision loss, etc biopsy of superficial temporal artery may be taken treatment is steroids

Question 46

what are the four main veins that drain the head

Answer 46

internal and external jugular vertebral veins emissary veins

Question 47

what are the purpose of the emissary veins

Answer 47

connect dural venous sinus with veins of scalp

Question 48

what two veins does the brachiocephalic vein split into

Answer 48

internal jugular and subclavian veins

Question 49

what two veins stem from the subclavian vein

Answer 49

external jugular and vertebral veins

Question 50

what is the venous blood flow starting from brain capillaries

Answer 50

brain capillaries cerebral veins inferior sagittal sinus to straight sinus superior sagittal sinus, occipital sinus, and inferior sagittal sinus to confluence sinus transverse sinus cavernous sinus to superior petrosal sinus sigmoid sinus internal jugular vein

Question 51

what is the cavernous sinus and what does it do

Answer 51

found on either side of the sella turcica drains ophthalmic veins potential area for things like infection

Question 52

explain danger spaces

Answer 52

areas susceptible to infection and nerve damage scalp - emissary veins - superior sagittal sinus nose - ophthalmic vein - cavernous sinus