Brain 2: brain blood flow, CFS brainstem Flashcards Preview

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Flashcards in Brain 2: brain blood flow, CFS brainstem Deck (43):
0

how many % is the brain's weight (out of total body) and how many % of energy/oxygen does it consume

Brain is 2% of total body weight but consumes 20% of all the oxygen and glucose

1

How are glucose and oxygen used in the brain

Neurons use glucose and oxygen to make ATP in the brain

2

How long does it take for neuronal function to be impaired or permanently damaged

interruption in blood flow for 1-2 minutes to be impaired and total deprivation of oxygen for about 4 minutes causes permanent injury

3

how does brain store glucose

No glucose is stored in the brain so the supply of glucose must be continous

4

what does a low level of glucose in the blood to the brain cause

mental confusion
dizziness
convulsions
loss of consciousness

5

how many % of cardio output goes to brain

15%

6

what is blood brain barrier

Tight junctions that seal together endothelial cells of capillaries in the brain and thick basement layer that surrounds the capillaries

7

What type of neuroglia at blood brain barrier and what does it do?

Astrocytes - their processes press up against the capillaries and secrete chemicals that maintain the permeability characteristics of tight junctions

8

What can cross the blood brain barrier

-Some water-soluble substances cross by active transport (ie glucose)
-Creatinine, urea, ions cross slowly
-lipid-soluble substances (O2, Carbon dioxide, alcohol, most anesthetic agents)

9

What can not cross the blood brain barrier

Proteins and most antibiotic drugs do not cross

10

What can break down the blood brain barrier

Trauma, certain toxins and inflammation

11

What is Cerebral spinal fluid

Clear colourless lipids, mainly water and protects brain and spinal cord from chemical and physical injuries

12

what does cerebral spinal fluid carry

carries small amount of O2, glucose, proteins, lactic acid, urea, cations, anions and some WBCs needed to neurons and neuroglia

13

Where does cerebral fluid circulate through

The cavities in the brain and spinal cord and around the brain and spinal cord in the subarachoid space

14

What is the total volume of cerebral spinal fluid?

80-150 ml in adult

15

what are ventricles in the brain

cavities within the brain filled with CSF
2 lateral ventricles (1 in each hemisphere of the cerebrum, Septum pellucidum)
Third ventricle
Fourth ventricle

16

What is a thin membrane that separates that the lateral ventricles

Septum pelluciadum

17

Functions of ventricles

1. Mechanical protection
-shock absorbing medium that protects brain and spinal cord from jolts
-fluid also keeps brain floating in the cranial cavity
2. Homeostatic function - the pH of CSF affects pulmonary ventilation and cerebral blood flow
3. Circulation - minor exchange of nutrients and waste products between blood and nervous tissue

18

Where is CSF formed

In the Choroid plexuses, networks of blood capillaries in the walls of the ventricles

19

what is difference between Blood brain barrier and blood-CSF barrier

BBB=tight junctions of brain capillary endothelial cells
Blood-CSF barrier=tight junctions of ependymal cells

20

What does Blood CSF barrier do

to protect brain and spinal cord from harmful blood borne substances

21

Circulation of CSF

CSF formed in Choroid plexus ->lateral ventricles ->Interventricular foramina ->Third ventricle ->Cerebral aquaduct -> Forth ventricle -> 2 lateral apertures and 1 median aperture -> central canal subarachoid space ->Arachoid villi ->superior sagittal sinus ->Straight sinus ->Sigmoid sinus -> internal jugular

22

brain stem contains

Medulla Oblongata
Pons
Midbrain

23

Where and what is in Medulla Oblongata

Starts at the foremen magnum and goes to pons
Mede up of sensory (ascending) tracts and motor/(descending) tract
Pyramids

24

what is pyramids

bulges of white matter of the anterior part of the medulla
formed by the corticospinal tracts

25

What is dicussation of pyramids

Crossing of axons in pyramids
90% of axons cross here
explains why each side of brain controls the opposite side of body

26

nuclei in medulla

- Cardiovascular center (regulates the heart beats and the diameter of BVs)
- Medullary rhythmicity area of the respiratory center (adjusts the basic rhythm of breathing along with areas in the pons)
- vomiting center (causes vomiting)
- deglutition center (causes swallowing)
Others causes sneezing, coughing, hiccupping

27

what and where is olive

just lateral to each pyramid

28

inferior olivary nucleus

- within the olive, receives input from cerebral cortex, red nucleus (midbrain), spinal cord
- it provides instructions that the cerebellum uses to make adjustments to mm activity as you learn new motor skills

29

gracile nucleus and cuneate nucleus

are associated with sensations of touch, pressure, vibration and conscious proprioception.
Gracile (leg), Cuneate (arm)

30

gustatory nucleus

from tongue to brain, receives gustatory input from taste buds of tongue

31

cochlear nuclei

part of the auditory pathway from inner ear to brain
receives auditory input from cochlea of the inner ear

32

Vestibular nuclei

equilibrium pathway from inner ear to brain

33

Cranial nerves in medulla

VIII vestibular cochlear nerves
IX glossopharyngral nerves
X vagus nerves
XI accessory nerves
XII hypoglossal nerves

34

Injury to Medulla

hard blow to the back of head/upper neck
can be fatal
damage to medullary rhythmicity area is really bad
alcohol overdose also suppresses the medullary rhythmicity area and may result in death

35

Where and what is pons

consists of nuclei and tracts
is a bridge that connects parts of brain with each other

36

relays signals for voluntary movements from cerebral cortex to cerebellum

pontine nucleus

37

pons' nuclei

pneumotaxic area: Rhythm of breathing
apneustic area: inhale/exhale
These 2 areas along with the medullary rhythmicity area help control breathing

38

pons'nuclei associated with cranial nerves

V trigeminal nerves
VI abducens nerves
VII facial nerves
VIII vestibulocochlear nerves (balance and equilibrium)

39

associated with sensations of touch, pressure, vibration and conscious proprioception

gracile nucleus and cuneate nucleus

40

from tongue to brain

gustatory nucleus

41

part of the auditory pathway from inner ear to brain

cochlear nuclei

42

equilibrium pathway from inner ear to brain

vestibular nuclei