Brain 2: brain blood flow, CFS brainstem

Question 0

How are glucose and oxygen used in the brain

Answer 0

Neurons use glucose and oxygen to make ATP in the brain

Question 1

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

Answer 1

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

Question 2

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

Answer 2

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

Question 3

how does brain store glucose

Answer 3

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

Question 4

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

Answer 4

mental confusion
dizziness
convulsions
loss of consciousness

Question 5

how many % of cardio output goes to brain

Answer 5

15%

Question 6

what is blood brain barrier

Answer 6

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

Question 7

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

Answer 7

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

Question 8

What can cross the blood brain barrier

Answer 8

• 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)

Question 9

What can not cross the blood brain barrier

Answer 9

Proteins and most antibiotic drugs do not cross

Question 10

What can break down the blood brain barrier

Answer 10

Trauma, certain toxins and inflammation

Question 11

What is Cerebral spinal fluid

Answer 11

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

Question 12

what does cerebral spinal fluid carry

Answer 12

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

Question 13

Where does cerebral fluid circulate through

Answer 13

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

Question 14

What is the total volume of cerebral spinal fluid?

Answer 14

80-150 ml in adult

Question 15

what are ventricles in the brain

Answer 15

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

Question 16

What is a thin membrane that separates that the lateral ventricles

Answer 16

Septum pelluciadum

Question 17

Functions of ventricles

Answer 17

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

Question 18

Where is CSF formed

Answer 18

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

Question 19

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

Answer 19

BBB=tight junctions of brain capillary endothelial cells

Blood-CSF barrier=tight junctions of ependymal cells

Question 20

What does Blood CSF barrier do

Answer 20

to protect brain and spinal cord from harmful blood borne substances

Question 21

Circulation of CSF

Answer 21

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

Question 22

brain stem contains

Answer 22

Medulla Oblongata
Pons
Midbrain

Question 23

Where and what is in Medulla Oblongata

Answer 23

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

Question 24

what is pyramids

Answer 24

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

Question 25

What is dicussation of pyramids

Answer 25

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

Question 26

nuclei in medulla

Answer 26

- 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

Question 27

what and where is olive

Answer 27

just lateral to each pyramid

Question 28

inferior olivary nucleus

Answer 28

- 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

Question 29

gracile nucleus and cuneate nucleus

Answer 29

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

Question 30

gustatory nucleus

Answer 30

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

Question 31

cochlear nuclei

Answer 31

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

Question 32

Vestibular nuclei

Answer 32

equilibrium pathway from inner ear to brain

Question 33

Cranial nerves in medulla

Answer 33

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

Question 34

Injury to Medulla

Answer 34

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

Question 35

Where and what is pons

Answer 35

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

Question 36

relays signals for voluntary movements from cerebral cortex to cerebellum

Answer 36

pontine nucleus

Question 37

pons' nuclei

Answer 37

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

Question 38

pons'nuclei associated with cranial nerves

Answer 38

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

Question 39

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

Answer 39

gracile nucleus and cuneate nucleus

Question 40

from tongue to brain

Answer 40

gustatory nucleus

Question 41

part of the auditory pathway from inner ear to brain

Answer 41

cochlear nuclei

Question 42

equilibrium pathway from inner ear to brain

Answer 42

vestibular nuclei