AWABS - Brain anatomy and Cerebral Physiology

Question 1

Functions of brain lobes / areas

Answer 1

Question 2

Thalamus

Answer 2

Collection of nuclei
Limbic system

Question 3

Functions of basal ganglia

Answer 3

Cognition
Control of movement
Procedural learning

Question 4

Brainstem components

Answer 4

Midbrain
Hindbrain - Pons and Medulla

Question 5

Cerebellum

Answer 5

3 lobes

Question 6

Arterial supply to the brain

Answer 6

Not labelled but also note anterior spinal artery

Question 7

Venous drainage of the brain

Answer 7

Question 8

Functions of CSF

Answer 8

Buoyancy
Protection from trauma
Chemical stability
Protection from brain ischaemia - spatial compensation

Question 9

Buoyancy effect of CSF

Answer 9

Reduced brain weight from 1400 g to 25 g

Question 10

Chemical stability effect of CSF

Answer 10

Rinses metabolic waste of CNS through BBB

Question 11

Composition of CSF compared to plasma

Answer 11

Question 12

Volume of CSF

Answer 12

Volume 150 ml
Constantly produced so builds up if issue with reabsorption

Question 13

Rate of CSF production

Answer 13

0.3-0.4 ml/min
500 ml/day

Question 14

Secretion method of CSF

Answer 14

Active secretion
Na/K/ATPase

Question 15

Site of production of CSF

Answer 15

Choroid plexuses of the lateral ventricles

Question 16

Reabsorption of CSF

Answer 16

Passive reabsorption by arachnid granulations into venous circulation

Arachnoid granulation aka Arachnoid Villi

Question 17

Properties of blood brain barrier

Answer 17

Question 18

Functions of blood brain barrier

Answer 18

Question 19

Circumventricular organs definition

Answer 19

Regions of the brain not enclosed by the BBB

Question 20

Cerebral blood flow

Answer 20

Permanent brain damage occurs after around 5 mins of no perfusion

Question 21

Cerebral metabolic rate (CMR)

Answer 21

CMR O2 = Cerebral metabolic rate for oxygen
CBF = Cerebral blood flow

Question 22

Factors which affect Cerebral Metabolic Rate / Cerebral blood flow

Answer 22

Autoregulation - myogenic theory
Chemical - PaCO2 and PaO2
Metabolic control
Neurogenic
Temperature

Question 23

Autoregulation

Answer 23

Ability of an organ to regulate its blood flow despite changes in perfusion pressure

CBF maintained between MAP of 60-150 mmHg
Shifts up in baseline HTN

Question 24

Myogenic theory / Bayliss effect

Answer 24

Increased MAP -> increased transmural tension -> vasoconstriction as muscle cross section increases

Question 25

CO2 effect on Cerebral Blood Flow

Answer 25

Question 26

O2 effect on Cerebral Blood Flow

Answer 26

Minimal response until PaO2 less than 50-60 mmHg

Question 27

Cerebral perfusion pressure

Answer 27

CPP = MAP - (ICP+CVP)

Question 28

Normal CPP

Answer 28

70-90 mmHg

Question 29

Normal ICP

Answer 29

5 - 15 mmHg

Question 30

Cranial contents

Answer 30

Brain 85%
CSF 10% (150ml)
Blood 5% (50-75ml)

Question 31

Effect of anaesthetic drugs on CBF / ICP

Answer 31