The brain consumes how much of the total body oxygen?

How much of this oxygen is used for ATP generation?

Brain consumes 20% of Total Body oxygen

60% of this Oxygen is used for ATP generation

1) Cerebral Metabolic Rate (CMRO₂) for Oxygen averages what?

2) Is CMRO₂ greater in white matter or grey matter?

1) 3-4 mls/100gm/ min

2) Greater in Grey matter

1) Where is grey matter located?

2) What is it responsible for?

1) Surface of the Cerebral cortex, hypothalamus, basal ganglia (and many other areas)

2) Processing of incoming stimulus and routing of response

1) Why is white matter white?  How white is it? 

2) What is it responsible for?

1) White matter is white because it is myelinated. 

I color matched it at Lowes- and it comes out as an Antique white (Baer color 1923)

2) Transmission of signals from one area to another

1) Where is the hippocampal area located?  What system is it a part of?

2) What does the hippocampal area play a part in?

1) Located in the temporal lobe.  Part of the limbic system

2) Plays a part in memory, motivation, emotion and spacial navigation.

Fill in the Blanks:

The brain has little ___1____ or ___2____ reserve a deficit of either produces devastating consequences.

1.  Oxygen

2) Glucose

Loss of Oxygen will produce:

1) Unconsiousness within?

2) Irreversible damage within? 

3) Which areas are most susceptible?

1) 10-20 seconds

2) 3-8 Minutes

3) Cerebellum and hippocampal areas

1)  How is blood supplied to the circle of Willis?

2) Why is the circle of willis important?

1) Supplied via 2 vertebral arteries

-fuse to form basilar arter

Supplied via 2 internal carotid arteries

2) Provides collateral circulation support should unilateral disruption occur.

It's all about the Cerebral Blood flow (CBF:)

1) What's the CBF average?  What percentage of the CO is this?  What is the average per 100gm/min?

2) Flows less than what will result in cerebral impairment and EEG slowing? 

3) Flows less than what produce irreversible damage and isoelectric EEG (FLAT LINE)

1) Averages 750 ml/min (15% of CO)

- or 50 ml/100g/min

2) 25ml/100g/min

3) 10ml/100g/min

Autoregulation

**Key concept**

1 ) PaCO₂ is _______ proportional to cerebral SVR

2) CBF is _________ proportional to PaCO₂

1) inversely

2) Directly

CBF changes ___A____/100gm/min for every__B__mmHg change in PaCO₂ between __C-D___mmHg.

Is the effect of Extrinsic CO2 permanent or Temporary?

a) 1-2 ml

b) 1mmHg

c/d) 20-80 mmHg

This effect is temporary

(Lasting 6-8 Hours)