supporting the brain

Question 1

meninges

Answer 1

3 layers of membranes that protect the brain and spinal cord

Question 2

part of meninges

Answer 2

• dura mater
• arachnoid membrane
• pia meter
• subarachnoid space

Question 3

dura mater

Answer 3

outer layer, thick, tough and flexible bot not stretchable

Question 4

arachnoid membrane

Answer 4

middle layer, located between dura mater and pia mater - soft and spongy

Question 5

subarachnoid space

Answer 5

fluid-filled space between the archnoid membrane and pia mater - cushions brain

Question 6

ventricular system

Answer 6

• ventricles: hollow spaces within brain, filled with cerebropsinal fluid
• interconnected
• cerebrospinal fluid: cleaf fluid

Question 7

four ventricles

Answer 7

• lateral ventricles
• 3rd ventricle
• cerebral aqueduct
• 4th ventricle

Question 8

lateral ventricles

Answer 8

this is sited in the centre of the telencephalon

Question 9

3rd ventricle

Answer 9

this is sited at the midline in the centre of the diencephalon

Question 10

cerebral aqueduct

Answer 10

this is a long tube in mesencephalon - connects 3rd and 4th ventricles

Question 11

4th ventricle

Answer 11

found between cerebellum and pons

Question 12

cerebrospinal fluid

Answer 12

• extracted from blood
• consists of ions, water, protein and glucose
• produced from choroid plexus

Question 13

CFS flow

Answer 13

• flows to 3rd ventricle where more is produced flows through cerebral aquaduct to 4th ventricle
• leaves ventricles to flow into subarachnoid space around CNS

Question 14

vital functions of CSF

Answer 14

1. protection
2. buoyancy
3. waste reduction
4. transport

Question 15

hydrocephalus

Answer 15

• accumulation of CSF within the cerebral ventricles (leads to ventricular dilation)
  -two types:
  1. obstructive hydrocephalus
  2. communicating hydrocephalus

Question 16

glia

Answer 16

• supporting cells of the nervous system, for example:
• astrocytes
• microglia
• oligodendrocytes
• schwann cells

Question 17

glia: astrocytes

Answer 17

• supports neuron
• nourish neurons: wrap blood vessels to receive, store and release nutrients to neurons
• help control the chemical composition of extracellular fluid

Question 18

astrocytes and phagocytes

Answer 18

• clean up debris in the brain
• special astrocytes engluf and digest debris around CNS
• form scar tissue in palce of dead tissue

Question 19

amytrophic lateral sclerosis: lou Gehrig’s disease

Answer 19

• attacks nerve cells
• rapidly progressive, leading to fatality
• lose all voluntary muscle control

Question 20

glia: microglia

Answer 20

• phagocytes
• representative of immune system in brain
• responsible for inflammatory reaction in response to brain damage

Question 21

Glia: oligodrocytes and schwann cells

Answer 21

• schwann cells (peripheral ns)
• wrap invidual axons
• oligodendrocytes (central ns)
• wrap several axons

Question 22

basic blood function

Answer 22

1. blood brings materials for brain functions: oxygen, nutrients, hormones
2. blood removes materials from brain: carbon dioxide, lactate, hormones, ammonia

Question 23

blood brain barrier

Answer 23

• semi-permeable barrier between blood and brain
• smallest blood vessels are line with endothelial cells
• small spaces in endothelial cell so substances can move across capillary walls
• in the brain, no spaces exist between ec so substances cannot pass

Question 24

BBB vital functions

Answer 24

1. protects brain from foreign substances
2. protects brain from hormones and neurotransmitters
3. maintains a constant enbironment for brain

Question 25

substances and BBB

Answer 25

- lipid molecules can penetrate through bbb - water soluble molecules can only use specialised carrier mediated transport mechanisms - active transport allows some susbtances to move across capillary walls