Excitable Cells

Question 1

What kind of a nervous system do ver primitive invertebrates i.e. sponges and jelly fish have?

Answer 1

Nerve net (diffuse network of neurons).

Question 2

What kind of nervous system do more complex invertebrates have?

Answer 2

Ventral chord (not dorsal like vertebrates)

Question 3

Primitive example of a vertebrate nervous system.

Answer 3

Amphixious, has a small central collection of neuronal control.

Question 4

Which brain division are common to all vertebrates?

Answer 4

Olfactory bulb, cerebral hemispheres, cerebellum, optic tectum, medulla oblongata.

Question 5

On top of the divisions common to all, what do mammals have?

Answer 5

Cerebral cortex.

Question 6

What protects the spinal chord?

Answer 6

Spinal column and meninges.

Question 7

What do dorsal roots to the spinal chord contain?

Answer 7

Sensory, afferent neurons.

Question 8

What do the ventral roots of the spinal chord contain?

Answer 8

Motor, efferent neurons.

Question 9

Which parts of the neural tube do the CNS and PNS derive from respectively?

Answer 9

CNS from walls, PNS from neural crest.

Question 10

What happens if the anterior neural tube fails to close?

Answer 10

Brain cannot form, organism is inviable.

Question 11

What happens if the posterior neural tube fails to close?

Answer 11

Spina bifida.
Paralysis from the opening down.
Linked to lack of folic acid during pregnancy.
Also to anti convulsants and mood stabilisers as these interfere with folate metabolism.

Question 12

How many sections does the spinal chord consist of during development differentiation?

Answer 12

3:
Prosencephalon (forebrain): 3 swellings at rostral end become primary vesicles- telencephalic (cerebral cortex, diencephalic, optic vesicles.
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)

Question 13

How many ventricles are there and what is there importance?

Answer 13

4, 2 lateral, 3rd and 4th.
Key to waste removal.
(Brain is hollow and bathed in CSF, subarachnoid)

Question 14

Divisions of the forebrain?

Answer 14

Telencephalon- cortex, olfactory bulb.

Diencephalon- thalumus, hypothalamus.

Question 15

Divisions of the midbrain?

Answer 15

Mesencephalon- tectum, tegmentum (part of brainstem)

Question 16

Divisions of the hindbrain?

Answer 16

Rhombencephalon- pons, medulla, cerebellum (part of brainstem).

Question 17

Function of the midbrain?

Answer 17

Movement and sensation (input from eyes and ears)

Question 18

Function of the pons?

Answer 18

Connects cerebellum to cerebral cortex, swells out from ventral surface.

Question 19

Functions of the medulla?

Answer 19

Autonomic functions, control blood pressure and respiration.

Question 20

Functions of the cerebellum?

Answer 20

Movement, extensive connection to spinal chord, diseases include ataxia and is selectively targeted by alcohol.

Question 21

Functions of the thalamus?

Answer 21

Relay, gating.

Question 22

Functions of the hypothalamus?

Answer 22

Homeostasis and reproduction.

Question 23

Structure and function of the cerebral cortex?

Answer 23

Clear division between two halves along saggital fissure.
Controls voluntary actions, cognition, perception, awareness.
Mammals have a more complex 6 layer structure (neocortex).
Folding solution to increasing number of cortical neutrons.
Split into lobes:
Frontal, parietal, occipital, temporal.

Question 24

Divisions of the nervous system?

Answer 24

Central
Peripheral
–> Somatic and Autonomic
–> Sympathetic and Parasympathetic.