NeuroAnatomy

Question 1

what cells carry action potentials?

Answer 1

neurons

Question 2

what are glial cells?

Answer 2

they are supporting cells that are non excitable and smaller than neuron but are much more plentiful.

Question 3

how many cell populations are present in the nervous system?

Answer 3

2, glial cells and neurons

Question 4

describe a typical neuron

Answer 4

multiple dendrites and one axon

Question 5

are motor and sensory neurons separate?

Answer 5

yes as the impulse can only travel in one direction

Question 6

describe the nucleus in a neuron

Answer 6

there is loose chromatin and prominent nucleolus

Question 7

what are the prominent organelles in neurons?

Answer 7

> mitochondria (due to high metabolic rate)
rough endoplasmic reticulum
diffuse Golgi apparatus

Question 8

what is the cytoplasm in the cell body?

Answer 8

perikaryon

Question 9

what is axoplasm?

Answer 9

the cytoplasm present in the axon of a neuron

Question 10

if a neuron dies will it regenerate?

Answer 10

no unless axons are in a proper conducive environment.

Question 11

what secretes the myelin sheath?

Answer 11

> schwann cells in the PNS

> oligodendrites in the CNS

Question 12

what does the myelin sheath do?

Answer 12

increases conduction speed in axons by salutatory cnduction

Question 13

describe the myelination of axons

Answer 13

schwann cells wrap themselves around the myelinated axon and a mesoaxon is formed. the cytoplasm of the schwann cells gets extruded leaving only the cell membrane.

Question 14

are non myelinated axons wrapped by schwann cells?

Answer 14

yes but they do not have the myelin sheath

Question 15

what is the effect of multiple sclerosis on the myelin sheath?

Answer 15

there is patchy loss/scarring of the myelin sheath leading to abnormal nerve conduction across affected axons

Question 16

motor neurons and inter-neurons are bi polar or multipolar?

Answer 16

multipolar: one cell body, multiple dendrites and one axon.

Question 17

describe sensory neurons

Answer 17

pseudo unipolar: one projection from the cells body so the impulses do not have to go through the cell body. outside of sensory nervous system

Question 18

where do the cell bodies in pseudo unipolar sensory cells sit?

Answer 18

in the dorsal ganglion

Question 19

where are bipolar neurons found?

Answer 19

they are found in the retina or olfactory mucosa.

Question 20

where do neurons in from the spinal cord synapse in the brain?

Answer 20

in the thalamus

Question 21

what are axons organised by?

Answer 21

depending on the information that they are carrying

Question 22

what are tracts?

Answer 22

bundles of axons carrying specific information within the white matter

Question 23

what forms grey matter?

Answer 23

collection of cell bodies or unmyelinated axons that is diffuse (nuclei in central nervous system that is called nuclei)

Question 24

what forms white matter or tracts?

Answer 24

collection of myelinated axons

Question 25

what is the collection of neural cell bodies outside the central nervous system?

Answer 25

ganglions

Question 26

what are the functions of astrocytes?

Answer 26

> go around synapses stopping fluid leaking

> surround the capillaries forming the blood brain barrier

Question 27

what are the functions of microglia?

Answer 27

they form fibroblasts and are involved in scar tissue formation

Question 28

what makes up the brainstem?

Answer 28

> pons
medulla
midbrain

Question 29

what is on top of the brain stem?

Answer 29

diencephalon, containing the hypothalamus

Question 30

what forms the ventricles?

Answer 30

the cavity inside the neural tube