Nervous System

Question 1

Define NEURON

Answer 1

An electrically excitable cell

Receives, processes & transmits info via electrical & chemical signals.

Question 2

Define NERVE

Answer 2

Bundle of axons in PNS - conduct impulses between CNS & body.
(axons & neuroglia)

Question 3

Define NERVOUS SYSTEM

Answer 3

Network of nerve cells & fibres which transmits nerve impulses between bodily parts & coordinates its action.

Question 4

MACROGLIA

+ main glial cells
+ functions

Answer 4

Cells in CNS & PNS

astrocytes, oligodendrocytes & Schwann cells

nutrition, support, synthesise myelin

Question 5

MICROGLIA

+ functions

Answer 5

tissue-based macrophages

phagocytosis & protect CNS neurons.

Question 6

Sensory (afferent) input neurons

Location.

Answer 6

Convery info from tissue stimulus -> CNS.

In PNS.

Question 7

Motor (efferent) output neurons

Location

Answer 7

Transmit signals from CNS to PNS (effector muscles/glands)

Motor cortex, brain stem & spinal cord.

Question 8

Interneurons (relay / association)

+ Location
+ Function

Answer 8

Transmit signals between neurons (sensory - motor) (via dendrites).

+ Brain, visual system, spinal cord. (CNS)
+ Information processing & decision making.

Question 9

Neurosecretory cells

Location

Answer 9

Secrete hormones.

Hypothalamus, adrenal medulla, thyroid gland & hormone secretory organs.

Question 10

Unipolar neuron

Answer 10

ONE neurite extends from cell body.

Mostly sensory.

Question 11

PSEUDOUNIPOLAR neuron

Answer 11

Dendrites & axons fused in a single process which divides into 2 processes (axon & dendrite).

Question 12

BIPOLAR neuron

Answer 12

Has 2 neurite extensions.

Specialised sensory neurons (olfactory cells, inner ear, retina)

Question 13

MULTIPOLAR neuron

Answer 13

Single axon & many dendrites.

Question 14

ANAXONIC neuron

Answer 14

axon cannot be differentiated from dendrites.

Often intermediate in multipolar neuron development.

Question 15

GLIA / NEUROGLIA

+ Functions.

Answer 15

Non-neuronal cells.

- maintain homeostasis: form myelin & support/protect neurons in C&PNS.

Question 16

Functions of glial cells

Answer 16

• support neurons
• supply nutrients & O2 to NS
• insulate neurons
• destroy pathogens & dead neurons

Question 17

State 4 CNS macroglial cells.

Answer 17

Astrocytes
Oligodendrocytes
Ependymocytes
Radial glia

Question 18

State 3 PNS macroglial cells.

Answer 18

Schwann, satellite, enteric glial cells.

Question 19

Astroglia functions

Answer 19

Form BBB

Regulate external environment of neurons : remove XS K+ ions & recycle neurotransmitters.

Question 20

Oligodendrocytes

Answer 20

form myelin - coat axons

Question 21

Ependymocytes

Answer 21

CSF filled.

line spinal cord & brain ventricular system.

Question 22

Radial glia

Answer 22

Involved in neurogenesis.

Question 23

Schwann cells

Answer 23

form myelin - coat axons

Question 24

Satellite cells

Answer 24

Regulate external chemical environment.

Question 25

Enteric glial cells

Answer 25

Regulate homeostasis in intrinsic ganglia of digestive system.

Question 26

Describe the structure of a nerve

Answer 26

3 layers: epineurium, perineurium, endoneurium. Nerve: covered by the EPINEURIUM, contains neurons bundled in fascicles. Each fascicle is covered by the PERINEURIUM. ENDONEURIUM covers each small fibre.

Question 27

CNS

Answer 27

Brain & spinal cord. INTEGRATION & CONTROL

Question 28

PNS

Answer 28

Cranial & spinal nerves Communication pathways between CNS & rest of body.

Question 29

Sensory (afferent) division

Answer 29

Conduct impulses from receptors to CNS

Question 30

Motor (efferent) division

Answer 30

Conduct impulses from CNS to effector muscles.

Question 31

Autonomic NS

Answer 31

Involuntary (unconscious) Conducts impulses from CNS to cardiac & smooth muscles, glands...

Question 32

Somatic NS

Answer 32

Voluntary Conducts impulses from CNS to skeletal muscles.

Question 33

Sympathetic NS

Answer 33

Fight or flight

Question 34

Parasympathetic NS

Answer 34

Rest & digest

Question 35

Enteric NS

Answer 35

Regulate GI tract function

Question 36

State the 3 branches of the ANS

Answer 36

Sympathetic, parasympathetic & enteric NS.

Question 37

Define REFLEX ARC

Answer 37

Neural pathway which controls physiological reactions.

Question 38

Unconditioned reflex

Answer 38

Automatic innative instinctive reaction to a stimulus.

Question 39

Conditioned reflex

Answer 39

Automatic response established by training.

Question 40

Outline the pathway of a reflex arc

Answer 40

Stimulus - sensory (afferent) nerve - CNS & motor nerve - motor (efferent) nerve - effector muscle/gland

Question 41

Neurons communicate via ____

Answer 41

Synapses

Question 42

Where are neurotransmitters synthesised?

Answer 42

Neuron cell body | then transported down axon

Question 43

What happens to vesicles without neurotransmitter?

Answer 43

Transported back to cell body.

Question 44

Describe synaptic transmission from the point where an action potential reaches axon terminal.

Answer 44

1. Membrane DEPOLARISATION. 2. Voltage-gated Ca2+ channels open. 3. Ca2+ influx triggers release of neurotransmitters from vesicles. 4. Neurotransmitters bind to receptors -> excites/inhibits postsynaptic neuron. 5. Neurotransmitters then recycled.

Question 45

Excitatory synapses induce cell ____ . | Induces ___ influx in post synaptic neuron.

Answer 45

depolarisation Na+

Question 46

Inhibitory synapses induce cell ___ . | Induces __ influx in post synaptic neuron.

Answer 46

hyperpolarisation Cl-