revision 3

Question 1

why do we need a nervous system?

Answer 1

-to control emotions
-to control movement
-to regulate organs

Question 2

why do we need a nervous system?
(detailed)

Answer 2

-controls functions of organisms e.g. movement
- communication between different areas of organism
-regulate responses to conditions or sensory stimuli- homeostasis in higher organisms
-found in most multicellular organisms varying in complexity

Question 3

what are the 3 parts of a neuron?

Answer 3

soma
dendrite
axon

Question 4

what’s a soma?

Answer 4

-cell body of the neuron
-contains the nucleus
-site of protein synthesis

Question 5

what’s a dendrite?

Answer 5

-many per neuron
-receive incoming inputs from other neuron’s
-converge on the soma

Question 6

what’s an axon?

Answer 6

-single axon carries impulse (action potential) to next neuron in series
-axon terminal branches into many terminal boutons insulated with fatty coating termed the myelin sheath

Question 7

what are interneurones?

Answer 7

-aka circuit or relay neurons
-form connections and circuits between neuron’s
-often connect afferent neuron’s to efferent neuron’s
-increase the ccomplexity of the nervous system
-involved in storing information
-short and simple in structure
-almost always found in the central nervous system only

Question 8

what is the most complicated nervous system?

Answer 8

-the human nervous system
-huge number go nerve cells, ganglia, and processing centres
-2 component nervous system

Question 9

what are the 2 human nervous system compartments?

Answer 9

central nervous system
-brain and spinal cord
-processing centre
-encased in bine
peripheral nervous systen
-information relay
-communication system
periphery <-> CNS

Question 10

functions of glial cells

Answer 10

-support and hold neurons in place
-nourish and supply nutrients/O2
-insulate neurons electrically
-protect from pathogens

neurons do a very specialised job and can’t act alone so are supported by glial cells which outnumber the neurons and have no electrical function

Question 11

what are astrocytes?

Answer 11

-star shaped gial cell
-support and protect neutrons
-contribute to blood-brain barrier (BBB)
-protects brain from toxins/ drugs in blood
-projections contact capillaries and neurons
-role in inflammatory response in brain
-control and co-ordinate other gial cell types
-CNS only

Question 12

what are Schwann cells?

Answer 12

-type of gial cell
-only in the PNS
-rich in lipid
-wrap around axons
-provide myelin sheath to axons
-gives characteristic white appearance
-myelin provides electrical insulation
-enhances speed of electrical conductance
-impulse “jumps” between nodes of ranvier
-termed saltatory conduction
-found next to neuron’s

Question 13

what’s the most complex brain?

Answer 13

the human brain