Nervous system -- Lecture 20

Question 1

genes in development:

homeotic genes (definition)

Answer 1

genes which are critical for making sure anatomical structure developing the correct # and in the correct locations

Question 2

genes in development:

mutations in homeotic genes:

Answer 2

lead to the appearance of body parts in inappropriate places

and/or

the wrong # of particular body parts

Question 3

homeotic genes:

bithorax genesdffg (what is it and what does it result in?)

Answer 3

mutation results in a duplication of the section of thorax that gives rise to the wings

results in a fly w/ 2 complete sets of wings

Question 4

what is morphogenesis in development?

Answer 4

development and final shaping of specific anatomical structures

Question 5

morphogenesis in development:

morphogenesis results from changes in:

Answer 5

cell growth and differentiation

cell shape

cell migration

cell death

Question 6

cell death in morphogenesis:

apoptosis (definition)

Answer 6

programmed cells earth is a part of development

Question 7

cell death in morphogenesis:

example of apoptosis in human embryos

Answer 7

developing human embryos begin w/ webbed fingers and toes

during development, cells that make up the webbing go thru apoptosis

Question 8

failure of morphogenesis:

example of failure of morphogenesis in humans:

Answer 8

syndactyly: failure of the tissue b/n 1 or more fingers or toes to got thru apoptosis

Question 9

nervous system:

what are the 3 functions?

Answer 9

interprets information about the body

interprets information about the environment

decides whether and how to respond

Question 10

nervous system:

how many subdivisions are there?

Answer 10

2

Question 11

nervous system:

what are the 2 subdivisions of the nervous system?

Answer 11

central nervous system (CNS)

peripheral nervous system (PNS)

Question 12

nervous system:

what does the central nervous system (CNS) consist of?

Answer 12

brain, spinal cord, and interneurouns w/in the brain and spinal cord

Question 13

nervous system:

what does the peripheral nervous system (PNS) consist of?

Answer 13

consists of sensory neurons and motor neurons

Question 14

nervous system:

pathway of how the CNS and PNS work together

Answer 14

sensory neurons (PNS) –> interneurons (CNS) –> brain process (CNS) –> interneurons (CNS) –> motor neurons (PNS)

Question 15

types of neurons:

vertebrates have ___ types of neurons

Answer 15

3

Question 16

types of neurons:

___ have 3 types of neurons

Answer 16

vertebrates

Question 17

types of neurons:

what are the 3 types of vertebrate neurons?

Answer 17

1) sensory neurons (PNS) – carry info about the body and environment to the CNS
2) interneurons (CNS) – provide a link b/n the sensory neurons, brain, and motor neurons
3) motor neurons (PNS) – carry impulses from CNS to effectors (muscles and glands)

Question 18

neuron (nerve cell) structure:

dendrites (what do they do)

Answer 18

receive signals (using receptors) and send electrical pulses (action potentials) to the cell body

Question 19

neuron (nerve cell) structure:

what is the action potential?

what direction does it travel?

Answer 19

electrical impulse carrying signal

travels from dendrite, across axon, to axon terminal

Question 20

neuron (nerve cell) structure:

cell body (what is it and what does it do)

Answer 20

consists of the nucleus sea do the metabolic machinery

can transmit the action potential to the axon

Question 21

neuron structure:

axon (what does it do)

Answer 21

conducts the action potential to the axon terminals (end)

Question 22

neuron structure:

axon terminals (what do they do)

Answer 22

a transmit the signal thru a synapse to the next cell

Question 23

neuron structure:

myelin sheath (what is it)

Answer 23

discontinuous covering around the axon, formed by layers of Schwann cells

Question 24

neuron structure:

nodes of Ranview (what are they)

Answer 24

gaps in the myelin sheath

Question 25

neuron structure:

Schwann cells (what are they)

Answer 25

cells that form layers to form the myelin sheath

Question 26

neuron structure:

myelin sheath (what does it do)

Answer 26

speeds the transmission action potentials down the axon

Question 27

damage to the ___ is behind several diseases

Answer 27

myelin sheath

Question 28

damage to the myelin sheath is behind several diseases:

multiple sclerosis (what is it)

Answer 28

disease in which the immune system destroys the myelin sheath

nerve signaling becomes slow and inefficient

causes coordination and walking problems, numbness, and vision problems

Question 29

damage to the myelin sheath is behind several diseases:

charcot-marie-tooth (CMT) syndrome (what is it)

Answer 29

group of inherited genetic disorders that can cause damage to the myelin sheath

causing muscle weakness, loss of sensation, and muscle atrophy

Question 30

the ___ nervous system interprets information gathered by sensory neurons

Answer 30

central