Lp 4 & 5

Question 1

3 primary germ layers that differentiate during the early stages of embryonic development give to rise

Answer 1

Ectoderm
Mesoderm
Endoderm

Question 2

Epithelial (epidermis of skin) and nervous tissue

Answer 2

Ectoderm

Question 3

Muscle, connectivity tissue (CT proper, bone, cartilage, blood) endothelium of blood vessels, synovial membranes, dermis (skin)

Answer 3

Mesoderm

Question 4

Mucosal epithelia (digestive, respiratory, urinary, reproductive)

Answer 4

Endoderm

Question 5

There are ? Segments from the brain and cranial nn
There are ? Segments from the SC and spinal nn

Answer 5

12
31

Question 6

Paired masses of mesoderm, called somites, form along the neural tube during early embryonic development and differentiate into?

Answer 6

Dermatomes, myotomes and sclerotomes

Question 7

Mapping gives a distorted image of the human body on the bran known as?

Answer 7

The homunculus ( little man)

Question 8

There is a homunculus mapped on the?

Answer 8

-sensory cortex
-motor cortex
-cerebellum

Question 9

A continuum of nerve fibres transmitting sensory and motor signals links periphery-centre-periphery?

Answer 9

Skin-brain-muscles

Question 10

A defined segment of skin innervated by the sensory component of a spinal nerve innervated by a distinct SC segment

Answer 10

Dermotomes

Question 11

Skeletal musculature innervated by motor axons of a given spinal nerve

Answer 11

Myotomes

Question 12

Embryonic layers differentiate into?

Answer 12

-Soma (body wall)- skin, connective tissue, & mm

-Viscera (internal organs)

Question 13

Transmit sensory information from skin, mm & bones (soma) to the brain

Answer 13

Afferent

Question 14

Transmit motor signals from the brain to skeletal m, smooth mm (erector pili & eye mm) & glands of the soma

Answer 14

Efferent

Question 15

Control Fxn of smooth mm ( intestinal, vascular), cardiac m & glands

Answer 15

Autonomic branches

Question 16

SC components

Answer 16

-Dorsal root: incoming sensory signals (somatic & visceral)
-Dorsal horn: sensory neurons to the brain
-Ventral horn: motor neurons
-Ventral root: outgoing motor signal to the soma (visceral motor signals are routed via the ANS)
-Lateral horns: ANS

Question 17

Dorsal & ventral roots are?

Answer 17

-part of PNS
-joined laterally forming spinal nerves

Question 18

Dorsal & ventral horns are?

Answer 18

Composed of grey matter (unmyelinated)

Question 19

Nerve tracts (axons) are?

Answer 19

Composed of white matter (myelinated)

Question 20

Intermediate grey matter?

Answer 20

Central portion that links the dorsal and ventral horns

Question 21

Proportional to amt of tissue innervated by a segment of SC=

Answer 21

Grey matter

Question 22

Lumbosacral & C4-T1 regions:

Answer 22

Increase grey matter

Question 23

Increase towards the brain d/t addition of more tracts (more ascending and descending fibres)=

Answer 23

White matter

Question 24

-link neurons w/ he SC
-responses of the NS to stimuli depend of the working of the association neuron pool
=

Answer 24

Association neurons (interneurons)

Question 25

Groups of neurons in the CNS; can include billions of cells; include both pre & post-synaptic neurons?

Answer 25

Neuronal pool

Question 26

-Composed of myelinated axons- white matter of the SC and brain -Bundles of axons sharing origin, terminus & fxn -example: the spinothalamic tract transmits signals regarding pain, temperature, crude touch & pressure

Answer 26

Longitudinal tracts

Question 27

Types of tracts?

Answer 27

Ascending & descending

Question 28

-origin: dorsal horn -sensory info to brain -synapse on association neurons in brain

Answer 28

Ascending

Question 29

-origin: motor cortex -motor output to mm -synapse on lower motor neurons in ventral horn

Answer 29

Descending

Question 30

-Pattern of synaptic connections in groups of neurons Purpose: -transmission of signals along predetermined pathway -interneuronal communication in predictable patterns

Answer 30

Circuits

Question 31

Types of circuits

Answer 31

-diverging -converging -reverberating -parallel-after discharge

Question 32

-Amplifying circuit -1 or a few presynaptic (input) fibres synapse on several postaynaptic neurons (output)

Answer 32

Diverging circuits

Question 33

-concentrate incoming signals -several presyaptic neurons synapse w/1 or a few postsynaptic neurons

Answer 33

Converging circuits

Question 34

-control rhythmic activity -common in reflexive pathways: breathing, wake/sleep cycles, some motor activities (walking) -series of neurons whose axons branch & synapse back on neurons up the chain (backtracking circuits) -simple to ++ complex -same signal travels continuously through circuit until part of the circuit ‘quits’

Answer 34

Reverberating circuits

Question 35

-effect: circuits relate prolonged burst of signals -impulses reach output cell a different time -complex mental activity -organization: ~neurons arranged in parallel groups ~they converge on a single output neuron

Answer 35

Parallel-after discharge

Question 36

Summation effect of neuronal transmission in time (temporal) & space (spatial) -involves synaptic input from many neurons -vital to higher brain fns, as well as spinal reflexes coordinating sensory input from a artery of sources

Answer 36

Integration

Question 37

The sum of different processes- all vital to our ability to respond appropriately and in time to various stimuli impinging on the body

Answer 37

Neurotransmission

Question 38

-direct (fast) transmission -excitatory or inhibitory depending on NT -link the axon of presynaptic neurons with the dendrites of postsnaptic neurons

Answer 38

Axodendritic synapses

Question 39

Link the axon of presynaptic neurons with the cell body of postaynaptic neurons

Answer 39

Axosomatic

Question 40

Link the axon of presyaptic neurons with the axon terminal of postsynapric neurons

Answer 40

Axoaxonic

Question 41

Membrane potential becomes more (+) & cell closer to generating AP

Answer 41

Synaptic potentiation

Question 42

Membrane potential becomes more (-) & cell moves father away from generating AP -due to K+ or CL- channels opening

Answer 42

Synaptic inhibition

Question 43

Changes in neuronal activity -affect signalling b/w neurons by increase or decrease their response to other NTs -released to many ells in an area, creating more widespread effects than a chemical synapse -important in modifying n impulses & signal transmission, especially pn signals

Answer 43

Neuromodulation

Question 44

Transmission of signals along a sequential & linear pathway -mode of action: All- nothing

Answer 44

Serial processing

Question 45

Transmission of signals along several pathways to everlasting different destinations -mode of action: non-repetitive & unpredictable

Answer 45

Parallel processing