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Flashcards in PNS and ANS Deck (41):
1

PNS:
Sensory inputs and motor outputs are categorized as what?
Sensory inputs are also classified as what?

Somatic or visceral

General or special

2

Structural components of the CNS:
- ______ _______ - pick up stimuli
- ______ ______ - axon terminals of motor neurons
- _____ - bundles of peripheral axons
- _____ - clusters of peripheral neuronal cell bodies

sensory neurons
motor endings
nerves
ganglia

3

Draw out the functional organization of the PNS chart.

Refer to notes.

4

How are sensory receptors classified functionally?

By location and by the type of stimulus detected.

5

What do peripheral sensory receptors detect?

Sensory stimuli

6

What are the different location based classifications of peripheral sensory recetpors?

Exteroceptors - stimuli outside the body

Interoceptors - stimuli from internal viscera
(aka visceroceptors)

proprioceptors - monitor degree of stretch

7

Where would exteroceptors be located? What do they detect?

Near or at body surface
Detect touch, pressure, pain, temperature most of special sense organs.

8

Where would interoceptors be located?
What do they detect?

internal viscera
detect temperature, taste, stretching of tissue (stomach)

9

Where would proprioceptors be located?

musculoskeletal organs

10

What are the different subdivisions of the stimulus detected classification of peripheral sensory nerves?

Mechanoreceptors - mechanical force - touch, pressure

Thermoreceptors - temp

Chemoreceptors - chemical composition of blood

Photoreceptors - light

Nociceptors - pain

11

If talking about sensory receptors that detects stretch in the stomach, what is it called?

Interoceptor mechanoreceptor

(have to use both classifications)

12

How are spinal nerves named?
How many pairs are there?

For point of issue from the spinal cord:
ex: cervical nerves (c1-C8)
31

13

What is a plexus?

Bundle of nerves

14

What are enlargements?

Nerve groups that supply the limbs (cervical and lumbar)

15

Spinal nerve arrangement:
- Spinal nerves arise from the spinal cord as a series of small ______
- These converge to form the ______ and ______ roots
- the roots join to form a mixed nerve called the _____ ______ _____
- this branches into the ______ ______ and ______ ______

rootlets
dorsal and ventral root
spinal nerve trunk
dorsal ramus and ventral ramus

16

What does the dorsal root contain?
The ventral root?
What do both the dorsal and ventral ramus contain?

Dorsal root - incoming sensory nerve fibres
Ventral root - outgoing motor nerve fibres

Ramus
- contains sensory and motor nerve fibres

17

Why is it a dorsal root ganglion? (i.e. why not ventral)

Unipolar is sensory - so cell bodies are in the PNS

Multipolar for motor - dendrites close to cell body, located in CNS

18

ANS controls ______ _____ functions

visceral motor

19

The ANS regulates ______ visceral functions (visceral motor division) such as what?
What does it innervate?

unsconscious
- heart rate, digestion, blood pressure, urination
Glands, smooth muscle and cardiac muscle

20

Give the chart from PNS onwards.

PNS
- Sensory
-- somatic
-- visceral
- Motor
-- somatic
-- visceral = ANS
--- Sympa
--- Parasympa

21

Comparison of motor systems:
Somatic vs. autonomic.

Somatic motor
- one motor neuron* from CNS to skeletal muscle
- conscious*
- axons well myelinated*, conduct impulses rapidly

Autonomic
- two motor neurons*
-- preganglionic in brain or spinal cord and,
-- postganglionic
(pre and post*)
Conduction is slower* due to:
- thinly myelinated or unmyelinated axons*
- motor neurons synapse in a ganglion (two synapses*, slows down impulse conduction)

22

In the sympathetic nervous system, what can the preganglionic fibres synapse on?

Postganglionic fibre or adrenal medulla

23

What are the two divisions of the ANS?

Mostly innervate same structures but opposite functions:
Sympathetic - fight or flight
Parasympathetic - rest and digest

24

Describe some responses to dangerous or exciting situations from the sympathetic system.

Widening of pupils, cold skin, sweating, inhibition of non-essential functions.

25

Which organs have only sympathetic stimulation?

sweat glands, adrenal medulla, arrector pili and blood vessels.

26

What are the housekeeping activities of the parasympathetic division?

SLUDD
- Salivation
- Lacrimation
- Urination
- Digestion
- Defecation

27

Which dominates, sympathetic or parasympathetic?

Para

28

Why do we get a lump in our throat when crying?

As a result of stress, trigger sympathetic, tries to circulate more air while triggering lacrimation
- as starting to cry, breathe faster
but, tears and mucus make us swallow more but the muscles are constricted here, causing a lump in our throat.

29

Parasympathetic will ____ the size of the pupil, sympathetic will _______ it.

decrease
increase

30

What are the anatomical differences between the sympathetic and parasympathetic.

1 - Arise from different regions of the CNS
-- S - thoracolumbar
-- P - craniosacral

2 - Length of postganglionic neurons
- S - long
- P - short

3 - Branching of axons
- S - highly branched (many organs)
- P - few branches (localized effect)

31

Role of the adrenal medulla:
- major organ of the _______ nervous system
- constitutes largest sympathetic ______
- secretes both _______ and _______

sympathetic
ganglia
norepineprhine and epineprhine

32

Describe the differences between innervation by the sympathetic and parasympathetic on the following structures:
- eye
- systemic blood vessels
- heart
- stomach, SI, LI
- ureter + bladder

Eye
- S - pupil dilates
- P - pupil constricted

Systemic blood vessels
- only sympathetic stimulation

Heart
- S - increase HR
- P - return HR to normal

Stomach, SI, LI
S - inhibit peristalsis, absorption and secretion
P - increased absorption, secretion and peristalsis

Ureter and bladder
S - inhibit detrusor muscle contraction + contraction of external urethral sphincter
P - contract detrusor, inhibit contraction of external urethral sphincter

33

What do general visceral sensory neurons monitor?

Stretch, temperature, chemical changes and irritation

34

Where are the cell bodies of visceral sensory neurons located?

Dorsal root ganglion

35

Where is the visceral sensory cortex located?

Insula

36

What sensory input does the insula receive?

General sensory input from thoracic and abdominal viscera
and gustation via thalamus

37

Which sense does not go to the insula?

Olfaction, sent to temporal lobe instead

38

Any incoming sensory information goes through what first?
What is the exception?

thalamus
olfaction

39

Visceral pain
- ___ pain results when visceral organs are cut
- _____ to localize
- visceral paint results from _____ irritation, _______ or spasms
- Visceral pain is often perceived to be of _____ origin
- this is called _______ pain

no
hard
chemical irritation, spasms, inflammation
somatic origin for visceral pain = referred pain

40

What is an example of referred pain?

Heart attack - feel in left limb or lower jaw
- either cuz sensory fibres and motor fibres enter/exit same place
or vasoconstriction of vessels supplying somatic region

41

Draw out the diagram with the different PNS divisions and cortexes of each.

Refer to notes