Lecture 5- Structure of the PNS Flashcards Preview

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Flashcards in Lecture 5- Structure of the PNS Deck (47)
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31

What part of the brain processes the stimuli relating to balance?

Cerebellum

32

What are the four main taste buds?

1. salt
2. sour
3. sweet
4. umami

33

What is the olfactory mucosa?

- in smelling
- has special receptor cells responsive to particular chemicals (often the ones released by individuals of other species)

34

What is the vomeronasal organ?

-in vertebrates' nose
-"sexual nose"
- detects pheromones in animals

35

What is the Flehmen response?

-in horses, horses laugh, curl their lips and cover nostrils, breaths in deeply carrying pheromones into the vomeronasal organ and can determine if mare is sexually receptive

36

What are mechanoreceptors for?

Touch + pressure

37

How are mechanically-gated dendrites activated?

Mechanically, when moves= AP

38

What are Pacinian corpuscles for?

Detecting deep pressure. reflect the magnitude of the stimulus.

39

What are the two thermoreceptors involved in cold environment?

-CMR1= 28C -thermoregulatory (important for informatory role)
-AKTM1= less than 8 C (pain)
-ion gates, changing due to temperature

40

What are the three thermoreceptors involved in warm environment?

TRPV 3- 33 C = thermoregulatory
TRPV 1- 42 C= pain/spicy (not in birds the spicy)
-also triggered by chemicals, capsicain= spicy
TRPV 2- 52 C = pain!

41

What are the receptors snakes have and we don't?

infrared

42

What are the three types of nociceptors?

1.Mechanical
2. Thermal
3. Polymodal (respond to chemical from damaged tissues)

43

What chemical changes the sensitivity of nociceptors?

-prostaglandins
-chemically enhances the pain

44

How does myelination affect the speed of how fast the pain signal gets to the brain?

-myelinated fibres= fast = acute pain
-unmyelinated fibres = slow = chronic pain

45

What is substance P?

-neurotransmitter involved in pain detection
-activates pathways for higher processing

46

What bits are involved in the pain pathway?

-first have the stimulus
-then AP goes on the afferent nerve fibre to the spinal column where substance P is released
-then brainstem's reticular formation= raises awareness
-thalamus relay station
-then cortical somatosensory areas
-also hypothalamus is involved= emotional and behavioural response to the stimuli

47

What is the analgesic pathway?

- supresses pain transmission in the brain stem
- periaqueductal grey matter
-triggers interneurons in the dorsal root of spinal column to produce endogenous opiates (morphine like substances)
-block the pathway from proceeding further