Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology of the mind > Senses > Flashcards

Senses Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Basics of the senses (5)

A

Stimulus from the physical/chemical environment&raquo_space;> reception&raquo_space;> transduction&raquo_space;> encoding and transmission&raquo_space;> perception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are sensory systems organised? (3)

A

Labelled lines - 1 pathway per modality
Properties (e.g. location) of stimuli are mapped onto brain structures e.g. retinotopic, chemotopic and tonotopic maps,
Firing properties code for everything else

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Strength of stimulus can be encoded by what? (2)

A

Spike rate/onset
Number of axons activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the macula responsible for? (1)

A

Central vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the fovea? (1)

A

Central/thinner region of retina
High resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the optic disc? (2)

A

Origin of blood vessels
Where optic nerve axons exit the eye (blind spot)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is light focused in the eye? (1)

A

Back of the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where does phototransduction occur? (1)

A

In outer segment of photoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to photoreceptors in the dark? (1)

A

Depolarise
Release glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two different photoreceptors? (2)

A

Rods - nighttime
Cones - daytime and colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the main visual pathway in mammals? (3)

A

Retina&raquo_space;> Lateral Geniculate Nucleus (in the thalamus)
»> Primary visual cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is in the cortical module V1? (2)

A

Neurones that represent different orientations of stimuli
Neurones that represent different input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is sound? (1)

A

A series of changes in a pressure which form a wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the auditory ossicles? (6)

A

Malleus = hammer
Incus = anvil
Stapes= stirrup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens in the middle ear at the oval window? (2)

A

Transmit pressure waves in air into pressure waves in liquid
This results in ~22x greater force at the oval window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the organ of corti? (3)

A

Lies within the cochlear duct (Scala media)
Vibration causes the organ of corti to move up and down against the tectorial membrane
It is the inner hair cells within the organ of corti that are the sensory receptors transducing deflections of their cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does mechano-electrical transduction occur? (1)

A

When stereocillia are perturbed we get mechano-electrical transduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Inner hair cells (4)

A

The endolymph of the cochlear duct (Scala media) is high in K+
Movement of stereocillia opens K+ channels causing depolarisation
Which opens Ca2+ channels resulting in transmitter release onto spiral ganglion cells
The axons of spiral ganglion cells form the auditory nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the main auditory pathway? (5)

A

Cochlea
Cochlear nucelus
(brainstem)
Inferior colliculus
Medial Geniculate Nucleus
(in the thalamus)
Primary Auditory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are 3 sensory systems associated with the nose & mouth? (3)

A

Olfactory (smell)
Gustatory (taste)
Trigeminal (crispiness/ some chemicals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where are olfactory sensory neurones located? (2)

A

In the olfactory epithelium which lines the nasal cavity below cribriform plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens to odourants in the nose? (2)

A

Odourants enter nasal cavity & dissolve in mucus secretion

Dissolved odourants bind to receptors on the cilia of olfactory sensory neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe olfactory transduction (4)

A

Odourants bind to G-protein coupled receptors on cilia

Activation leads to production of cAMP

Leads to depolarisation as:
cAMP binds to and opens cation (Ca2+ & Na+) channels

Ca2+ opens Cl- channels -> Cl- efflux

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Encoding and transmission in the olfactory system (3)

A

Olfactory sensory neurons send their axons through the cribriform plate to synapse in the olfactory bulb

Olfactory bulb is 1st stage of olfactory processing

Signals are then sent directly to many brain areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does the olfactory system target the cortex (4)

A

The olfactory system targets cortical and subcritical structures directly (i.e. not via the thalamus)

Projects directly to emotion (amygdala) and memory (hippocampal) centres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe reception at the gustatory system (5)

A

Tounge is main organ of taste but pharynx, palate and epiglottis also contribute

Odours and olfactory system strongly contribute to taste perception

Visual appearance

Texture

First step is break down of food by enzymes in saliva to solubilise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Taste buds are localised to which three types of papillae? (3)

A

Circumvallate papillae – largest, contain many thousands of taste buds, located at posterior

Foliate papillae – elongated structure, contain hundreds of taste buds, lie along posterior lateral edge

Fungiform papillae – smallest, contain one or two taste buds, widespread across anterior portion and tip of tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe taste transduction (4)

A

Dissolved molecules interact with receptors
Triggers membrane depolarisation & action potential firing
Accompanied by increase in intracellular calcium which initiates transmitter release
Transmitters excite afferent nerve fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe the gustatory pathway (3)

A

1st order neurons project to medulla

2nd order neurons project to thalamus

3rd order neurones project to gustatory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is somatosensation? (1)

A

Ability to sense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the somatosensory system? (1)

A

Responds to the external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the Viscerosensory system? (1)

A

Responds to the internal environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are primary afferent axons? (2)

A

Axons bringing information from the somatic receptors are referred to as (primary) afferents

Afferents feed into the spinal cord via a spinal nerve and the dorsal root

34
Q

What are efferents axons? (2)

A

Axons taking information from CNS to peripheral structures are referred to as (motor) efferents

Efferents leave the spinal cord via a ventral root and the spinal nerve

35
Q

Features of the somatosensory system (3)

A

Touch
Temperature
Pain

36
Q

What receptors are involved in touch? (2)

A

Sensory receptors in the skin.
Respond to physical distortion

37
Q

What receptors are involved in temperature? (1)

A

Thermoreceptors in the skin sense temperature

38
Q

What receptors are involved in pain? (1)

A

Nociceptors in the skin respond to pain

39
Q

What is a pseudounipolar neurone? (1)

A

Basic structure of a sensory neurone

40
Q

Describe the structure of a pseudounipolar neurone? (5)

A

Receptor endings on periphery
Terminals in spinal
Cell body in dorsal root ganglion
No dendrites as such
Can be unmyelinated too.

41
Q

What are the different cutaneous (skin) receptors (5)

A

Meissner’s Corpuscles
Merkel’s disks
Pacinian Corpuscles
Ruffini’s corpuscles
Free nerve endings

42
Q

Describe Meissner’s corpuscles (3)

A

Comprised of looping axonal terminals and intertwined supporting cells
Low frequency vibrations

43
Q

Describe Merkel’s disks (3)

A

Dome structure comprised of axon terminals and Merkel cells
Small forms and shapes

44
Q

Describe Pacinian Corpuscles (3)

A

Sensory axon surrounded by fluid filled capsule gives it an onion-shaped appearance
High frequency vibrations

45
Q

Describe Ruffini’s corpuscles (2)

A

Nerve terminals intertwined with collagen fibrils (20%)
Pressure

46
Q

Describe free nerve endings (2)

A

Free nerve endings that penetrate into epithelial cells, no apparent morphological specialisation
Noxious (harmful)

47
Q

Describe sensory transduction (4)

A

Stimulus deforms or changes the nerve ending
Alters the membrane permeability of the receptor membrane
Produces a receptor (generator) potential
Triggers an action potential which travels along the axon to the CNS

48
Q

Describe the classification of sensory afferent innervating somatosensory receptors (3)

A

Large diameter, rapidly conducting afferents (I/II) associated with low threshold mechanoreceptors.

Small diameter, slow conducting afferents (III/IV) associated with nociceptors and thermoreceptors.

N.B. Conduction velocity is positively correlated with axon diameter.

49
Q

Describe mechanosensory pathway (3)

A

3 neurone chain
1st order neurone – primary afferent (into dorsal horn, spinal cord)
2nd order neurone central neurone (to thalamus)
3rd order neurone – central neurone (to cortex)

50
Q

How are mechanosensory pathways transmitted? (1)

A

Through the dorsal column-medial lemniscal pathway

51
Q

What is nocioception? (1)

A

The sensory process that provides the signals that trigger pain

52
Q

What is pain? (2)

A

Pain is the feeling or perception of irritation, soreness, stinging, aching, throbbing, miserable, or unbearable sensations arising from a part of the body.

53
Q

Where does transduction of painful stimuli occur? (1)

A

In the free nerve endings of unmyelinated ‘C’ fibres and thinly myelinated ‘A alpha’ fibres

54
Q

What are the three different types of nocireceptors (3)

A

Mechanical: respond to strong pressure
Thermal: respond to burning heat / extreme cold
Chemical: respond to histamine or other chemicals

55
Q

Describe the anatomy and physiology of nociceptors (2)

A

Nociceptors are found in the periphery as simple free nerve endings

Peripheral nerve fibre branches & innervates as naked, unmyelinated endings the dermis

56
Q

Increasing inflammatory response (3)

A

Pain afferents send signals to the CNS but also release signalling molecules such as Substance P locally to increase the inflammatory response

57
Q

Which neurotransmitters do pain afferents use? (3)

A

Pain afferents release the excitatory neurotransmitter glutamate.

The synaptic terminals also have vesicles containing neuropeptides.

One important neuropeptide in pain afferents is substance P

58
Q

What is the anterolateral system? (1)

A

The overall pathway for conveying pain / temperature

59
Q

Describe the spinothalamic pathway (3)

A

Processes afferent inputs from peripheral mechano-, thermal and polymodal nociceptors

It is a contralateral pathway i.e. sensory inputs cross at the level of spinal cord and ascend on opposite side

Information is relayed to the thalamus and then onto the somatosensory cortex

60
Q

Why are sensory pathways ascending pathways? (1)

A

Take signals from periphery up to the brain

61
Q

Describe spinal motor output (3)

A

Alpha motoneurones —> muscles
Each motoneurone is associated with muscle fibers forming a functional entity called the motor unit

62
Q

How do motor neurones vary? (4)

A

Vary in size, amount of tension produced, speed of contraction, and degree of fatigability

63
Q

Which neurones are located medially in the motor pool of spinal cord (1)

A

Motoneurons innervating axial musculature are located medially

64
Q

Which neurones are located laterally in the motor pool of spinal cord (1)

A

Motoneurons innervating the distal musculature are located more laterally

65
Q

Why is a controller necessary for muscles ? (1)

A

Make sure that muscle is contracting for the right purpose

66
Q

What are muscle spindles? (1)

A

The spindle is the sensory apparatus of muscle

67
Q

What do muscle spindles do? (5)

A

Lies parallel to muscle fibres

Intrafusal muscle fibres

Detects changes in muscle length

Contributes to proprioception i.e. detection of position and movement of body in space

Enables regulation of muscle contraction and precisely matches force generation to motor task

68
Q

What are extrafusal fibres? (2)

A

Extrafusal fibres form bulk of muscle and generate muscle tension
Extrafusal fibres receive their motor innervation from alpha motor neurons.

69
Q

What are intrafusal fibres? (2)

A

Intrafusal fibres (spindles) have a sensory function and do not generate tension

Intrafusal fibres receive their motor innervation from gamma motor neurons

70
Q

What are the two proprioceptive muscle afferent? (2)

A

Ia and II afferents

71
Q

What kind of receptor is the Golgi tendon organ? (1)

A

The Golgi tendon organ is a mechanoreceptor

72
Q

What does the golgi tendon organ do? (5)

A

Lies in series with muscle fibres

Detects changes in muscle tension, as when the muscle contracts the force acts directly on the tendon

Acts like a strain gauge i.e. monitors muscle tension & the force of contraction

Innervated by Ib afferents

Contributes to proprioception i.e. detection of position and movement of body in space

73
Q

What kind of input can activate motor neurones? (1)

A

Those arriving through 1a afferent

74
Q

What are the two types of reflex responses? (2)

A

Monosynaptic - the stretch reflex flash file
Polysynaptic - the reflex arc flash file

75
Q

Which pathway generates the monosynaptic reflex? (1)

A

1a afferent pathway

76
Q

What is a homonymous interaction? (1)

A

1a afferent activate on their own

77
Q

What is a heteronomous activation? (1)

A

Activate opposite

78
Q

What is a monosynaptic reflex? (3)

A

Stretch reflex
-> Sensory afferent -> Motoneurone -> OUTPUT
One synapse

79
Q

What is a polysynaptic reflex? (3)

A

Crossed Extensor reflex (FRA reflex)
-> Sensory afferent -> Interneurone -> Motoneurone -> Output

80
Q
A

Biology of the mind (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions