Life Book (11th Edition) Chapter 45 - Sensory Systems Flashcards Preview

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Flashcards in Life Book (11th Edition) Chapter 45 - Sensory Systems Deck (29)
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1

What is meant by sensory adaptation?

Sensory adaptation is when sensory receptor cells (afferent neutrons) are able to ignore maintained or repeated stimuli.

2

State some sensory receptor cells that demonstrate little sensory adaptation.

Pain receptors and the mechanoreceptors that control balance.

3

Think of a benefit of sensory adaptation

Allows your body to ignore unchanging stimuli (like clothes) that is usually unimportant and helps you react to new stimuli such as someone punching your arm.

4

Why should pain receptors not show large sensory adaptation?

Because pain receptors let you know what is wrong with something in your body. Such as that punch to the arm.

5

Action potentials arriving at the visual cortex of the brain will be interpreted as ______________

Light

6

Action potentials that arrive at the olfactory bulb will be interpreted as ________________

Smells

7

What is a sensory system

A set of organs and tissues for detecting a stimulus

8

What is a sensory organ?

A sensory organ is one that converts a stimulus into an electrical signal

9

Name some common examples of sensory organs.

Ears 👂🏻, eyes 👀, nose 👃🏻

10

What is sensory transduction?

The transformation of environmental stimuli or information into neural signals

11

What are receptor proteins?

A protein that has the ability to open or close an ion channel in response to a particulate type of stimulus.

12

A change in membrane potential of a sensory receptor cell due to a particular stimulus is known as a ________ ________

Receptor potential

13

Name all the types of sensory cell membrane receptor proteins. Hint: I MET Mr Cameron Pollock

Mechanoreceptor 🔧, electroreceptor⚡️, thermoreceptor🔥, chemoreceptor💊, photoreceptor ☀️.

14

Receptor potentials are graded membrane potentials or action potentials?

Graded membrane potentials

15

State one difference between action potentials (AP) and graded membrane potentials (GMP).

APs can travel long distances whereas GMPs travel short distances.

16

State two ways in which receptor potentials (graded membrane potentials) can generate action potentials.

1. The receptor potential triggers action potentials in sensory receptor cell itself. 2. Receptor potential can cause pre-synaptic neutron to release neurotransmitters that cause post-synaptic neurone to generate action potentials.

17

Which sensory receptors are iononotropic and which are metabotropic? Hint: I MET Mr Cameron Pollock

Ionotropic: mechanoreceptor, thermoreceptor and electroreceptor. Metabotropic: chemoreceptor and photoreceptor

18

Photo and chemoreceptors activate what in response to its stimulus?

Photo and chemoreceptors activate a G-protein signalling cascade that opens ion channels on the receptor cell.

19

What is an odorant?

A molecule in the environment that binds to and activates an olfactory receptor protein on the cilia of olfactory receptor neutrons (ORN)

20

Why is it hard to smell when you have a cold? 🤧

You get a runny nose when you get a cold and that extra mucous creates a thicker layer of mucous around the Olfactory receptor neurons (ORN). Odorant molecules will find it harder to diffuse through the thicker layer of mucous and so few odorant molecules will bind to the receptor proteins (chemoreceptors) on the ORN.

21

What is the function of the mucous film part of the olfactory epithelium.

It’s gives protection to the epithelial tissue lining the nasal cavity

22

Can ORNs regenerate themselves and if so why?

Yes - the epithelial lining is constantly shed so ORNs have to regenerate.

23

Explain how an action potential is generated in ORNs

1. Odorant molecules diffuse across mucous film and binds with receptor proteins on ORNs activating a G-protein. 2. The G-protein then activates an enzyme that increases the number of a second messengar (cAMP in vertebrates) in the receptor cell's cytoplasm. 3. cAMP then opens a ion channel allowing Na+ into the cell causing depolarisation of that part of the cell, generating the action potential. In short: Odorant molecule - receptor protein - G-protein - enzyme - second messenger - Influx of Na+ causing depolarisation - Action potential generated in ORN.

24

Each ORN expresses how many receptor protein types?

Just one type

25

State the trend in odorant molecules and perceived smell.

The greater the concentration of odarent molecules the greater the frequency of action potentials and this the greater the intensity of the smell.

26

What is a pheromone?

A type of chemical signal molecule that is used to communicate with individuals of the same species.

27

Tastebuds are ____________

Chemoreceptors

28

The sense of taste is called _________

Gustation

29

State the name of each type of sensory receptor cell membrane protein below: