Brainscape's Knowledge GenomeTM

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


See full index

Biology M5: Communcation, homeostasis and energy > Neuronal communcation > Flashcards

Neuronal communcation Flashcards

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

What is homeostasis and why is it needed?

A

different organs have different functions in the body and they must be coordinated to maintain a relatively constant internal environment e.g pancreas and liver work together to maintain blood glucose

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

What is cell signalling and what are the different ways it occurs?

A

coordination at a cellular level occurs through cell signalling. One cell releases a chemical which will affect the target cell: transfer of signals locally (between neurones) or over bigger distances (hormones)

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

How does coordination in plants happen?

A

The use of plant hormones (e.g phototropsim)

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

give two differences between hormonal and neuronal communication

A

Hormonal: uses chemicals in the endocrine system, much slower
Neuronal: uses electrical impulses, much faster communication

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

Role of neurones

A

transmit electrical impulses rapidly around the body so it can respond to internal and external stimuli, the different types of neurones carry information from sensory receptor to the effector

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

Cell body in neurones

A

Cell body: nucleus surrounded by cytoplasm, large amounts of endoplasmic reticulum and mitochondria which are involved in the production of neurotransmitters

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

Dendrons in neurones

A

short extensions that come from the cell body, they divide into smaller branches called dendrites and are responsible for transmitting electrical impulses towards the cell body

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

Axons in neurones

A

singular elongated nerve fibres that transmit impulses away from the cell body

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

Role of a Sensory neurones

A

transmit impulses from sensory receptors to a relay neurone, motor neurone or the brain.
Have one dendron to carry impulses to cell body (in the centre)
One axon to carry impulses away from cell body

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

Role of a relay neurone

A

Transmit impulses between neurones, many short axons and dendrons

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

Role of a Motor neurone

A

Transmit impulses from relay neurones to effectors, such as a muscle or a gland, one long axon and many short dendrites (cell body one end)

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

Myelinated neurones

A

Schwann cells produce the myelin sheath which covers the entire axon on myelinated neurones as an insulating layer

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

Effects of myelination

A

Insulating layer and makes conduction of impulses faster - myelinated impulses can travel as fast as 100m per second/ non-myelinated 1m every second

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

Nodes of Ranvier

A

small gaps between Schwann cells occurring every 1-3mm in humans.
This way the impulse has to jump from neurone to neurone which means it is transmitted faster.
Non-myelinated neurones have impulses travelling continuously along

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

Role of Sensory receptors

A

convert the stimulus they detect into a nerve impulse

Information is passed through the CNS to the brain

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

Features of sensory receptors

A
  • specific to one type of stimulus

- act as a transducer, convert stimulus into an impulse called a generator potential

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

4 main types of sensory receptors

A

mechanoreceptor: pressure and movement (pacinian corpuscle)
chemoreceptor: chemicals (olfactory receptors)
thermoreceptor: heat (end-bulbs of krause)
photoreceptor: light (cone cell, different wavelengths of light)

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

Pacinian corpuscle

A

detect mechanical pressure

located deep within the skin and are most abundant in the hands and soles of feet

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

Structure of a pacinian corpuscle

A

end of a sensory neurone is found in the centre of the corpuscle surrounded by connective tissue
within the neurone’s membrane there are sodium ion channels which transport them through the membrane

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

Conversion in pacinian corpuscle

A

at normal state/resting potential, the stretch-mediated sodium ion channels are too narrow to allow sodium to pass through

When pressure is applied the corpuscle changes shape and the membrane around the neurone stretches

Sodium ion channels now widen and sodium can diffuse into the neurone

Influx of the ions changes the potential of the membrane so it is now depolarised which creates a generator potential

generator potential then creates an action potential

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

What is resting potential

A

the potential difference across the membrane when a neurone is not transmitting an impulse. The outside of the membrane is more positively charged than the inside of the axon. The membrane is polarised and is at a potential of about -70 mV

22
Q

Outline the creation of a resting potential

A
  1. Sodium ions are actively transported out of the axon and potassium ions are transported in (ratio of 3:2).
  2. There are more sodiums outside of the axon and more potassiums inside the axon so the sodiums move back into the axon cytoplasm down the electrochemical gradient.
    Most gated Na+ channels are closed but many K+ ones are open and so potassium can diffuse out
23
Q

What is a neurotransmitter?

A

chemical messengers - endogenous chemicals that allow neurotransmission

24
Q

What is an excitatory neurotransmitter?

A

neurotransmitter that results in the depolarisation of the postsynaptic neurone - if threshold is reached in the postsynaptic membrane an action potential is triggered

25
Q

Give examples of excitatory neurotransmitters

A

Acetylcholine, dopamine, serotonin,

26
Q

What is an inhibitory neurotransmitter?

A

neurotransmitter that results in the hyperpolarisation of the postsynaptic membrane. This prevents the action potential being triggered.

27
Q

Give examples of inhibitory neurotransmitters

A

GABA, glycine

28
Q

Describe the process of the transmission of impulses across synapses

A
  1. action potential reaches the end of the presynaptic neurone
  2. depolarisation of the presynaptic neurone causes calcium ion channels to open
  3. calcium ions diffuse into the presynaptic knob
  4. this causes synaptic vesicles to move the the membrane and fuse with it
  5. the neurotransmitter is released by exocytosis
  6. neurotransmitters diffuse across the synapse and bind with receptors of the postsynaptic membrane
  7. sodium ion channels open
  8. sodium ions channels diffuse into the postsynaptic neurone
  9. this triggers an action potential that is then propagated across the postsynaptic neurone
29
Q

How and where is acetylcholine broken down?

A

Acetylcholinesterase breaks down Ach in the

30
Q

What is saltatory conduction?

A

when the action potential ‘jumps’ from one node of ranvier to another - much faster than a wave of depolarisation along the whole length of the axon membrane

31
Q

State two factors, other than myelination, that affect the speed at which an action potential travels

A

axon diameter - the bigger the diameter the faster the impulse
temperature - the higher the temp, the faster the nerve impulse (ions diffuse faster at high temps, but after 40 degrees the proteins in the channels can denature)

32
Q

What is the all-or-nothing principle?

A

a certain threshold must be reached for an action potential to be created (usually -50mV)

33
Q

what is spatial summation?

A

a number of presynaptic neurones connect to one postsynaptic neurone - each release neurotransmitter which builds up enough to trigger an action potential

34
Q

What is temporal summation?

A

a single presynaptic neurone releases neurotransmitter as a result of an action potential several times over a short period - this builds up in the synapse until the quantity is sufficient to trigger an action potential

35
Q

What is the role of the cerebrum in the brain?

A

controls voluntary actions; learning, memory, personality and conscious thought

36
Q

What is the role of the cerebellum?

A

controls unconscious functions; posture, balance, non-voluntary movement

37
Q

Whats is the role of the medulla oblongata?

A

used in autonomic control; heart rate and breathing rate

38
Q

What is the role of the hypothalamus?

A

regulatory centre for temperature and water balance - also controls complex patterns of feeding, sleeping and aggression

39
Q

What is the role of the pituitary gland?

A

stores and releases hormones that regulate many body functions - the master gland

40
Q

What areas does the cerebrum contain?

A

left and right hemispheres, somatosensory area, motor area, visual cortex

41
Q

What covers the cerebrum?

A

the cerebral cortex - sophisticated processes such as reasoning and decision making occur here

42
Q

What is the pituitary gland split into?

A

Anterior - produces hormones for reproduction and growth

Posterior - stores and releases hormones produced by the hypothalamus (such as ADH)

43
Q

what is a reflex action?

A

the body’s response to danger without the use of conscious thought. A very fast action performed to prevent or minimise damage to the body

44
Q

what is a knee jerk reflex?

A

a spinal reflex, the neural circuit only goes up to the spinal chord and not the brain

45
Q

What is the blinking reflex?

A

involuntary blinking of the eyelids - occurs when the cornea is stimulated (eg by being touched)

46
Q

When else does the blinking reflex occur, other than when the cornea is stimulated?

A

When there are sounds greater than 40-60 dB or as a result of very bright light

47
Q

Why is the blinking reflex known as a cranial reflex?

A

it occurs only in the brain, not in the spinal chord

48
Q

What is skeletal muscle?

A

make up the bulk of body muscle tissue - is responsible for movement

49
Q

What is cardiac muscle?

A

only found in the heart, cardiac muscle cells are myogenic which means they can contract without the need for nervous stimulation (which is what causes the heart to beat in a regular rhythm)

50
Q

What is involuntary/smooth muscle?

A

found in many parts of the body such as the walls of hollow organs such as the stomach or bladder and also in blood vessels and the digestive tract

Biology M5: Communcation, homeostasis and energy (1 decks)

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