Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology Michael > B1.2 Nerves and Hormones > Flashcards

B1.2 Nerves and Hormones Flashcards

(81 cards)

Start Studying
1
Q

What is the nervous system?

A

What allows you to respond to changes in environment

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

What is the nervous system made up of?

A

Neurones (nerve cells)

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

What is a stimulus? Can you name them? (8)

A

A change in environment e.g. Light, sound, touch, pressure, pain, chemical or a change in position or temperature

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

What are stimuli detected by?

A

Groups of cells called receptors - they change stimulus energy (e.g. light energy) into electrical impulses

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

Where are receptors found? Can you name the 5 different places?

A

Sense organs - the eyes, ears, nose, tongue and skin

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

What receptors do the eyes contain?

A

Light receptors which are sensitive to light - They have nuclei which contain their genetic material and are filled with cytoplasm and surrounded by a cell membrane

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

What receptors do the ears contain? (2)

A

Sound receptors which are sensitive to sound - they also contain balance receptors which are sensitive to a change in position

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

What receptors does the nose contain?

A

Smell receptors which are sensitive to chemical stimuli

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

What receptors does the tongue contain?

A

Taste receptors which are sensitive to chemical stimuli - They can detect bitter, salt, sweet and sour, plus the taste of savoury things like monosodium glutamate (MSG)

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

What receptors does the skin contain?

A

Receptors which are sensitive to touch, pressure, pain and temperature change

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

What happens at the central nervous system?

A

Where all the information from the receptors are sent to, and where actions and reflexes are coordinated

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

What does the CNS consist of?

A

The brain and spinal cord - Neurones transmit information as electrical impulses to and from the CNS

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

What are effectors?

A

Muscles or glands which respond to nervous impulses and bring about a response to a stimulus

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

How do effectors respond to nervous impulses?

A

Muscles contract and glands secrete chemical substances called hormones

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

What are the 3 different types of neurones?

A

Sensory, Relay and Motor

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

What do the sensory neurones do?

A

Carry electrical impulses from receptors in sense organs to the CNS

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

What do the relay neurones do?

A

Found in the CNS, they carry impulses from the sensory neurones to the motor neurones

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

What do the motor neurones do?

A

Carry impulses from the CNS to the effectors

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

What is a synapse?

A

The connection between two neurones

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

How do the nerve signals move across a synapse?

A

The nerve signals are transferred by chemicals which diffuse across the gap and cause new electrical signals to set off in the next neurone

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

How does the synapse affect how quickly information is delivered?

A

Although it is still very fast, it does slow it down

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

What is a reflex?

A

A fast, automatic response to certain stimuli which doesn’t require you to think consciously

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

Examples of reflexes?

A

Bright light in eye - pupil shrinks meaning less light enters the eye and stops them from getting damaged
Adrenaline production - your body is ready for action
Knee-jerk reflex - helps maintain posture and balance

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

What is a reflex arc?

A

The passage of information in a reflex from receptors to effectors, is called a reflex arc - the neurones in a reflex arc go through the spinal cord or through an unconscious part of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the 5 main stages involved in a reflex arc?
1. Stimulus is detected by receptors, impulses are sent along sensory neurones to the CNS 2. The impulses reach a synapse between the sensory neurone and a relay neurone 3. Impulses reach a synapse between the relay neurone and the motor neurone 4. The impulses then travel along the motor neurone to the effector 5. If the effector is a muscle, it will contract; if it's a gland, it will secrete a hormone
26
What is homeostasis?
The maintenance of a constant internal environment
27
What bodily levels need to be controlled? (4)
Temperature, water content of the body, ion content of the body and blood glucose content
28
Why does the internal body temp need to be constant at around 37°C?
Because the metabolic reactions in our body are controlled by enzymes which work best at around 37°C
29
What controls the body temperature?
A part of the brain is sensitive to the blood flowing through the brain and it receives information from skin receptors which provide info on skin temperature
30
How do ions get into the blood?
The food we eat contains ions (e.g. sodium) which are absorbed into the blood stream - excess ions need to be removed
31
How are excess ions removed from the body?
Some is lost through sweat, but is mainly removed by the kidney and then got rid of in urine
32
How does water get into the body?
Through the food we eat and what we drink
33
How is water removed from the body?
Through the skin as sweat, via the lungs in breath and via the kidney in urine
34
How does the balance of sweat and urine change on a cold day when you're not exercising?
You will sweat less and will produce more urine which is pale because the urea is diluted
35
How does the balance of sweat and urine change on a hot day when you're exercising?
You will sweat a lot and produce less urine which will be more concentrated and is a darker colour - you will also lose more water through breath because you breathe faster when you exercise
36
How does glucose get into the blood?
Eating food containing carbs puts glucose into the blood from the gut
37
How is glucose removed and how does this change when you exercise?
The normal metabolism of cells removes glucose from the blood but a lot of exercise means that more glucose is removed as it fuels body cells as a source of energy
38
What maintains the right levels of glucose in the blood so your cells get a constant supply of energy?
A hormone called insulin
39
What are hormones?
Chemical messengers which travel in the blood to activate target cells
40
Give 3 examples of hormones
Follicle stimulating hormone, luteinising hormone and oestrogen - all hormones involved in the menstrual cycle
41
Where hormones produced?
In glans e.g. the pituitary gland and the ovaries
42
What are hormones like in the blood?
They are carried by blood plasma and travel around the body relatively slowly - they also tend to have long-lasting effects
43
What's the difference between nerves and hormones?
Although they do similar jobs - Nerves: Fast action, act for a short time and acts on a precise area Hormones: Slower action, act for a long time and acts in a more general way
44
Name 2 examples of a nervous and hormonal action
Nervous: information is passed to effectors quickly e.g. pain signals Hormonal: response lasts for a longer time e.g. adrenaline released into the body
45
What is the menstrual cycle?
The monthly sequence in which the female body releases an egg and prepares the uterus in case it receives a fertilised eggs
46
What events are in involved in the menstrual cycle?
The build-up of the protective lining in the uterus ready for the implantation of a fertilised egg, the release of an egg from the woman's ovaries and the breakdown of the uterus lining if a fertilised egg is not implanted - this results in bleeding (a period)
47
What happens in stage 1 of the menstrual cycle?
Day 1 - bleeding starts and the uterus lining breaks down for about 4 days
48
What happens in stage 2 of the menstrual cycle?
Day 4 to day 14 - the uterus builds up again into a spongy layer full of blood vessels ready to receive a fertilised egg
49
What happens in stage 3 of the menstrual cycle?
Day 14 - an egg is released into the ovary
50
What happens in stage 4 of the menstrual cycle?
Day 14 to day 28 - the wall is maintained, if no fertilised egg was implanted by day 28, the spongy lining breaks down again and the cycle starts again
51
Where is FSH produced and what is it's role in the menstrual cycle?
Produced by the pituitary gland, it causes an egg to mature in one of the ovaries and stimulates the ovaries to produce oestrogen
52
Where is Oestrogen produced and what is it's role in the menstrual cycle?
Produced in the ovaries, causes the pituitary gland to produce LH and inhibits further release of FSH
53
Where is LH produced and what is it's role in the menstrual cycle?
Produced by the pituitary gland, it stimulates the release of an egg at around the middle (14 days) of the menstrual cycle
54
How do the levels of hormones in the menstrual cycle change throughout the menstrual cycle?
Levels of one hormone can predict the level of another hormone e.g. FSH stimulates the ovaries to produce oestrogen so if FSH levels rise, so would oestrogen
55
How can you reduce chances of pregnancy?
Contraception and taking hormones like oestrogen and progesterone from a woman
56
What happens when a woman takes oestrogen everyday?
Although oestrogen helps to stimulate the release of an egg, if it is taken everyday, oestrogen levels are permanently high which inhibits FSH production and stops eggs from being released
57
What happens when a woman takes progesterone everyday?
It increases the production of a thick cervical mucus which prevents sperm from reaching the egg
58
What is an example of an oral contraceptive?
The pill
59
The pill was first introduced in the 1950s, what were the issues related to this early version of the pill?
This pill contained high levels of oestrogen and progesterone - the high levels of oestrogen was linked to blood clots so nowadays the pill contains lower levels of oestrogen
60
What alternatives are there to the OG pill?
Progesterone-only pills, but they're not as effective
61
What benefits are there of the combined oral contraceptive?
The pill's over 99% effective at preventing pregnancy and it also is thought to reduce the risk of getting some types of cancer
62
What drawbacks are there of the combined oral contraceptive?
It isn't 100% effective, it can cause side effects like: headaches, nausea, irregular menstrual bleeding and fluid retention, and it also doesn't protect against STDs
63
Some women have low amounts of ____ so their eggs don't mature, what is ____? And how is it resolved?
FSH - FSH and LH can be injected by women to stimulate egg maturation and release in their ovaries (these are fertility drugs)
64
What problems are there with fertility drugs?
They don't always work, some women need them several times which is expensive, and too many eggs could be stimulated resulting in multiple pregnancies
65
How is IVF carried out?
1. FSH and LH are given to the woman to stimulate the maturation of multiple eggs 2. Eggs are then collected from the woman's ovaries 3. The eggs are fertilised in the lab using the man's sperm 4. The fertilised eggs then grow into embryos 5. Once the embryos have formed 1 or 2 are transferred to the woman's uterus - transferring more than 1 improves chance of pregnancy
66
What are the drawbacks of IVF?
Some women react to the hormones e.g. abdominal pain, vomiting and dehydration, also there have been reports of an increase in cancer due to the hormones and multiple births can happen
67
What is the main benefit of IVF?
It gives an infertile couple a child
68
What do plants need to do in order to survive?
They need to be able to detect and respond to stimuli
69
What is auxin?
A plant hormone that controls growth near the tips of shoots and roots
70
What does auxin control? (3)
Phototropism, gravitropism and a plants growth in response to moisture
71
What is phototropism?
Plant growth in response to light
72
What is gravitropism?
Plant growth in response to gravity
73
Where is auxin produced? And where does it work?
In the tips of shoots and roots and movies backwards to stimulate cell elongation which occurs in cells just behind the tips
74
What happens if the tip of a plant is removed?
No auxin is available and the shoot may stop growing
75
What does extra auxin do to the plant's shoots/roots?
It promotes growth in the shoot, but inhibits growth in the roots
76
How do shoots grow towards the light?
When a shoot tip is exposed to light, more auxin is accumulated on the shaded side which makes the shaded side's cells grow faster and thus makes the shoot bend towards the light as it grows
77
How do shoots grow away from gravity?
When a shoot is growing sideways, more auxin is accumulated on the lower side, this causes the lower side to grow faster and makes the shoot bend upwards as it grows
78
How do roots grow towards gravity?
When a root is growing sideways, more auxin is accumulated on the lower side, this causes the lower side to grow slower than the upper side and makes the root bend downwards as it grows (as extra auxin in roots inhibits growth)
79
How do roots grow towards moisture?
An uneven amount of moisture on either side of the root causes the auxin to accumulate on the side with more moisture - this makes the other side grow faster and this grows the root towards the moisture
80
What are selective weed killers made of? How do they work?
Weeds are broad-leaved, unlike grasses and cereals which have narrow leaves. SWK contain plant growth hormones which disrupt the broad-leaved weeds growth patterns, which soon kills them
81
How do rooting powders help plants grow?
Plant cuttings won't always grow in soil - adding rooting powder (containing auxin) produces roots for the cutting rapidly and starts growing it as a new plant. This helps growers produces clones very quickly

Biology Michael (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions