B1.2 Nerves and Hormones

Question 1

What does CNS stand for?

Answer 1

Central nervous system

-Brain and spine

Question 2

What does PNS stand for?

Answer 2

Peripheral nervous system

-Linked with CNS by sensory neurons

Question 3

What are receptors

Answer 3

Specialised cells on the surface

-Receive stimuli

Question 4

What are the 3 types of neurones?

Answer 4

Sensory
Motor
Relay

Question 5

What is the role of a sensory neurone?

Answer 5

Carry electrical impulses from receptors to the spinal chord

Question 6

What is the role of a motor neurone?

Answer 6

Sending electrical impulses from the brain to muscles

Question 7

In what order do the neurones go?

Answer 7

STORM
Sensory
Relay
Motor

Question 8

Does a reflex arc involve the brain

Answer 8

No

Question 9

What is a reflex arc?

Answer 9

A nerve pathway involved in a reflex action, that is simpler than the other electrical impulses.
Involves a sensory neruone and a motor neurone

Question 10

What is a synapse?

Answer 10

A gap between two neurones

Neurotransmissions diffuse across them

Question 11

How do synapses work?

Answer 11

An electrical impulse travels along an axon
This triggers the nerve-ending of a neurone to release neurotransmitters
These diffuse across the synapse
Bind with receptors on the next neruone
This stimulates the second neurone to transmit the electrical impulse
Repeats

Question 12

What is a receptor?

Answer 12

A receptor is a group of specialised cells that react to a stimulus. They detect a specific change in the environment.

EG
Receptor = eye
Stimulii = light

Question 13

What system involves the brain and spinal cord?

Answer 13

The central nervous system

Question 14

What are neurones?

Answer 14

Neurones are nerve cells that carry information in the form of tiny electrical signals

Question 15

What are the properties of a sensory neurone?

Answer 15

The sensory neurone SENSES the stimuli and stimulates signals that are sent to the brain and spinal cord

Question 16

Which neurone transmits messages thoughout/within the central nervous system?

Answer 16

The relay neurone

Question 17

What does the motor neurone do?

Answer 17

Carry signals from the central nervous system to the effectors (that carry out the action)

Question 18

What is the axon of a motor neurone

Answer 18

The central strand

Question 19

Where are the dendrites?

Answer 19

At the end of the motor neurone by the nucleus

Question 20

What is the synapse?

Answer 20

The gap where two neurones meet and an electrical signal is diffused accross

Question 21

How does a reflex action occur?

Answer 21

stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector

The actions do not interact with the brain

Question 22

What is an effector?

Answer 22

Any part of the body that produces a response

eg -> a muscle contracting, gland releasing

Question 23

What is the eye an example of?

Answer 23

A sense organ

Question 24

Which type of neurone transmits a signal from a sense organ to the central nervous system?

Answer 24

Sensory neurone

Question 25

What is a hormone?

Answer 25

A chemical substance produced by a gland and carried by the blood that alter the activity of target organs

Question 26

How are hormones and nerves similar?

Answer 26

They can both control the body

Question 27

What are the characteristics of a hormone?

Answer 27

Signal : chemical transmission : nerve cells in the blood stream Effectors : cells in particular tissues Response : chemical change Speed of response : slow Duration of response : Long ( until hormone breaks down)

Question 28

What hormone does the ovary produce?

Answer 28

Oestrogen

Question 29

Where is insulin produced?

Answer 29

The pancreas

Question 30

What controls the pituatiry gland?

Answer 30

The hypothalimus in the brain

Question 31

Where is adrenalin produced?

Answer 31

The adrenal gland

Question 32

What and when are the four stages of the menstrual cycle?

Answer 32

``` Stage 1 (days 1-4) the uterus sheds its lining (bleeding) Stage 2 ( days 4-14 ) the uterus lining is rebuilt, thick spongy layer Stage 3 ( day 14) An egg is released from the ovary Stage 4 (14 -28) The uterus lining remains for the egg to be fertilised, if not the cycle begins again ```

Question 33

What major hormones are in the menstrual cycle?

Answer 33

- FSH (follicle stimulating hormone) - Oestrogen - LH ( luteinising hormone)

Question 34

How is an egg released from the ovaries?

Answer 34

The pituitary gland causes the production of FSH which in turn causes an egg to mature The ovaries release oestrogen which triggers the release of LH LH (released by the pituitary gland) determines when an egg is released into the uterus

Question 35

What are the four types of pathogen that cause disease?

Answer 35

Virus Bacteria Fungi Carcinogen

Question 36

What does FSH do?

Answer 36

Secreted by the pituitary gland Causes an egg to mature Stimulates release of oestrogen

Question 37

Which hormone, secreted by the ovaries, is responsible for stopping the production of FSH and stimulating the release of LH?

Answer 37

Oestrogen | It stops the production of FSH so only one egg is produced

Question 38

What is the job of the Luteinising Hormone?

Answer 38

Released by the pituatary gland | Triggers ovulation

Question 39

What are the benefits of oral contraceptives?

Answer 39

- Oestrogen greatly reduces the chances of pregnancy by reducing the production of FSH - Allows choice to have children

Question 40

What were the risks of old fashioned oral contraceptives?

Answer 40

- Mood swings - Weight loss or gain - Change in blood pressure This was due to more oestrogen being in the pills than there are today

Question 41

How can fertility drugs aid the probability of pregnancy?

Answer 41

They contain FSH or LH which the patient is lacking in and so stimulates the production, maturing, and release of eggs This can often lead to twins, triplets etc and also complications with birth such as a premature birth

Question 42

How can IVF help the possibility of pregnancy?

Answer 42

If the quality of the mans sperm is affecting the chance of pregnancy, the egg can be fertilised outside of the womb. Fertility drugs can also be used to increase the amount of eggs available for fertilisation

Question 43

Why might some people disagree with IVF?

Answer 43

It could lead to the production of 'designer babies' if the parents have a choice of which child they want eg a girl in a family of boys/boy in a family of girls

Question 44

How are hormones transported around the body?

Answer 44

In the blood stream

Question 45

What is a tropism?

Answer 45

A plants response to a stimulus A positive tropism = towards A negative tropism = away from

Question 46

What are auxins?

Answer 46

Auxins are a family of hormones made in the tips of shoots or roots of plants They can elongate cells and therefore respond to a stimulus by changing the shape of a plant eg If the sun is on the left, the auxins elongate the cells in the right side of the plant stem to cause it to bend towards the light

Question 47

How can plant hormones be used commercially?

Answer 47

- In weed killers to kill some plants but cause others to survive - In rooting powders to make stem cuttings grow and thrive

Question 48

How do cells in roots react to the presence of auxins?

Answer 48

They grow less

Question 49

Are shoots positively or negatively.. phototropic gravitropic

Answer 49

Positively phototropic | Negatively gravitopic

Question 50

Are roots positively or negatively... phototropic gravitopic

Answer 50

Negatively phototropic | Positively gravitopic

Question 51

When a root bends gravitopically, does the bottom or top side grow more?

Answer 51

The top side grows more to bend the root downwards