Coordination and control Flashcards
What are stimuli?
Changes in the environment
What does the nervous system allow people to do?
React to their surroundings and coordinate their behaviour
What detects stimuli?
Cells called receptors
What is the pattern of reflex arcs?
Stimulus, receptor, sensory neuron, relay neuron, motor neuron, effector, response
Why is it important for adrenaline to be released in stressful situations?
So your body can prepare to either fight or flight. This helps to increase chances of survival in dangerous situations
What do electrical impulses travel along?
Along neurons
What is diffusion?
When particles are in a high concentration and they move about to places with low concentration to make it balanced
What is a synapse?
The space between two neurons
How do signals pass from one neuron to another?
A neurotransmitter chemical is released into the synapse
What happens to the neurotransmitter when reaches the other neuron?
It fits into a tailor-made receptor on the surface of the target neuron. The second neuron receives the signal. The chemical is then absorbed by the reuptake, channel ready to be used again
What are effectors?
Muscles or glands
What are hormones?
Chemical messengers
What does testosterone do?
Muscle development, secondary sexual characteristics
What does oestrogen do?
Secondary sexual characteristics
How do hormones travel?
In the blood to target organs. They attached to complimentary receptors on target cell membranes
How do you increase your temperature?
Eating to provide calories, shivering, hair raising, exercise, respiration, environment, putting on clothes
How do you decrease your temperature?
Sweating, cold drinks, environment, fan, taking off clothes
How do you increase the amount of water in your body?
Drinking water, eating, respiration
What is the equation for respiration?
Glucose + oxygen -> carbon dioxide + water + energy
How do you decrease the amount of water in your body?
Going to the toilet, sweating, tears, water vapour, vomit
How do you increase the amount of glucose in your body?
Eating and drinking
How do you decrease the amount of glucose in your body?
Respiration for energy, time between meals
How do you increase the amount of ions in your body?
Sodium chloride (food), drinks, chemical reactions
How do you increase the amount of ions in your body?
Urine, sweat, faeces
What is homoeostasis?
The process by which a body tries to control things, such as water, blood, temperature, and ions
Why do bodies need homoeostasis?
So all levels of blood, water etc don’t rise or fall too much, because it could be life-threatening
How does homoeostasis work?
It detects changes in the bodies internal environment, and regulates a response
What is an enzyme?
A biological catalyst that speeds up reactions. It is a protein
What do enzymes do?
They break down things in your body, but are not broken down themselves
How do enzymes denature?
If the temperature is too high
What happens if someone’s body temperature increases above 40 to 42°C?
Possible death from heatstroke and heat exhaustion
What is the normal body temperature?
37°C
What happens when your body temperature drops below 35°C?
Possible death from hypothermia
What happens if you drink too much water?
It’s thins the blood and cells burst because they take in too much water
What happens when you do not have enough water in your body?
You become dehydrated
What is an ion?
A charged particle
What is a commonly used ion?
Salt NaCl
What is glycogen?
A long line of glucose molecules
How is insulin produced?
By the pancreas
What does insulin store?
Its stores glucose as glycogen
What happens when the body has above the average blood sugar levels?
Go hyperactive, have an episode and the body shuts down
What happens when you have below the average blood sugar level?
Have an episode on the body shuts down
What is the order of the menstrual cycle?
Menstruation, uterus lining thickens, ready to receive embryo, breaks down if no implantation
What is another word for egg cell?
Corpus luteum
What does FSH do ?
Causes eggs to mature, stimulates ovary to produce oestrogen
What does oestrogen do?
Causes the lining of the womb to develop, inhibits FSH production, stimulates the release of a mature egg
In relation to contraception, why did families 100 years ago have lots of children?
Because they didn’t have any effective methods of contraception, unless they had an operation which had high risks and were very painful
How does the contraceptive pill work?
The contraceptive pill may contain oestrogen and progesterone. Some are only progesterone pills. The contraceptive pill prevents the production of FSH so no eggs mature
How has the contraceptive pill changed over time?
Smaller doses are now given, they are takes for 21 days. But they are now more likely to increase breast cancer because of different chemical amounts
How many types of contraceptive pill are there?
3
What is IVF?
In vitro fertilisation
Why might people need to use IVF?
If the Fallopian tubes are damaged and the woman can’t get pregnant naturally
What is the equation for photosynthesis?
Carbon dioxide+water+sunlight chlorophyll -> oxygen+ glucose
What is the reverse of photosynthesis?
Respiration
What do plant roots need for cellular reactions to happen?
Nitrates, phosphates and potassium
What do palmy shoots allow the plant to do?
Photosynthesise as they are above the plant
What is hydrotropism?
A growth response due to water
What is phototropism?
A growth response due to light
What is gravitropism?
A growth response due to gravity
What is auxin?
A plant hormone
What does auxin do?
Speeds up growth on one side of the plant so it can lead towards the sun
The root grows more on the side with ….. auxin
Less
The shoot grows more on the side with …… auxin
More
Name two glands that secrete hormones to control the menstrual cycle
Ovaries, pituitary gland
