B5 quick revision Flashcards
Define homeostasis.
To maintain a stable internal environment.
What are the 3 components of a negative feedback?
Receptor
coordination center
effector.
What is negative feedback used for?
It is an automatic control system that keeps your internal environment stable.
Define neurones.
A nerve cell, a specialized cell transmitting nerve impulses.
Define vertebrates.
Animals with backbones.
Define sensory neurones.
Neurones that carry electrical impulses from the receptor to the central nervous system.
Define motor neurones.
Neurones that carry electrical impulses from the central nervous system to the effectors.
Define effectors.
All your muscles and glands which respond to nervous impulses.
It produces a response.
Define nervous impulses.
A way that nerve cells communicate to each other.
Define receptor.
It detects a stimulus ( change in the environment)- level is too high or low is an example.
Define coordination centre.
It receives and processes the information then organizes a response.
What do reflexes do?
They help prevent injuries.
What do synapses do?
They connect two neurones together.
Define reaction time.
How quickly you respond to a stimulus.
How long is a reaction time normally?
Often less than a second.
Give 3 factors that can affect reaction time.
Age, gender and drugs e.g. caffeine speeds a persons reaction time.
Give 3 ways you can measure a reaction time.
Ruler method, computer, and calculating the mean.
Other than the nerves, what is another way to send information around the blood?
Hormones.
What role do hormones in the endocrine system?
Hormones are chemical messengers sent in the blood.
What are particular cells in particular organs called?
Target organs.
Name the 6 types of glands and what do they produce?
The pituitary glands/mater gland- produces hormones
Ovaries- in the females only-produces oestrogen
Testes-in the males only-produces testosterone
Thyroid- produces thyroxide
Adrenal gland-produces adrenaline
The pancreas-produces insulin.
What are the 3 differences between nerves and hormones?
Nerves are very fast, hormones are slower
Nerves act for a very short time, hormones act for a long time
Nerves act on a very precise area, hormones act in a more general way.
What affect do diabetes have on controlling your blood sugar levels?
It limits your ability to control blood sugar levels.
What 2 hormones control blood glucose level?
Insulin and glucagon.
What can excess glucose be stored as?
Glycogen in the liver and muscles.
What is the difference between insulin and glucagon?
Insulin is added when the blood sugar is too high and glucagon is added when the blood sugar is too low.
What 2 factors can reduce diabetes?
Limiting the intake of food with carbohydrates e.g. sugar
regular exercise-which helps remove excess glucose from blood.
How can you treat people with type 1 diabetes?
By injecting insulin to remove glucose from the blood quickly once the food has been digested.
What causes blood 1 diabetes?
Having little or no insulin which means your blood level can rise and kill you.
What causes type 2 diabetes?
Being overweight.
Define type 2 diabetes.
When a person become resistant to their own insulin- they still produce insulin but their body doesn’t respond properly to the hormone.
How many hormones control the menstrual cycle and list them all in order.
4.
- FSH- Follicile- stimulating hormone
- Oestregen
- LH- Luteinising hormone
- Progesterone.
Which 2 hormones are produced in the pituitary glands?
LH and FSH- Luteinising hormone and follicile- stimulating hormone.
What are the 4 stages of a menstrual cycle?
- menstruation starts
- the uterus lining builds up again.
- an egg develops and is released
- the wall is then maintained.
