B3 Flashcards
What does the the nervous system do ?
Enables humans to react to their surroundings and to coordinate their behaviour
- Information is sent through the nervous system as electrical impulses – electrical signals that pass along nerve cells known as neurones
What does the central nervous system (CNS) consist of ?
The brain and the spinal cord
What does the peripheral nervous system consist of ?
All of the nerves
How does the CNS coordinate a response ?
- Recpetor cells turn stimulus into an eletrical impulse
- Impulses are sent along the sensory neruone to the CNS
- Here a response is coordinated - sends an electrical impulse along the motor neurones to the effectors
- The effectors carry out a response
What is the reflex arc ?
- Receptors
- Sensory neurone
- Relay neurone
- Motor neurone
- Effector
What is adrenaline ?
- A hormone that is released from the adrenal gland - on top of kidneys
- Responsible for the fight or flight response
- Increase heart rate, send blood to muscles & dilates pupils
What are hormones ?
Chemical messengers that are secreted by endocrine glands
What is thyroxine?
- Produced by the thyroid gland in the neck
- Responsible for controlling metabolic rate
What is testerone ?
- Proudeced in the testes
- Responsible for the development of sperm
-Male sex charecteristics
What is oestrogen ?
- Produced in ovaries
-Responsible for female sex charceteristics
How long is the menstural cycle ?
28 days
What does oestrogen do and what day does it peak ?
- Causes a thicking of the uterus lining
- Peaks on day 10
What day of the menstrual cycle does ovulation occur?
Day 14
What does FSH do and when does it peak ?
- Causes the egg to mature
- Peaks on day 14
What does LH do and when does it peak ?
- Stimulates the release of the egg during ovulation
- Peaks day 14
What does progesterone do and when does it peak ?
- Maintains the thickness of the uterus
- Peaks day 21
What is the pill ?
The pill is designed to prevent pregnancy and is composed of estrogen and progesterone (mostly progesterone). Progesterone inhibits LH, which prevents ovulation.
What is the contraceptive implant ?
- Causes a low release of progestrone to prevent ovaries from releasing the egg , thicker mucus in the cervix so the sperm can’t swim
What happens in IVF ?
- Mother is given FSH & LH to stimulate the eggs to mature
- Eggs are collected & fertilised by the fathers sperm in a lab
- The fertilised eggd develop into embroys
- These embryos are then implaned into the mothers uterus
What does insulin do?
- If the glucose levels are too high, the pancrease will release insulin
- Insulin binds to the target organ
What does a motor neurone do ?
A neurone which carries nerve impulses from the central nervous system to effectors
What does a sensory neruone do ?
A neurone which carries nerve impulses from receptors to the central nervous system
What does a relay neurone do ?
A neurone that acts as a coordinator, transmitting impulses from the sensory to the motor neurone in the spinal cord
What is homeostatsis
The regulation of the internal conditions of a cell or organism
What is type 1 diabetes ?
Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin to control blood glucose levels
Type 1 diabetes is characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections
How does the body regulate its temprature ?
- If the body temperature is too high, the hair erector muscles relax, blood vessels dilate (vasodilation) and sweat is produced from the sweat glands
- If the body temperature is too low, hair erector muscles contract, blood vessels constrict (vasoconstriction), sweating stops and skeletal muscles contract (shiver)
What is type 2 diabetes ?
Type 2 diabetes the body cells no longer respond to insulin produced by the pancreas - the person still makes insulin but their cells are resistant to it and don’t respond as well as they should
A carbohydrate-controlled diet and an exercise regime are common treatments for Type 2 diabetes
What does glucagon do ?
Converts glycogen to glucose (for respiration)
