Biology B3

Created by

ccbells

Cards (52)

What is the nervous system ?
The nervous system lets you react to what goes on around you
What is the central nervous system? What does it consist of?
Central nervous system (CNS) consists of the Brain and Spinal cord
How does the body coordinate a response? 
stimulus → receptor → sensory neurone → CNS → motor neurone → effector → response
What is a Stimulus?
A change in the environment
What type of neurone connects a receptor to the CNS
A sensory neurone
What is an effector 
Muscles or glands that bring about a response to a stimulus
What type of neurone connects the CNS to an effector?
A motor neurone
Describe the reflex arc 
Stimulus detected by a receptor
Impulse passed along sensory neurone to CNS
Impulse passed along motor neurone to effector
Effector brings about the response
What are Neurones 
Transmit information as Electrical impulses
What are Hormones? 
Chemical messages sent in the blood
What is the function of the pituitary gland ? 
it releases hormones into the blood
FSH is a hormone released from the pituitary gland
What is the function of the Pancreas?
Is where insulin is produced
What is the function of the ovaries? 
Produces oestrogen & progesterone
What is the function of the testes? 
For males only
Produces sperm and testosterone
Main male sex hormone
important for the development of the male reproductive system
What is the menstrual cycle? 
Time period when blood, tissue and unfertilized egg leaves the body.
Lasts for 28 days and egg is usually released on day 14 (ovulation)
Function of oestrogen 
Causes uterus lining to thicken and grow.
Inhabits the production of FSH.
Function of FSH 
causes an egg to mature in the ovary.
stimulates ovaries to produce oestrogen.
Function of LH 
stimulates ovulation
ovulation happens when LH & FSH levels peak
Function of progesterone 
Maintains the uterus lining
Inhabits the release of FHS & LH
Low progesterone levels allows the FSH to increase
What are contraceptives? 
Things that prevent pregnancy
What is the main component of oral contraceptives?
Progesterone & oestrogen
How do oral contraceptives work? 
Inhibit the production of FSH to prevent egg maturation
What is the effectiveness rate of oral contraceptives?
More than 99%
what are the side effects
mood swings, weight gain
What is the effectiveness rate of contraceptive implants?
More than 99%
How do contraceptive implants work? 
They cause a slow release of progesterone to prevent the ovaries from releasing eggs and thicken mucus in the cervix to prevent sperm from swimming through.
What is a benefit of contraceptive implants? 
Users do not need to remember to take them every day.
what are some non hormonal methods 
physical barrier methods - condoms
- easy to use & obtain & also protect from STI
- Condoms can rip
Over 99% effective.
- Can be made more effective with spermicidal agents, some people can be allergic to it
what are diaphragms? 
These are flexible , dome -n shaped devices that cover the cervix. They are inserted before sex.
What is an IUD also known as?
The coil
How does an IUD prevent pregnancy? 
- Stops fertilized embryos from implanting
- Copper kills sperm
What is the typical lifespan of an IUD?
Up to 10 years
Who should fit an IUD?
A doctor
What is a potential risk associated with IUDs? 
Small chance of ectopic pregnancy
Pros of Hormonal Methods 
1. More effective at preventing pregnancy than non hormonal methods
2. Allows couples to have sex without needing contraception each time
Cons of Hormonal Methods 
1. Side effects like headaches, acne, and mood swings
2. Need to be used correctly
3. Do not protect against STIs, only condoms do
What is homeostasis? 
Maintaining a stable internal environment
What is the role of insulin?
Controls blood sugar levels
How does insulin affect glucose in the blood? 
Insulin converts glucose into glycogen
Where is glycogen stored in the body?
Glycogen is stored in the liver and muscle cells