Biology Chapter 10 and 11 Flashcards
What are hormones
Chemical molecules released directly into the blood.
What do hormones do
They control things in particular cells and organs (target organs) that need constant adjustment
Where are hormones made (secreted)
Various glands called endocrine glands
What makes up the endocrine system
Endocrine glands
What is the role of the pituitary gland (master gland)
It produces many hormones that act on other glands directing them to release hormones
What does the thyroid produce
Thyroxine
What does thyroxine do
It regulates the rate of metabolism, hearts rate and temperature
What does the adrenal gland do
Produces adrenaline
What does adrenaline do
Prepares the body for a flight or fight response
What do the ovaries do
Produce oestrogen to be used in mensural cycle
What do the testes do
Produce testosterone which controls puberty and sperm production
What does the pancreas do
Produces insulin which is used to regulate the bloods glucose level
If blood glucose levels are too high what is added
Insulin
If blood levels are too low what is added
Glucagon
What is diabetes
When your body can’t control your blood sugar levels
Type 1 diabetes
The pancreas don’t produce enough insulin, there blood sugar level is too high
Solutions for type one diabetes
Insulin injections around meal times
Eat less food that is high in glucose
Type 2 diabetes
Your body cells don’t respond properly to insulin, your blood sugar levels are too high because you are over weight.
Menstrual cycle
The monthly release of an egg from a woman’s ovaries
Stages of mensural cycle:
- Uterus lining breaks down for about 4 days (mensuration starts)
- Uterus lining builds up for about 10 days
- An eggs develops and is released from the ovaries (ovulation)
- The wall is maintained for 14 days, if no fertilised egg lands on it the whole cycle will start again
What hormones control the mensural cycle (FOL P)
FSH
LH
Oestrogen
Progesterone
Roles of FSH
Causes the egg to mature
Stimulates the produce of oestrogen
Roles of oestrogen
Causes the lining of the uterus to grow
Stimulates the release of LH and inhibits release of FSH
Roles of LH
Stimulates the release of an egg (ovulation)
Roles of Progesterone
Maintains the the uterus lining
Inhibits the release of LH and FSH
How can oestrogen be used as a contraceptive method
because it inhibits the release if FSH so if oestrogen is taken daily the egg won’t mature, then the egg that is released won’t be fertile
Examples of hormonal contraception
The pill-contains oestrogen and progesterone
Contraceptive patch- contains oestrogen and progesterone, lasts a week
Contraceptive implant- put under skin of arm, releases progesterone, makes it hard for the sperm to reach the egg
Non hormonal contraceptive methods (barriers)
Condoms
Female condom
Diagram (plastic cap)
What hormones can be used to increase fertility
LH
FSH
What is the process of IVF (in vitro fertilisation)
Collecting a woman’s eggs and fertilise them in sperm in a lab
The eggs then grows into embryos in an incubator
Once some of the embryos are tiny balls of cells they are transferred to a woman’s uterus
What is ICSI (Intra-cytoplasmic sperm injection)
Where sperm in injected directly into an egg
What is homeostasis
Maintaining a stable internal enviroment
Why does the inside of your body need to be kept steady
Your cells need the right conditions in order to function properly
What is a receptor
A cell which detects a stimulus
What is the role of a coordination centre
It receives then processes information then organises a response
What is the role of an effector
It produces a response which counteracts the change
Examples of receptors
Taste receptors (on tongue) Sound receptors (in ear)
They can form part of a larger, complex organs (e.g. the retina of the eye is covered on light receptor cells)
Examples of effectors
Muscles (respond by contraction)
Glands (respond by secreting hormones)
What is the central nervous system (CNS)
Brain and spinal cords
What is a sensory neurone
Neurones that carry information as electrical impulses from receptors to CNS
What are motor neurones
The neurones that that carry electrical impulses from the CNS to effectors
What are effectors
All your muscles and glands which respond to nervous impulses
What is the order of the nervous system
Stimulus~Receptor~Sensory neurone~CNS~Motor neurone~Effector~Response
What is a synapse
The connection between two neurones
What happens at a synapse
A nerve signal is transferred by chemicals
They diffuse across the gap
They then set of a new nerve signal to the next neurone
What are reflexes
Rapid automatic responses to certain stimuli that don’t involve the conscious part of the brain
Example of a reflex
When a bright light shines in your eyes your pupils go smaller so lees damage is done
What is a reflex arc
The passage if information in a reflex (receptor to effector)
What is the order of a reflex arc
Stimulus Sensory neurone Relay neurone Motor neurone Then it reaches a muscle which contracts
What is reaction time
How quickly you respond to a stimulus
