2 Coordination And Control Flashcards
What is a receptor?
They are cells that detect stimuli ( changes in the environment )
What is inside a receptor cell? 3
A nucleus Cytoplasm Cell membrane
How do you respond to changes in your surroundings? 2
- impulses from receptors pass along sensory neurons to the brain or spinal cord - impulses are sent along motor neurons from the brain to the effector organs
What is a reflex?
Some responses to stimuli are automatic and rapid and are called reflex actions
Why are reflex actions so important?
Reflex actions run everyday bodily functions and help you avoid danger
How is the menstrual cycle controlled?
- hormones control the release of an egg from the ovary - and the build-up of the lining of the womb in the menstrual cycle
What is ovulation?
When 14 days after the egg starts maturing it is released from the ovary
How can hormones be used to stop pregnancy?
- oral contraceptives contain hormones which stop FSH production so no eggs can mature
What does FSH do?
Makes eggs mature in the ovaries
How are conditions inside your body controlled?
Homeostasis and it is the result of the coordination of your nervous system, your hormones and your body organs
What three neurons do reflex actions involve?
1 sensory neurons 2 motor neurons 3 relay neurons ( connecting 1&2 )
What stimuli do plants respond to? 3
Light Moisture Gravity
Why do plants respond to their environment?
Because of the hormone auxin
Why do farmers and gardeners use plant hormones?
We can use plant growth hormones as weed killers and as rooting hormone cuttings
How much should we use plant hormones to produce our food?
Plant hormones are very useful as weed killers but can be damaging to the environment
Why do you need a nervous system?
The nervous system uses electrical impulses to enable you to react quickly to your surroundings and coordinate what you do
What are the junctions between nerves called?
Synapses
What are the five stages of a reflex action?5
Stimulus Receptor Coordinator Effector Response
Give an example of something that is a reflex action?2
When something is near your face you blink When something is hot you pull your hand back
When is ovulation
About 14 days after the egg starts maturing
What are the five stages of your nervous system? 5
Receptor Sensory neurons Coordinator Motor neuron Effector
What is the difference between a sensory neuron and a motor neuron? 2
- the cells which carry impulses from your sense organs to your central nervous system - the cells which carry information from the CNS to the rest of your body are motor neurons
What is the name of the hormone in plants?
Auxin
What three things to plants respond to?
Light Moisture Gravity
How does a plant respond to gravity and moisture?
Its roots grow in the direction of gravity/moisture
Where is auxin produced in plants?
The root tip
When light shines on to one side of a plant what happens?
Auxin accumulates on the side opposite to the lift source Becoming unevenly distributed So growth in side of most auxin
What gland secretes FSH?
Pituitary gland
What gland secretes oestrogen?
Ovaries
What does FSH do?
It stimulates the ovaries to produce oestrogen
What does oestrogen do?
It stimulates the lining of the womb to build up ready for pregnancy It slows down the production of more FSH
Where is the pituitary gland?
The lower part of the brain
How do the ovaries and the pituitary gland work together?
As the oestrogen levels rise they slow down the production of FSH and encourage production of LH by the pituitary gland. When LH levels peak in the middle of the cycle they stimulate the release of a mature egg
Which two hormones will help women produce and release mature eggs?
LH and FSH
Describe the key features of asexual reproduction?
No fusion f gametes Only one parent No mixing of genetic material No genetic variation
What is the name of the junction between neutrons?
Synapse
How is information passed across this junction?
Chemically
Describe the blink reflex?
Light sensitive cell to sensory neuron Sensory neurone to brain Brain to motor neurone Motor neurone to eyelid muscle
How can hormones be used to prevent pregnancy?
Inhibits FSH production So the egg does not mature
What sense organs would detect how safe it is to cross a road?
Eyesight Hearing
Which sense organs help you to keep your balance?
Ears
What are stimulus’ detected by?
Receptor
What is the name of the cell which impulses travel to the centeral nervous system along?
The sensory neurone
What is the name of the cell which impulses travel from the centeral nervous system to the effector?
Motor neuron
What does the moving in a reflex?
Muscle
Where in the body are cells sensitive to light?
Eyes
Where in the body are cells sensitive to changes in position?
Ears
How is information passed from a sensory neurone to a motor neurone?
Chemically
What is the function of LH?
Stimulates the release of a MATURE egg cell
What is the function of FSH?
It stimulates the development of IMMATURE cells into eggs in the ovary
What is the function of progesterone?
Inhibits production of both LH and FSH
What is the function of oestrogen?
It stimulates the production of LH but inhibits FSH production
Why does progesterone continue to be produced the ought pregnancy?
Continues to inhibit FSH production and LH So that no eggs are matured or released Because danger to later convicted fetid if two develop in the uterus
How could FSH be used to treat infertility?
Could stimulate eggs to mature in woman whose own level of FSH is too low
How could LH be used to treat infertility?
Could stimulate egg release when a woman’s own LH production depressed by oestrogen
Once eggs are developed why are they released?
Oestrogen produced by ovary LH produced by pituitary gland LH causes egg release
What is a hormone?
A substance released in one part onto have an effect elsewhere in the body
How are hormones transported around the body?
In blood
How does sweating help the body?
Reduces body temperature
On a hot day in terms of water what is different?
More sweat less urine
Describe a reflex when someone touches a hot pan?
Heat detected by receptors in skin
Impulses travel along sensory neurone
To spinal cord
Chemical transmission across synapse
Via relay neurone
Impulses to muscle
Via motor neurone
Muscle contracts moving hand
What is the name of the structure that detects the stimulus?
Receptor
What is the name of the neurone that carries impulses to the central nervous system?
Sensory neurone
What is the name of the neurone that carries impulses away from the central nervous system?
Motor neurone
Describe what happens at a synapse when an impulse arrive?
information passes from one neurone to another
information passes across gap
by chemical diffusion
Describe the role of hormones in IVF treatment?
FSH or LH injected
FSH causes eggs to mature
LH stimulates egg released
