Homeostatis and Response Flashcards
(38 cards)
Which word means a change in the environment?
Stimulus
Give two examples of effectors
Muscles or glands
Which sense organ has receptors sensitive to light?
The Eye
Which two sense organs has receptors sensitive to chemicals?
The Nose and Tongue
What three conditions are controlled by homeostatis in the body?
Blood glucose concentration
Body temperature
Water levels
What is included in the central nervous system(CNS)?
Brain and spinal cord
A person accidentaly touches a hot pan. Her hand automatically moves away. Describe the structures in a reflex action.
A receptor detects a stimulus.
A sensory neurone transmits impulse to CNS
A relay neurone in the CNS passes the impulse on.
A motor neurone is stimulated.
The motor neurone passes the impulse on to an effector.
Action is taken (the response).
What is the generalised order during a nervous response?
Stimulus –> receptor –> coordinator –> effector –> response –>
Name the three different types of neurones.
Sensory,relay and motor neurones
What moves across the synapse?
A chemical messenger
What is a synapse?
A tiny gap at the junction between two nerve cells.
What three parts are contained in the brain?
Cerebral cortex, cerebellum amd medulla
Describe the three main parts of the brain.
Cerebral cortex- memory and thought
Cerebellum- movement
Medulla- heartbeat and thinking.
What part of the eye controls the amount of light entering it?
Iris
Why does the pupil get smaller?
It is a reflex response and stops damage to the retina.
Why do hormones take so long to act?
They have to travel through the bloodstream
What system releases hormones?
Endocrine system
Which gland is located at the base of the neck?
The thyroid gland
How can Type 2 diabetes be caused?
Lack of exercise and poor diet
Why do hormones last for such a long time?
They have an effect until they are broken down
Which hormones are produces in the male and female reproductive organs?
Testosterone and oestrogen
Is glucagon released by the pancreas when the blood sugar is too high?
Glucagon is not released when the blood sugar is high. Glucagon causes glycogen to be converted to glucose, which increases blood sugar.
How does the pituitary gland affect thyroxine levels?
If the level is too low, it releases Thyroid Stimulating Hormone (TSH). This makes the thyroid gland produce thyroxine.
Why is glucose needed for respiration?
Glucose is a reactant needed for the process
