Module 5 Flashcards
What is homeostasis?
Conditions inside body need to keep steady, even when external environmental changes. Important because cells need right conditions in order to function properly including conditions for enzyme action. To sustain regulation in body to maintain a stable internal environment in response to changes in external and internal conditions.
How does th ebody perform homeostasis?
You have loads of automatic control systems in body to regulate internal environment, both nervous and hormonal communicatoin systems. All automatic control systems made up of 3 main components which work together a steady condition, cells called resceptors, coordination centres and effectors.
What is negetive feedback?
When levels of something gets too high or too low
What happens when a receptor detects a stimulus a level too high?
Coordination centre recieves and processes information then organises a response. Effector produces a response which conteracs change and restores optimum level, level deccreaes/increases if too low.
What happens in response to change in level in homeostasis?
Effectors will just cary on producing responses for as long as stimulated by coordinatoin centre. Might cause oppisate problem making level change too much. Luckily receptor detects if level becomes too different and negative feedback starts again.
Whst is the central nervous system?
In vertebrates this consists of brain and spinal cord. In mammals, CNS is connected ot body by sensory neurones and motor neurones. Recieves information from receptors and then coordinates a rsponse. Response carried out by effectors.
What is sensory neurons?
neurones that carry information as electrical impulses from receptors to CNS.
What is the motor neurones?
Neurones that carry electrical impulses from CNS to effectords.
What are the effectors?
All muscles and glands which respond to nervous impulses.
What are receptors and effectros ?
Receptors are cells that detect stimuli. Are many different types of receptors, such as taste receptors on toungue and sound receptors in ears. Receptors can form part of larger complex organs. Effectors respond to nervous impulses and bring about a change. Muscles and glands are known as effectors-they respond in different ways. Muscles contract in response to a nervous impulse, whereas glands secrete hormones.
What are synapses?
The connection between 2 neurons is called a synapse. Nerve signal is transferred by chemicals which diffuse across the gap. Theses chemicals then set off a new electrical signal in next neurone.
What are reflexes?
Reflexes are rapid, automatic responses to certain stimuli that doesn’t involve the conscious part of brain-can reduce chances of being injured.
What happens if someone shines a bright light in your eyes?
Pupils automatically get small er so less light gets into eye-stops it getting damaged. If get a shock, body releases hormone aderaline automatically. Passage of infomation in a reflex is called a reflex arc.
What is the passage of the reflex arc and the CNS?
Neurons in reflex arcs go through spinal cord or through and unconscious part of brain. When stimulus is detected by receptors, impulses are sent along sensory neurone to relay neurone in CNS. When impulses reach a synapse between sensory neurone and relay neurone, trigger chemicals to be released. Chemiclas cause impulses to be sent along relay neurone. When impulses reach synapse between realy neurone and motor neurone, same thing happens. chemicals are released and cause impulses to be sent along motor neurone. Impulses then travel along motor neurone to effector. Muscles then contracts and move hand away from bee . Muscle contracts and moves hand away from bee.
Where is the brain, and what is it made up of?
Along spinal cord, brain is part of centrel nervous system. Made of billions of interconnected neurones. Brain is in charge of all complex behaviours. Controls and coordinated everything you do.
What is the cerebral cortex/
This is outer wrinkly bit. Responsible for things e.g. consciousness, intelligence, memory and language.
What is the medulla?
Controls unconcious activitiese.g. breathing.
What is the cerebellum?
responsible for muscle coordination.