5 - Homeostasis and Response Flashcards
How does the nervous system communicate with parts of the body?
Electrical impulses along neurones
What are the two communication systems in the body?
The nervous system and the endocrine system
How does the endocrine system communicate with parts of the body?
Hormones (chemical messages) via the blood
What are the two parts that make up the nervous system?
The central nervous system and the peripheral nervous system
What is a stimulus?
A change in the environment which causes a response in the body
How many organs can detect stimuli?
5
What stimuli can ears detect?
Sound and balance
What stimuli can eyes detect?
Light
What stimuli can skin detect?
Temperature and pressure (pain)
What stimuli can the nose detect?
Chemicals
What stimuli can the tongue detect?
Chemicals
Receptors for sound and balance?
Cochlea
Receptors for light?
Rods and cones on retina
Receptors for temperature and pressure?
Mainly nerve endings on the skin
Receptors in the nose?
Olfactory receptors
Receptors on the tongue?
Found on taste buds
What is a sense organ?
Organ made up of a cluster of receptor cells, which are sensitive to specific stimuli
Describe the pathway of an electrical impulse in the nervous system
Stimulus - receptor- sensory neurone - coordinator (CNS) - motor neurone - effector - response
What are sensory neurones?
Cells that carry impulses from sense organs to CNS
What are motor neurones?
Cells that carry impulses to make effector organs respond
What is an effector?
A muscle or gland - muscles respond to arrival impulses by contracting
How do muscles respond to arrival impulses?
By contracting
What is the cerebral cortex concerned with?
Consciousness, intelligence, memory and language
What is the cerebellum concerned with?
Mainly coordinating muscular activity and balance
What is the medulla concerned with?
Unconscious activities e.g. Controlling heartbeat, breathing
What is the hypothalamus concerned with?
Controlling body temperature
What is the pituitary gland concerned with?
Produces many different hormones which play a big part in coordinating and controlling body systems
How can matching changes in behaviour with the damaged part of the brain help scientists?
They can map the function of some parts of the brain
How can electrical stimulation of the brain help scientists?
They cans stimulate parts of the brain and see what effects it has e.g. hunger, fear
How can MRI scans of brains help scientists?
So they can understand development. Can link a loss of a certain function with damage to a particular region of the brain
How do scientists map brain regions?
By studying patients with brain damage, electrically stimulating areas of the brain and using MRI scans
What are potential problems when treating brain complications?
Processes involve neurones and chemicals released in synapses which can easily be damaged
Drugs do not always reach brain
Surgery is difficult as its not fully understood what part of brain does what
What are reflexes for?
To protect the body from harm or control basic body functions
What extra neurone is used in reflex actions?
Relay neurone
How does caffeine affect reaction time?
It decreases reaction time
What happens when an electrical impulse arrives at the synaptic knob?
Vesicles containing neurotransmitters migrate to the nerve cell membrane
Where do vesicles release neurotransmitters?
Into the synaptic gap where they diffuse across to the next neurone and attach to their receptor sites
Where may synapses occur?
Between sensory and relay neurones, and between relay and motor neurones
What are neurotransmitters?
Chemicals that diffuse between neurones and attach to receptor sites
What is the eye?
A sense organ containing many receptors that are sensitive to light intensity and colour
How are light sensitive cells arranged in the eye?
How are light sensitive cells arranged in the eye?
