B10 Flashcards
What are receptors
an organ or cell able to respond to light, heat, or other external stimulus and transmit a signal to a sensory nerve.
Stimulus
a thing or event that evokes a specific functional reaction in an organ or tissue.
Effectors
an organ or cell that acts in response to a stimulus.
Homeostatis
the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Neutrons
The neuron is the basic working unit of the brain, a specialized cell designed to transmit information to other nerve cells, muscle, or gland cells. Neurons are cells within the nervous system that transmit information to other nerve cells, muscle, or gland cells
Nerves
Nerves are cells called neurones, which make up our nervous system. Nerves are specialised cells - they carry messages from one part of the body to another, as tiny electrical signals.
Central nervous system
the complex of nerve tissues that controls the activities of the body. In vertebrates it comprises the brain and spinal cord.
Sensory neurones
Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from the organism’s environment into internal electrical impulses.
Motor neurone
motor neuron is a neuron whose cell body is located in the spinal cord and whose fiber projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.
Reflex
reflex is an involuntary or automatic, action that your body does in response to something
Reflex arc
A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord
The nervous system
It means that humans can react to their surroundings and coordinate their behaviour
What are the main things that the nervous system is made up from
It is made up of the central nervous system The sensory neurones Motor neurones Receptors Effectors
How do reflexes help prevent injury
Reflex’s are automatic responses meaning you do think about them
This makes them very quick
They can help stop you getting injured
The neurones in reflex arcs go through the spinal cord or through an unconscious part of the brain
The passage of information in a reflex (from receptor to effector) is called a reflex arc
What way does the reflex receptor work
A bee stings your finger. Bee sting is detected by receptors
The impulses are sent along a sensory neurone to the CNS
In the CNS a relay neurone passes on the impulses from the sensory neurone to a motor neurone
Impulses are sent along the motor neurone to the effector
The effector here is a muscle. It contracts to move the hand away from the touch of pain
The person doesn’t control any of these movements
Homeostasis what is it
Homeostasis is the fancy word for keeping the conditions in your body and cells at the right level. This happens in response to changes inside the outside of the body.
This is really important because your cells need the right conditions to work properly
This includes having the right conditions for enzymes to work
What in your body uses control system for homeostasis
In the body their are loads of control systems that keep conditions in your body steady
The control systems are automatic meaning you don’t actually think or control them
They can control conditions in the body using the nervous system or hormones
They are normally made up of three parts receptors, coordination centres and effectors
Level of the blood glucose
If the level is too high, the control system decrease the level
If the level is too low, the control system increase the level
How does a control system work
If the level of something changes
A receptor detects a stimulus (change in environment)
It then send information to the coordination centre
The coordination centre receives and processes the information
It then organises a response
A effector produces a response
This returns the level to its optimum (ideal) level
How can you measure reaction times
A reaction time is the time it takes for response to a stimulus
It often take less than a second. This means it may be measured in milliseconds.
It can be affected by factors such as age, gender or drugs
