B10.1 - B10.6 - Human Nervous System✔️ Flashcards
Define homeostasis?
The bodys balancing of internal conditions to maintain optimum conditions for functioning, in response to internal and external changes
Example of three internal conditions controlled by the body?
-body temperature
-water contents of the body
-blood glucose concentration
What are receptors?
Cells that detect changes in the internal or external enviorment - changes known as stimuli - receptor cells part of nervous or hormonal control systems
what are stimuli?
Changes in the internal or external enviorment and are detected by receptor cells
What are coordination centres?
Areas that recieve and process the information from the receptors they send out signals and coordinate the response examples are the brain,spinal cord and some organs like the pancrease
What are effectors?
Muslces or glands that bring about response to the stimulus - response restores conditions in the body to optimun levels
What are neurones?
Special cells where information is passed along as electrical impulses - found in bundles of hundreds or even thousands which are known as nerves
What is the central nervous system?
central nervous system (CNS) is made up of the brain and spinal cord
What are sensory neurones?
The cells that carry impulses from your sense organs to your CNS
What are motor neurones?
Cells that carry informtion from the CNS to the rest of your body - carry impulses to the correct effectors
How might an effector respond to an impulse?
-muscles will respond by contractiing
-glands respond by secreting chemical substances
Order in which the nervous system detects a stimulus and acts?
Stimulus - receptor - coordinator(CNS) - effector
Step 1 - nervous sytems response to a stimulus?
Receptor sends an impulse along a sensory neurone carrying information about a change in the enviorment to the coordinator (CNS)
Step 2 - nervous sytems response to a stimulus?
Once the incoming information has been processed the coordinator (CNS) sends impulses down motor neurones
Step 3 - nervous sytems response to a stimulus?
The motor impulses stimulate the effectors to bring about the response needed in any particular situation
What are reflexes?
Our bodys automatic, rapid and sub-conscious reaction to harm or incoming danger they do not involve the conscious part of your brain example of some of the functions are breathing and moving food through your digestive system
Describe the process of the reflex ark ?
Electrical impulse passes from the receptor along the sensory neurone then passes along a relay neurone (found in the CNS) and straight back to the motor neurone from there it arrives at the effector (muscle or gland)
Why is the reflex arc so rapid and takes place so quick?
The impulse bypass the conscious areas of your brain so the time between stimulus and reflex action is as short as possible because it does not require us to think
What are relay neurones?
Involved in the reflex ark and connect sensory neurones an motor neurones and are found in the CNS (usually in the spinal cord)