B10 THE NERVOUS SYSTEM Flashcards
What is your internal enviroment
The conditions inside your body
What is homeostasis
The process of keeping everything constant inside yout body(internal envrioment has to stay the same)
What is controlled through homeostasis (3 things)
Internal body temprature
Water levels
Sugar levels
What are receptor cells
Speciallised cells which detect a change in the environment (stimulus) and stimulate electrical impulses in response
What is the coordination centre and example
receives and processes information from receptors around the body(brain and spinal cord)
What are effectors
include muscles and glands - that produce a specific response to a detected stimulus
What is the nervous system
System which controls all the actions which are body makes
What does the cns include
Brain and spinal cord
What does the peripheral nervous system include and what does it do
Contains nerves taking info from the sense organs to the cns and back to the effectors
Detailed explanation on the nervous system
Info passes along cells called neurones as electrical impulses to the cns.(bunches of neurones are called nerves.) the cns coordinates the response of effectors which may be muscles contracting or glands secreting hormones
The nervous system journey
Stimulus–> receptor–> sensory neurone—>coordination (cns)–>motor neurone—->effector——->response
Types of neurone explanations
First neurone in the chain is the sensory neurone. It’s connected to the receptor and carries the message to the cns
The second neurone is the motor neurone. Which carries messages from the cns and is connected to the effector
What are reflex actions
Actions are automatic. Messages bypass the brain. We do them without thinking, involuntarily
What is the relay neurone
Passes electrical impulses from the sensory neurone to the motor neurone found in the spinal cord and brain
Nervous system journey but with a reflex action
Stimulus–> receptor–> sensory neurone—> relay neurone–>motor neurone—->effector——->response
What is the synapse
The gap where 2 neurones conmect
How do electrical impulses travel through the synapse
They Travel to one end of the nerve cell and cause a chemical to be released called a neurotransmitter this diffuses across the gap more slowly than an electrical impulse would travel.
Reaction time required practical method
1-One student holds a ruler vertically so the zero end points downwards. The other student puts their thumb and fingers in a C shape around the ruler, level with the zero marking (weakest hand)
2=Without warning, the first student drops the ruler and the second student has to catch it as quickly as they can.
3=Write down the number just above the second student’s thumb. The lower the number, the shorter the reaction time. Write the number in the results table and convert it into a reaction time in ms.
4=Repeat steps 2 to 4 four more times.
5=Now repeat but cause a distraction in the room.
6-Repeat steps 2 to 4 five more times and record the results in the table.
7-Calculate the mean. giving your answer to the nearest whole number.
8-Plot your mean results in a bar chart
