Psychology CHP.4 Flashcards
For SAC/Exam
The nervous system is split
into the central nervous system + peripheral nervous system
The central nervous system diagram
the central nervous system:
- brain + spinal cord
- -brain: forebrain, midbrain, hindbrain
- –forebrain: cerebrum, thalamus, hypothalamus, limbic system
- –midbrain: reticular formation
the peripheral nervous system diagram
the peripheral nervous system:
- somatic + autonomic nervous system
- -somatic nervous system: sensory and motor nerves
- -autonomic nervous system: sympathetic + parasympathetic nervous system
two major divisions of the nervous system
central nervous system (CNS)
peripheral nervous system (PNS)
The CNS and PNS
The human brain needs to receive information from the body’s sense organs which receive information from the environment. The brain is connected to muscles and glands so that an organism can respond and act on their current environment
central nervous system
- made up of the brain + spinal cord
the spinal cord
- enables the brain to communicate with the rest of the body by sending messages from the brain to the PNS and back.
- the upper section of the spinal cord is responsible for communication between the brain and upper parts of the body
- the lower section of the spinal cord is responsible for the lower parts
the peripheral nervous system
two functions:
-send information from the body’s organs, glands and muscles to the CNS, from both the inside and outside world
- communicate information from CNS to the body’s organs glands and muscles via motor neurons
somatic nervous system
-responsible for voluntary movement of skeletal muscle
autonomic nervous system
- responsible for sending information between CNS, non-skeletal muscles and internal organs
- is involuntary but some actions such as breathing and blinking can be voluntary
sympathetic nervous system
- emergency system that activates when in danger or stressed
- important role in organisms survival as it readies body for the fight, flight and freeze response. Prepares organs to deal with threats or stressors.
parasympathetic nervous system
- operates when relatively calm
- responsible for maintaining automatic day-to-day bodily functions e.g normal breathing. aka homeostasis
- – allows us to do everyday tasks and keeps body functions in balance
neurons
receive information from other neurons, process then communicate it to other neurons
neurons are made up of 3 elements
- dendrites
- soma
- axon
dendrites
- tree-like
- receives information from other neurons or sensory receptors via synapses and deliver it to the cell body or soma
soma
- is the cell body
- largest part of the neuron
- controls metabolism & maintenance of the cell
axon
- nerve fibre
- carries information from the soma to their ends to other cells in contact with the neuron
- -information carried as an electrical impulse is also “action potential”
- -terminal buttons on the end of axon makes a chemical (neurotransmitter) when information is sent down the axon as electrical impulses
glial cells
- cells not part of the neuron but support ut
- hold neurons together
Motor Neurons
> motor neurons send messages from the CNS to the certain muscles the organism intends to move
Sensory neurons
> sensory neurons convey the sensation, detected by sensory receptors to the brain
interneurons
they connect the spinal motor and sensory neurons
glial cells main functions
- surround neurons and hold them in place
- supply nourishment and oxygen to neurons
- remove dead neurons
- insulate one neuron from another and increase speed of transmission of nerve impulses
- to do this glial cells produce myelin
myelin
- fatty substance that covers just the axon to insulate it from neurons or surrounding fluid
- produced in brain + spinal cord by glial cells
- process of producing myelin is myelination
- myelinated neurons are faster in conducting messages
reaction times
can be voluntary or involuntary, factors such as preparation, practice and strength can improve our reaction times
