The human nervous system Flashcards
Nervous system
Body’s communication network that consists of all nerve cells allows the organisms to sense organise, react to information in the environment
The CNS central nervous system
Coordinates the actions and interactions of the brain and the spinal cord body’s main control center
It is the largest part of the nervous system
The spinal cord is an information highway connecting to the peripheral nervous system to the brain
The peripheral nervous system PNS
Includes the sensory nerves outside the brain and the spinal cord that connect the CNS to the rest of the body
- process changes in internal and external stimuli communicate that information to the CNS
Two major divisions
- motor pathways signals from brain to muscles/ glands
- sensory pathway : signals from sensory receptors to the brain
Somatic nervous system
Includes the nerves that transmit signals from your brain to the skeletal muscles to allow voluntary movement
Autonomic nervous systems
Regulates involuntary and unconscious actions
- breathing, blood pumping through veins, digestion, heartbeat, work of other internal organs
Sympathetic nervous system
Emergency response system if something alarms, enrages or challenges you flight, fight or freeze
- accelerate your heartbeat
- raise of blood pressure
- slow your digestion
- raise your blood sugar
- cool you with perspiration
Making you alert and ready for action
Parasympathetic nervous system
Functions to calm the person rest and digest
Reduces body arousal, energy, decreases blood sugar increases blood flow to the digestive organs, decreases heart rate
Maintains homeostasis
- a constant internal body environment
- counterbalances the activities of the sympathetic nervous system
- inhibits the production of adrenaline
- decrease heart rate, respiration and blood pressure
-increases digestion and production of saliva
Neurons
Specialised cell in the nervous system that receives and sends messages with electrochemical signals
- messengers of the body
- basic units on which the entire brain and nervous system are built
Glial cells
Cells that provide physical support for the neurons to grow on and around acts like glue
Surrounds neurons, get nutrients to the neurons clean up remains of neurons that have died and provide insulation.
Soma life support
The cell body of the neuron responsible for maintains the cell of the cell
Synapse
Contact point: meeting point between neurons
Synaptic vesicles store various neurotransmitter chemicals that are released at the synapse
Receptor sites receive signals
Reflex arc
Signal is sent form a sensory organ to the spinal cord, which processes the information instead of passing it on to the brain
Afferents neurons
Neurons that Carry incoming information from the sensory receptors to the brain and the spinal cord
Motor neurons efferent neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
Neutral transmission
Process by which the information travels through a neuron each neuron receives an impulse and must pass it on to the next neuron and make sure the correct impulse continues on its path
Excitatory neurotransmitter and inhibitory
Excitatory excite neurons and cause them to fire more action potential are triggered inhibitory prevent the next neuron from firing
Serotonin
Connected to feelings of happiness regulation of emotion it regulates the sleep cycle along with melatonin and also regulates intestinal movements appetite
- inhibitory
Major for drug treatments for depression and anxiety
Too much of it is asssociated with hallucinations and anorexia
Too little of it is associated with depression, some anxiety, sleep disorder
Ecstasy increases serotonin in the short term and decreases in the long term
Dopamine
Pleasure of chemical of the brain released into pleasure centres of the brain relegated to reward and motivation learning
- inhibitory
- it is also associative with addiction movement and motivation
Too much dopamine is associated with schizophrenia
Too little is associated with some forms of depression as well as the musclular rigidity and tremors found in Parkinson disease
