unit 3 aos 1 Flashcards
central nervous system
comprises of the brain and spinal cord
peripheral nervous system
entire network of nerves located outside the CNS
carried info to and from the CNS via somatic + autonomic
brain
an intricate network of cells that helps process info received through neural pathways from the body and helps direct actions in the body
neural pathways
a route based on interconnected neurons that form a communication network:
- within the brain
- between brain and nervous system
- between brain and body
spinal cord
long, thin, bundle of nerve tissue connecting the brain and rest of the body via the PNS
initiates spinal reflex w/o the brain
roles of the spinal cord
- receives sensory info from the body (via PNS) and sends this info to the brain for processing
- receives motor info from the brain and sends it to relevant parts of the body (via the PNS)
roles of the PNS
- carries info to the CNS from the body’s muscles, organs, glands, and sensory organs
- carries information from the CNS to the body’s muscles, organs, and glands
Somatic nervous system
connects the CNS to the body’s internal organs and glands, providing feedback to the brain about their activities
afferent info
sensory info coming to the CNS
efferent info
motor info leaving the CNS
autonomic nervous system
connects the CNS to the body’s internal organs and glands, providing feedback to the brain about their activities
visceral muscles
muscles involved in the activity of internal organs and glands
sympathetic nervous system
activates internal muscles, organs, and glands to prepare for vigorous activity to deal with a stressor, threat, or emergency
parasympathetic nervous system
calms or restores the body to its normal state of functioning after the need for sympathetic nervous system activation has passed
enteric nervous system
embedded within the walls of the gastrointestinal tract and dedicated to its functioning
link between sympathetic and parasympathetic
The sympathetic and parasympathetic systems counterbalance each other’s activities without conscious effort
one is dominant, there’s no on/off
gastrointestinal tract
the part of the digestive system that comprises the hollow organs that food and liquid travel through during digestion
(mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus, liver, pancreas, gall bladder)
roles of the enteric nervous system
- ENS and brain interact for gut movement (detect physiological condition of the GIT + provide outputs to control gut)
- nutrient management, regulating gastric acid
- interacting with parts of the immune and endocrine systems located in the gut
parts of the enteric nervous system
rectum, intestines, duodenum, stomach, eosophagus
liver, pancreas, gallbladder
conscious response
a reaction to a sensory stimulus that involves awareness
- voluntary and with some degree of control over it
unconscious response
a reaction to a sensory stimulus that does not involve awareness
- involuntary, automatic, we cannot ordinarily control its occurrence
spinal reflex
an unconscious, involuntary response to certain stimuli controlled solely by neural circuits in the spinal cord
spinal reflex
an unconscious, involuntary response to certain stimuli controlled solely by neural circuits in the spinal cord
why are spinal reflexes adaptive?
Spinal reflexes are considered adaptive as they save time in situations that may be very harmful to the organism.
neurotransmitters
a chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, glands or other tissue. attaches itself to the receptor sites of post-synaptic neurons
synaptic gap
the tiny space between the axon terminal of a presynaptic neuron and the dendrite of a postsynaptic neuron
neural synapse + its components
the site where communication typically occurs between adjacent neurons
- synaptic gap
- terminal buttons of pre-synaptic neuron
- dendrites of post synaptic neuron
excitatory effect
when a neurotransmitter stimulates or activates a postsynaptic neuron to perform its functions
inhibitory effect
when a neurotransmitter blocks or prevents a postsynaptic neuron from firing and therefore performing its functions
reuptake
Neurotransmitter that does not bind to receptors in the postsynaptic neuron is absorbed back into the terminal buttons by the presynaptic neuron
difference between visceral muscles and skeletal muscles
skeletal muscles are inactive in the absence of motor messages from the brain whereas visceral muscles act independently of the brain
differences between somatic nervous system and autonomic nervous system
- ## somatic nervous system initiates skeletal muscle movement, autonomic nervous system regulates activity of visceral muscles
glutamate
main excitatory neurotransmitter in the CNS that enhances transmission by making post-synaptic neurons more likely to fire
role of glutamate
- learning and memory
- strengthening of synaptic connections
- enables synaptic plasticity
- thought and movement
GABA
Gamma amino buryic acid
main inhibitory neurotransmitter in the CNS making post synaptic neurons less likely to fire
role of GABA
- prevents seizures by inhibiting firing
- reduces anxiety
- prevents over excitation
- regulates post synaptic activation in pathways