Nervous System Functioning Flashcards
Divisions of nervous system
Central Nervous System and Peripheral Nervous system,
Parts of CNS
Brain and spinal cord
PNS branches
Somatic and Autonomic nervous system
Subparts of the Autonomic nervous system
Sympathetic and parasympathetic nervous system
Functions of CNS
communicates with the body by conveying messages to the PNS
processes interprets and stores information
issues orders to muscles, glands, organs
The brain
an intricate network of cells that plays a vital role in processing information received through neural pathways from the body and in directing actions within the body
Spinal cord upper/lower function
upper- communication with brain and upper parts of body
lower- communication between the brain and lower parts of the body
spinal cord functions
receive sensory information from the body and send these messages to the brain for processing
receive motor information from the brain and send it to relevant parts of the body( via PNS)- control muscle, organs and glands
spinal cord comprises of
white and grey matter
white- axons that run length of spinal cord uninterrupted and bundled together
grey- cell bodies, together with axons and dendrites, located near centre of spinal cord
what are interconnected axons in CNS called
tracts, circuits or pathways
Differentiate ascending/descending tracts
ascending tracts- somatosensory information, comes in from parts of body, through spinal nerves to brain
descending tracts- motor information, leaves brain travels down spinal cord and exit via spinal nerves to muscles, organs, glands
PNS function
sends messages to CNS via sensory neurons
carries out messages from CNS via motor neurons
transfer information from sensory organs to CNS, then convey info from CNS to muscles, organs and glands
distinguish afferent/efferent pathways
afferent- ascending, sensory tracts
efferent- descending, motor tracts
Somatic nervous system
controls our conscious voluntary responses
functions incontinuously
why is SNS called skeletal
has both a sensory and motor function
functions of SNS
transmits messages from sensory receptors to CNS
controls the voluntary movement of skeletal muscles through CNS messages
ANS
directs our unconscious/involuntary functioning
ANS function
keep homeostasis in body
autonomic=self governing, operate usually independently from the brain
controls visceral muscles( internal organs and glands muscles)
sympathetic nervous system functions
increases visceral muscle activity
mobilises body internal resources
prepares for vigorous action in times of stress/emergency
sends message to adrenal gland to release adrenaline and noradrenaline
body changes of sympathetic
dilate pupils/inhibit tears inhibits salivation increases heart rate, vasodilation/blood pressure increase increase respiration rate/bronchi dilate inhibits digestion sweat glands increase production of sweat release adrenaline releases sugar/glucose relaxes bladder/intestine inhibition of food intake gall bladder inhibits bile release
parasympathetic NS
calms bodily activity, conserves energy and returns internal system to homeostasis (balanced level of activity)
decreasing visceral muscle activity
reverse symp effects- dominates symp in relaxed times
why does it take longer to return body to homeostasis than arousal
lingering hormones such as adrenaline in blood
body changes of paraysympathetic
constricts pupils/stimulate tears stimulates salivation heart rate/blood pressure decrease decrease respiration/bronchi constrict decrease glucose release from liver inhibit liver hormone secretion stimulates digestion contracts bladder and intestines decrease production of sweat stimulates bile release from gall bladder
conscious responses to stimuli
reaction involving awareness paid attention to stimulus voluntary reaction often goal directed more complex can be learnt/controlled vary