nervous system and endocrine system Flashcards
define stimuli
changes in organism’s lifestyle
define receptors
nerve endings on nerve cell that detect changes in internal and external environmenet
define coordination
method which receptors pick up stimuli and pass information to effectors
what is the importance of responding to stimuli
ensuring survival of organism
maintaining constant internal environment so that enzyme and cell can function efficiently
what is the function of human nervous system
detect changes in external and internal environment
send nerve impulses to effectors to respond appropriately
coordinates function and activates inside body
what is the use of myelin sheath
speed u[ transmission of impulses by allowing impulses to hop from one gap to another
acts as an insulator to prevent leakage of nerve impulses
draw the 3 types of neuron
cell body
dendrites
axon
myelin sheath
name the uses of each neuron
motor: receives information from integrating centre and send to effectors
sensory: detect stimuli via receptors and send info to integrating centre
interneuron: connect sensory neuron to motor neuron
what is in CNS
brain and spinal cord
controls all activities
what is in peripheral nervous system
cranial nerve & spinal nerve
controls sensory organ and effectors to CNS
name the 3 parts of brain and their function
cerebrum: thinking, reasoning, speech
cerebellum : movement and balance
medulla : involuntary action
function of spinal cord
controls reflex action
connect PNS to brain
contains cell bodies of neurons
describe the process of transmission1 of info in nervous system
stimulus –> receptors –> sensory –> interneuron –> motor –> effector –> receptor
describe how a synapse work
info reach pre synaptic cleft
synaptic vesicles release neurotransmitters into synaptic cleft
neurotransmitters diffuse across to post synaptic neuron
bind with receptors on postsynaptic membrane to fire electrical pulses
what is the importance of synapse
enables neuron to hv a connection with other neuron
ensure impulses flow in one direction
define the types of action
voluntary: conscious by cerebrum
involuntary: non conscious control which involves medulla or spinal cord
define a reflex action
fast automatic response to stimulus
involves spinal cord as integrating centre
label the eye and their function
sclera- protect eye
retina - contains light sensitive receptors
cornea - refracts light
iris- controls how much light enters pupil
lens- focus light onto retina
optic nerve - carries impulses to brain
fovea
what is rod cells
sensitive to low light intensity
detects grey
around retina
what is cone cells
detects colour
in fovea and retina
describe what happens when we see far objects
CCC
ciliary muscle relax
suspensory ligament taut
eye lens become thin
what happens to eye in bright light
radial muscle relax
circular muscle contract
pupil constrict
define a hormone
chemical messenger produced by endocrine glands
define endocrine glands
ductless glands that release and produce hormones into bloodstream
define target cells
specific cells affected by hormones
what is the function of hormones
regulated activities in tissues and organs
describe how hormones work
hormone enters blood stream
goes into target cells
binds with receptors on plasma membrane
cell response in specific manner
