The Eye
What stimulus does the eye detect
light
what are the three layers of the skin
epidermis, dermis and hypodermis/subcutaneous layer
state two types of stimulus
light
moisture
tempature
chemical
touch
Define a drug
A drug is any substance that alters the normal functioning of the human body
State the functions of the Lens
transparent, elastic, biconvex structure that focuses light rays onto the retina
state the three functions of the skin
sensing
regulating
protecting
what are the two parts of the nervous system
Central nervous system
peripheral nervous system
What are the two categories of drugs that have opposite effects?
Stimulus and depressants
Carries impulses from the retina to brain
Optic nerve
state three methods of how the skin regulates body temperature in hot weather
excess sweating
vasodilation
hair errector muscles relax
what are the three types of neurons and their functions
Sensory neurons- Transmit impulses from receptors to CNS
Motor- transmit impulses to effector
Relay- transmit impulses though CNS
State one short term effect of alcohol and on long term effect
impaired muscular saired mental function
blurred vidion
slurred speech
memory lapses
Drowsiness
Name the three layers at the back of the eye and their functions
sclera- tough, white, fibrous coat that protects the eye ball
Choroid-provides retina with food to retina
Retina- contains photo receptors where images are formed
What term refers to tempature regulation in humans
Homeostasis
State two specialized parts of nerve cells
dendrites
myelin sheath
axon
synaptic knobs
State the disease which is a result of excess alcohol consumption
cirrhosis( scarring of the liver)
State the two types of photo receptors found in the eye and what conditions they best function in
rods- low light intensities
Cones- high light intensities
What chemical in the skin protects humans from harmful UV light
Melanin
describe a full cranial reflex where low light intensity is the stimulus
Stim- low light
receptor-light sensitive cells in retina
Sensory neuron
relay neuron
motor neuron
effector- circular iris muscles
Response- eye widens to allow more light to enter
Three frequently abused prescription dugs and a effect of the over use
Tranquilizer's
antibiotics
Diet pills