| A | B |
|---|
| specialized cell | uniquely suited to perform a particular function |
| epithelial tissue | glands and tissues that cover interior and exterior body surfaces |
| connective tissue | support for the body and connects its parts |
| nervous tissue | transmits nerve impulses throughout the body |
| muscle tissue | along with bones, enable the body to move |
| homeostasis | animals maintain a controlled, stable environment |
| feedback inhibition | process in which the product or result |
| neuron | cells that transmit impulses |
| cell body | The largest part of a typical neuron |
| dendrite | spreading out from the cell body are short, branched extensions called |
| axon | long fiber that carries impulses away from the cell body of a neuron |
| myelin sheath | insulating membrane surrounding the axon in some neurons |
| resting potential | electrical charge across the cell membrane of a resting neuron |
| action potential | reversal of charges across the cell membrane of a neuron |
| threshold | minimum level of a stimulus required to activate a neuron |
| synapse | location at which a neuron can transfer an impulse to another cell |
| neurotransmitter | are chemicals used by a neuron to transmit an impulse across a synapse to another cell |
| mininges | layers of connective tissue |
| cerebrospinal fluid | bathes the brain and spinal cord and acts as a shock absorber that protects the central nervous system |
| cerebrum | the largest and most prominent region of the human brain |
| cerebellum | the second larges region of the brain |
| brain stem | connects the brain and spinal cord |
| thalamus | receives messages from all of the sensory receptors throughout the body and then relays the imformation to the proper region of the cerebrum for further processing |
| hypothalamus | the control center for recognition and analysis of hunger, thirst, fatigue, anger, and body temperature |
| reflex | is a quick, automatic response to a stimulus |
| reflex arc | the pathway that an impulse travels from your foot back to your legs |
| sensory receptors | react to a specific stimulus such as light or sound by sending impulses to other neurons, and eventually to the central nervous system |
| pupil | located in the middle of the iris |
| lens | small muscle attached to the lens change its shape to help you adjust your eyes' focus to see near or distant objects |
| retina | innermost layer of the eye; contains photoreceptors |
| rods | photoreceptor in eye that is sensitive to light but not to colors |
| cones | are less sensitive that rods, but they do respond to light of different colors, producing color vision |
| cochlea | fluid-filled part of the inner ear; sends nerve impulses to the brain through the cochlear nerve |
| semicircular canals | one of the three structures within the inner ear that help monitor the position of the body |
| taste buds | sense organ that detects taste |
| drug | any substance, other than food, that changes the structure or function of the body |
| stimulants | increase the actions regulated by the nervous system |
| depressants | decrease the rate of functions regulated by the brain |
| fetal alcohol syndrome | group of birth defects caused by the effects of alcohol of the fetus |
| drug abuse | intentional misuse of any drug for nonmedical purposes |
| addiction | uncontrollable dependence on a drug |
