Biology Vocab From Chapter 28

Front 1

Central nervous system (CNS)

Back 1

the bodies main information processing center is made up of the brain and spinal cord

Front 2

Peripheral nervous system (PNS)

Back 2

the nervous tissue outside the CNS, delivers information to the CNS and other organs through nerves

Front 3

Nerve

Back 3

one or more bundles of neuron fibers, surrounded by connective tissue

Front 4

Stimulus

Back 4

information about an environmental change

Front 5

Sensory Neurons

Back 5

neurons that carry information about the stimuli to the CNS – some detect stimuli directly – ex. Pain

Front 6

Sensory Receptors

Back 6

highly specialized cells

Front 7

Interneurons

Back 7

neurons located entirely within the CNS

Front 8

Motor neurons

Back 8

neurons that carry signals away from the CNS (ex. Muscle contracting or glands secreting hormones)

Front 9

Reflex

Back 9

a rapid automatic response

Front 10

Reflex arc

Back 10

the nervous system pathway that regulates a reflex

Front 11

THE CNS AND PNS CARRY OUT THREE MAIN FUNCTIONS:
SENSORY INPUT

Back 11

*PNS receives info. about environmental change
*Neurons carry information to sensory neurons
*Most stimuli received by sensory receptors

Front 12

INTEGRATION

Back 12

*CNS interprets information
*This involves neurons called interneurons
*Example would be sitting down

Front 13

MOTOR OUTPUT

Back 13

*CNS orders a response
*Muscle contraction or secretion of hormone
*Neurons responsible for carrying these signals are called motor neurons

Front 14

Dendrites

Back 14

fibers that receive signals and carry then toward the neuron cell body

Front 15

Axon

Back 15

a fiber that carries electrical impulses away from the cell body and towards other cells

Front 16

Myelin sheath

Back 16

a thick coat of material that insulates the axons of neurons

Front 17

Nodes

Back 17

the uninsulated spaces between the myelin sheath

Front 18

Resting Potential

Back 18

the voltage across the plasma membrane of a resting neuron (potential = energy)

Front 19

Depolarization

Back 19

voltage change – because the charge difference across the membrane decreases

Front 20

Threshold

Back 20

a neuron will only fire if the stimulus is strong enough to depolarize the membrane to a certain level

Front 21

Action potential

Back 21

stronger depolarization – start of the nerve signal

Front 22

Synapse

Back 22

junctions between two neurons or a neuron and another cell where electrical or chemical signals are relayed

Front 23

Synaptic Cleft

Back 23

tiny space separating a knob from a transmitting neuron from a receiving neuron or other cell

Front 24

Neurotransmitters

Back 24

chemical messenger that carries information from one neuron to another or to another cell (chemical signal mostly consisting of small nitrogen containing organic compounds-def. from chapter

Front 25

Somatic nervous system

Back 25

subdivision of the motor division of the peripheral nervous system that controls the voluntary movement of skeletal muscles. Carrys signals form the CNS to skeletal muscles

Front 26

Autonomic nervous system

Back 26

Subdivision of the motor division of the peripheral nervous system that regulates the internal enviroment. Carries signals to organs such as the intestines, the heart, and the glands.

Front 27

sympathetic division

Back 27

increase the general level of activity in the body adn makes more energy available. This division prepares the body for intense activities that consume energy, such as running or taking a difficult exam.

Front 28

parasympathetic division

Back 28

calms the body and returns it to regular maintenance functions. It increases your heart rate and glucose release. It also stimulates your digestive systme to continue breaking down food.

Front 29

cerebrum

Back 29

the largest and most complex part of the brain, divided into two halves called hemispheres

Front 30

left hemisphere

Back 30

controls movement of the right side of your body

Front 31

right hemisphere

Back 31

controls movement of the left side of your body

Front 32

corpus callosum

Back 32

supports communications between the hemispheres

Front 33

cerebral cortex

Back 33

outer region fo the cerebrum

Front 34

cerebellum

Back 34

coordination center for body movements

Front 35

brainstem

Back 35

lower section of your brain that includes the medulla oblongata, pons,and midbrain

Front 36

thalamus

Back 36

sorts information going to and coming from the cerebral cortex

Front 37

hypothalamus

Back 37

helps regulate body temperature, blood pressure, hunger, thirst and emotions. Master control of the endocrine system.

Front 38

limbic system

Back 38

system of regions of the brain taht interact with the cerebral cortex in emotion and memory.

Front 39

sensation

Back 39

an awareness of these sensory stimuli

Front 40

perception

Back 40

meaningful interpretations of sensory data.

Front 41

cornea

Back 41

transparent area of the sclera, helps to focus the light as it travels to the back of the eyeball

Front 42

iris

Back 42

gives your eye the color

Front 43

pupil

Back 43

dark opening in the center of the eye, contorls how much light enters it

Front 44

retina

Back 44

inner surface of the eye

Front 45

cones

Back 45

a type of photoreceptor, stimulate bright light prodcuing the color

Front 46

rods

Back 46

a type of photoreceptors taht do not distinquish color but light.

Front 47

auditory canal

Back 47

tunal that leads to the eardrum

Front 48

eardrum

Back 48

a sheet of tissue that seperates the outer ear from the middle ear.

Front 49

auditory tube

Back 49

conducts air between the middle ear and the back of the throat keeping the air pressure equal on either side of the eardrum

Front 50

tolerance

Back 50

resistance to a drug's effects such that mor of the drug is needed to produce the same effect

Front 51

addiction

Back 51

uncontrollable dependence on a drug

Front 52

withdrawl

Back 52

psychological and/or physical symptoms experienced when a person stops taking a drug to which he or she is addicted

Front 53

stimulant

Back 53

drug that increases activity in the CNS activity (central nervous system) ex. (caffine, nicotine, adn cocaine)

Front 54

depressant

Back 54

drug that decresase or slows down the CNS activity ex. (alcohol or tranquilizers)

Front 55

marijuana

Back 55

drug made from dried pieces of hemp plant

Front 56

hallucinogens

Back 56

drugs that cause the user to see, hear, and perceive things that do not exist

Front 57

Ecstasy

Back 57

a synthetic drug that causes stimulant-like effects such as increased energy level as well as hallucinogen like effects such as an exaggerated emotional attachment to other people

Front 58

Inhalants

Back 58

substances that have short term effects such as speech, clumsiness, and increased heart rate