Chapter 27

Question 1

Nervous System

Answer 1

quickly sends a message along a nerve fiber that releases a chemical message directly
function - detects stimuli in the env and performs coordinated reaction in response

Question 2

Central nervous system (CNS)

Answer 2

brain and spinal cord

Question 3

Neurons - nerve cell

Answer 3

has a cell body, dendrites, axon, myelin sheath, and nodes of ranvier

Question 4

Cell body

Answer 4

contains nucleus and other organelles

Question 5

dendrites

Answer 5

fan out to receive signals from sensory receptors or other neurons

Question 6

Axon

Answer 6

longer than dendrites
conducts impulses away from cell body

Question 7

Myelin Sheath

Answer 7

formed from membranes of tightly spiraled cells, helps impulses travel faster on long axons, make nerves look white
insulating layer
help signals travel faster and more efficiently

Question 8

nodes of ranvier

Answer 8

gaps between myelin sheath

Question 9

three types of neurons

Answer 9

Sensory neurons, interneurons, and motor neurons

Question 10

Sensory neurons

Answer 10

takes impulses from sensory receptors to the CNS

Question 11

Interneurons

Answer 11

occur entirely within the CNS
take nerve impulses between various parts of CNS as part of integration
form complex pathways in the brain where processes that account for thinking, language, and memory occur

Question 12

motor neurons

Answer 12

take nerve impulses from CNS to muscles or glands

Question 13

The Nerve Impulse

Answer 13

dependent of concentration gradients
maintained buy sodium-potassium pump
- actively transports sodium ions outside axon and actively transports potassium ions inside

Question 14

Action Potential

Answer 14

is all or none
either an axon conducts a nerve impulse or it does not

Question 15

synapse

Answer 15

point of communication between two neurons
presynaptic neurons - send signal
postsynaptic neuron - releases neurotransmitters

Question 16

Neurotransmitters

Answer 16

acetylcholine and norepinephrine
a single neuron has many dendrite, plus the cell body
excitatory neurotransmitter drives neurons closer to creating potential

Question 17

Drug abuse

Answer 17

stimulants increase activity of CNS
depressants decrease activity of CNS
Brain less active after cocaine
- prevents synaptic uptake of dopamine
methaphetamine
- blocks uptake of dopamine

Question 18

Vertebrate brains

Answer 18

central nervous system
- brain can be divided into hindbrain. midbrain, and forebrain
- forebrain most prominent in humans
cerebrum, diencephalon, cerebellum, and brain stem

Question 19

Cerebrum

Answer 19

coordinates activities of the other parts of the brain

Question 20

diencephalon

Answer 20

hypothalamus - helps maintain homeostasis by regulating sleep, hunger, thirst, body temp, and water balance
thalamus - receiving end for all sensory input except smell
pineal gland - secretes hormone melatonin

Question 21

cerebellum

Answer 21

receives sensory input from eyes, ears, joints, and skeletal muscles
receives motor output from cerebral cortex about where the parts should be
integrates info to maintain posture and balance
ensure coordinated, Smooth, voluntary movements

Question 22

Brain stem

Answer 22

contains midbrain, pons, and medulla oblongata
connects rest of the brain to spinal cord
midbrain contains important visual and auditory reflex centers
medulla oblongata contains reflex centers for regulating heartbeat, breathing, and vasoconstriction.
pons link medulla with midbrain

Question 23

limbic system

Answer 23

complex network that includes diencephalon and areas of cerebrum
emotional response center
hippocampus - makes prefrontal areas aware of past experiences
amygdala - causes experiences to have emotional overtones

Question 24

Memory

Answer 24

prefrontal area of frontal lobe active during short term memory

Question 25

Peripheral Nervous system

Answer 25

lies outside CNS contains nerves - bundles of axon 12 cranial nerves, ganglia outside CNS, 31 spinal nerves has somatic and autonomic systems

Question 26

somatic system

Answer 26

voluntary control of muscles sensory neuron - interneuron - motor neuron - effector

Question 27

autonomic system

Answer 27

involuntary system divided into parasympathetic and sympathetic division parasympathetic - promotes all internal responses associated with a relaxed state - uses neurotransmitter acetylcholine sympathetic division - flight or fight situations - uses neurotransmitter norepinephrine

Question 28

Endocrine system

Answer 28

consists of glands and tissue that secrets hormones uses blood to send a hormone to a target organ - slower acting but long lasting endocrine glands do not have ducts - secrets hormones directly into blood exocrine glands have ducts and secret product into duct for delivery to a specific organ

Question 29

Hormones

Answer 29

Steroid hormones - activate gene expression Peptide hormones - small chains of amino acids - first messenger that activates signal

Question 30

Hypothalamus gland

Answer 30

part of brain part of nervous and endocrine system contains specialized hormone secreting neurons control secretion of pituitary gland

Question 31

pituitary gland

Answer 31

connect to brain by stalk anterior pituitary - secretions controlled by hypothalamic releasing hormones secretions stimulate other glands

Question 32

prolactin

Answer 32

anterior pituitary hormone produced in quantity during pregnancy and after childbrith

Question 33

oxytocin

Answer 33

posterior pituitary causes uterine contractions during childbirth and milk let down when a baby is nursing

Question 34

Thyroid gland

Answer 34

to produce its hormones needs iodine simple goiter can be caused by lack of iodine in diet

Question 35

Grave's disease

Answer 35

overproduction of thyroid hormones also known as hyperthyroidism

Question 36

Adrenal glands

Answer 36

sit atop the kidneys each gland has an inner adrenal medulla and outer adrenal cortex hypothalamus exerts control over both areas Adrenal medulla - epinephrine and norepinephrine rapidly bring about all the body changes when an individual reacts to an emergency situation adrenal cortex - mineralocorticoids like aldosterone and glucocorticoids like cortisol

Question 37

Addison's disease

Answer 37

hypo secretion of adrenal cortex hormone buildup stimulates melanin production and skin bronzes

Question 38

Pancreas

Answer 38

has insulin and glucagon insulin - lowers blood glucose glucagon - raises blood glucose

Question 39

Diabetes

Answer 39

Type 1 - insulin dependent - pancreases not producing insulin Type 2 - non-insulin dependent controlled through diet and exercise