chapter 12 nervous system

Question 1

Brain and spinal cord

Consists of nervous tissue, connective tissue, and blood vessels

Functions to process and coordinate sensory data from inside and outside body

Motor commands control activities of

peripheral organs (e.g., skeletal muscles)

Higher functions of brain include intelligence, memory, learning, and emotion

which nervous system is this one ?

Answer 1

CNS

Question 2

Includes all nervous tissue outside CNS and ENS

Delivers sensory information to the CNS
Carries motor commands to peripheral tissues

Nerves (peripheral nerves)
Bundles of axons with connective tissues and blood vessels

Carry sensory information and motor commands

Cranial nerves connect to brain
Spinal nerves attach to spinal cord

which nervous system is this one ?

Answer 2

PNS

Question 3

Controls subconscious actions, contractions of smooth and cardiac muscle, and glandular secretions
Sympathetic division has a stimulating effect
Parasympathetic division has a relaxing effect

which system is this one ?

Answer 3

ANS

Question 4

Controls skeletal muscle contractions
Both voluntary and involuntary (reflexes)

which system is this one ?

Answer 4

SNS

Question 5

100 million neurons in walls of digestive tract
As many or more than in spinal cord
Use the same neurotransmitters as the brain
Initiates and coordinates visceral reflexes locally
Without instructions from CNS
Can be influenced by ANS

which system is this one ?

Question 6

Basic functional units of the nervous system
Send and receive signals

Function in communication, information processing, and control
Cell body (soma)

Large nucleus and nucleolus
Perikaryon (cytoplasm)

Mitochondria (produce energy)
RER and ribosomes (synthesize proteins)

what is the term for this ?

Answer 6

Neuron

Question 7

Neurofilaments and neurotubules
Similar to intermediate filaments and microtubules

Neurofibrils
Bundles of neurofilaments that provide support for dendrites and axon

where does this belong?

Answer 7

Cytoskeleton of perikaryon

Question 8

Dense areas of RER and ribosomes in perikaryon
Make nervous tissue appear gray (gray matter)

where is this located?

Answer 8

nissl bodies

Question 9

Small
All cell processes look similar
Found in brain and special sense organs

which neuron is this ?

Answer 9

anaxonic

Question 10

Small and rare
One dendrite and one axon
Found in special sense organs (sight, smell, hearing)

which neuron is this ?

Answer 10

bipolar

Question 11

Axon and dendrites are fused
Cell body to one side
Most sensory neurons of PNS

which neuron is this ?

Answer 11

unipolar

Question 12

def the nodes of ranvier

Answer 12

lie between internodes
Where axons may branch

Question 13

Have one long axon and two or more dendrites
Common in the CNS
All motor neurons that control skeletal muscles

which neuron is this ?

Answer 13

multipolar

Question 14

Regions of CNS with many myelinated axons

which matter?

Answer 14

white matter

Question 15

Contains unmyelinated axons, neuron cell bodies, and dendrites

which matter?

Answer 15

gray matter

Question 16

defn repolarization ?

Answer 16

When the stimulus is removed, membrane potential returns to normal

Question 17

def the hyper polarization

Answer 17

Results from opening potassium ion channels
Positive ions move out, not into cell

Opposite effect of opening sodium ion channels

Increases the negativity of the resting potential

Question 18

Characteristics of graded potentials

Answer 18

Membrane potential is most changed at site of stimulation;
effect decreases with distance
Effect spreads passively, due to local currents

Graded change in membrane potential may

involve depolarization or hyperpolarization

Stronger stimuli produce greater changes in membrane potential and affect a larger area

Question 19

defn propagation

Answer 19

Moves an action potential along an axon in a series of steps

Question 20

Occurs in unmyelinated axons
Affects one segment of an axon at a time
Step 1: Action potential develops at initial segment
Depolarizes membrane to +30 mV
Step 2: Local current develops
Depolarizes second segment to threshold

which propagation is this ?

Answer 20

continuous propagation

Question 21

Myelinated
Large diameter
Transmit information to and from CNS rapidly 
(120 m/sec), for example
Sensory information such as position and balance
Motor impulses to skeletal muscles

which fiber is this ?

Answer 21

FIber A

Question 22

Myelinated
Medium diameter
Transmit information at intermediate speeds (18 m/sec)

which fiber is this ?

Answer 22

FIber B

Question 23

Unmyelinated
Small diameter
Transmit information slowly (1 m/sec)
Example: most sensory information

which fiber is this ?

Answer 23

fiber C

Question 24

Chemicals released by axon terminals that alter
Rate of neurotransmitter release
Or response by postsynaptic cell
Effects are long term and slow to appear
Responses involve multiple steps and intermediary compounds
Affect presynaptic membrane, postsynaptic membrane, or both
Released alone or with a neurotransmitter

what is this term ?

Answer 24

Neuromodulators

Question 25

Small peptide chains
Synthesized and released by axon terminal

def this term ?

Answer 25

Neuropeptides

Question 26

Bind to the same receptors as opium and morphine
Classes of opioids in CNS
Enkephalins
Endorphins
Dynorphins

defn this term ?

Answer 26

opioids

Question 27

what are the dissolved gases in neurotransmitters

Answer 27

Nitric oxide (NO)
Carbon monoxide (CO)