Chapter 48 Bio Notes

Front 1

the three overlapping fuctions of the nervous system

Back 1

sensory input; motor output; integration

Front 2

sensory input

Back 2

gathered by sensory recepors is conduction to integration centers in the brain and
the spinal cord - is called CNS

Front 3

motor output

Back 3

conveyed to effector cells - muscle or gland cells; integration of sensory input and motor output in continuous background activity within CNS

Front 4

peripheral nervous system

Back 4

carry sensory and motor info between the body and the CNS in nervers

Front 5

nerves

Back 5

bundles of neuron extensions wrapped in connective tissue

Front 6

neuron or nerve cell

Back 6

consits of cell body which contains a nucleus and organelles and a fiber like processes dendrites and axons that conduct signals

Front 7

dendrites vs axons

Back 7

dendrite - highly branched short, carry messages toward cell body;
axons - longer, transmit signals to other cells.

Front 8

axon hillock

Back 8

where axons originate in cell body

Front 9

myelin sheath

Back 9

wrap around axons, insulating

Front 10

synaptic terminals

Back 10

specialized endings in terminal branches of axons which release neuro transmitters that relay signals across synapse to a post synaptic cell, another neuron or effector cell

Front 11

presynaptic cell

Back 11

the transmitting cell

Front 12

reflex arc

Back 12

the simplest type of nerve circuit. regulates and automatic response called a reflex.

Front 13

sensory neuron

Back 13

transmits info from a sensory receptor to a motor neuron which signals an effector cell to carry out the response.

Front 14

second neuro circuit

Back 14

even a simple nerve jerk reflex has this. a sensory neuron relays info from stretch receptor in the thigh muscle to interneurons in spinal cord which inhibit motor neurons to flexor muscles.

Front 15

interneurons

Back 15

neurons confined wholly with the spinal cord. Spinal cord interneurons help integrate sensory information and generate coordinated muscle commands.

Front 16

ganglia

Back 16

nerve cell bodies, often of similar function are clustered into ganglia in the CNS;

Front 17

nuclei

Back 17

clusters of cell bodies in the brain

Front 18

three types of nerve circuits

Back 18

1.circuits in which info is spread from one pre-synaptic neuron to several post synaptic neurons.
2.convergent circuits in which several presynaptic neurons communicate info to single post synaptic neuron;
3.circular paths

Front 19

supporting cells, or glia

Back 19

very numerous, give structural integrity and physiological support to nervous system; recent studies indicate that glia may have synaptic communication with each other and with neurons.

Front 20

radial glia

Back 20

guide the embyonic growth of neurons

Front 21

astrocytes

Back 21

are supporting glia in the CNS that induce the formation of the blood-brain barrier which restricts the passage of most substances into the brain.

Front 22

oligodendrocytes in the CNS;
Schwann cells in PNS

Back 22

insulate axons in a myelin sheath by wrapping around them and forming concentric membrane layers.

Front 23

nodes of ranvier

Back 23

the gaps between adjacent schwann cells

Front 24

resting potential or membrane potential

Back 24

of a typical, non-transmitting neuron is about -70 mv.

Front 25

ions inside and outside of cell

Back 25

the priciple cation outside of cell is sodium; the priciple anion is outside of cell is chloride.
the principle cation inside of cells is K; and many other anions are grouped together and symbolized as A-

Front 26

sodium-potassium pumps

Back 26

maintain these resting concentration gradients by using energy from ATP to move sodium ions back out of the cell, K in

Front 27

the excitable cells

Back 27

neurons in muscle cells, they are able to generate change in their membrane potential which may generate electrical impulse.

Front 28

3 other ion channels

Back 28

gated ion channels that open and close in response to stimulae; chemically gated ion channels that respond to a chemical stimulus such as neurotransmitters; voltage gated ion channels that respond to a change in membrane potential.

Front 29

hyperpolarization

Back 29

a great increase in the membrane potential as a result of an ion channel such as K+ channels

Front 30

depolarization

Back 30

the inside of cell becomes less negative as a result of an ion channel

Front 31

graded potential

Back 31

the magnitude of a voltage change proportional to the change of the stimulus; the stronger the stimulus the more graded ion channels that open;

Front 32

threshhold potential

Back 32

the maxiumum amount of depolarization a cell can reach before it triggers and action potential usu. about 50-55 mv

Front 33

action potential

Back 33

the graded depolarization from a dendrite or cell body spreads along the membrane to an axis. It is an all or nothing event. An action potential causes the membrane potential first to reverse polarity then return rapidly to the resting potential.

Front 34

rapid spike of depolarization

Back 34

voltage gated ions channels in an axis plasma membrane are activated when depolarization reaches the threshhold potential. K activation gates open rapidly and K inactivation gates open at resting state close slowly.

Front 35

refractory period

Back 35

before K inactivation gates are reopened, the neuron cannot respond to another stimulus.

Front 36

saltatory conduction

Back 36

voltage gated ion channels are concentrated in the nodes of ranvier; action potentials can be generated only at these nerves and the nerve impulse jumps from node to node resulting in this faster mode of transmission.

Front 37

neurons in which synapses can occur

Back 37

between sensory receptors and neurons or between neurons and muscle or gland cells.

Front 38

electrical synapse

Back 38

allow action potentials to flow directly from presynaptic to postsynaptic cells via gap junctions.

Front 39

chemical synapse

Back 39

the electrical message is converted to a chemical message that travels from teh spresynaptic cells across a synaptic cleft to the post synaptic cell, where it is converted back into an electrical signal.

Front 40

synaptic terminal

Back 40

contains many synaptic vessicles in which 1000's of neurotransmitters are stored.

Front 41

presynaptic membrane

Back 41

the depolarizaiton of this membrane causes the release of neurotransmitters into the cleft;

Front 42

postsynaptic membrane

Back 42

contains receptor proteincs associated with particular ion channels; binding of neurotransmitter to the receptors on these chemically gated channels allows ions to cross the membrane either depolarizing or hyperpolarizing it. enzymes rapidly break down the neurotransmitter or it is taken up into adjacent cells

Front 43

excitatory postsynaptic potential EPSP (are graded potentials)

Back 43

at an excitatory synapse, binding of neurotransmitters to receptors opens a chemically gated channel - allows Na+ in and K+ out of cell. Electorchemical dgadient drives more Na+ in - positive charge depolarizes membrand creating EPSP and brings membrane potential closer to threshold potential.

Front 44

Inhibitory postsynaptic potential IPSP (graded potentials)

Back 44

at in hibitory synapse, binding of nt opens ion gates allowing K+ out and/or CL- in, hyperpolarizing membrand and producing IPSP

Front 45

what determines magnitude of EPSP's and IPSP's

Back 45

number of nt molecules that bind to receptors - they spread their voltage changes alone the membrane of postsynaptic cell.

Front 46

Summation

Back 46

summation of several EPSP's is usually necessary to bring axon hillock to theshold potential.

Front 47

what determines membrane potential of axon hillock

Back 47

sum of all EPSP's and IPSP's

Front 48

different effects same neurotransmitter can have on different types of cells

Back 48

alter membrane permeability of postsynaptic cell by binding to receptors on ion channels
trigger signal-transduction pathways in postsynaptic cell

Front 49

Acetylcholine

Back 49

very common nuerotransmitter in invertebrates and vert.'s depending on type of receptor - can be inhibitory or excitatory in vertebrate CNS.
in neuromuscular junctions - acetylcholine released from a motor axon deplarizes the postsynaptic muscle cell

Front 50

biogenic amines

Back 50

neurotransmitters derived from amino acids, often trigger signaltransduction pathways in p.s. cells

Front 51

epinephrine, norepinephrine and dopamine

Back 51

biogenic amines derived from tyrosine.

Front 52

serotonin

Back 52

syntehsized from tryptophan

Front 53

which biogenic amines affect sleep, mood, attention and learning

Back 53

dopamine and serotonin

Front 54

glycine, glutamate, aspartate, gamma aminobutyric acid (GABA)

Back 54

amino acids that function as nt's on the CNS

Front 55

which is most common inhibitory transmitter in brain?

Back 55

GABA

Front 56

neuropeptides

Back 56

short chains of amino acids that function as nt's - often through signal-transduction pathways.

Front 57

Substance P

Back 57

excitatory nt that functions in pain perception

Front 58

excitatory postsynaptic potential EPSP (are graded potentials)

Back 58

at an excitatory synapse, binding of neurotransmitters to receptors opens a chemically gated channel - allows Na+ in and K+ out of cell. Electorchemical dgadient drives more Na+ in - positive charge depolarizes membrand creating EPSP and brings membrane potential closer to threshold potential.

Front 59

Inhibitory postsynaptic potential IPSP (graded potentials)

Back 59

at in hibitory synapse, binding of nt opens ion gates allowing K+ out and/or CL- in, hyperpolarizing membrand and producing IPSP

Front 60

what determines magnitude of EPSP's and IPSP's

Back 60

number of nt molecules that bind to receptors - they spread their voltage changes alone the membrane of postsynaptic cell.

Front 61

Summation

Back 61

summation of several EPSP's is usually necessary to bring axon hillock to theshold potential.

Front 62

what determines membrane potential of axon hillock

Back 62

sum of all EPSP's and IPSP's

Front 63

different effects same neurotransmitter can have on different types of cells

Back 63

alter membrane permeability of postsynaptic cell by binding to receptors on ion channels
trigger signal-transduction pathways in postsynaptic cell

Front 64

Acetylcholine

Back 64

very common nuerotransmitter in invertebrates and vert.'s depending on type of receptor - can be inhibitory or excitatory in vertebrate CNS.
in neuromuscular junctions - acetylcholine released from a motor axon deplarizes the postsynaptic muscle cell

Front 65

biogenic amines

Back 65

neurotransmitters derived from amino acids, often trigger signaltransduction pathways in p.s. cells

Front 66

epinephrine, norepinephrine and dopamine

Back 66

biogenic amines derived from tyrosine.

Front 67

serotonin

Back 67

syntehsized from tryptophan

Front 68

which biogenic amines affect sleep, mood, attention and learning

Back 68

dopamine and serotonin

Front 69

glycine, glutamate, aspartate, gamma aminobutyric acid (GABA)

Back 69

amino acids that function as nt's on the CNS

Front 70

which is most common inhibitory transmitter in brain?

Back 70

GABA

Front 71

neuropeptides

Back 71

short chains of amino acids that function as nt's - often through signal-transduction pathways.

Front 72

Substance P

Back 72

excitatory nt that functions in pain perception

Front 73

endorphines

Back 73

neuropeptides produced in brain during physical or emotional stress that have painkilling and other functions. opiates bind to endorphin receptors in brain

Front 74

local regulators for vertbrate CNS anbd PNA

Back 74

nitric oxide NO and C0

Front 75

hydra nervous system

Back 75

nerve net - simple diffuse, controls the radially symetrical body cavity

Front 76

ehinoderm nervous system

Back 76

central nerve ring with radial nerves connected to a nerve net in each arm

Front 77

cephalization

Back 77

concentration of sense organs, feeding structures and neural structures in teh head - evolved in bilaterally symmetrical animals

Front 78

flatworm cns

Back 78

simple brain and 2 longitudinal nerve cords

Front 79

cns of mollusks and arthorpods

Back 79

complicated brain and venral nerve cord with segmantally arranged ganglia

Front 80

vertebrate

Back 80

dorsal nerve cord

Front 81

CNS of vertebrates

Back 81

spinal cord and brain

Front 82

PNS function in vertebrates

Back 82

carries info to and from CNS and regulates homeostasis.

Front 83

from what does CNS develop (vertebrates)

Back 83

embryonic dorsal hollow nerve cord

Front 84

ventricles

Back 84

spaces in the brain continuous with narrow central canal of spinal cord, filled with cerebrospinal fluid.

Front 85

function of cerebrosinal fluid

Back 85

cushions brain, carries out circularoty functions.

Front 86

meninges

Back 86

portective layers of connective tissues that cover brain and spinal cord. axons are in bundles or tracts

Front 87

white matter

Back 87

named for white matter in myelin sheaths.

Front 88

gray matter

Back 88

neuron cell bodies, dendrites, unmyelinated axons

Front 89

what makes us vertbrate PNS

Back 89

cranial nerves and spinal nerves with associated ganglia

Front 90

how many pairs of cranial nerves and spinal nerves in mammal PNS

Back 90

12 pairs of c.n.
31 pairs of s.n.
most cranial and all spinal nerves contain both sensory and motor neurons

Front 91

two divisions in PNS

Back 91

sensory division - sensory, or afferent neurons that bring info to CNS
motor division - efferent neurons that carry signals away from CNS to effector cells

Front 92

2 parts of motor division

Back 92

somatic nervous system - carries signals to skeletal muscles
autonomic nervous system - maintains internal environment by involuntary control of smoothe and cardiac muscles

Front 93

2 divisions of ANS

Back 93

sympathetic division - accelerates heart and metabolic rate, arousing organism for action, generating energy
parasympathetic division - carries signals that enhance self-maintenance activities that conserve energy - such as digestion and slowing heart rate

Front 94

3 differentiations of neural tube (embryonic development)

Back 94

forebrain, midbrain, hindbrain - evident as 3 bilaterally symmetrical anterior bulges.

Front 95

cerebrum

Back 95

most sophisticated integrative center, outgrowth of forebrain

Front 96

5 brain regions that develop from inital bulges in humans

Back 96

telencephalon and diencephalon from forebrain
mesencephalon from midbrain
metencephalon and myelencephalon from hindbrain

Front 97

cerebral cotex

Back 97

highly convoluted outer gray matter.

Front 98

what develops from diencephalon portion of forebrain

Back 98

thalamus, epithalamus and hypothalamus

Front 99

what is included in adult brainstem

Back 99

midbrain - from mesencephalon
pons - from metencephalon
medulla oblongata from myelencephalon

Front 100

cerebellum

Back 100

not a part of brainstem, develops from the metencephalon.

Front 101

brainstem

Back 101

a stalk with a caplike swelling atht eh end of the spinal cord that extends deep within the brain

Front 102

medulla oblongata (or medulla)

Back 102

contains control centers for such homeostatic functions as breathing, swallowing, heart and blood vessel actions and digestion

Front 103

pons

Back 103

fucntions with the medulla in some of above activities and in conducting information between the rest of the brain and s.c.

Front 104

why does right side of brain control much of movement in left side, and vice versa

Back 104

tracts of motor neurons fro mid and forebrain coss in medulla

Front 105

midbrain

Back 105

receives and integrates sensory info and send info to specific regions of forebrain.

Front 106

where do fibres involved in hearing pass

Back 106

pass through or terminate in inferior colliculi

Front 107

in vision?

Back 107

superior colliculi - form optic lobes in nonmamals, only coordinate visual reflexes in mammals where vision is integrated in cerebrum

Front 108

reticular formation

Back 108

a system of voer 90 nuclei that extends through the brain stem and filters the sensory informaiton reaching the cerebral cortex

Front 109

RAS reticular activating system

Back 109

part of filtering system and regulates sleep and arousal

Front 110

what causes level of arousal

Back 110

amount of input the cortex receives.

Front 111

where are sleep-producing nuclei located

Back 111

pons and medulla

Front 112

where is center that causes arousal

Back 112

midbrain

Front 113

EEG

Back 113

electorencephalogram. recording of brain waves.

Front 114

What are produced by person lying quietly with eyes closed.

Back 114

slow syncrhonous alpha waves

Front 115

what is associated with opened eyes or thinking about complex problem

Back 115

rapid, irregular beta waves

Front 116

what occurs during deep sleep

Back 116

quite slow and synchronized delta waves

Front 117

REM sleep

Back 117

periods of delta waves alternae with periods of a desynchronized EEG and rapid eye movements - most dreaming occurs

Front 118

cerebellum

Back 118

develops from part of teh metencephalon may be involved in learning motor responses.
integrates info from auditory and visual systems with sensory input from joints and muscles - provide automatic coordination of movements and balance.

Front 119

where do epithalamus, thalamus and hypothalamus develop from

Back 119

embryonic diencephalon.

Front 120

epithalamus

Back 120

includes projecting pineal gland and a choroid plexus - producing cerebrospinal fluid

Front 121

thalamus

Back 121

major input center for sensory information going to cerebrum and an output center for motor info from cerebrum.
also receives input fro cerebrum and other parts of brain regulating emotion and arousal.

Front 122

hypothalamus

Back 122

major brain region for homeostatic regulation. produces posterior pitutitary hormones and releasing of hormones that control anterior pituitary.
contains regulating centers for many autonomic functions - and in sexual and mating behaviors, alarm resonse and pleasure

Front 123

biological clock

Back 123

internal mechanism important for maintainging these circadian thythms.

Front 124

suprachiasmatic nuclei SCN

Back 124

located in hypothalamus - function as bioloical clock

Front 125

what keeps mamal clock synchronized with natural cycles of light and dark

Back 125

sensory neurons providing visual info to the SCN

Front 126

what is human cycle

Back 126

25 hours.

Front 127

cerebral hemisphers

Back 127

right and left lobes of cerebrum

Front 128

what does cerebrum develop from

Back 128

embryonic telencephalon

Front 129

basal nuclei (also called basal ganglia)

Back 129

located deep in white matter, important in planning and learning movements

Front 130

neocortex

Back 130

out six layers of neurons running along the brain surface - unique to mammals

Front 131

corpus callosum

Back 131

thick band of fibers through which communication between two brain hemispheres travel

Front 132

cognitive functions of cerebrum

Back 132

learning and cognition - proces of knowing, consciousness and decision making.

Front 133

how many lobes is the surface of each hemisphere divided into

Back 133

4

Front 134

primary motor cortex

Back 134

at boundary between fronal and parietal lobe of CC - sends signals to skeletal muscles

Front 135

primary somatosensory cortex

Back 135

receives and partially ingegrates input from touch, pain, pressure, and temp. receptors

Front 136

where does sensory info go first

Back 136

primary sensory areas located in different lobes of the brain.

Front 137

what integrates the different sensory inputs

Back 137

association areas adjacent to the primary sensory areas. They send signals to association areas in frontal lobes. these areas determine motor response directed by pirmary motor cortex

Front 138

left hemisphere specilization

Back 138

language, math and logic; fine visual and auditory data and directing detailed mvmt.

Front 139

right brain

Back 139

pattern recognition, spatial perception and emotional processing. perceiving images within a whole context

Front 140

Broca's area

Back 140

in frontal lobe - involved in speech generation

Front 141

Wernicke's area

Back 141

posterior temporal love - involved in speech comprehension

Front 142

limbic system

Back 142

hippocampus and olfactory cortex - with sections of thalamus, hypoth. and inner portions of cortex - forming a ring aournd the brain stem.
generates emotions.

Front 143

transferring info from short-term to long-term memory involves what

Back 143

hypocampus

Front 144

what facilitates above

Back 144

rehersal, positive or negative emotional state and associatiosn with previously learned and stored material.