Bio Chapter 8 Nervous/endocrine

Front 1

Action Potential

Back 1

electrochemical signals sent by the nervous system

Front 2

Soma

Back 2

central cell body of neuron that contains the nucleus; site of all biosynthesis including neurotransmitters

Front 3

What are neurons with one/multiple dendrites called?

Back 3

one: bipolar

multiple: multipolar

Front 4

How do action potential travel down a neuron?

Back 4

Dendrites receive the signal and transmit them to the soma. Then, axons carry the action potential away from the cell body

Front 5

Axon Hillock

Back 5

Integrates the signal for transmission

Front 6

Neuron Picture

Back 6

Front 7

Resting membrane potential

Back 7

-70mV

Front 8

What helps establish the resting potential?

Back 8

Sodium pottasium pump

Front 9

What does it mean that neuron cells are polarized at resting potential?

Back 9

Negative on the inside and positive on the outside of the membrane

Front 10

Depolarization

Back 10

A change in the membrane potential from resting membrane potential of -70 to a less negative or even positive potential

Causes an action potential

Front 11

Repolarization

Back 11

After depolarization occurs, repolarization returns the membrane potential back to normal

Front 12

What do voltage gated sodium channels do?

Back 12

they are located in the plasma membrane of the axon. They all sodium ions to flow down their gradient into the cell when the membrane potential changes. This allows depolarization to occur to +35mV and allows an action potential to propagate through the axon. The sodium ions flow down the interior of the axon and slightly depolarize the next section of the membrane. Then the process starts over again and continues until the action potential propagates all the way through the axon

Front 13

Threshold potential

Back 13

-50 mV

cause voltage gated sodium channels to open

Front 14

What happens during repolarization?

Back 14

1.) After the depolarization due to voltage gated sodium channels, the voltage gated sodium channels inactivate

2.) Voltage gated potassium channels open slowly and stay open for a longer period of time causing hyperpolarization by allowing extra potassium to leave the cell causing the interior of the cell to be negative again (-90 mV)

3.) Sodium potassium pump returns cell to resting potential

Front 15

Myelin

Back 15

an insulating sheath that surrounds the axons of many neurons

does not allow ions to exit or enter the neuron so depolarization cannot occur

speeds up action potential by making it jump from one node of Ranvier to the next

Front 16

Schwann cells

Back 16

type of glial cell located in the peripheral nervous system; create the myelin sheath

Front 17

nodes of Ranvier

Back 17

periodic gaps in the myelin sheath that is concentrated with voltage gated sodium and potassium channels that allow depolarization and repolarization to occur

Front 18

Saltatory conduction

Back 18

jumping of action potential from node to node

Front 19

glial cells

Back 19

specialized, non neuronal cells that provide structural and metabolic support to neurons

Front 20

Oligodendrocytes

Back 20

type of glial cells located in the central nervous system; create myelin sheath

Front 21

Other types of glial cells

Back 21

1.) astrocytes: in central nervous system; guide neuronal development; regulate synaptic communication

2.) Microglia: in CNS; remove dead cells

3.) Ependymal cells: produce and circulate cerebrospinal fluid

Front 22

All Action Potentials are of the same size

Back 22

yuh

Front 23

Equilibrium potential for sodium and potassium

Back 23

Sodium: +50 mV

Potassium: -90 mV

Front 24

Are there more sodium or potassium channels in the membrane?

Back 24

the equilibrium potential for potassium is -90 mV. Since the resting membrane potential is -70 mV, this shows that there are more potassium channels than sodium

Front 25

Refractory period

Back 25

After an action potential occurs, there is a period of time that another one cannot occur. this is the refractory period

Front 26

2 phases of the refractory period

Back 26

1.) absolute refractory period: neuron cannot fire action potential no matter how strong depolarization is because the voltage gated sodium channels have been inactivated (they only activate again once resting membrane potential has been reached)

2.) Relative refractory period: neuron can be induced to transmit action potential because voltage gated sodium channels are active again after hyperpolarization, but requires a greater depolarization; this is because the neuron has been hyperpolarized (more negative than resting potential) by the voltage gated potassium channels that cause the neuron to have a potential of -90 mV

Front 27

Synapse

Back 27

Junction between axon terminus of one neuron and dendrites, soma, or axon of another neuron

Front 28

2 types of synapse

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1.) electrical synapse: occurs when cytoplasm of 2 cells are joined by gap junctions; action potential spreads directly from one cell to other

2.) Chemical synapse: found at the end of axons where they meet their target cell; action potential here is converted to chemical signal

Front 29

Synaptic knob

Back 29

End of the axon

Front 30

How is a an action potential transmitted across a chemical synapse?

Back 30

1.) action potential reaches the synaptic knob

2.) presynaptic membrane is depolarized and opens voltage gated calcium channels

3.) calcium moves into presynaptic cell and causes exocytosis of neurotransmitter in secretory vesicles

4.) neurotransmitter binds to receptor proteins on postsynaptic membrane

5.) ligand gated ion channels open after neurotransmitter binds to it and alters the membranes polarization

6.) if threshold voltage is reached, action potential is initiated

Front 31

Acetylcholine

Back 31

neurotransmitter in the neuromuscular junction

Front 32

Excitatory neurotransmitter

Back 32

neurotransmitter that causes depolarization in the postsynaptic membrane and allows an action potential to occur

Front 33

Inhibitory neurotransmitter

Back 33

causes hyperpolarization which drives the membrane potential farther away from the threshold needed for action potential

Front 34

Temporal summation

Back 34

presynaptic neuron fires action potentials very rapidly; the excitatory or inhibitory post synaptic potentials pile up and the additive effect will allow depolarization or hyperpolarization

Front 35

Spatial summation

Back 35

ALL EPSP and IPSP from all synapses on postsynaptic membrane are added at a given moment in time

Front 36

Efferent neurons

Back 36

carry info from CNS to appropriate glands/organs

Front 37

Afferent neurons

Back 37

carry info toward CNS

Front 38

Peripheral Nervous system

Back 38

includes axons, dendrites, and cell bodies that are not part of central nervous system

Somatic: voluntary movement (if you need to or want to) of skeletal muscle; excitatory only

Autonomic: involuntary processes such as digestion, circulation etc; excitatory or inhibitory

Front 39

Division of Autonomic system

Back 39

Sympathetic: fight or flight

parasympathetic: rest and digest

Front 40

Central nervous system

Back 40

Brain and spinal cord

Front 41

Where are most neuronal cell bodies found?

Back 41

in the Central nervous system; they bunch together in the CNS to form nuclei

Front 42

What are cell bodies bunched together outside of the CNS called?

Back 42

Ganglia

Front 43

3 divisions of the brain

Back 43

1.) Hindbrain (rhombencephalon)

2.) Midbrain (mesencephalon)

3.) Forebrain (prosencephalon)

Front 44

Hindbrain

Back 44

1.) medulla: located below pons; area of brain that connects to spinal cord; regulates vital autonomic functions such as blood pressure and digestion; contains respiratory rhythmicity center

2.) pons: located above medulla; coordinates balance

3.) cerebellum: located behind medulla; coordinates complex movements; pons and cerebellum receive info from vestibular apparatus in ear which monitors acceleration and position due to gravity

Front 45

Midbrain

Back 45

located above pons;

relays visual and auditory information; contains Reticular Activating System which controls arousal and wakefulness

Front 46

Forebrain

Back 46

1.) diencephalon: thalamus and hypothalamus; thalamus is located above hypothalamus and contains processing centers for sensory info and relays info between spinal cord cerebral cortex.

hypothalamus is located above midbrain and controls emotions, hormones, and serves as the primary link between nervous and endocrine system by controlling the pituitary gland

2.) Telencephalon:

Cerebrum which controls memory, planning, higher learning etc

Basal Nuclei: regulation of motor movement

Limbic System: has amygdala and hippocampus

Amygdala controls emotions; hippocampus controls memory and learning

Front 47

Left side of brain vs Right side

Back 47

Left side: controls motor functions of right side of body; responsible for speech and logic

Right side: controls motor functions of left side of body; responsible for music and creativity

Front 48

Corpus Callosum

Back 48

a thick bundle of axons that connects the two hemispheres of the brain

Front 49

Cerebrum

Back 49

the main part of the brain that consists of both hemispheres

Front 50

Cerebral cortex

Back 50

1.) frontal lobe: initiate all voluntary movement; helps in complex reasoning skills and problem solving

2.) Parietal lobe: involved in touch and taste sensations

3.) Temporal lobes: involved in sound and smell sensations; involved in short term memory, language comprehension

4.) Occipital lobe: process visual sensation

Front 51

Brocas area

Back 51

speech production

Front 52

Wernickes area

Back 52

language comprehension

Front 53

Limbic system

Back 53

located between cerebrum and diencephalon; important in emotion and memory and learning; includes amygdala and hippocampus

Front 54

Cranial nerves

Back 54

there are 12 pairs of cranial nerves that convey sensory and motor information to and from the brainstem

Front 55

Spinal nerves

Back 55

There are 31 pairs of spinal nerves that convey information to and from the spinal cord

Front 56

Vagus Nerve

Back 56

a cranial nerve; part of the parasympathetic system;

Front 57

Anatomy of Somatic System

Back 57

1.) All somatic motor neurons innervate skeletal muscle cells, use acetylcholine, and have their soma in the brain stem or front part of spinal cord

2.) All somatic sensory neurons have a long dendrite that goes from a sensory receptor to the soma which is in the dorsal root ganglion. The axon goes into the spinal cord and the first synapse is in the CNS

Front 58

Anatomy of Autonomic System

Back 58

1.) contains preganglionic and postganglionic neurons. The preganglionic neuron sends and axon to the postganglionic neuron which send an an axon to an organ or gland.

2.) All autonomic preganglionic neurons release acetylcholine; all parasymathetic postganglionic also release acetylecholine; all sympathetic postganglionic release norepinephrine

Front 59

Sympathetic vs. Parasympathetic system

Back 59

Sympathetic: preganglionic neurons are in thoracic and lumbar region of spinal cord; preganglionic axon is short; ganglia is far from target; postganglionic axon is long; usually releases norepinephrine

Parasympathetic: preganglionic neurons are in brainstem and sacral spinal cord; preganglionic axon is long; ganglia is close to target; post is short; releases acetylcholine

Front 60

Four properties that sensory receptors need to communicated to CNS

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1.) stimulus modality (type of stimulus)

2.) Stimulus location

3.) Stimulus intensity

4.) Stimulus duration

Front 61

Structure of outer ear

Back 61

contains auricle or pinna and external auditory canal

Front 62

Structure of middle ear

Back 62

contains ossicles which are three small bones known as malleus, incus, and stapes

Front 63

Structure of inner ear

Back 63

contains cochlea, semicircular canals, utricle and saccule

Front 64

What do the semicircular canals, utricle and saccule do?

Back 64

they help with balance

Front 65

Eustachian tube

Back 65

passage from back of throat to middle ear that equalizes pressure on both sides of the ear drum

Front 66

Organ of Corti

Back 66

the basilar membrane and tectorial membrane; primary site at which auditory stimuli is detected

Front 67

How is sound converted to hearing in the ear?

Back 67

Sound waves travel through the outer ear and cause tympanic membrane to vibrate. This causes the bones of the middle ear to vibrate; then, the stapes, the last bone of the middle ear causes vibrations on the oval window; this causes perilymph and endolymph which are fluids in the cochlea to vibrate; this causes the basilar membrane to vibrate which is in the cochlea; this causes hair cells to move against the tectorial membrane; this causes neurotransmitters to release and stimulates dendrites of afferent neurons; nerve impulses are created

Front 68

Oval window

Back 68

membrane that divides inner ear from middle ear

Front 69

Pitch (frequency)

Back 69

distinguished by different regions of the basilar membrane vibrating;

low frequency is at the apex of the cochlea while high frequency is detected near the oval window

Front 70

How can you determine the source of where a sound is coming from?

Back 70

based on the difference detected between two ears; if the sound is coming from your right, your right ear will receive the sound waves slightly sooner and more intensely than your left

Front 71

Loudness of sound

Back 71

based on amplitude of vibration; more vibration will cause more frequent action potentials

Front 72

Vestibular complex

Back 72

made of the three semicircular canals, the utricle, the saccule, and the ampullae

all of these things contain endolymph and hair cells which detect rotational acceleration of the head

Front 73

Reflex Arc

Back 73

Does not involve the brain for motor output BUT signals still go to the brain

Front 74

Interneuron

Back 74

Small neuron in spinal cord that is Always inhibitory

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Monosynaptic Reflex

Back 75

Always the excitatory reflex because there is only one synapse

Front 76

Disynaptic Reflex

Back 76

Always inhibitory because there are two synapses due to an interneuron

Front 77

Cones in eye

Back 77

for color vision

3 types of cones: red, green, blue that work together to produce color

Cones are located in the FOVEA mah nigga

Front 78

Rods in eye

Back 78

for black and white vision

Located in periphery

Front 79

How the eye works

Back 79

No light: photoreceptors are depolarized (sodium channels are open) and either stimulate or inhibit the bipolar cell

Light: photoreceptor is hyperpolarized and either inhibits or stimulates the bipolar cell

Front 80

2 types of hormones

Back 80

Peptide hormones and steroid hormones

Front 81

Peptide hormones

Back 81

1.) Poplypeptide made in the ER

2.) Hydrophillic (can travel in blood)

3.) Bind to cell surface receptors

4.) Use second messenger systems

5.) stored in vesicles

6.) Rapid response

Front 82

Steroid Hormones

Back 82

1.) Made of cholesterol

2.) Made my smooth ER

3.) Hydrophobic (travel using proteins)

4.) Bind to nuclear/cytoplasmic receptors

5.) Use transcription factors and regulate gene expression

6.) Slow response

Front 83

Pituitary

Back 83

1.) Controlled by hypothalamus

2.) Connected to hypothalamus by the Infundibullum

3.) Anterior Pituitary (controlled by hormones from the hypothalamus via a portal system)

4.) Posterior Pituitary (Controlled by Axons that extend down from hypothalamus)

Front 84

Portal System

Back 84

Two consecutive Capillary beds

Front 85

Anterior Pituitary Hormones

Back 85

FSH

LH

ACTH

TSH

Prolactin

I(Nothing)

GH

Front 86

Posterior Pituitary

Back 86

Oxytocin

ADH (Vasopressin)