Physiology Exam 2

Front 1

Explain the diffusion of ions

Back 1

1. Ions diffuse across the plasma membrane through protein channels
2. Ions diffuse down an electrochemical gradient

Front 2

What is chemical from the word "electrochemical?"

Back 2

Concentration gradient

Front 3

What is electrical from the word "electrochemical?"

Back 3

Attraction or repulsion of electrical charges

Front 4

What is electrical potential?

Back 4

Measure of electrical driving force (measured in volts or mV)

Front 5

What is a membrane potential?

Back 5

1. Electrical potential difference between the ICF and ECF
2. Results from the unequal distribution of positive and negative charges on either side of the membrane

Front 6

What is the resting membrane potential in a cell?

Back 6

-70 mV

Front 7

Explain the formation of the resting membrane potential

Back 7

1. The Na-K pump actively transports Na+ out and K+ into the cell, which creates concentration gradients of Na+ and K+ ions.
-ICF has high [K+] and low [Na+]
-ECF has low [K+] and high [Na+]
2. The resting cell membrane is permeable to K+ due to the presence of K+ leak channels in the membrane
3. K+ diffuses out of the cell down its concentration gradient
4. Outward movement of a positively-charged ion makes the inside of the cell more negative. The resulting negative electrical potential inside the cell creates an electrical gradient which acts to pull K+ back in
5. At some point, the concentration gradient an electrical gradient for K+ will counterbalance each other. This point is the equilibrium potential for K+ (E of K almost = -90 mV)
6. Since the resting membrane is most permeable to K+, the RMP is fairly close to the K+ equilibrium potential
7. The resting membrane is slightly permeable to Na+, so some Na+ leaks into the cell. This causes the RMP to be slightly less negative than -90 mV; typically about -70 mV

Front 8

Equilibrium potential

Back 8

The potential across the membrane at which the electrical force exactly balances the concentration gradient (chemical force) on the ion

Front 9

Nernst equation

Back 9

E of ion = (60/z) x log (C[out]/C[in])

Using this, you can calculate the equilibrium potential

Front 10

E ion of the Nernst equation

Back 10

Equilibrium potential of the ion in millivolts (mV)

Front 11

C[in] of Nernst equation

Back 11

The intracellular concentration of the ion (mM)

Front 12

C[out] of Nernst equation

Back 12

The extracellular concentration of the ion (mM)

Front 13

z of Nernst equation

Back 13

The charge on the ion

Front 14

log of Nernst equation

Back 14

The base 10 logarithm

Front 15

What are two factors that determine the membrane potential?

Back 15

1. The concentration gradients of permeable ions, primarily K+ and Na+.
2. The relative permeability of the membrane to K+ versus Na+ Depends on ion channels
-The resting membrane is most permeable to K+, so the RMP is close to E of K.
-The RMP is very sensitive to changes in [K+] in the ICF and ECF
-The RMP is only slightly affected by [Na+] because the resting membrane is much less permeable to Na+

Front 16

What are the functions of the nervous system?

Back 16

Sensation, communication, integration, and control

Front 17

What are neurons?

Back 17

-Functional cells of the nervous system
-Excitable cells
-Produce electrical signals to communicate information

Front 18

The nervous system is organized into three parts? What are they?

Back 18

1. Central nervous system
2. Peripheral nervous system
3. Enteric nervous system

Front 19

What organs are part of the central nervous system?

Back 19

Brain and spinal cord

Front 20

What organs are part of the peripheral nervous system?

Back 20

Nerves, ganglia, and sensory receptors

Front 21

What are nerves?

Back 21

Bundles of axons

Front 22

What are ganglia?

Back 22

Cluster of neural cell bodies

Front 23

What are sensory receptors?

Back 23

-Specialized cells that detect a specific type of stimulus
-Are transducers that convert stimuli into changes in membrane potential

Front 24

What is afferent division?

Back 24

Sensory neurons, input to CNS from sensory receptors

Front 25

What is efferent division?

Back 25

Motor neurons, output from CNS to effectors

Front 26

Parts of afferent division

Back 26

1. Somatic Sensory
2. Visceral Sensory
3. Special Senses

Front 27

Somatic Sensory

Back 27

From skin, muscles, bones & joints (general senses)

Front 28

Visceral Sensory

Back 28

From internal organs

Front 29

Special Senses

Back 29

Vision, hearing, equilibrium, olfaction, taste

Front 30

Parts of efferent division

Back 30

1. Somatic Motor
2. Autonomic

Front 31

Somatic Motor

Back 31

To skeletal muscles (voluntary)

Front 32

Autonomic

Back 32

To heart, smooth muscle, glands (involuntary)

Front 33

Two parts of the autonomic system

Back 33

1. Sympathetic division
2. Parasympathetic division

Front 34

Enteric nervous system

Back 34

Nerve network of the GI tract

Front 35

Cell body

Back 35

Contains the nucleus and most organelles

Front 36

Dendrites

Back 36

Branch from the cell body, RECEIVE signals from other cells through synapses

Front 37

Axon

Back 37

Extends from the cell body, conducts action potentials

Front 38

Axon hillock

Back 38

Region where axon joins the cell body; trigger zone for AP

Front 39

Axon terminals

Back 39

Contain vesicles with neurotransmitter form synapses with other cells

Front 40

Sensory neurons

Back 40

Input to CNS from sensory receptors; dendrites located at receptors, axons in nerves, cell bodies in ganglia outside the CNS

Front 41

Motor neurons

Back 41

Output from CNS to effectors; cell bodies and dendrites located in the CNS, axons in nerves

Front 42

Interneurons

Back 42

Communicate and integrate information within the CNS; located entirely within the CNS.
Most abundant type of neuron.

Front 43

Glial cells

Back 43

Supporting cells of the CNS and PNS

Front 44

Graded potentials

Back 44

-Small, localized changes in membrane potential
-Formed at the cell body and dendrites
-Can be depolarization (rise) or hyperpolarization (lower)
-Spread passively and weaken with distance
-Amplitude is dependent on stimulus strength

Front 45

Action potentials

Back 45

Nerve impulses.
-Large change in membrane potential
-Formed and transmitted along the axon
-Rapid epolarization of membrane potential
-Actively conducted along the axon
-"All or none" - size is independent of stimulus strength

Front 46

Three phases of the action potential

Back 46

1. Rising (Depolarization) Phase
2. Falling (Repolarization) Phase
3. Undershoot

Front 47

Rising (Depolarization) Phase

Back 47

-Initial depolarization above threshold is required to generate an AP
-Voltage-gated Na+ channels open
-Activation gate opens in response to initial depolarization
-Rapid Na+ INFLOW --> rapid DEPOLARIZATION

Front 48

Falling (Repolarization) Phase

Back 48

-Voltage-gated Na+ channels close
-Inactivation gate - closes when depolarization reaches eak
-Voltage-gated K+ channels open
-Rapid K+ OUTFLOW --> REPOLARIZATION

Front 49

Undershoot

Back 49

-Voltage-gated K+ channels remain open, high K+ permeability results in hyperpolarization
-Resting states of ion channels and resting potential restored at end of undershoot phase

Front 50

Properties of action potentials

Back 50

1. Threshold
2. "All or none"
3. Regenerative
4. Refractory period

Front 51

Threshold

Back 51

Stimulus must exceed a certain strength to evoke an AP

Front 52

"All or none" (AP property)

Back 52

Amplitude of AP is constant, independent of stimulus strength

Front 53

Regenerative

Back 53

AP does not decrease in strength as it travels along the axon

Front 54

Refractory period

Back 54

Short delay following an AP before another AP can be formed, absolute refractory period and relative refractory period

Front 55

Absolute refractory period

Back 55

Period in which another AP can NOT be formed

Front 56

Relative refractory period

Back 56

Period in which a larger stimulus is required to form another AP

Front 57

Why is refractory period important?

Back 57

-Absolute refractory period sets an upper limit on frequency of action potentials
-During relative refractory period, a stronger stimulus can result in increased FREQUENCY of APs
--Stimulus intensity is coded by the frequency of APs
-Refractory period prevents AP from traveling backward along the axon

Front 58

What are the two conduction's of action potentials?

Back 58

Unmyelinated axons and myelinated axons

Front 59

Unmyelinated axons

Back 59

-AP depolarization spreads a short distance down the axon (local current flow)
-Depolarization stimulates formation of AP farther down the axon
-Axons are "leaky" to Na+ and K+; need to regenerate AP often along the axon
--> slow conduction speed
-Increasing axon diameter increases conduction speed

Front 60

Myelinated axons

Back 60

-Myelin sheath formed by membrane of Schwann cells in PNS, oligodendrocytes in CNS
-Insulates axon, reduces leakage of Na+ and K+
-Nodes of Ranvier - gaps in myelin sheath are sites of AP regeneration
-AP "jumps" from node to node (saltatory conduction)
--> Faster conduction speed (up to 120 m/s)

Front 61

Contains:
-Gap junctions
-Uncommon in the nervous system

Back 61

Electrical Synapses

Front 62

-Most common type in the nervous system
-Release a chemical neurotransmitter which binds to a receptor

Back 62

Chemical Synapses

Front 63

This part of the synapse contains:
-Axon terminal
-Synaptic vesicles

Back 63

Presynaptic cell

Front 64

Direct electrical connection between cells

Back 64

Gap junctions

Front 65

Contain neurotransmitter

Back 65

Synaptic vesicles

Front 66

Space between the presynaptic cell and postsynaptic cell

Back 66

Synaptic cleft

Front 67

-Part of synapses
-A neuron or muscle fiber
-Has receptor proteins

Back 67

Postsynaptic cell

Front 68

Synapse between a motor neuron and a skeletal muscle cell

Back 68

Neuromuscular junction

Front 69

This is the neurotransmitter in the synapse

Back 69

Acetylcholine

Front 70

What does acetylcholine do?

Back 70

-Binds to receptors on the postsynaptic membrane
-ACh receptor is a chemically-gated ion channel
-Opening of chemically-gated channels results in a graded postsynaptic potential

Front 71

Explain the Synaptic Transmission at the Neuromuscular Junction

Back 71

1. Action potential arrives at the presynaptic axon terminal
2. Voltage-gated calcium (Ca2+) channels open in the presynaptic membrane, allowing Ca2+ ions to flow into the presynaptic cell
3. Synaptic vesicles migrate to the presynaptic membrane, releasing acetylcholine (ACh) into the synaptic cleft
4. ACh molecules diffuse across the synaptic cleft and bind to postsynaptic ACh receptors
5. ACh binding to receptors opens chemically-gated ion channels in the postsynaptic membrane. These channels are permeable to Na+ to K+ ions
6. Na+ ions flow into the postsynaptic cell, causing a graded depolarization of the postsynaptic membrane (an EPSP)
7. ACh is rapidly broken own by acetylcholinesterase; ion channels close and membrane returns to resting state

Front 72

Graded potential in the postsynaptic cell membrane that results from binding of neurotransmitter to receptors (synaptic transmission)

Back 72

Postsynaptic potential

Front 73

Excitatory postsynaptic potential (EPSP)

Back 73

-Depolarizes the postsynaptic membrane toward the threshold for an AP
-Can result from opening of Na+ channels or closing of K+ channels
--->Increases the likelihood of an AP forming in the postsynaptic cell

Front 74

Inhibitory postsynaptic potential (IPSP)

Back 74

-Hyperpolarizes the postsynaptic membrane or holds it near the resting level
-Can result from opening of K+ channels or Cl- channels
-->Decreases the likelihood of an AP forming in the postsynaptic cell

Front 75

-Neurons have multiple inputs from other neurons
-EPSPs and IPSPs formed at the dendrites and cell body spread toward the trigger zone
-APs are triggered at the axon hillock only when the membrane reaches threshold

Back 75

Synaptic inputs

Front 76

Connection pathways between groups of neurons

Back 76

Neural Networks

Front 77

A single presynaptic neuron branches, and its collaterals synapse on multiple target neurons

Back 77

Divergent pathway

Front 78

A group of presynaptic neurons provide input to a smaller number of postsynaptic neurons

Back 78

Convergent pathway

Front 79

What does the summation of many EPSPs and IPSPs determine?

Back 79

Determines if APs are formed in the postsynaptic cell

Front 80

EPSPs from different synapses can add together of IPSPs can cancel out EPSPs

Back 80

Spatial summation

Front 81

EPSPs can add together if they occur close together in time

Back 81

Temporal summation

Front 82

This type of receptor binds to acetylcholine

Back 82

Cholinergic receptors

Front 83

The type of cholinergic receptor found in neuromuscular junctions and autonomic ganglia that have fast response, direct, and always excitatory

Back 83

Nicotinic cholinergic receptor

Front 84

The binding of ACh that directly opens chemically-gated channels, allowing Na+ to flow in

Back 84

Ion channel-receptor

Front 85

The type of cholinergic receptor that are found in parasympathetic target cells: heart, GI tract, etc, have a slower response, indirect, and can be excitatory or inhibitory

Back 85

Muscarinic cholinergic receptor

Front 86

These type of receptors bind to norepinephrine and epinephrine

Back 86

Adrenergic receptors

Front 87

What are the two types of adrenergic receptors?

Back 87

1. Alpha adrenergic receptors
2. Beta adrenergic receptors

Front 88

These adrenergic receptors are found in vascular smooth muscle: excitatory, and activate secondary messenger system

Back 88

Alpha adrenergic receptors

Front 89

These adrenergic receptors are excitatory or inhibitory, and are located in cardiac muscle or bronchial smooth muscle

Back 89

Beta adrenergic receptors

Front 90

What type of beta adrenergic receptors is excitatory?

Back 90

Beta 1

Front 91

What type of beta adrenergic receptors is inhibitory?

Back 91

Beta 2

Front 92

What are the three types of amines?

Back 92

Norepinephrine, dopamine, and serotonin

Front 93

The type of amine that activates the sympathetic, "fight-or-flight" response, and associated with adrenaline

Back 93

Norepinephrine

Front 94

The type of amine that activates pleasure and reward centers of the brain

Back 94

Dopamine

Front 95

The type of amine that deals with general mood

Back 95

Serotonin

Front 96

What are the three types of amino acids?

Back 96

Glutamate, gamma-aminobutyric acid, and glycine

Front 97

This amino acid is excitatory in CNS

Back 97

Glutamate

Front 98

These amino acids are inhibitory in CNS?

Back 98

Gamma-aminogutyric acid, and glycine

Front 99

What are the five classes of neurotransmitters?

Back 99

Acetylcholine, amines, amino acids, neuropeptides, and gases

Front 100

What type of peptides do neuropeptides secrete?

Back 100

Endogenous opioids

Front 101

What is an endogenous opioid?

Back 101

Pain receptor

Front 102

What neurotransmitter is produced under gases?

Back 102

Nitric oxide

Front 103

What is nitric oxide?

Back 103

An unstable gas synthesized from oxygen and the amino acid arginine. It acts as a neurotransmitter that diffuses freely into a target cell rather than binding to a membrane receptor

Front 104

What are the three examples of synaptic pharmacology?

Back 104

1. Nicotinic cholinergic synapses
2. Muscarinic cholinergic synapses
3. Monoamine synapses

Front 105

What are the types of nicotinic cholinergic synapses?

Back 105

1. Botulinum toxin
2. Curare
3. Nerve gas

Front 106

What is one type of muscarinic cholinergic synapse?

Back 106

Atropine

Front 107

What is nitric oxide?

Back 107

An unstable gas synthesized from oxygen and the amino acid arginine. It acts as a neurotransmitter that diffuses freely into a target cell rather than binding to a membrane receptor

Front 108

What are the types of monoamine synapses?

Back 108

1. MAO inhibitors
2. SSRIs (selective serotonin reuptake inhibitors)

Front 109

What are the three examples of synaptic pharmacology?

Back 109

1. Nicotinic cholinergic synapses
2. Muscarinic cholinergic synapses
3. Monoamine synapses

Front 110

What are the types of nicotinic cholinergic synapses?

Back 110

1. Botulinum toxin
2. Curare
3. Nerve gas

Front 111

Which type of nicotinic cholinergic synapse blocks ACh release ("Botox")?

Back 111

Botulinum toxin

Front 112

What is one type of muscarinic cholinergic synapse?

Back 112

Atropine

Front 113

Which type of nicotinic cholinergic synapse blocks the ACh receptor and could paralyze you?

Back 113

Curare

Front 114

What are the types of monoamine synapses?

Back 114

1. MAO inhibitors
2. SSRIs (selective serotonin reuptake inhibitors)

Front 115

Which type of nicotinic cholinergic synapse inhibits ACh-esterase?

Back 115

Nerve gas

Front 116

Which type of nicotinic cholinergic synapse blocks ACh release ("Botox")?

Back 116

Botulinum toxin

Front 117

What is one type of muscarinic cholinergic synapse and what does it do?

Back 117

Atropine - blocks muscarinic ACh receptors

Front 118

What blocks muscarinic ACh receptors?

Back 118

Atropine

Front 119

Which type of nicotinic cholinergic synapse blocks the ACh receptor and could paralyze you?

Back 119

Curare

Front 120

Which type of nicotinic cholinergic synapse inhibits ACh-esterase?

Back 120

Nerve gas

Front 121

What is one type of muscarinic cholinergic synapse and what does it do?

Back 121

Atropine - blocks muscarinic ACh receptors

Front 122

What blocks muscarinic ACh receptors?

Back 122

Atropine

Front 123

What type of monoamine synapse blocks breakdown of NE, dopamine, and serotonin (non-selective)?

Back 123

MAO inhibitors

Front 124

What type of monoamine synapse increases concentration of serotonin at synapses?

Back 124

Selective serotonin reuptake inhibitors

Front 125

What is a clinical application of a SSRI?

Back 125

Antidepressant drugs

Front 126

This kind of protein activates a secondary messenger system

Back 126

G protein

Front 127

What kind of binding of ACh to receptor activates a G protein, activated by binding of GTP, also the activated G protein subunit interacts with a K+ ion channel, causing it to open or close

Back 127

G protein coupled receptor (GPCR)

Front 128

Describe the development of the CNS

Back 128

-CNS develops from NEURAL TUBE of embryo starting at 3 WEEKS
-Anterior neural tube first differentiates into forebrain, midbrain, and hindbrain (4 weeks), then further develops into 6 major brain regions + spinal cord (6-11 weeks);
-Forebrain greatly enlarges to form cerebral hemispheres

Front 129

What are the supporting structures of the CNS?

Back 129

1. Meninges
2. Brain Ventricles and Cerebrospinal Fluid (CSF)
3. Glial cells

Front 130

What are the three parts of the meninges

Back 130

1. Dura mater
2. Arachnoid
3. Pia mater

Front 131

Explain the brain ventricles and cerebrospinal fluid

Back 131

-CSF produced by the CHOROID PLEXUSES of the brain ventricles
-it circulates through ventricles and into SUBARACHNOID SPACE
-its composition is regulated; low protein concentration is compared to plasma

Front 132

What are the types of glial cells?

Back 132

1. Astrocytes
2. Microglia
3. Oligodendrocytes
4. Ependymal cells

Front 133

This is connective tissue coverings of the CNS?

Back 133

Meninges

Front 134

Supporting cells of the NS

Back 134

Glial cells

Front 135

These glial cells provide physical and metabolic support to neurons

Back 135

Astrocytes

Front 136

These are tight junctions between capillary endothelial cells; also regulates passage of substances from blood to CNS interstitial fluid

Back 136

Blood-brain barrier

Front 137

These glial cells are phagocytes, protective functions

Back 137

Microglia

Front 138

These glial cells are the myelinate axons in CNS

Back 138

Oligodendrocytes

Front 139

These glial cells produce CSF and secrete them

Back 139

Ependymal cells

Front 140

What are the parts of the spinal cord?

Back 140

Gray matter and white matter

Front 141

What are the parts of the gray matter?

Back 141

Dorsal and ventral horn

Front 142

What are the parts of the white matter?

Back 142

Ascending tracts and descending tracts

Front 143

What kind of information does ascending tracts carry?

Back 143

Sensory information

Front 144

What kind of information does descending tracts carry?

Back 144

Motor information

Front 145

What are the parts of the spinal nerves?

Back 145

Dorsal root and ventral root

Front 146

What does the dorsal root have?

Back 146

Incoming axons of sensory neurons (cell bodies in dorsal root ganglia)

Front 147

What does the ventral root have?

Back 147

Outgoing axons of motor neurons (cell bodies in ventral horn)

Front 148

How many parts of spinal nerves are there?

Back 148

31

Front 149

Explain the parts of the reflex arc

Back 149

Sensory receptor --> sensory neuron --> integrating center --> motor neuron --> effector (muscle)

Front 150

Example of monosynaptic reflex

Back 150

Muscle spindle stretch reflex

Front 151

Example of polysynaptic reflex

Back 151

Withdrawal reflex and crossed extensor reflex

Front 152

What does the brain stem consist of?

Back 152

Medulla, pons, and midbrain

Front 153

What is the function of the brain stem?

Back 153

-Transition from spinal cord to higher brain regions
-Sensory and motor tracts pass through
-Origins of cranial nerves

Front 154

Network of neurons involved in arousal of cerebral cortex (sleep/wake)

Back 154

Reticular formation

Front 155

Explain the medulla oblongata

Back 155

-Ascending (somatosensory) tracts convey sensory information to higher brain areas
-Descending (corticospinal) tracts carry motor signals, cross over in pyramids of the medulla
-Respiratory and cardiovascular control centers
-Other involuntary control centers (swallowing, vomiting)

Front 156

Explain the pons

Back 156

-Connections between cerebellum and other CNS areas
-Respiratory centers coordinate with medulla to control breathing

Front 157

Explain the midbrain

Back 157

-Visual and auditory reflexes
-Role in unconscious motor control (red nucleus, substantia nigra)

Front 158

Explain the cerebellum

Back 158

-Major role in coordination of movement

Front 159

What does the cerebellum contain

Back 159

Cortex (gray matter) and arbor vitae (white matter)

Front 160

What are the parts of the diencephalon?

Back 160

1. Thalamus
2. Hypothalamus
3. Pineal gland

Front 161

Sensory "relay station" from lower CNS centers to the cerebral cortex

Back 161

Thalamus

Front 162

-Regulates appetite, thirst, body temperature
-Regulates endocrine function via control of the pituitary gland
-Activates sympathetic division of ANS
-Mediates physiological responses of emotional states (via autonomic NS)

Back 162

Hypothalamus

Front 163

Endocrine gland, secretes melatonin

Back 163

Pineal gland

Front 164

Cerebrum

Back 164

-Higher brain functions, sensory perception, voluntary control of movement
-Lobes: frontal, parietal, temporal, occipital

Front 165

What does cerebral gray matter contain?

Back 165

1. Cerebral cortex
2. Basal ganglia (basal nuclei)
3. Limbic system

Front 166

What does cerebral white matter contain?

Back 166

1. Associaton fibers
2. Commissural fifbers (corpus callosum)
3. Projection fibers

Front 167

This connects two hemispheres of cerebrum

Back 167

Corpus callosum

Front 168

These fibers contain descending and ascending pathways

Back 168

Projection fibers

Front 169

Deep gray matter areas, involved in subconcious control of movement

Back 169

Basal ganglia

Front 170

"Emotional brain"

Back 170

Limbic system

Front 171

Center of strong emotions (fear, anger); role in memory processing

Back 171

Amygdala

Front 172

Major role in consolidation of long-term memory

Back 172

Hippocampus

Front 173

Highest-level processing and integration area

Back 173

Cerebral cortex

Front 174

Which two increase surface area of cortex?

Back 174

Gyri and sulci

Front 175

How many distinct cell layers is the cortex?

Back 175

6

Front 176

Give a list of functional brain areas

Back 176

1. Frontal lobe
2. Parietal lobe
3. Occipital lobe
4. Temporal lobe

Front 177

Primary motor area, speech (Broca's) area

Back 177

Frontal lobe

Front 178

Higher-level thinking, planning, judgment, personality

Back 178

Prefrontal cortex

Front 179

Primary somatosensory area; snesory association areas

Back 179

Parietal lobe

Front 180

Visual cortex

Back 180

Occipital lobe

Front 181

Auditory cortex; language association (Wernicke's) area

Back 181

Temporal lobe

Front 182

What is cerebral lateralization?

Back 182

Left brain-right brain

Front 183

What is the precentral gyrus in charge of?

Back 183

Motor

Front 184

What is the postcentral gyrus in charge of?

Back 184

Sensory

Front 185

What are the three structural types of sensory receptors?

Back 185

1. Free nerve endings
2. Modified nerve endings
3. Separate sensory receptor cells

Front 186

Type of stimulus that receptor is most sensitive

Back 186

Adequate stimulus

Front 187

Responsive to particular sensory modalities

Back 187

Chemoreceptors, mechanoreceptors, photoreceptors, thermoreceptors, nociceptors

Front 188

Type of sensory receptors that have specific chemicals (taste, olfaction), pH, O2

Back 188

Chemoreceptors

Front 189

Type of sensory receptors that have touch, pressure, stretch, vibration, sound, acceleration

Back 189

Mechanoreceptors

Front 190

Type of sensory receptors that have light, rods, and cone

Back 190

Photoreceptors

Front 191

Type of sensory receptors that have warm, cold

Back 191

Thermoreceptors

Front 192

Type of sensory receptors that have pain: noxious stimuli (chemical, mechanical, thermal)

Back 192

Nociceptors

Front 193

Sensory receptors produce __ in response to sensory stimuli

Back 193

Graded receptor potentials

Front 194

Graded potential formed by sensory receptors

Back 194

Graded receptor potentials

Front 195

Sensory neurons convert receptor potentials into streams of ___

Back 195

Action potentials

Front 196

How does sensory transduction work?

Back 196

Stimulus --> sensory receptor --> sensory neuron --> CNS

Front 197

Area supplied by one sensory neuron

Back 197

Receptive field

Front 198

Smaller receptive fields result in more sensitive discrimination

Back 198

Two-point discrimination test

Front 199

Conveys APs from sensory neurons to the CNS

Back 199

Afferent division of PNS

Front 200

Touch, temperature, pain, proprioception (general senses, part of afferent division)

Back 200

Somatic sensory

Front 201

Mechanical and chemical stimuli from internal organs (part of afferent division)

Back 201

Visceral sensory

Front 202

Vision, hearing, equilibrium, olfaction, taste (part of afferent division)

Back 202

Special senses

Front 203

From receptors to spinal cord or brainstem (sensory pathways in the CNS)

Back 203

First-order sensory neurons

Front 204

From spinal cord or brainstem to thalamus (sensory pathways in the CNS)

Back 204

Second-order neurons

Front 205

From thalamus to cerebral cortex (sensory pathways in the CNS)

Back 205

Third-order neurons

Front 206

What are two types of sensory pathways in the CNS?

Back 206

1. Ascending tracts in spinal cord (somatic senses)
2. Cranial nerve sensory pathways

Front 207

What are the three sensory areas of the cerebral cortex?

Back 207

1. Somatosensory cortex
2. Visual cortex
3. Auditory cortex

Front 208

Where is the somatosensory cortex, visual, and auditory located?

Back 208

Somato = Parietal
Visual = Occipital
Auditory = Temporal

Front 209

What are the four properties of stimuli?

Back 209

1. Modality
2. Location
3. Intensity
4. Duration

Front 210

Modality of stimulus indicated by:

Back 210

1. Specificity of receptors and sensory neurons activated
2. Specific neural pathways in the CNS --> specific areas in the brain ("labeled line coding")

Front 211

Location of stimulus indicated by:

Back 211

1. Specific neural pathways connect receptive fields to specific locations in the cortex
2. Sound localization uses differences in timing from R and L ears
3. Lateral inhibition

Front 212

This increases contrast between adjacent receptive fields

Back 212

Lateral inhibition

Front 213

Intensity of stimulus encoded by:

Back 213

1. Number of receptors activated
2. Frequency of action potentials in sensory neurons

Front 214

Duration of stimulus is coded by ____

Back 214

Duration of APs

Front 215

Decrease in response to a persistent stimulus over time

Back 215

Receptor adaptation

Front 216

Non-adapting or slowly adapting

Back 216

Tonic receptors. Fairly constant response to sustained stimulus (e.g. muscle spindle stretch response)

Front 217

Rapidly adapting

Back 217

Phasic receptors. Respond to initial change in stimulus, then decrease response (e.g. olfactory receptors)

Front 218

__ activate skeletal muscles
voluntary (mostly): control of movement, posture, breathing

Back 218

Somatic motor neurons

Front 219

-Has one motor neuron pathway from CNS to muscle

Back 219

Somatic motor pathway

Front 220

-Motor neuron cell bodies located in ventral gray horn of spinal cord
-Axons travel through spinal nerves
-Axon terminals located at the neuromuscular junctions

Back 220

Somatic motor pathway

Front 221

What are the three components of the neuromuscular junction?

Back 221

1. Axon terminal of motor neuron
2. Synaptic cleft
3. Motor end plate

Front 222

Axon terminals secrete __ into the synaptic cleft

Back 222

Acetylcholine

Front 223

__ are at the motor end plate

Back 223

Nicotinic cholinergic receptors

Front 224

Binding of ACh open cation channels --> strong EPSP --> ? --> ?

Back 224

exceeds threshold --> muscle AP

Front 225

-Involuntary control of autonomic effectors (visceral organs, blood vessels, etc.)
-Activated by the hypothalamus, pons, & medulla, and spinal cord (autonomic reflexes)
-Two motor neuron pathway from CNS to effectors
-2 divisions

Back 225

Autonomic division

Front 226

The autonomic division is activated by __

Back 226

Hypothalamus, pons & medulla, and spinal cord

Front 227

-Both systems are active, but parasympathetic dominates during normal maintenance states; sympathetic system dominates during short-term stress, exercise, cold, drop in BP

Back 227

Dual innervation

Front 228

Tell me what you know about sympathetic division

Back 228

-Thoracolumbar outflow
-Short preganglionic, long postganglionic fibers
-Ganglia located in sympathetic chain and collateral ganglia
-Postganglionic neurons secrete norepinephrine as the neurotransmitter at target cells
-Adrenal medulla is functionally part of the sympatehtic system

Front 229

-This is stimulated directly by preganglionic sympathetic fibers
-Secretes epinephrine and norepinephrine as hormones

Back 229

Adrenal medulla

Front 230

In the sympathetic division, where is the ganglia located?

Back 230

Sympathetic chain and collateral ganglia

Front 231

What neurotransmitter do postganglionic neurons secrete in the sympathetic division?

Back 231

Norepinephrine

Front 232

Tell me what you kjnow about parasympathetic division

Back 232

-Craniosacral outflow
--Vagus nerve is the major parasympathetic nerve to visceral organs
-Long preganglionic, short postganglionic fibers
-Postganglionic neurons secrete acetylcholine as the neurotransmitter at target cells
-Terminal ganglia located in or near target organs

Front 233

__ is the major parasympathetic nerve to visceral organs

Back 233

Vagus nerve

Front 234

In the parasympathetic division, postganglionic neurons secrete __ as the neurotransmitter at target cells

Back 234

Acetylcholine

Front 235

Tell me what you know about the preganglionic fibers in both sympathetic and parasympathetic division

Back 235

ACh --> nicotinic cholinergic receptors

Front 236

What kind of fibers are in charge of adrenergic receptors (alpha and beta), muscarinic, etc.

Back 236

Postganglionic fibers

Front 237

Tell me what you know about the alpha-adrenergic receptors in the sympathetic division

Back 237

-Constriction of blood vessels
--G-protein coupled receptors, acativate phospholipase C second-messenger pathway

Front 238

Tell me what you know about beta-adrenergic receptors in the sympathetic division

Back 238

-Beta 1 stimulates heart; Beta 2 bronchodilation
--G-protein coupled receptors, activate cAMP second-messenger pathway

Front 239

Tell me what you know about beta-adrenergic receptors in the parasympathetic division

Back 239

ACh --> muscarinic cholinergic receptors
--G-protein coupled receptors, open or close K+ channels (excitatory or inhibitory)

Front 240

Tell me the summary of sympathetic and parasympathetic effects

Back 240

SYMPATHETIC
-Increases heart rate and contractility
-Inhibits digestive tract motility and secretion
-Vasoconstriction in peripheral blood vessels, vasodilation in skeletal muscle
-Bronchiole dilation
-Pupil dilation
-Mobilization of energy reserves (glycogen and lipids)
PARASYMPATHETIC
-Decreases heart rate (no effect on contractility)
-Stimulates digestive tract motility and secretion
-No effect on blood vessels
-Bronchiole constriction
-Pupil constriction
-No metabolic effects

Front 241

Variscosities

Back 241

Contain neurotransmitter