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Physiology 001 > Physiol Exam 1: Chps. 1-7, 9 > Flashcards

Physiol Exam 1: Chps. 1-7, 9 Flashcards

1
Q

a. Distinguish: atoms vs. molecules vs. ions (including cations & anions)

b. Identify examples of each: atoms vs. molecules vs. ions (including cations vs. anions)

A

a. Atoms: smallest particle of an element that retains the characteristic of chemical properties
Molecules: group of chemically combined atoms (at least 2)
Ions: atoms or molecules that have a + or - charge (due to unequal # of protons and electrons)
* Cations: positively charged ions
* Anions: negatively charged ions

b. Atoms: H
Molecules: H2O
Ions: Al2S3, Ca3N2
* Cations: Na+, K+, H^2, Ca^2, NH4+
* Anions: Cl-, HCO3-, PO4^3-

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2
Q

a. Name the 4 categories of macromolecules
b. Identify examples of each macromolecule category

A
  1. Carbohydrates - Glucose, fructose, lactose, sucrose, glycogen, starch, fiber
  2. Nucleic Acids - DNA, mRNA
  3. Lipids - Cholesterol, fatty acids, phospholipids, triglycerides
  4. Proteins - Enzymes, channels, pumps
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3
Q

Define enzyme, describe its function & name some characteristics essential to its function

A

Enzymes: catalytic proteins for anabolic (build) or catabolic (break) reactions
* Function: ↑ rate of a reaction (by ↓ activation energy)
— Specificity
— Not used up (reused)

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4
Q

Name the 5 types of membrane proteins (including sub-types) & describe each of those membrane protein’s function

A
  1. Enzyme: degrades chemical messenger, terminating its effect
  2. Cell-identity marker: glycoprotein that helps distinguish body’s own cells from foreign cells
  3. Receptor: binds to chemical messengers (ex. hormones)
    4a. Leakage channel: constantly open; tunnel allows substances to pass into & out of cell
    4b. Gated channel: opens & closes to allow substances through at certain times
  4. Carrier: bind to glucose, ions & other substances to transfer them to other side of cell
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5
Q

Define homeostasis; define set point; name the type of feedback that most often maintains vs. opposes homeostasis

A

Homeostasis: dynamic constancy of the internal environment
Set point: average
Negative feedback - mostly maintain homeostasis
Positive feedback - opposes homeostasis

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6
Q

Name the 5 common components of a feedback loop, memorize how they are sequenced & describe each component

A
  1. Stimulus: A change in the body or environment
  2. Sensor/receptor: Inside body detecting change (always active) & sends info to…
  3. Integrating center: Assesses change around a set point & sends instructions
  4. Effector: Carries out instructions of integrating center
  5. Response
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7
Q

Describe negative feedback

A

Counteracts the change

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8
Q

Memorize the details of the 2 negative feedback loops for thermoregulation

A

a) Body Temperature Fall BELOW Normal
1. Stimulus - Cold environmental temps. lower body temp. to below normal
2. Receptor - Sensory receptors in skin detect cold, sending information to brain
3. Integrating center - Hypothalamus of brain compares sensory input regarding temperature decrease to normal set point of 37 C
4. Effectors - BV in skin constrict; sweat glands become inactive; skeletal muscles shiver to generate heat
5. Response - Body temperature returns to normal

b) Body Temperature Rises Above Normal
1. Stimulus - Exercise or hot environmental temps raise body temp. to above normal
2. Receptor - Sensory receptors in skin detect heat, sending information to brain
3. Integrating center - Hypothalamus of brain compares sensory input regarding temperature decrease to normal set point of 37 C
4. Effectors - BV in skin dilate; sweat glands secrete sweat, which, if evaporated, will cool the skin’s surface
5. Response - Body temperature returns to normal

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9
Q

Describe antagonistic effectors & their purpose

A

Homeostasis often maintained by opposing effectors moving conditions in opposite directions = finer control
— Effectors that do the opposite of one another to help fine tune and regulate the responses around the set point to maintain homeostasis; effectors that help us get to the set point quicker

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10
Q

Describe positive feedback

A

Positive feedback: A change in normal value that is amplified or accelerated
— Continues the change

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11
Q

Distinguish positive feedback from negative feedback

A

Negative feedback - counteracts the change
Positive feedback - continues the change

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12
Q

Recognize examples of negative vs. positive feedback

A

Negative feedback:
* Thermoregulation
Positive feedback :
* Child birth
* Breast feeding

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13
Q

Memorize the details of the negative feedback loop for blood pressure regulation involving the nervous system

A

Lying down
1. Stimulus - Standing up = BP falls
2. Sensor - BP receptors respond
—> Sensory nerve fibers
3. Integrating center - Medulla oblongata of the brain
—> Motor nerve fibers
4. Effector - HR increases
5. Response - Rise in BP

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14
Q

Memorize the details of the 2 negative feedback loops for blood sugar regulation involving the endocrine system (hormones)

A

A) Eating
1. Stimulus -↑ glucose
2. Sensor - Pancreatic islets (of Langerhans)
3. Integrating center - Pancreatic islets (of Langerhans)
— compare it to set point (~70-140 mg/dL after a meal)
4. Effector - Pancreatic islets (of Langerhans) and ↑ insulin
— ↑ Cellular uptake of of glucose
5. Response - ↓ Blood Glucose

B) Fasting
1. Stimulus - ↓ Blood Glucose
2. Sensor - Pancreatic islets (of Langerhans)
3. Integrating center - Pancreatic islets (of Langerhans)
— compare it to set point (~70-100 mg/dL during fasting)
4. Effector - Pancreas ↓ Insulin, ↑ Glucagon, targeting the liver
— ↓ Cellular uptake of glucose; ↑ Glucose secretion into blood by liver
5. Response - ↑ Blood glucose

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15
Q

Memorize how water is distributed amongst the ICF, ECF, interstitial fluid & plasma

A

ICF = 2/3
ECF = 1/3
- Interstitial fluid = 80%
- Blood plasma = 20%

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16
Q

Define selectively permeable for cell membranes

A

Selectively permeable: some particles (certain ions) can go in/out

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17
Q

Distinguish non-carrier mediated transport from carrier-mediated transport & identify examples for each type of transport

A

Non-carrier mediated: transport does NOT require membrane protein carriers
* Simple diffusion of lipid-soluble molecules
* Simple diffusion of ions through membrane channel proteins
* Osmosis through membrane water channel proteins

Carrier-mediated: transport requires membrane protein carriers
* Facilitated diffusion = passive transport
(no ATP)
* Active transport = ATP required
* Specific carrier proteins called pumps

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18
Q

Distinguish passive transport from active transport

A

Passive transport = No ATP
Active transport = ATP

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19
Q

Define diffusion & describe how a concentration gradient drives it

A

Diffusion: net movement of particles (molecules or ions) from regions of higher to regions of lower concentration
* Due to concentration gradient; higher the concentration gradient, the faster the rate of diffusion
* Continues until no difference = NO net diffusion

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20
Q

Describe the types of particles that the cell membrane is permeable & identify examples for the different types

A

Permeable to:
1. Non-polar (Lipid-soluble AKA hydrophobic) molecules, small & large
* Ex. steroid hormones & O2
2. Small molecules with polar bonds but uncharged
* CO2, ethanol & urea
3. Small amounts of H2O

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21
Q

Describe the types of particles that the cell membrane is impermeable to & identify examples for the different types

A

IMpermeable to:
1. Large polar (Charged AKA hydrophilic) molecules: carbohydrates (ex. glucose) & amino acids (& their polymers)
* Require carrier proteins
2. Charged inorganic ions (Na+,K+,Cl-,Ca^2+ )
* Require ion channels
- Leakage
- Gated

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22
Q

Describe the 4 factors that affect rate of diffusion through a cell membrane

A

Depends on:
1. Concentration difference
* “Steep” (high rate) vs. “shallow” (low rate)
2. Cell membrane permeability
* Ex. At rest, neuron cell membrane 20x more permeable to K+ than to Na+
3. Temperature (T)
* Higher T = faster
4. Surface area
* Microvilli; Alveoli

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23
Q

Define osmosis & describe the 2 requirements needed for osmosis

A

Osmosis = Water
* Net DIFFUSION of H2O across selectively permeable membrane from high [H2O]→low [H2O] where H2O=Solvent
* Requirements:
1. Solute at different concentration across membrane
2. Membrane relatively impermeable to solute
- Osmotically active = Solute that can NOT pass freely through membrane

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24
Q

Describe osmotic pressure & osmotically active. How are they related to each other?

A

— Osmotic pressure: force exerted to stop osmosis; indicates how strongly H2O wants to diffuse
— Osmotically active = Solute that can NOT pass freely through membrane
* Osmotic pressure is proportional to osmotically active solute concentration

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25
Q

Memorize the range (& unit in Osm & mOsm) for plasma osmolality (blood)

A
  • Plasma osmolality ~0.3 Osm or ~300 mOsm
  • Range: 275-295 mOsm
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26
Q

Convert the concentration of solutions into molality & osmolality

A

EX) Since electrolytes ionize in water,
*1 mol NaCl → 1 mol Na+ (+) 1 mol Cl-
*1 m NaCl = 2 Osm

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27
Q

Describe the 3 characteristics that carrier proteins exhibit

A
  1. Specificity: Interact with specific molecule(s) only
  2. Competition: Molecules with similar chemical structures compete for carrier site; rate of transport is affected
    • Ex. Amino acids
  3. Saturation: All carrier sites filled = Transport Maximum (Tm)
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28
Q

Define transport maximum

A

All carrier sites filled = Transport Maximum (Tm)
- carrier proteins working at maximum speed

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29
Q

Define facilitated diffusion

A

Facilitated diffusion: Carrier-mediated transport of particles through the cell membrane along/down concentration gradient

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30
Q

Name the cells that contain GLUT4 carriers & describe how GLUT4 carriers are inserted into the cell membrane from the cytoplasm

A
  • Location: muscle cells and adipocytes
  • In unstimulated muscle cell, GLUT4 within membrane of a cytoplasmic vesicle
  • In stimulated muscle cell, vesicle fuses with cell membrane
  • Due to:
    1. exercise OR
    2. insulin
  • Result: More glucose into muscle via facilitated diffusion
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31
Q

Define active transport & name the 2 requirements

A

Active transport: Movement of molecules & ions against their concentration gradients; “Uphill”: from [lower] to [higher]
* Requires both
1. Carrier protein
2. ATP

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32
Q

Define primary active transport & name the energy source that powers it

A

Primary active transport: uses carrier proteins that changes shape
— DIRECTLY uses ATP to transport molecules up/against its concentration gradient

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33
Q

Name the ions exchanged, the amounts exchanged & their starting & ending locations for the Na+/K+ pump

A

Overall: Exchanges 3 Na+ out for 2 K+ in

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34
Q

Describe the 3 purposes of the Na+/K+ pump

A
  1. Na+ gradient as energy for moving other molecules (important for secondary active transport)
  2. Electrochemical signals in muscles & nerves
  3. Osmotic reasons
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35
Q

Define secondary active transport & name the energy source that powers it

A

Secondary active transport: Energy for uphill (against) movement of a particle (ex. glucose) comes from downhill transport of Na+
— ATP powers it indirectly

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36
Q

Distinguish primary active transport from secondary active transport

A

Primary active transport: Directly uses ATP
Secondary active transport: Indirectly uses ATP

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37
Q

Distinguish symport from antiport & identify examples for each type of transport

A

Symport: Molecule or ions move in same direction as Na+
*Ex. Glucose-Na+
Antiport: Molecule or ions move in opposite direction as Na+
*Ex. Na+-H+

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38
Q

Distinguish apical surface from basolateral surface for epithelial membranes

A

Apical surface: faces lumen; 2 K+ in
Basolateral surface: faces inside of body; 3 Na+ out

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39
Q

Distinguish endocytosis from exocytosis

A

Endocytosis: In
* Includes receptor- mediated endocytosis (specific)
Exocytosis: Out

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40
Q

Describe receptor-mediated endocytosis

A

Receptor-mediated endocytosis: specific, a certain particle (LDL, cholesterol) has to bind to a receptor in order to enter the cell

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41
Q

Define membrane potential & describe how certain particles create it (4)

A

Membrane potential: difference in charge across cell membrane

*Fixed anions: proteins & phosphates that can’t leave
* Attract cations
*K+most permeable
- More K+ in (150 mEq/L) vs. out (5)
* Na+/K+ pumps: 3 Na+ out for 2 K+ in
• Constantly “pumping” in the background unless there is no ATP available

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42
Q

Describe the charge on the inside vs. outside of the cell membrane

A

Inside of cell membrane = Negative
Outside of cell membrane = Positive

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43
Q

Define equilibrium potential

A

Equilibrium potential: theoretical voltage across membrane if only 1 ion allowed to diffuse through membrane

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44
Q

Memorize the value (&unit) for EK vs. ENa

A

K+ equilibrium potential (EK):
Potential difference if K+ only diffusible ion = -90 mV for given [K+] inside vs. out

Na+ equilibrium potential (ENa):
Potential difference if Na+ only diffusible ion = + 66 mV [Na+] inside vs. out

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45
Q

Compare the extracellular vs. intracellular concentrations of Na+, K+, Cl- & Ca2+ ions

A

Intracellular - Extracellular
Na+ = 12 mM - 145 mM
K+ = 150 mM - 5 mM
Cl- = 9mM - 125 mM
Ca2+ = 0.0001 mM - 2.5 mM

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46
Q

Define resting membrane potential (RMP)

A

Resting membrane potential: > EK of -90 mV because:
1. Some Na+ can diffuse across cell membrane into cell
2. K+ diffusion out of the cell
* RMP = -70 mV

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47
Q

Memorize the value (& unit) for RMP of a typical neuron & describe how certain particles create it

A

RMP = -70mV inside the cell membrane vs. outside
* Range: -65 mV to -85 mV
Why?
1. Some Na+ can diffuse across cell membrane into cell
2. K+ diffusion out of the cell

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48
Q

Distinguish paracrine vs. synaptic vs. endocrine signaling

A
  1. Paracrine signaling: to target cells (of the same organ)
    - EX) Paracrine
  2. Synaptic signaling: neurons regulate target cells
    - EX) Neurotransmitter
  3. Endocrine signaling: regulators travel in the blood to target cells
    - EX) Hormones
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49
Q

Identify examples of nonpolar vs. polar regulatory messenger/molecules

A

Nonpolar Chemical Messengers - Steroid hormones (estrogen, testosterone, progesterone, cortisol), Thyroid hormones (T3 & T4), NO
Polar Chemical Messengers - Epinephrine, Norepinephrine, ACh, Insulin

50
Q

Distinguish the location(s) for the receptor proteins for nonpolar vs. polar regulatory molecules

A

Nonpolar’s receptor - In cytoplasm OR nucleus
Polar’s receptor - Cell membrane

51
Q

Describe the events that occur after a nonpolar vs. polar regulatory molecule binds to its receptor

A

Nonpolar - Regulate gene transcription/ translation
Polar - 1st messenger binds to receptors on the cell membrane, and activates the 2nd messenger with signal transduction
— Signal transduction: transmission of info from 1 side of a membrane to the other using membrane proteins

52
Q

Name examples of 2nd messengers, describe how they perform their action & describe their purpose

A
  • Examples: ions (Ca2+) or molecules produced within cytoplasm (cyclic AMP, cAMP)
  • Action: Enter cytoplasm to mediate actions of regulatory molecules
    *Purpose: Amplify signals
53
Q

Memorize the details of the negative feedback loop for blood osmolality regulation: dehydration

A
  1. Stimulus - Dehydration: ↓ Blood volume, ↑ Plasma osmolality
  2. Sensor - Osmoreceptors in the hypothalamus
  3. Integrating center - Osmorecpetors in the hypothalamus
    — Compares it to the set point (range: 275-295 mOsm)
  4. Effector - ADH secretion from posterior pituitary gland (thirst) → kidneys (help reabsorb water)
  5. Response - ↑ Water intake, ↑ Water retension
54
Q

Distinguish isotonic vs. hypotonic vs. hypertonic solutions & describe the effect on a cell’s volume when the cell is placed in each solution

A
  • Isotonic solutions: “equal tension”
    — RBCs in isotonic sol. will not gain or lose H2O
    — EX of isosmotic solution:
    • Normal saline (0.9 g NaCl per 100 ml sterile water)
    • Ringer’s lactate
    • 5% dextrose AKA D5W (5 g glucose per 100 ml sterile water) but hypotonic when given to a patient
  • Hypotonic solutions: Fewer osmotically active solutes & lower osmotic pressure than plasma
    — RBC: will expand; possibly burst (hemolyse)
  • Hypertonic solutions: More osmotically active solutes & higher osmotic pressure than plasma
    — RBC: will shrink (crenate)
55
Q

Define hemolyse/hemolysis vs. crenate/crenation

A

Hemolyse: will expand; possibly burst
Crenate: shrink

56
Q

Distinguish neurons vs. neuroglia in terms of their function & prevalence

A

Neurons: conducts action potentials (AP)
* Mostly can NOT divide by mitosis
Neuroglia: support
* More abundant (5x more neuroglia than neurons)

57
Q

Distinguish the dendrite vs. cell body vs. axon of the neuron

A

Dendrite: receive chemicals & transmits electrical signals to the cell body.
Cell body: contains nucleus (organelle) & Nissl bodies
Axon (nerve fiber): conducts APs away from the cell body

58
Q

Distinguish sensory neuron vs. motor neuron vs. interneuron

A
  • Sensory neuron
    — Receptors → CNS
    — EX) Dorsal root ganglion
  • Motorneuron
    — CNS → Effector (muscle, gland)
    — Somatic motor neuron vs. (pre ganglionic neuron) autonomic motor neuron (post ganglionic neuron)
    — EX) Lateral horn of spinal cord
  • Interneuron
    — Entirely within CNS
59
Q

Identify the 2 neuroglia that belong in the PNS vs. 4 in the CNS

A

PNS Neuroglia:
1. Schwann cells
2. Satellite cells
CNS Neuroglia:
1. Oligodendrocytes
2. Microglia
3. Ependymal cells
4. Astrocytes

60
Q

Describe the function(s) of each neuroglia in the PNS

A
  1. Schwann cells - insulation and regeneration for axons
  2. Satellite cells - insulate and regulate chemical environment of the cell body
61
Q

Describe the function(s) of each neuroglia (4) in the CNS

A
  1. Oligodendrocytes - insulation
  2. Microglia - Phagocytose foreign and degenerated material (dendrites or bad myelin)
  3. Ependymal cells - secrete CSF
  4. Astrocytes - form tight junctions = blood-brain barrier
    • Uptake glucose → lactate
    • Recycle neurotransmitter - Ex: glutamate (Glu) to glutamine (Gln)
    • Regulate ECF K+ in brain
    • Form CNS synapses
62
Q

Compare the number of axon(s) each Schwann cell surrounds vs. each oligodendrocyte

A

Schwann cells - ONE per axon
Oligodendrocytes - Covers SEVERAL axons

63
Q

Define graded potentials, name the locations they are produced & describe the 2 types that can be produced

A
  • Graded Potential: a change in the membrane potential with amplitudes that are varied based on stimulus intensity
  • Location: Dendrite and cell body
  • Types:
    1. Excitatory (makes membrane potential positive)
    OR
    2. Inhibitory (makes membrane potential negative)
64
Q

Memorize the value (and unit) for the threshold membrane potential for a neuron

A

Threshold membrane potential = -55 mV

65
Q

Distinguish depolarization vs. repolarization vs. hyperpolarization

A

Depolarization: RMP goes ↑ = more positive or less negative
Repolarization: return to RMP
Hyperpolarization: RMP goes ↓ = more negative or less positive

66
Q

Describe the 2 types of channels found on the axon cell membrane & identify the ion that moves through each type of channel

A
  1. Non-gated channels
    * Leakage channels: for K+
  2. Gated channels
    * Voltage-gated channels: for Na+
    — 1. activation gate
    — 2. inactivation gate
    * Voltage-gated channels: for K+
    — 1. activation gate
67
Q

Distinguish when a channel is closed vs. open vs. inactivated & identify the status of the activation & inactivation gates for each channel situation

A

Closed (at RMP, -70 mV):
* Activation gate blocking
* Inactivation gate open

Open (caused by depolarization [-55 mV])
* Activation gate open
* Inactivation gate open

Inactivated (during refractory period)
* Activation gate open
* Inactivation gate blocking

68
Q

Define electrochemical gradient

A
  1. Electro - Ion goes from an environment that’s positive → an environment that’s negative
  2. Chemical - High concentration of ion → low concentration of ion
69
Q

Memorize the details of the depolarization phase of the AP

A
  • Na+ moves down electro- chemical gradient = inward (influx)
  • Eventually channel becomes inactivated
70
Q

Memorize the details of the repolarization phase of the AP

A
  • K+ moves down electrochemical gradient = outward (efflux)
  • After- hyperpolarization: channels stay open just a bit longer
71
Q

Define the all-or-none law & describe how it affects the duration & amplitude of all AP

A
  • AP ALWAYS same amplitude or NONE produced (all-or-none law)
  • All AP have ~ the same:
    — Duration (time): due to inactivation of Na+ channel
    — Amplitudes: concentration gradient of Na+; amt. of Na+ enters is consistent = AP always the same
72
Q

Describe how the nervous system determines the quality vs. quantity (2 methods for quantity) of a stimulus

A

What kind of stimulus is it? (Quality)
* Labeled line code: each axon to the brain leads from a receptor that recognizes a particular stimulus type
- Axons in optic nerve = provides info on light receptors in the eye

How intense is the stimulus? (Quantity)
1. Recruitment:
* Neurons with lower threshold fire 1st
* Stronger stimuli activate neurons with higher threshold
2. Within a neuron, ↑ frequency of AP (# per unit time) = greater stimulus strength
* Ex: Warm vs Hot

73
Q

Distinguish absolute vs. relative refractory period & describe when and why each period occurs

A

Absolute refractory period: Axon CANNOT produce new AP
— Occurs during depolarization and repolarization of AP, thus voltage gated Na channels aren’t activated

Relative refractory period: Axon CAN produce new AP but requires stronger stimulus
— Occurs after hyperpolarization, but very difficult to produce another AP, due to K+ diffusing

74
Q

Compare graded potentials to AP’s in terms of location produced in the neuron, threshold, gradation, summation & refractory period

A

Graded potential:
- Location: Dendrite and cell-body
- Threshold: no
- Graded: yes
- Summation: yes
- Refractory period: no

Action potential:
- Location: axon’s cell membrane
- Threshold: yes (-55mV)
- Graded: no; “all or none”
- Summation: no; voltage gated channel is inactive
- Refractory period: yes; absolute (no AP) and relative refractory period (possible but difficult to make AP)

75
Q

Describe the propagation of action potentials after they are generated

A

1 AP does NOT travel entire axon
- New AP has to be made

76
Q

Distinguish the propagation of APs on unmyelinated axons

A
  • Depolarization (Na+ influx) → new depolarization @ adjacent axon with voltage-gated channels → new AP
  • Propagate along entire length
  • Conducted without decrement/diminished (AP will continue till the end)
  • Velocity: slow, ~1 m/s (2.23 miles/hr)
77
Q

Distinguish the propagation of APs on myelinated axons

A
  • Myelin = insulation; no APs
  • Nodes of Ranvier (about 1-2 mm away from each other) with voltage-gated Na+ & K+ channels for APs
  • Node-to-node = saltatory conduction (signal jumps from one node to another)
  • Velocity: fast, >100 m/s (223 miles/hr)
78
Q

Name the 2 factors that influence conduction speed of an AP & describe how each factor affects the speed

A
  1. Presence of myelination
  2. Thicker axon/ axon with a larger diameter
    • less resistance inside axon
    • is also myelinated
79
Q

Define synapse and the types

A

Synapse: functional connection between neuron & 2nd cell
* Neuron → neuron (dendrite, cell body or axon)
* Neuron → effector (gland or muscle)
* If muscle = neuromuscular junction AKA neuromuscular synapse
1. Electrical synapse
2. Chemical synapse

80
Q

Describe electrical synapse and the different types of substances that travel through it

A
  • Occurs at gap junctions
    • 6+6 connexin proteins form water- filled channels that join electrically & mechanically
      1. Ions & molecules can pass
      2. APs can cross gap junction:
    • Cardiac muscle
    • Smooth muscle
  • Other locations:
    • Neuroglial cells (Ca2+ )
81
Q

Memorize the details of how an AP leads to the release of neurotransmitters into the synaptic cleft

A
  • AP reaches presynaptic terminal bouton
    — Open voltage-gated Ca2+ channels
    — Ca 2+influx & binds to synaptic vesicles with neurotransmitter
    — Vesicles fuses with membrane & exocytosis neurotransmitter
  • Exocytosis requires ATP
82
Q

Describe the effect of altering the number of APs in a neuron has on neurotransmitter release by that neuron

A

This process of chemical synapse applies to how many neurotransmitters are released
* In general, more APs → more neurotransmitters exocytosed

83
Q

Distinguish agonists from antagonists

A
  • Agonist: a particle different than the neurotransmitter that can bind to & activate the receptor
  • Antagonist: a particle different than the neurotransmitter that can bind to & reduce the activity of the receptor
84
Q

Define cholinergic fibers, cholinergic receptors & cholinergic synapses

A

Cholinergic = ACh
* Cholinergic fiber - the axon that releases ACh as a neurotransmitter
* Cholinergic receptor - the receptor that receives ACh
* Cholinergic synapse - a location where the axon that releases ACh makes a connection with another target cell

85
Q

What are monoamine neurotransmitters made from and name examples of monoamines

A
  • From amino acids
  • Catecholamines: from precursor tyrosin
    1. Dopamine
    2. Norepinephrine (functions as neurotransmitter & hormone)
    3. Epinephrine (functions as hormone only)
  1. Histamine: from precursor histidine
  2. Serotonin: from precursor tryptophan
86
Q

Define adrenergic fibers, adrenergic receptors & adrenergic synapses

A

Adrenergic = Norepinephrine
* Adrenergic fiber - the axon that releases norepinephrine as a neurotransmitter
* Adrenergic receptor - the receptor that receives norepinephrine
* Adrenergic synpase - a location where the axon that releases norepinephrine makes a connection with another target cell

87
Q

Memorize the type of neurotransmitter dopamine is (excitatory or inhibitory)

A

Inhibitory neurotransmitter for midbrain neurons

88
Q

Name the enzyme that degrades monoamines & name its specific location

A

monoamine oxidase (MAO) in presynaptic terminal bouton

89
Q

Identify the amino acid neurotransmitters considered excitatory (1) vs. inhibitory (2) & describe how these inhibitory neurotransmitters produce inhibition

A

Excitatory:
GLUTAMATE
- NMDA receptor (memory)
- AMPA receptor (possibly memory)
- Kainate receptor

Inhibitory: Cl- goes in making cell inside more negative
1. GABA: IPSP via Cl- channels
- Role: motor functions in cerebellum
- Most common neurotransmitter in brain; (Huntington’s disease)
2. Glycine: IPSP via Cl- channels
- Role: help control skeletal movements (inhibits antagonistic muscle)

90
Q

Identify the most common neurotransmitter in the brain

A

GABA
- Role: motor functions in cerebellum

91
Q

Describe the function(s) and what it’s made from for the following neurotransmitters: substance P, nitric oxide

A

Substance P for pain sensations
- polypeptides as neurotransmitters

Nitric oxide (NO) ; gases as neurotransmitters
- crosses cell membrane easily
- CNS: made by presynaptic & postsynaptic neurons
- PNS: autonomic neurons targeting smooth m. to relax
- Endothelial cells (blood vessel) to smooth m., causing vasodilation
- Macrophages use to kill bacteria

92
Q

Distinguish divergence from convergence

A

Divergence: 1 neuron synapses w/ many
Convergence: many neurons synapse on 1

93
Q

Distinguish spatial summation from temporal summation

A

Spatial summation: Release of neurotransmitters from 2 presynaptic neurons to reach threshold (-55 mV)
Temporal summation: Successive release of neurotransmitter from one presynaptic neuron that reaches threshold (-55 mv)

94
Q

Name the 2 divisions of the ANS & the 4 general effectors each division innervates

A

Sympathetic division and Parasympathetic division
1. Smooth muscle
2. Cardiac muscle
3. Endocrine glands
4. Exocrine glands

95
Q

Name the neurotransmitter(s) released by sympathetic vs. parasympathetic preganglionic neurons

A

ALL ANS preganglionic fibers releases ACh

96
Q

Name the neurotransmitter(s) released by sympathetic vs. parasympathetic postganglionic neurons

A
  • Most postganglionic sympathetic fibers use NE, and some ACh
  • Most postganglionic parasympathetic fibers use ACh, and some NO
97
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: radial m. (Iris), circular m. (iris),

A

Sympathetic:
* Radial m. - Contracts (dilate pupil)
* Circular m. - None

Parasympathetic:
* Radial m. - None
* Circular m. - Contracts (constrict pupil)

98
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: SA node

A

Sympathetic: Increases heart rate

Parasympathetic: Decreases heart rate

99
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: cardiac m. (heart)/ contractility

A

Sympathetic: Increases

Parasympathetic: Decreases (atria)

100
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: skeletal m. vessels

A

Sympathetic: Relaxes (vasodilation)

Parasympathetic: None

101
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: bronchiolar smooth m.

A

Sympathetic: Relaxes (bronchodilation)

Parasympathetic: Contracts (bronchoconstriction)

102
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: GI tract smooth m. in walls,

A

Sympathetic: Relaxes

Parasympathetic: Contracts

103
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: GI tract secretion,

A

Sympathetic: Inhibits

Parasympathetic: Stimulates

104
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: urethral sphincter

A

Sympathetic: Contracts

Parasympathetic: Relaxes

105
Q

Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: sweat glands for thermoregulation

A

Sympathetic: Increases

Parasympathetic: None

106
Q

Name the structure that is considered a modified sympathetic ganglion & identify the type of innervation it receives

A

Adrenal medulla
— Receives ONLY preganglionic innervation

107
Q

Identify the 4 cranial nerves associated with the parasympathetic division

A

Cranial nerve III, VII, IX, X

108
Q

Name the locations where α1 vs. β1 vs. β2 adrenergic receptors are found & describe the action produced by each receptor when stimulated (use the bulletpoint information & NOT table 9.4)

A

▪ a1 : Blood vessels; Constricts smooth m. in blood vessels & gut (vasoconstriction)
▪ b1 : Heart; ↑ HR + contraction strength of heart
▪b2 : Lungs; Relax smooth muscle in bronchioles

109
Q

Memorize the details of the mechanism after a β adrenergic receptor is stimulated (1.at the heart & 2. at the bronchioles) vs. an α adrenergic receptor is stimulated (at blood vessels)

A

β Adrenergic Receptors
1. Epinephrine OR Norepinephrine binds to its (adrenergic) receptors
2. G-proteins subunits dissociate and one of the subunits go to a membrane protein/enzyme, adenylate cyclase
3. Adenylate cyclase is activated; breaks ATP into cyclic AMP
4. Cyclic AMP activates protein kinase , which opens ion channels:
* β1 at heart: HCN channel (for Na+)
* β2 bronchioles: K+ channel

α1 Adrenergic Receptors
1. Epinephrine OR Norepinephrine binds to its (adrenergic) receptors
2. G-proteins subunits dissociate and one of the subunits go to a membrane protein/enzyme, Phospholipase C
3. Phospholipase C take a phospholipid from the cell membrane and turns it into 2 different molecules, DAG and IP3
— IP3 travels into cytoplasm to the endoplasmic reticulum to help release Ca+ into the cytoplasm
4. Ca binds to calmodulin→
* Activates protein kinases
* α1 at blood vessels = vasoconstriction

110
Q

Name the locations in the body for nicotinic cholinergic receptors (3)

A
  1. Neuromuscular junctions (neuron and skeletal muscle)
  2. autonomic ganglia (preganglionic and postganglionic)
  3. some CNS
111
Q

Identify the effect on membrane potential after ACh binds to the nicotinic receptor & describe the ions & their movement that permit this effect

A
  • General effect: ALWAYS excitatory; membrane potential is +
  • Opens Na+/K+ ion channel w/in protein
    — More Na+ in than K+ out = depolarization → excitation
112
Q

Name the agonist vs. antagonist of the nicotinic receptor

A

Agonist - Nicotine
Antagonist - Curare

113
Q

Name the locations in the body for muscarinic cholinergic receptors

A

Most parasympathetic axons to effectors

114
Q

Identify the effects on membrane potential after ACh binds to muscarinic receptors & describe the mechanism to produce this effect

A
  • General effect: EITHER excitatory or inhibitory
    — there are different subtypes/ 5 types of muscarinic receptors: M1-M5
115
Q

Name the agonist vs. antagonist of the muscarinic receptor

A

Agonist: Muscurine
Antagonist: Atropine

116
Q

Name the enzyme that degrades ACh & name its specific location

A

Acetylcholinesterase (AChE)
- found in post-synaptic membrane/cell

117
Q

Name 3 neurotransmitters released by nonadrenergic, noncholinergic postganglionic fibers

A
  • ATP
  • vasoactive intestinal peptide (VIP)
  • nitric oxide (NO)
118
Q

Define duel innervation

A

Most visceral organs receive dual innervation = innervation from both divisions (sympathetic and parasympathetic)

119
Q

Name the 4 structures & organs that receive only sympathetic innervation

A
  1. Adrenal medulla
  2. Arrector pili
  3. Sweat gland
  4. Most blood vessels
120
Q

Describe the functions of the medulla oblongata

A

Medulla oblongata regulates the visceral reflexes from visceral functions

Physiology 001 (8 decks)

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