Human Phys exam 1 Flashcards
(124 cards)
1
Q
What is physiology?
A
Study of biological function (normally in homeostasis)
2
Q
What is pathophysiology?
A
Study of diseased states of the body (abnormal)
- When something in the body is not in homeostasis
3
Q
What is homeostasis?
A
State of dynamic constancy in the internal environment
- Different for each variable of the body
4
Q
What are homeostatic control systems
A
Negative and positive feedback
Set points
5
Q
What are set points?
A
Value for which a variable operates optimally
6
Q
What is dynamic constancy?
A
Correction in the opposite direction o deviation - move it back to set point.
Continuous process, always fine adjustments to stay in homeostasis
7
Q
What is negative feedback loop?
A
- Sensors.
- Integrating center
- Effector
8
Q
What are sensors?
A
In the body to detect change and send information to the integrating center
9
Q
What is integrating center?
A
Asses change around a set point
10
Q
What is an effector?
A
Which can make the appropriate adjustments to counter the change from the set-point
11
Q
What is positive feedback?
A
- Stimulus causes deviation from set point
- Cellular response amplifies deviation
- Further deviation leads to additional cellular response
- and so on and so on until stimulus stops
(end product stimulates process)
12
Q
Positive Feedback equals what?
A
Arrow
13
Q
Negative Feedback equals what?
A
Loop
14
Q
What does intrinsically mean?
A
Cells within the organ sense a change and signal to neighboring cells to respond appropriately
15
Q
What does extrinsically mean?
A
The brain (or other organs) regulate(s) an organ using the endocrine or nervous systems
16
Q
What are the 4 main groups of cells?
A
- Muscle cells
- Neurons
- Epithelial cells
- Connective tissue cells
17
Q
Describe muscle cells and tissue.
A
-Generate mechanical force
18
Q
What are the three types of mechanical force and are the voluntary or involuntary?
A
Skeletal = voluntary
Cardiac = involuntary
smooth = involuntary (GI Tract)
19
Q
Describe neurons and nervous tissue.
A
Neuron: conduct electrical signals (impulses) to other cells.
Make up the:
-Brain
-Spinal cord
-Nerves
20
Q
Describe Epithelial cells and tissue.
A
-Linings and coverings of organs and cavities
-Specialized for: secretion, absorption (single layered) and protection (double layered)
-Shape and type of epithelial cell vary per location in the body
-structure and function may differ on one side of the cell compare to the other (apical vs basal)
21
Q
describe connective cell and tissue.
A
Connect, support and anchor structures to the body:
-bone
-cartilage
-blood
-connective tissue proper (protein/collagen fibers and adipose tissue)
-structure: extracellular or connective tissue matrix lies btw all the types of connective cells
22
Q
describe body fluids.
A
Watery solution of dissolved oxygen, nutrients, and waste
Two components
-intra and extra cellular
23
Q
What are intracellular fluids?
A
(Cytosol) 65%. of all fluids
24
Q
What are extracellular fluids?
A
Plasma in the blood and intestinal fluid (between cells -out of bloodstream and pancreas)
25
Why is binding so important?
Binding of molecules to receptors causes changes in cells and serves in transporting, communicating and affecting the overall function of organs.
26
What are examples of molecules binding?
-Hormones
-Enzymes
-Neurotransmitters
-Gases
27
What are some examples of binding?
-Opening a channel in the membrane
-Changing shape of a channel elsewhere in the membrane
-Blocking actions of other molecules
28
What's a ligand?
Any molecule or ion that is bound to a protein by one. of the following forces:
-Electrical attractions
-Weaker attractions due to hydrophobic forces between non polar regions on the two molecules
29
The region of a protein in which the ligand binds is known as an...
Active site
-multiple ligands move around at the same time
-when two ligand arrive at an active site they can both fit, a competition begins
30
When a ligand binds to a protein the proteins specific function is...
Inhibited or activated
31
What is competition in regards to molecular binding?
The presence of multiple ligands able to bind to the same site
32
What's an agonist?
Triggers response to activate or increase an action. Often mimics a naturally produced ligand
Ex: Decongestant - mimic epinephrine but on a subtype receptor of epi
33
What's an antagonist?
Molecules that do not activate as the natural ligand would. Often occupies the site blocking the natural ligand and its effect
Ex: Antihistamine - a histamine blocker by occupying those binding sites
34
In order to bind properly proteins must have the right...
Conformational shape
35
The ____ _____ determines the type of chemical that is bound.
Active site
36
Some ligands only bind to one ligand while others can bind to ____ ____.
Many ligands
37
Increasing the specific molecular shape and active site increases the ...
Chemical specificity
38
Ligand =
Substrate
39
Protein =
Enzyme
40
Enzymes can be defines as
Protein catalysts
41
Give background information on enzymes.
-Enzymes increase the rate of reaction by lowering the activation energy of the reaction
-enzyme itself is unchanged: a single catalyst molecule can act over and over again to catalyze many reactions
-enzymes end in ase
42
The strength of ligand-protein binding is a property of the binding site known as what?
Affinity
43
Define affinity.
-The affinity of a binding site for a ligand determines how likely it is that a bound ligand will leave the protein surface and return to its unbound state.
-Specificity depends only on shape of binding site, affinity depends on the strength of attraction in binding site of protein to ligand.
44
What is saturation?
The fraction of total actives sites that are occupied at any given time.
45
The percent saturation depends on:
The concentration ligand and the affinity
46
How are enzymes involved in reactions that occur in the body?
-Chemical reactions involve breaking of chemical bonds in reactants and the making of a new chemical bond in the products
-when this is happening energy is added or released and doesn't disappear
47
What are the determinants of chemical reaction rates?
1. Reactant concentration (high concentration = faster reaction)
2. Activation energy (higher the AE slower the reaction)
3. Temperature (high temp = faster rxn unless it is at the denaturing temp)
4. Catalyst (presence of catalysts - faster rxn)
48
What are the "things" involved in simple diffusion?
molecules, ions, and water
49
What is carrier mediated transport?
Facilitated diffusion and active diffusion.
50
What is diffusion?
The random movement of molecules from a region of higher concentration towards one of lower concentration
51
What determines movement of molecules? (diffusion)
-Concentration difference
-Distances beyond 100um will mean the diffusion time is too long to be effective.
Ex: Moving O2 from lungs to blood crosses epithelial cells 1-2 um thick
52
Molecules are always ...
Moving and collidingq
53
Diffusion rate is affected by what?
Concentration difference (gradient)
Membrane permeability to each molecule
Temperature
Surface area
54
Neural membrane at rest is more permeable to ___ than to _____
K+ , NA+
55
What does semipermeable mean?
Some materials allowed through, others not
56
How do non polar molecules diffuse?
Rapidly
-Lipophilic (lipid-loving) substances move through easily
Ex. Steroid hormones, O2, CO2, and fatty acids
57
How do polar molecules and hydrophilic molecules diffuse?
Do not diffuse readily through the membranes without the help of special molecules and structures
58
What are ions?
Charged particles
59
A simple artificial lipid bilayer is practically ____ to ions
Impermeable
60
What is an ion channel?
-Integral membrane proteins form channels through which ions can freely diffuse according to their gradient
-These small channels can be specific and only allow the diffusion of certain ions at certain times
61
What is the fastest way to administer drugs?
IV
62
What is osmosis?
The net diffusion of water across a membrane
63
What are aquaporins?
PASSIVE
-Movement of water facilitated by channel proteins called aquaporins
-Water may get stuck in hydrophobic fatty acids without these
64
Why do kidneys have aquaporins?
For their role in regulation of plasma
Kidneys have aquamarines in epithelial cells
call also insert more aquaporins or remove them
65
Explain osmosis
A difference in concentration of solutes exists on either side of the membrane
Membranes must be impermeable to solute making the water move
The net movement of water is from the side with more water (diluted, low solute) to the side with less water (concentrated, high solute)
Water will move faster with a high concentration
66
What does diluted indicate?
More water, less solute
67
What dose concentrated indicate?
Less water, more solute
68
What is molarity (1M)
A compound is measured as its molecular weight in grams
moles solute / 1L solution.
69
Give examples of molarity.
-Glucose and NaCl each weigh different grams, each dissolved in 1 L water separately
- Glucose has 180 grams dissolved in 1L water, NaCl has 58.5 grams dissolved in 1L water. There is more water used to make the 1 molar solution of NaCl.
70
What should you consider before administering drugs?
Dosage, Allergies, and side effects
71
What is osmolality?
Number of solutes in plasma
72
What is tonicity?
The effect of solution on osmotic movement
73
What is isotonic?
Solutions have the same concentration of nonpenetrating solutes as normal plasma
(balanced)
74
Plasma cells have the same osmolity as a ____ glucose or ___ NaCl
0.3m 0.15m
75
What does normal saline consist of?
0.9g NaCl/100mL water
76
What does 5% dextrose consist of?
5g Glucose/100mL water
77
What does hypo-osmotic mean?
Solutions have lower solute concentration, lower osmolality. These solutions are also hypotonic and the cell will lyse (swell)
78
What does hyper-osmotic mean?
Solutions have a higher concentration than the cell. These solutions are also called hypertonic and cause the cell to crenate (Shrink).
79
Mediated transport vs transport/carrier proteins
Passive
conformational changes in transport proteins each time a molecule crosses
Makes the process much slower and moves fewer ions compared to simple diffusion
80
What is facilitated diffusion?
Passive
No energy is required, channel is specific and movements are diffusional
81
Examples of facilitated diffusion
glucose
-polar molecule that needs a transporter
82
T/F: facilitated diffusion moves molecules from high to low concentration?
True
83
T/F: Low to high could also be described as moving with the gradient or down the gradient?
False
84
T/F: lyse is to swell as crenate is to shrink?
True
85
Water channel is always ...
Open
86
Mediated transport: active transport
Involves the use of ATP to pump a molecule against its gradient
Molecule specific and limited by saturation and the ratee of conformational change
87
Active transport
Moves molecules against their concentration gradient
Low-High
88
What are the two types of active transport?
Primary and Secondary
89
What is primary Active transport?
Uses ATP pump is an enzyme
90
What is secondary active transport?
Uses electrochemical gradient across membrane
91
Sodium-potassium pump (primary active transport
- Na/K ATPase pump
- Moves 3 sodium out 2 potassium in
- Both work against concentration gradient
- Maintains distribution of high intracellular K and low Na
- Found in every cell
- shape of transporter changes
92
Why is the sodium potassium pump necessary?
Na+ gradient (Na is used in secondary transport)
Prevents constant osmosis
Maintains membrane potential - counter K leaks
93
What is secondary active transport?
- The movement of a molecule with its electrochemical gradient is coupled with the movement of a second molecule (ex Na and glucose)
- Require the proteins to have two binding sites (one for each molecule)
- Transported molecules can be moved in the same or opposite directions ( cotransport =. same, counter transport = opposite)
- Primary active transport will move Na+ back out of the cell maintaining the gradient
94
Examples of secondary active transport
Respiratory or renal image (countertransport)
95
Describe membrane potential (Em)
An unequal distribution of changes across the membrane, leaving the inside cell negatively charged compared to the outside
96
Membrane potential expanded ...
Permeability (higher K+)
Na/K pump
Negative molecules in cell (anions that cannot penetrate the membrane)
97
At rest our cells will have a ____ attraction coming in
Positive
98
Membrane potential of K+
- K+ accumulates at higher concentration in the cell
- the Na/K pumps actively bring in K+
- The membrane is very permeable to K+
- Negative anions inside the cell attract cations outside the cell
99
Membrane potential can be measured in what?
Volts
100
Membrane potential of Na+
- sodium is important for establishing membrane potential
- To keep so much sodium out, the inside would have to be positive to repel sodium ions
- The membrane is less permeable to Na so the actual membrane potential is closer to that of the more permeable K+
101
K membrane potential is what?
-90mV
102
Na membrane potential is what?
66mV
103
Resting potential range is what?
-65mV to -85mV
104
Neuron membrane potential is what?
-70mV
105
What is used to calculate equilibrium potentials?
Nernst Equations
106
What 4 ions contribute the most to membrane potential?
K+
Na+
Cl-
Ca2+
107
The equilibrium has a negative value when the concentration inside the cell is _____ that outside the cell
Greater
108
K membrane potential
Inside of the cell is negative and it would take 90mV to prevent diffusion of k out of the cell
109
Na membrane potential
Inside of the cell is positive and it would take 66mV to prevent diffusion of na into the cell
110
How does a cell move away from resting potential?
Permeability and concentration
111
What do changes in permeability cause?
A change in permeability of the membrane for any ion will change the resting potential.
ex when a neuron sends an impulse it changes the permeability of na driving the membrane potential closer to the equilibrium potential for na
112
What does changes in concentration cause?
A change in the concentration of any ion inside or outside will change the resting potential
113
Paracrine
cell to cell
localized
114
Synaptic
Neurons have a synapse communication they must cross
115
Endocrine
Hormones regulate via the blood stream
116
Receptor proteins
Targets that are specific to a molecule. targets may be on the cell membrane or inside the cell
117
Second messenger
Regulatory molecules may bind to receptors on the cell membrane but then require a second action to carry out the function of the binding
longer process
two steps
118
Secondary messengers examples
cAMP
norepinephrine binds at receptor in membrane
G-proteins activate adenylate cyclase enzyme in membrane to produce cAMP
cAMP activates protein kinase
Protein kinase activated carious out the action intended opening the ion channel
119
Na/K pump is
Primary
120
H+/K+ pump is
primary
121
Na/Glucose is
co-transport
122
K+ and Cl- is
co transport
123
Ca+ and Na+ is
counter transport
124
Cl- and HCO3- is
Counter transport
