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Anatomy and Physiology 1 > 1. Homeostasis > Flashcards

1. Homeostasis Flashcards

1
Q

Anatomy

A

study of bodily structure - often revealed by dissection and seperation of body parts

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2
Q

Physiology

A

normal functions of living organisms and their parts

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3
Q

Homeostasis

A

maintenance of nearly constant conditions in the internal environment

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4
Q

affector

A

in

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5
Q

effector

A

out

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6
Q

3 examples of homeostasis

A
  1. Lungs provide oxygen and remove CO2
  2. Kidneys maintain constant ion concentrations
  3. GI tract provides nutrients
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7
Q

the cell

A

basic living unit of the body - specially adapted to perform one or more particular functions

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8
Q

3 certain features cells have in common

A
  1. oxygen reacts with carbs, fats and proteins to release energy
  2. deliver end products of their chemical reactions into surrounding fluids
  3. most cells can reproduce themselves
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9
Q

Protoplasm

A
  • the different substances that make up the cell
  • cytoplasm + nucleus
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10
Q

Protoplasm is composed of 5 basic substances:

A

WEPIC
1. water
2. electrolytes
3. proteins
4. lipids
6. carbs

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11
Q

Water and protoplasm

A
  • 70-85% water content (exception is fat cells)
  • cellular chemicals are dissolved in the water
  • chemical rxns take place among the dissolved chemicals or at the surfaces of suspended particles or membranes
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12
Q

Electrolytes/ions and protoplasm

A
  • Provide the inorganic chemicals for cellular reactions
  • Necessary for the operation of some cellular control mechanisms
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13
Q

Example of importance of electrolytes and ions in the protoplasm

A

Transmission of nerve impulses or muscle contraction (more details later)

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14
Q

proteins and protoplasm

A
  • 2nd most abundant after water
  • 10-20% of cell mass
    2 main types: structural and functional
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15
Q

structural proteins

A
  • provide cytoskeleton of organelles like cilia, nerve axons, mitotic spindles
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16
Q

functional proteins

A
  • mainly enzymes that breakdown stuff
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17
Q

lipids and protoplasm

A
  • phospholipids and chloesterol (2% of cell)
  • insoluble so it forms the cell membrane and intracellular membrane barriers
  • tryglyceride - 95% of the cell mass of adipose cells
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18
Q

carbohydrates and protoplasm

A
  • small amounts intracellular (1%)
  • more in muscle and liver cells
  • energy: glucose is dissolved ECF and can be used when transferred into the cell
  • stored energy: stored in glycogen
  • structural function: glycoproteins
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19
Q

Cytoplasm

A

14
- contains many dissolved proteins and parts of the cell except nucleus
- fluid is called cytosol

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20
Q

Endoplasmic reticulum

A

Rough (granular) - 5
- has ribosomes (rna and proteins)
- synthesizes new proteins
Smooth (agranular) - 8
- synthesize lipid substances

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21
Q

Golgi apparatus

A

6
- secretory cells
- substances transported from ER are processed in the golgi
- forms lysosomes (12) and secretory vesicles (4)

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22
Q

Lysosomes

A

12
- intracellular digestive system
- digests: damaged cell structures, particles ingested by cell, unwanted particles
- lysosome membrane must break down to allow enzymes to work

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23
Q

Peroxisomes

A
  • similar to lysosomes but
    1. formed by self-replication or budding from rough ER
    2. contain oxidases
  • oxidizes compounds that may be poisonous
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24
Q

Ex of peroxisomes

A
  • 50% of alcohol is detoxified by liver peroxisomes
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25
Q

Secretory vesicles

A

4
- packages of substances that the cell will secrete

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26
Q

Ex of secretory vesicles

A

pancreatic acinar cells have secretory vesicles which store protein enzymes that will be released in small intestine

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27
Q

Common pathway of secretion in cells

A

Secretory substances fromed by ER-golgi complex, released into cytoplasm in secretory vesicles

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28
Q

Mitochondria

A

9
- self replicate
- create energy in the form of ATP
- a cell can have up to thousands of mitochondria per cell (<100 to 1000s)

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29
Q

Nucleus

A

2
- control center of cell
- contains DNA (genes)

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30
Q

Microtubules

A

7
- cytoskeleton

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31
Q

Cell membrane

A
  • lipid bilayer
  • phospholipid molecules
  • hydrophobic ends to center of membrane
  • hydrophilic ends to the surfaces
  • impermeable to water soluble substances
  • fat soluble go in easily
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32
Q

integral proteins

A
  • penetrate all the way through the cell membrane
  • can be structural or carrier
  • structural: channels that allow substances to pass
  • active transport
  • can act as enzymes
  • receptors for water coluble chemicals (peptide hormones)
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33
Q

peripheral proteins

A
  • do not pass through
  • attached to integral proteins
  • act as enzymes
  • controllers of transport through pores
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34
Q

Carbs

A
  • combo with lipids or proteins
  • contains glkycocalyx
  • function: negative charge repels other negative charges, attaches cells to one another, receptor substances for binding hormones, immune reactions
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35
Q

Glycocalyx

A

loose carbohydrate coat on outer surface of cells

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36
Q

cells - ECF and ICF

A

cells are bathed in extracellular fluid, contain intracellular fluid and pass things back and forth between the two cell membranes

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37
Q

Water content in body

A
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38
Q

Should you use the term water content of fluid content

A

fluid - measures a whole space including solutes

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39
Q

major ions found in ICF

A

potassium, magnesium, phosphatem

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40
Q

major ions found in ECF

A

sodium, chloride, bicarbonate

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41
Q

Explain this

A

shows what ions are found where

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42
Q

Explain this

A

shows how much of each ion is found in cell space

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43
Q

Cell membrane function

A
  • interacts with external environments
  • seperates ECF and ICF
  • an organ that supervises and operates transport of substances into and out of cells using electrochemical changes
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44
Q

Dynamic functions of the cell membrane

A
  • bidirectional transfer in and out of cell to maintain cell health and prevent cell death
  • ionic transfer to maintain difference in electrical potential between its inner and outer surfaces to generate the membrane potentials
  • modulation of metabolic activity by means of hormone receptors on its outer surface
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45
Q

Membrane physiology types of movement

A

diffusion, active transport, endocytosis, exocytosis, chemical messengers

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46
Q

Membrane physiology - types of diffusion

A

simple, facilited, osmosis

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47
Q

Membrane physiology - types of active transport

A

primary, secondary

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48
Q

Membrane physiology - types of endocytosis

A

pinocytosis and phagocytosis

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49
Q

Diffusion

A

random molecular movement of substances molecule by molecule
- through intermolecular spaces in membrane
- in combination with carrier protein
- causesd by kinetic energy

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50
Q

Simple diffusion

A
  • kinetic movement of molecules or ions occur through a membrane opening or intermolecular spaces
  • no interaction with carrier proteins
  • based on concentration gradient
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51
Q

rate of simple diffusion is determined by

A
  1. amount of substance available
  2. velocity or kinetic motion
  3. number and size of openings in the membrane
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52
Q

how does simple diffusion occur in cell membrane

A
  1. through the lipid bilayer (if substance is lipid soluble)
  2. through channels of proteins that penetrate through the cell membrane (water soluble)e
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53
Q

Example of lipid soluble substances

A

oxygen, nitrogen, carbon dioxide, alcohol

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54
Q

Example of protein channels

A
  • selectively permeable to certain substances
  • sodium channel - inner surface is strongly negatively charged
  • potassium channel - smaller than sodium channels, not negatively charged
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55
Q

How are channels opened and closed with examples

A

GATES
1. voltage gating - respond to electrical potential across the cell membrane (action potential)
2. chemical or ligand gating - binding of chemical substance with the protein
- this causes conformational/ chemical bonding changes in protein and opens it (acetlycholine and transmission of nerve signals from one nerve to another

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56
Q

Explain this

A

voltage gating
- the presence of sodium and potassium ions causes changes in the electrical potential across the cell and open and close

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57
Q

Explain this

A

chemical/ligand gated channels
- the presence of signalling molecules attach to binding sites and cause the channel to open to allow ions to pass through

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58
Q

Facilitated diffusion

A
  • like simple diffusion but goes toward and away from concentration gradient
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59
Q

Carrier-mediated diffusion

A
  • type of facilitated diffusion
  • the diffusion rate increases with the concentration of diffusing substance but there is a maximum
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60
Q

Explain this

A

simple diffusion is endless but carrier mediated diffusion has a maximum

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61
Q

carrier proteins in facilitated diffusion

A
  • the pore is large enough to transport specific molecule
  • binding receptor on the inside of the protein carrier
  • binding causes a conformational change that causes pore to open on opposite side
  • binding force is weak so it releases the attached molecule
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62
Q

rate of transport in facilitated diffusion

A
  • limited by the rate at which carrier protein molecules can undergo changes back and forth
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63
Q

how is glucose and amino acids transported?

A

facilitated diffusion

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64
Q

why is insulin important

A

it increase facilitated diffusion by 10-20 fold by increasing the number of carrier proteins

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65
Q

Factors that affect net rate of diffusion

A
  1. net diffusion is proportional to the concentration outside minus the concentration inside
  2. electrical gradients across membranes can attract or repel charged ions
  3. pressure differences across membranes
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66
Q

Explain pressure in detail

A

pressure is the sum of all the forces of the different molecules striking a unit surface area
- more molecules strike the pore on the high-pressure side than on the low-pressure side therefore net diffusion occurs from high to low pressure

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67
Q

Osmosis

A

process of net movement of water caused by a concentration difference

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68
Q

Selectively permeable membranes

A

water passes through better than solutes

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69
Q

osmotic pressure

A

the amount of pressure required to stop osmosis

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70
Q

how to determine osmotic pressure

A
  • the concentration of solution in terms of number of particles (molar concentrations, osmoles per kg, 1milliosmole per liter concentration = 19.3 mm Hg osmotic pressure)
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71
Q

osmolar concentration (osmolaLity)

A

osmoles per liter of solution

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72
Q

why do we use osmolar concentration more

A
  • its easier to measure L of water than osmoles per kg of water
  • for dilute concentrations, the difference between osmolarity and osmolality is less than 1%
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73
Q

isotonic

A
  • same concentration of solutes - no change in size of cell
74
Q

hypotonic

A
  • lower concentration of solutes
  • cell swells
75
Q

hypertonic

A
  • higher concentration of solutes
  • cells shrink
76
Q

active transport

A
  • requires energy
  • when a cell moves against a concentration/electrical/pressure gradient
77
Q

substances that are actively transported

A
78
Q

primary active transport

A
  • energy is derived from breakdown of ATP or some other high energy phosphate compound
79
Q

secondary active transport

A
  • energy is in the form of ionic concentration differences (already existing ions, doesn’t need to be made)
  • the differences were made in primary active transport
80
Q

similarity between primary and secondary transport

A
  • depend on carrier proteins that penetrate through the membrane
  • carrier protein is capable of imparting energy to the transported substance
81
Q

EX of primary active transport

A

Sodium potassium pump
- pumps sodium out of cells and potassium into cells
- responsible for maintaining the sodium and potassium concentration differences across the cell membrane
- establishes negative electrical voltage inside the cell
- basis of nerve function

82
Q

How does the sodium-potassium pump maintain cell volume

A
  • protein and other organic molecules cant escape the cell
  • these are negatively charged and attract positive ions like sodium and potassium
  • water follows by osmosis so cell swells
  • pumps 3 sodium ions for every 2 potassium ions to prevent cell swlling
83
Q

sodium-potassium pump and being electrogenic

A
  • creates an electrical potential across the membrane (negative on the inside and positive on the outside)
  • one of the major energy using processes in the body
84
Q

calcium pump

A
  • primary active transport
  • pumps calcium out of cells - intracellular fluids has way lower concentration of calcium than extracellular fluid
  • it pumps calcium into mitochondria and muscle cells sacroplasmic reticulum
85
Q

sarcoplasmic reticulum

A

network of specialized smooth ER that is important in transmitting the electrical impulse as well as in the storage of calcium ions

86
Q

hydrogen pump

A
  • primary active transport
  • in the stomach gastric glands and parietal cells
  • in the late distal tubules and cortical collecting ducts of kidneys
    ask for more info
87
Q

co-transport

A

secondary active transport
- diffusion of energy of one substance pulls another substance with it
- same direction

88
Q

ex of co-transport

A

sodium-glucose and sodium-amino acid

89
Q

counter-transport

A

secondary active transport
- transports in opposite directions

90
Q

ex of counter-transport

A

sodium-calcium and sodium-hydrogen
1. sodium binds on the carrier protein outside of cell and other substance to carrier protein on inside of cell
2. causes conformational change and energy released by the sodium ion moves to the interior and the other substance moves out of the cell

91
Q
A
92
Q

endocytosis

A

mechanism by which large particles enter cells to obtain nutrients and other substances from the surrounding fluids

93
Q

General overview of pinocytosis

A
  • smaller
  • ingestion of minute particles that form vesicles of ECF and particulate constituents inside the cell cytoplasm
94
Q

General overview of phagocytosis

A
  • larger
  • ingestion of large particles such as bacteria, whole cells or portions of degenerating tissue
95
Q

Steps in pinocytosis

A
  1. macromolecules attach to specialized protein receptors on surface membrane
  2. Receptors are concentrated in coated pits
  3. Beneath pits is latticework of fibrillar proteins - clathrin and sometimes actin and mysoin
  4. Will invaginate and the fibrillar proteins will surround the pit - encloses the macromolecule and small amounts of ECF
  5. Invaginated part of the membrane breaks away
96
Q

What does pinocytosis require

A
  • energy in the form of ATP from inside the cell
  • Calcium ions in ECF
97
Q

Steps in phagocytosis

A
  1. Cell membrane receptors attach to surface ligands of the particle (bacterium, dead cell, tissue debris)
  2. Edges of the membrane around the point of attachment evaginate outward to surround particle (pseudopodium)
  3. Actin and other contractile fibrils in the cytoplasm surround the phagocytic vesicle and contract around its outer edges, pushing the vesicle to the interior
  4. Vesicle thus seperates from the cell membrane
98
Q

Where does pinocytosis and phagocytosis occur

A

pino - happens in most cells - especially rapid in macrophages
phago - occurs in certain cells - macrophages

99
Q

Opsonization

A

intermediation of antibodies

100
Q

Digestion of pino/phago contents

A
  1. Lysosomes attach to the vesicles and empty their acid hydrolases to the inside of the vesicle
  2. Digestive end products like amino acids, glucose, phosphates diffuse into cytoplasm
  3. Residual body is removed by exocytosis
101
Q

Exocytosis

A
  1. Secretory vesicles diffuse to cell membrane
  2. Secretory vesicles fuse to cell membrane
  3. Empty their substances to the exterior
102
Q

How is exocytosis stimulated?

A

Entry of calcium ion into the cell

103
Q

Cellular sheets

A
  • cells in a layer together
104
Q

Basic mechanism of active transport via cellular sheets

A
  • simple of facilitated diffusion through the membrane on one side of the sheet
  • active transport through the cell membrane on the other side of those cells
105
Q

Where is active transport via cellular sheets

A
  1. epithelium of intestines
  2. epithelium of renal tubules
  3. epithelium of exocrine glands
  4. epithelium of gallbladder
  5. membrane of choroid plexus (brain)
106
Q

What is this a mechanism of

A

Transport of sodium ions through the epithelial sheet of the intestines. gallbladder and renal tubules

107
Q

Total body of water decreases with

A
  1. age (75% neonatal, 57% adult)
  2. increased adipocity (fat) - fat is only 10% water
108
Q

Total body of water averages about how much body weight

A

60%

109
Q

ICF and ECF and body of water

A

ICF - 40%
ECF - 20%
- 15% ECF is interstitial fluid
- 5% ECF is plasma volume (non cellular part of blood)
- transcellular fluid variable - found in body cavities and includes intraocular fluid, cerebrospinal fluid, synovial fluid, urine, bile and fluids of the digestive tracts

110
Q

How to measure volumes of body fluid

A
  • indicator dilution principle/technique
  • pick a marker substance that is distributed into the compartment of interest, administer a known amount of it and then measure its volume distribution
111
Q

indicator dilution principle/technique

A

volume = mass/concentration

112
Q

What does it mean when an indicator must behave well

A
  1. disperse evenly throughout the compartment
  2. disperse only in the compartment being measured
  3. not be metabolized or excreted
  4. not be toxic
113
Q

If you’re measuring (1) TBW or (2) ECF, the marker must

A
  1. marker must diffuse into ECF and ICF
    - ex) tritiated water, heavy water ,antipyrine, sulfanilamide, thiourea and urea
  2. marker must not diffuse across cell membrane
    - ex) radioactive sodium, radioactive bromise, radioactive chloride, thiosulfacte ion, inulin, sucrose
114
Q

Measuring (1) intracellular F or (2) PV or (3) interstitial

A
  1. ICF = TBW - ECF
  2. use a dye that combines with plasma proteins
  3. ICF = ECF - PV
115
Q

How to determine blood volume

A
  • The substance that used to determine blood volume must stay in the intravascular system
  • either binds to plasma proteins (vital dye or radioactive iodine)
    OR
  • combines with rbc (radioactive elements)
  • must also determine packed cell volume (PCV) or hematocrit
116
Q

blood volume from plasma volume and rbc volume

A
117
Q

blood volumes in adult animals

A
118
Q

Units for body fluids

A

major components = mmol/L or mewmol/L
osomotic effect = mOsm/L
total osmotic pressure = 300 mOsm/L
total osmotic pressure after correction for intermolecular attraction = 280 mOsm/L
colloid osmotic pressure = PV + 1.5 mOsml/L

119
Q

Equilibrium osmolality - hyposmolal

A

ECF = ICF
- net water diffusion into cell
- particles move from cytoplasmic to extracytoplasmic side of cell membrane and increase osmolality of ECF
- cells are dilated and ICF diluted until osmolal equilibrium is reached - RBC in hypotonic can increase in size enough to rupture (hemolysis)

120
Q

Equilibrium osmolality - hyperosmolal

A

ECF = ICF
- water displaced from cell
- particles from ECF into cytoplasm
= cells are smaller and ICF more concentrated than at equil

121
Q
A
  1. isotonic
  2. hypotonic
  3. hypertonic
122
Q

Effects of dehydration

A

disorders in digestive/alimentary, resp, urinary
- anorexia, excessive insensible evaportation (skin, lungs) or diuresis

123
Q

diuresis

A

excessiv filtering by kidneys and overproduction of uring

124
Q

Dehydration and calls

A
  • Decreases in ECF water (increases ECF osmolality) so water is pulled out of ICF to equilibrate osmolalities and causes shrunken cells
125
Q

How to assess degree of dehydration

A
  • examine skin fold elasticity and depth of sunken eyes
  • moisture and temp of oral cavity (tackiness)
126
Q

percentages of dehydration

A

5% - slight dehydration - 5 seconds to return to normal
7-8% - moderate - 5-10 seconds, eyes sunken in the orbit, oral mucosa is sticky
10% - severe - >10 seconds, very sunken, softened eyes, dry and cold oral mucosa

127
Q

Loss of electrolytes causes what kind of dehydration

A
  • hypo-osmotic dehydration
  • decreased ECF volume and increases ICF volume
  • Sweating (NaCl deficiency)
  • Vomitting (loss of water, Na, Cl, and H)
  • Diarrhea (gut secretion > gut absorption - loss of anions, cations and water)
128
Q

Microcirculation

A
129
Q

Capillaries

A
  • size of RBC
  • humans have 10 billion
  • 300-1200/mm3 tissue - more in metabolically active tissue
  • areas of exchange of particles between plasma and interstitial fluid through diffusion, filtration and ultra filtration
130
Q

types of capillaries

A
  1. continuous - most common, tightest, gaps allow gas, water, glucose to pass, blood-brain barrier capillaries have no gaps
  2. fenestrated capillary - leakier with small pores like small intestine, kidneys where alot of blood-tissue exchange occurs
  3. discontinuous - leakiest, largest molecules, ex) liver, spleen, bone marrow
131
Q

Special types of pores

A
  1. liver - wide open - almost all dissolved substances including proteins can pass through
  2. brain - tight junctions - allow only expremely small molecules through (water, oxygen,co2)
  3. kidney - glomerular tufts - fenestrae (penetrate through middle of endothelial cells - this is the ultra filtration as only small particles can pass)
132
Q

glomerular capillary tuft

A

highly intricate and specialized microvascular bed that filters plasma water and solute to form urine

133
Q

Vasomotion

A

blood doesnt flow continiously through capilaries

134
Q

Intermittent flow

A

turning on and off every few seconds or minutes

135
Q

What causes intermittent flow

A

intermittent contraction of the metaarterioles and precapillary sphincters

136
Q

Mechanisms of blood flow control

A
  1. acute control - rapid changes in vasocontriction and vasodilation
  2. long-term control - changes in physical sizes and numbers of blood vessels supplying the tissues
137
Q

Acute control - 2 theories

A

oxygen lack theory and vasodilator theory

138
Q

Oxygen lack theory

A

ACUTE CONTROL
- oxygen needed to cause vascular muscle contraction
- lack of oxygen (hypoxia) causes release of nitric oxide which causes smooth muscles and sphincters to relax, blood vessels dilate and more blood flows into the oxygen deficient area
- high oxygen would cause the precapillary and metaarteriole sphincters to contract until cells use up the excess oxygen

139
Q

Vasodilator theory

A

ACUTE CONTROL
- the greater the rate of metabolism or the less availability of oxygen, the greater the rate of formation and release of vasodilator substances:

140
Q

vasodilator substances

A

adenosine, carbon dioxide, adenosine phosphate, compounds, histamine, potassium ions and hydrogen ions

141
Q

specific tissues involved in acute control

A
  1. kidney: macula densa cells of the distal tubule
  2. brain: carbon dioxide and hydrogen ions increases blood flow
142
Q

Long term control

A

change in tissue vascularity: actual physical reconstruction of tissue vasculature to meet needs of tissues
- determined by maximum blood flow need
- collateral circulation (alternate/back up routes) - can be arteries, capillaries or veins

143
Q

Humoral stimuli

A

control of hormone release in response to changes in extracellular fluids like blood or ion concentration in the blood

144
Q

Humoral control types

A
  1. Norepinephrine and Epineprine
  2. Angiotensin 2
  3. Antidiuretic hormone (vasopressin)
  4. Bradykinin
  5. Histamine
145
Q

Norepinephrine and Epineprine

A

NE - powerful vasoconstrictor
E- less powerful but can cause vasosdilation in some tissues

146
Q

Angiotensin 2

A

powerful vasoconstrictor
- cause many arterioles to constrict at the same time increasing arterial pressure

147
Q

Antidiuretic hormone (vasopressin)

A
  • one of the bodys most potent vasoconstrictors
  • generally levels are too low to have much effect
148
Q

Bradykinin

A

powerful arteriolar dilation and increased capillary permeability
- special role in inflamed tissue
- control of normal flow in skin, salivary and GI glands

149
Q

histamine

A

powerful vasodilator and increases capillary porosity
- edema - allergic reactions

150
Q
A
151
Q

How are small and large molecules exchanged between blood plasma and interstitial fluid

A

Small: ions and metabolites transported via small pores
large: molecules is severely restricted and exerts osmotic force, some is transported via a few large pores or cytoplasmic vesicles

152
Q

Endothelium and exchanges between bp and if

A
  • acts as a membrane
  • permeable to small particles
  • impermeable to large protein particles of vascular ECF
  • COP: proteins exert 25mm Hg
  • fluid moves from extravascular to inravascular
  • small amount of protein crosses capillary wall via vesicular transport - enter lymph
  • oxygen, glucose, CO2 via diffusion or filtration
153
Q

COP

A

colloid osmotic-pressure (oncotic pressure)
- pressure induced by plasma proteins like albumin, in a blood vessels plasma (or any other body fluid such as blood and lymph)
- this causes a pull on fluid back into the capillary
- colloids displace water molecules
- creates a relative water molecule defecit with water moving back into the circulatory system within the lower venous pressure end of capillaries

154
Q

how does COP affect hydrostatic blood pressure

A
  • pushes water and small molecules out of the blood into the interstitial spaces at the arterial end of capillaries and interstitial colloidal osmotic pressure
  • this determines the partitioning of extracellular water between the blood plasma an extravascular space
155
Q

4 pressures involved in water and solute transfer

A

Pc = Hydrostatic pressure of blood in capillaries
Pint/if = hydrostatic pressure of interstitial fluid
COPp = COP of plasma proteins -
COPint/if = COP of interstitial fluid

156
Q

notes about Pint/if

A

usually negligible and disregarded - except in kidney (30 mm Hg)

157
Q

notes about COPint/if

A

can be increased by local production of substances that make the endothelium more permeable to proteins

158
Q
A

Pc and Pint/if - liquid applying pressure
COPp - because its high in concentration, more pressure inward from water coming into it
COPint/if - because its high in concentration, more pressure outward from water coming out

159
Q

Filtration occurs when (in terms of pressure)

A

Pc > COPp - stuff leaves capillary

160
Q

Reabsorption occurs when (in terms of pressure) and at which side

A

COPp > Pc - stuff comes in
- at venular end via osmosis (oxygenated side)

161
Q

Filtration/reabsorption and vessels

A

vasomotion at metarterioles controls volume of blood in capillaries and whether absorption or filtration occurs
- open capillary - filtration
- closed - reabsorption

162
Q

Lymphatic system

A

part of the immune system, complementary to the circulatory system

163
Q

How much filtered fluid isnt reabsorbed and where and how does it go?

A

0.4 to 0.8 mL/L
- returns to blood via lymphatic system

164
Q

30% of plasma proteins where does it go

A

leak into interstitial fluid of intestines and liver and is reabosrbed via lymphatics

165
Q
A

Large molecules like proteins enter easily
- overlapping edges of the endothelial cells free to flap inward forming an opening
- backflow closes the valves so fluid has difficulty leaving

166
Q

Lymph

A

fluid that flows through the lymphatic system
- clear fluid portion plus leukocytes and a few red blood cells

167
Q

Protein content from tissue draining

A

most tissues - 2g/dl
liver - up to 6g/dl
intestines - 3-4g/dl

168
Q

Postprandial

A
  • after a meal
  • route of absorption of nutrients esp fats
  • thoracic duct lymph as much as 1-2% fat
169
Q

Chylomicrons

A

lipoproteins that carry dietary lipids from the intestines to other tissues and the liver

170
Q
A
171
Q

plasma volume and lymphatic system

A

daily volume returned

172
Q

bacteria and lymph

A

can enter the lymph - are removed and destroyed as they pass through the lymph nodes

173
Q

Flow of lymph

A

Caused by
- one way valves
- rhythmic myogenic activity of lymph vessels
- tissue pressure
-arterial pulsation
- pressure changes associated with skeletal muscle contraction respiration

174
Q

Where does the flow of lymph originate

A

muscle tissue NOT nerve impulses

175
Q

Lymphatic vessels

A
  • when the collecting lymphatic or vessel becomes stretched by fluid, the smooth muscle of the vessel automatically contracts
  • allows each segment to act independently
176
Q

Intermittent compression of the lymphatics

A
  • contraction of surrounding skeletal muscles
  • pulsations of arteries adjacent to the lymphatics
  • compression of tissues by objects outside the body
  • movement of parts of the body - exercise increases flow from 10 to 30 fold
177
Q

Lymph and homeostasis

A

plays a role in
- concentration of proteins in interstitial fluids
- volume of IF
- interstitial fluid pressure

178
Q

Edema

A
  • abnormal increase in interstitial fluid volume
  • high blood pressure
    -decrease COPp
  • increased capillary permeability to protein
  • lymphatic blockage
179
Q

High blood pressure

A

limits the ability of COPp to draw fluid into the capillary
- venous obstruction (clot or external pressure)
- cardiac insufficiency
- excessive vasodilation (histamine release - hives)

180
Q

Decreased COPp

A
  • dietary amino acid deficiency
  • liver disease
  • severe burns
  • kidney failure

Anatomy and Physiology 1 (2 decks)

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