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72 Cards in this Set
- Front
- Back
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Nucleus
Characteristics Location Function |
-Surrounded by cytoplasm
- largest membrane bound organelle - located in center of cell - Cell division - control of genetic information - replication and repair of DNA - Transcription of info stored in DNA Made up of a 2 membraned nuclear envelope |
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Nucleolus
Characteristics Location Function |
- small dense
- composed of RNA, DNA, histones Inside the nucleus Hold histones that regulate DNA activity |
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Ribosomes
Characteristics Location Function |
- Synthesized in nucleolus
- Secreted into the cytoplasm -float free in cytoplasm - may attach to outer membrane of endoplasmic reticulum Provide sites for cellular protein sythesis |
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Endoplasmic Reticulum
Characteristics Location Function |
- made up of tubular or saclike channels (cisternae)
- may be rough or smooth - in cytoplasm Synthesizes and transports protein and lipid components of cell organelles |
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Difference between smooth and rough ER?
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Rough ER has ribosomes attached.
Smooth contains enzymes enzymes involved in synthesis of steroid hormones and responsible for removing toxins from cell |
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Golgi Apparatus
Characteristics location function |
- network of flattened smooth membranes and vesicles
- near nucleus of the cell -processes proteins from ER - directs traffic in the cell (protein, polynucleotdides, polysaccharides) Secretory vesicles from the ER collect at the end of the Golgi and break off and migrate…vesicles fuse w/ the plasma membrane and contents released from the cell |
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Lysosome
Characteristics location function |
- saclike structure originating from Golgi
- contain digestive enzymes Throughout cell Intracellular digestive enzyme |
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Peroxisomes
Characteristics location function |
Look like lysosomes but are larger and oval
Throughout cell -Contain enzymes that use oxygen to remove hydrogen atoms from substrates that produce hydrogen peroxide - help synthesize phospolipids needed for nerve cell myelination |
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Mitochondria
Characteristics location function |
- spherelike or rod or flilamentous
- bounded by a double membrane - has cristae Throughout cell - houses enzymes that generate most of the cell’s ATP -outer membrane is smooth and surrounds mitochondria - inner membrane contains enzymes of respiratory chain |
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Vaults
Characteristics location function |
- shaped like octagonal barrels
- throughout the cell Cellular truck: pick up molecules synthesized in the nucleus and move to other places in cell…fxn not fully confirmed by science |
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Cytosol
Characteristics location function |
- gelatinous, semiliquid portion of cytoplasm
- throughout the cell - intermediary metabolism - ribosomal protein synthesis - storage of carbs, fat and secretory vesicles 55% of the total cell volume |
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Cytoskeleton
Characteristics location function |
- composed of protein filaments: microtubules and actin filaments
- throughout the cell - composed of protein filaments: microtubules and actin filaments |
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Passive vs Active Transport
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Passive
- Small uncharged molecules move easily through pores of lipid bilayer - Occurs naturally through any semipermeable barrier (can be reproduced in lab) - Driven by osmosis, hydrostatic pressure, and diffusion - no energy expenditure Active - Large molecules - only occurs across living membranes (cannot be duplicated in lab) - requires life, biologic activity, energy expediture |
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osmolality:
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conc of molecules per WEIGHT of water
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osmolarity
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conc of molecules per VOLUME of water
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Types of transport by vesicle formation
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Endocytosis
Exocytosis Potocytosis |
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Endocytosis
3 types |
enfolds substances from outside of cell and separates from the plasma membrane
1. Pinocytosis - drinking 2. Phagocytosis - eating 3. Receptor mediated endocytosis - is rapid and enables the cell to ingest large amounts of specific ligands without ingesting large volumes of extracellular fluid |
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Exocytosis
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secretion of macromolecules across membrane
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Potocytosis
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Cellular uptake through the opening and closing of caveolae. Uptake mechanism for a variety of SMALL molecules and ions.
Remain attached to plasma membrane…do not form a membrane-enclosed vesicle like in endocytosis |
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Anabolism
Catabolism |
Energy using
Energy releasing |
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Glycolysis
takes place in End products of glycolysis |
cytoplasm
does not require O2 - respiration (w/o O2 - fermentation) 2 NADH 2 pyruvate 2 ATP (from C6H12O6 - glucose) |
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3 stages of cellular respiration
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1) Glycolysis
2) Citric acid cyle (aka: Krebs or TCA) 3) Electron transport chain |
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Krebs cycle
takes place in 2 cycles yields |
mitochondria when O2 is present
2 ATP 6 NADH 2 FADH 6 free electrons |
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Electron transport
occurs in End product |
- requires O2 directly
- occurs in the cytochrome complexes in the inner mitochondrial membrane - 3 ATP per NADH, 2 ATP per FADH2 |
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End products of cellular respiration
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36 ATP
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5 types of cellular adaptation
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atrophy
hypertrophy hyperplasia dysplasia metaplasia |
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atrophy:
examples |
shrinkage in cellular size
2 types - physiologic (occurs in developement - thymus gland, brain shrinkage as result of hormone changes) & pathologic (dec in workload/ stimulation - muscle) |
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hypertrophy:
inc. size due to: examples: |
an increase in the size of cells and consequently in the size of the affected organ. can be physio or patho.
caused by hormone stimulation or increased functional demand. inc. in protein (not fluid) patho: heart secondary to hypertension or problem valves physio: Increase in size of heart and skeletal muscles in response to increased demand because they cannot adapt by mitotic division and production of new cells to share the work |
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hyperplasia:
ex. |
an increase in the number of cells resulting from an increased rate of cellular division
- Compensatory Hyperplasia: adaptive mechanisms that enables certain organs to regenerate a) Ex. Removal of part of the liver results in hyperplasia of the remaining liver cells to compensate for the loss - Hormonal Hyperplasia: occurs primarily in estrogen-dependent organs such as the uterus and breasts a) Ex. After ovulation, estrogen stimulates the endometrium to grow and thicken to receive fertilized ovum |
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dysplasia
ex. |
abnormal changes in the size, shape, and organization of mature cells - cancer cells
Dysplatic changes in epithelial cells of cervix and respiratory tract |
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Metaplasia
example |
reversible replacement of one mature cell by another
Ex. Replacement of normal columnar ciliated epithelial cells of bronchial airway lining by stratified squamous epithelial cells |
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5 types of necrosis
Coagulative Liquefactive Necrosis Caseous Necrosis Fat Necrosis Gangrenous Necrosis |
Coagulative: coagulation caused by protein denaturation - gelatinous state to firm, opaque state like a cooked egg white); tissue will appear firm and slightly swollen
- Liquefactive: cells are digested by their own hydrolases and the tissue becomes soft, liquefies, and is walled off from healthy tissue, forming cysts -Caseous: combination of coagulative and liquefactive necrosis; dead cells disintegrate, but the debris is not digested completely by hydrolases - appears like clumped cheese Fat: cellular dissolution caused by lipases which break down triglycerides, releasing free fatty acids, which then combine with calcium, magnesium, and sodium ions forming soaps - chalky white - breast and pancreatic tissue Gangrenous: death of tissue and results from severe hypoxic injury Usually due to arteriosclerosis, or blockage, or major arteries especially in lower leg |
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Types of Gangrenous Necrosis
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Dry: result of coagulative necrosis
Skin becomes very dry and shrinks = wrinkles and color change to dark brown or black Wet: neutophils invade a site leading to liquefactive necrosis Usually in internal organs. Site becomes cold, swollen, and black Foul odor from pus. Can lead to severe systemic symptoms Gas: caused by infection of injured tissue, gas bubbles form in muscle cells. |
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Cell cycle
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1) interphase: G1, S, G2
2) Cell Division (mitosis) - PMAT 3) Cytokinesis - cytoplasmic division (often considered part of M phase because it occurs as part of telophase) |
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What happens to extracellular cations and anions during acidosis? s
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Too much H+ in ECF - acidosis
H moves from ECF -> ICF cations like K+ shift to ECF to allow H+ to go into cell (→ hyperkalemia b/c of increased K in ECF). |
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what happens to extracellular cations and anions during alkalosis?
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Alkalosis, not enough H+ in ECF,
so H+ shifts from ICF→ ECF; cations like K+ shift into ICF, leading to ECF hypokalemia |
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Buffer System:
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a. Occurs in response to changes in acid-base status. Buffers are able to absorb excess H+ or OH- without a significant change in pH. Located in both ICF and ECF
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BEST BUFFERS are ______ +______
Most important ECF buffer system: Most important ICF buffer system |
weak acid + conjugate base
ECF: carbonic acid bicarbonate and Hgb ICF: phosphate and protein |
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Carbonic Acid - Bicarbonate Buffer Pair
- operates in both ____ & ___ pK = - Ratio at reg pH is: bicarb: carbonic acid Using the pK value the normal pH is |
- lungs and kidneys
- pK = 6.1 - ratio 20:1 - pH 7.4 |
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Lungs decrease carbonic acid by?
Kidneys can reabsorb bicarb or generate new bicarb from? |
Blowing off CO2
from CO2 and water (not as rapid as the lung buffer) |
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Protein Buffering System
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Hgb binds w/ H to form HHb and HHbCO2 -> becomes a wk acid
UNSATURATED Hgb (venous) is a better buffer than O2 saturated HGb (arterial) |
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Renal Buffering System
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ii. Buffers (dibasic phosphate [HPO42-] and ammonia [NH3]) bind with H+, allowing more H+ to be excreted before the limiting pH value (4.4-4.7) is reached
Renal buffering of H+ requires CO2 and H2O which form H2CO3. |
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To correct metabolic alkalosis administer ____. Why?
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the administration of K+ corrects alkalosis caused by hyperaldosteronism or hypokalemia by causing H+ to move back into ECF
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4 Ways water moves across the membrane
2 in the blood vessel 2 in the tissues |
In the blood vessel:
a. Capillary hydrostatic pressure- blood pressure, which pushes the water out of the capillary. b. Plasma oncotic pressure- this is exerted primarily by the large proteins in the bloodstream, like albumin. They attract water and are thus pulling water back into the capillary In the tissue: a. Interstitial hydrostatic pressure- pressure within the tissue, pushing water back into the bloodstream: this is negligible in the normal person b. Tissue oncotic pressure- proteins pulling water into the tissues; again this is negligible in the normal person because most proteins are too large to pass through the capillary membrane and thus stay in the bloodstream |
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Difference between oncotic and hydrostatic pressure
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Oncotic - pressure pushes water out
Hydrostatic - large proteins attract water |
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What detects increased plasma osmolarity?
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osmoreceptors in the hypothalamus trigger thirst
(ADH release is also stimulated by osmoreceptors) |
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What can sense a decrease in blood volume and trigger release of ADH?
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Volume receptors and baro(pressure)receptors
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Antidiuretic hormone (ADH)
secreted by: |
secreted by the posterior pituitary and causes the kidneys to reabsorb more water, increasing the circulating volume
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Major extracellular cation?
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Sodium
It regulates water balance (water is very attracted to it), helps potassium maintain muscle irritiablity and de/repolarization, helps with acid-base balance and much more. Normal values – 135-145 mEq/L |
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sodium’s main “partner” anion. It tends to follow sodium around, helping to provide electroneutrality?
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Chloride
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Aldostrone
- produced where? - is triggered when ____ is low and ___ is high |
a hormone produced in the adrenal cortex. Release is triggered when plasma sodium concentration is low and plasma potassium concentration is high. It causes the kidneys to HOLD ON TO sodium and water and EXCRETE potassium, restoring normal electrolyte values and increasing blood volume.
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The Renin Angiotensin System - when kidneys are not receiving adequate blood flow they secrete ____.
Angiotensin II acts as a _____ and also stimulates the release of ___ |
Renin -> angiotensin I -> angiotensin II (vasocontrictor inc blood pressure and flow to the kidneys/ tissues) -> stimulates the release of aldosterone
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3 Natriuretic Peptides-
help maintain ___ and ___. Stimulate kidneys to ____. |
1) Atrial Natriuretic Peptide (ANP)- produced by the heart
2) Brain Natriuretic Peptide (BNP)- produced by the brain 3) Urodilatin- produced by the kidneys iv. These hormones help maintain sodium and chloride balance when blood pressure/volume is elevated. They stimulate the kidneys to EXCRETE sodium, which is followed by water, decreasing blood volume. |
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2 regulation mechanisms of sodium and chloride
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1) Renin Angiotensin system: HOLDS ON TO sodium, EXCRETES potassium
2) Natriuretic Peptides - stimulate the kidneys to EXCRETE sodium, which is followed by water, decreasing blood volume. |
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Affinity maturation:
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antibodies that bind more strongly to the antigen are replicated - natural selection of antibodies
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cytokines:
classified as ____ or ____ can be either ____ or ____ |
substances secreted by the cells of the immune system
- interleukins or interferons - inflammatory or anti-inflammatory These molecules bind to target cells and change function of the target cell. Some work only locally, others (less common) work long distances, such as systemically. |
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interferon:
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released by cells of the immune system to inhibit virus replication
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IgA
When does it respond? How does it protect? |
Dominant immunoglobulin in the secretory immune response (1st line defense). Acts BEFORE local or systemic disease develops.
-Found in normal body secretions (including breast milk) & blood -Works to stop viral & bacterial invasion through the mucosal membranes of the GI, pulmonary & GU tracts -Prevents a carrier state that may spread disease to other people - Dominant Ig in Secretory Immune system (lymphoid tissue that protects the external body surface) |
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IgE
When does it respond? How does it protect? |
Responds to parasitic infection of mucosal tissues. Least in circulation.
*Main function is to initiate an inflammatory response that draws eosinophils to the site of parasitic infection -Mediator of allergic response |
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IgG
When does it respond? How does it protect? |
-Responds 2nd in the primary immune response;
-Most abundant Ig in secondary immune response *Most abundant in circulation (80-85%) -Capable of crossing placenta→provides the major protection against infection for the first 3 - 4 months of an infant's life -Activates complement system via classical pathway (except subclass IgG4) to cause the lysis of Gm (-) bacteria & animal cells -Subclasses IgG1 & 3 are prominent opsonins |
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IgM
When does it respond? How does it protect? |
-1st responder during primary immune response
-Most effective at fixing complement & aggragating target microorganisms for eventual elimination from the body -Provides the specificity for the humoral immune response |
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IgD
When does it respond? How does it protect? |
Located primarily on the surface of developing B lymphocytes. Function unknown - function as some sort of a B cell antigen.
Low concentration in the blood. |
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In-utero what Ig is the fetus able to produce?
What Ig does it lack? |
able to produce IgM
lacks IgA (gets from breast milk) |
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What layer of cells separates maternal and fetal blood?
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trophoblasts
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What system of transport facilitates the maternal antibodies to to the fetus or neonate?
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Active transport
a. Because the immunoglobins are too large, they must be transported by active transport. b. Active transport of IgG is mediated by the surface Fc portion of free IgG, but not for IgM, IgE or IgA. c. Because of this system umbilical titers for antibodies can be higher than maternal blood |
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After birth these maternal IgG antibodies levels drop as they are catabolized. At what age is the newborn most deficient of IgG?
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5-6 months
This is when they are often prone to respiratory infections. |
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Netrophils:
- how soon do they arrive at the site? - Why is a neutrophil short lived at the inflammatory site? |
the primary phagocytes in the early inflammatory site, arriving within 6-12 hours after the initial insult.
- B/c it is a mature cell unable to divide and sensitive to acidic environment -> becomes part of the pus. |
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Monocytes mature where?
They become? Monocytes act in response to? |
-mature in bone marrow
-become macrophages -respond to the chemotactic factor released by the neutrophil. can show up as soon as 24hrs, but usually will arrive in 3-7days |
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Macrophages are much better suited to defend against infection. Why?
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- because they can survive and divide in the acidic inflammatory site.
-larger and better phagocytes then monocytes. larger cell surface makes them better killers - Activated macrophages also secrete factors that stimulate growth, differentiation and activation of additional cells. -They also control the initiation of the healing process |
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3 Levels of human defense
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1) Barrier - 1st line against infection and tissue injury
2) Inflammatory response 3) Adaptive (acquired) Immunity - immune system signals the cell of adaptive immunity |
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What is the most important factor of initiating an immune response?
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Foreigness to the host
others size c. Complexity (the bigger you are, the more chance you have to be complex) d. Sufficient quantity (sometime this can actually be a very small amount, but it is enough for that Ag to provoke a response) |
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Coagulation system:
Functions |
forms a fibrinous meshwork at an injured or inflamed site that is mainly made of an insoluble protein called fibrin
Functions: a. Prevents the spread of infection to adjacent tissues b. Keeps microorganisms and foreign bodies at the site of greatest inflammatory cell activity c. Forms a clot that stops bleeding d. Provides a framework for future repair and healing |
