Exam 2
Explain the roles of diffusion, filtration, and osmosis in capillary exchange.
-Diffusion and osmosis through gaps and pores water and small substances dissolved in water move freely through fenestrations (pores) when a gradient exists. -Diffusion through membranes of endothelial cells lipid-soluble substances such as oxygen, carbon dioxide, and certain lipids enter and exit capillary by diffusing across membrane of one side of endothelial cell and out membrane on other side -Transcytosis larger molecules molecules enter by endocytosis and exit by exocytosis
How many do we need in order to get to the common pathway?
10
Fibrin equation:
10 + 5 --> thrombin --> Fibrin
Intrinsic equation:
12--> 11-->9 & 8 + Calcium -->10
Arteries vs Vein shape
Arteries are rounder where veins are shaped longer and more oval.
What is the arteries function?
Arteries control blood to the organs where veins return blood to the heart
Do Veins or Arteries have a thicker media?
Arteries have a thicker tunica media
Arterioles vs Venules structure
Arterioles has thin walls with all three tunics where small venules only have the tunica intima (larger ones have all three)
Why does severe swelling result when lymphatic vessels are blocked or damaged?
Because an accumulation of excess interstitial fluid that is blocked from being transported to the cardiovascular system
Why does venous blood need assistance in returning to the heart? What mechanisms are in place to assist in venous return?
Because the gradient pressure is very small, the sympathetic nervous system- decreases diameter=vasoconstriction, skeletal muscle pumps- contract= pumps blood towards the heart, and respiratory pumps = when we breathe deoxygenated blood gets pumped towards the heart.
Describe the structure and functions of erythrocytes.
Biconcave disc, no nucleus/ no organelles Sends signals to the body
Appendix
Blind-ended , worm shaped tube that juts from large intestine Defends body from bacteria in large intestine, specifically those that could be pathogenic
Why does a vascular spasm occur?
Blood vessel is injured, vasocontriction to stop blood loss
What do veins and venules have in common?
Both Veins and Venules have little smooth muscle
what is the bottom layer in blood?
Bottom layer contains Erythrocytes (red form all the red blood cells)
Hormonal:
Cardio Output is affected by: Epinephrine Norepinephrine Thyroid hormone Resistance hormones: Epinephrine and norepinephrine released from the adrenal medulla Angiotensin (powerful vasoconstrictor) Atrial natriuretic peptide
Discuss the structure and function of hemoglobin, as well as its breakdown products.
Consist of four polypeptide subunits Two alpha chains Two beta chains Each polypeptide bounds to a heme group which binds to oxygen
Capillary walls vs blood vessels structure
Consist of only endothelium and has a nucleus
Arterial pressure calculation:
Diastolic pressure + 1/3 (pulse pressure) Pulse pressure= systolic pressure-diastolic pressure
Explain how platelets differ structurally from the other formed elements of blood.
Don't have a nuclei or organelles found in most whole cells Contains several types of granules Contain cytoskeletal elements
Discuss the process of thrombolysis.
Endothelial cells release tissue plasminogen activator Tpa activates plasminogen Plasmin degrades fibrin, and the clot dissolves
Why do lymph nodes get swollen when you are sick?
Enlarge when increased pathogens become trapped
Tonsils
Epithelium lining tonsils indents deeply forming tonsillar crypts (trap bacteria and debris) Location puts them in contact with a large number of potential pathogens
What are the key differences between erythrocytes and leukocytes?
Erythrocytes have no nucleus where leukocytes are larger than erythrocytes with a prominent nucleus Platelets
What are the functions of blood
Exchanging gases Distributing solutes performing immune functions maintaining body temperatures- carries heat away from tissues function in blood clotting -platelets persevering acid-base homeostasis - pH 7 stabiling blood pressure
Peyer's Patches
Exposed to a large amount of potential pathogens due to their location Prevents bacteria from the small intesine that escaped from the large intesine
What is found in plasma?
Formed elements: cells and cell fragments found suspended in plasma
In which direction does hydrostatic pressure push fluid in a capillary bed?
From an area of higher hydrostatic pressure to an area of lower hydrostatic pressure --> pushes water out of the capillary
What are the three factors that determine blood pressure? How does each factor influence blood pressure?
Heart rate--> increases = increases CO= increases blood pressure Peripheral resistance--> increases CO= increases blood pressure CO--> decreases peripheral resistance = decreased BP
Distinguish between the terms hemostasis and coagulation.
Hemostasis forms a gelatinous blood clot that plugs broken vessels Coasgulation creates a hard mask with fibrin
Explain how blood pressure varies in different parts of the systemic and pulmonary circuits.
Highest in large systemic arteries lowest in large systemic veins
Inreinsic vs Extrinsic cascade clotting cascades:
Intrinsic: inside pathway Extrinsic: outside initiated
How do lymphocytes differ from all other cells in terms of their development in the bone marrow?
It's mostly in lymphatic tissue, circulate, and have two different types T& B.
What is the stimulus for erythropoietin production and release?
Lack of oxygen
Trace the pathway of lymph circulation through the body
Lymphatic Capillaries-->Lymphatic Collecting Vessels--> Lymph Nodes-->Lymphatic Collecting Vessels-->9 Lymphatic Trunks -->then branch into either the Right Lymphatic Duct --> Right Subclavian Vein or the Thoracic Duct --> Left Subclavian Vein
Compare and contrast lymphatic vessels and blood vessels in terms of structure and function
Lymphatic vessels are thinner , transport lymph, have trunks and ducts
what is the middle layer in blood?
Middle layer aka the buffy coat, consist of Leukocytes and platelets
In which direction does osmotic pressure push or pull fluid in a capillary bed?
Moves water from a solution with a lower solute concentration to one with a higher solute --> draws water into the capillary
What do muscular arteries and artioles have in common?
Muscular arteries and Artioles both control blood flow
Compare and contrast the relative prevalence and morphological features of the five types of leukocytes.
Neurophils: multi-lobed, pale lilac granules, 40-70% of WBC Eosinohils: biolobed nucleus, coarse red granules, 1-4% of WBC Basephils; usually "U" or "S" shaped, multilobed (2-5), 0-1% of WBC Lympocytes: Pale blue cytoplasm, nucleus round or slightly indented, 20-45% of WBC Monocytes: gray-blue cytoplasm, Large U or kidney shaped nucleus, 4-8% of WBC
Describe functions for each of the five major types of leukocytes.
Neutrophils: eat bacteria Eosinophils: kill parasitic, lessen severity of allergic reactions Basophils: release histamine (allergic reaction) Lymphocytes: carry out immune response Monocyctes: macrophages phagocytize microbes and cellular debris
Explain why blood type O- is the universal donor and type AB+ is the universal recipient.
O- has neither A or B antigens so that means it can be donated to both A, B, and AB blood types AB+ has both A and B antigens so they don't have any antibodies so they can receive blood from anyone, can't give them anything that they don't have
Describe the overall composition of plasma, including the major types of plasma proteins, their functions, and where in the body they are produced.
Pale yellow liquid whose volume is 90% water Albumin osmotic pressure (brings water into blood) Found in the first layer Plasma Proteins: Albumin, Immune, Transport, Clotting Produced: Erythrocytes
Formation of Fibrin:
Produce factor Xa --> goal of both intrinsic and extrinsic pathways Produce thrombin--> factor Xa is used to produce enzyme thrombin, happens in a common pathway Fibrin is produced-> thrombin is used to produce fibrin to hold platelet plug together and seal wound, final result of common pathway
MALT
Protects mucous membranes Oral and nasal cavities Gastrointestinal tract Respiratory passages Small amount in genitourinary tract
What are the functions of the lymphatic system:
Regulation of tissue volume Lymphatic vessels pick up excess fluid an delivers it back to the cardiovascular system Absorption of dietary fats Dietary fats enter lymphatic vessels to be delivered to blood vessels (get rid of) Immune functions Lymphoid organs filter pathogens from lymph and blood
Spleen
Spleen-Purplish-brown organ, size of a large soap bar Internal structure consist of a network of reticular fibers made by reticular cells Red pulp: degrades erythrocytes White pulp: filter out pathogens from blood
Explain the basic process of erythropoiesis
Stimulus: blood levels of oxygen fall below normal Receptor: Kidney cells detect falling oxygen levels Control Center: Kidneys produce more erythropoietin and release hormones into the bloodstream Effector/Response: Production of erythrocytes increases Homeostasis: Blood levels of oxygen rise to normal
What happens in thromboysis?
TPA--> activates plasminogen --> degrade fibrin--> break up the clot *the point of this is to get a heated blood vessel and to get rid of clot*
When considering blood donation, do we consider the antigens on the donor's erythrocytes, the antibodies in the donor's blood, or both? Explain.
The antibodies because those attack the immune system and cause agglutination. You don't make the antibodies for the type you have.
What is erythropoesis?
The formation of need red blood cells from stem cells in red bone marrow 1. Hematopic stem cells: can become any type of formed element 2. erythrocyte: cell now committed to becoming a red blood cell. 3. proerythoblast: step requires a hormone called erythropoietin (epo) 4. early erythroblast: hemoglobin synthesized rapidly 5. late erthroblast: nucleus shrinked and ejected 6. reticulocyte: cell enters blood steam 7. final erythrocyte
Discuss the role of the megakaryocyte in the formation of platelets.
The little arms come off of the megakaryocyte and get caught in the blood flow in the pockets
Type O
There is no O antigen O denotes absence of A and B antigens only O denotes absence of A and B antigens only
What happens when antibodies bind their specific antigen?
They clump
What action does erythropoietin trigger, and how does this return the variable to the homeostatic range?
Time of erythrocyte maturation decreases and hematocrit rises, returns to homeostatic range by decreasing erythropoietin secretion
It is obviously important to clot a broken blood vessel. Why is it equally important to eventually break down that clot?
To bring wound edges together= heal faster
what is the first layer in blood?
Top layer is plasma
Thymus
Two lobes, doesn't trap pathogens, generates T cells capable of protecting body from pathogens located in the middle of your chest
Type A-
Type A- only A antigen is present on erythrocytes Aggultinates: O+ , A+, B-, B+, AB-, AB+
Type AB-
Type AB- both A and B antigen are present on erythrocytes Aggultinates: O+, A+, B+, AB+
Type B-
Type B- only B antigen is present on erythrocytes Aggultinates: O+, A-, A+, B+, AB-, AB+
Type O-
Type O- neither A nor B antigens are present on erythrocytes Aggultinates: O+, A-, A+, B-, B+, AB-, AB+
Veins vs Arteries function
Veins return blood back to the heart where arteries conduct blood under high pressure to organs
What happens during a formation of the platelet plug?
Vessel injury exposes collagen fibers and caused endothelial cells to produce vWF vWF makes platelets sticky which causes them to bind with collagen which activated platelets then release granules the granules activate/attract more platelets which forms the platelet plug
Are platelets cells? Explain your answer.
Yes, but cell fragments created from megakaryocytes. They contain granules and is involved in hemostasis.
Peripheral Resistance
as this increases, blood flow decreases, affected by: blood vessel length, blood vessel diameter, and blood vessel viscosity
What happens in a clot retraction?
coagulated clot--> clot retracts--> serum squeezed out of clot and wound edged are brought closer together
Elastic Artery
conduct blood under high pressure (conducting artery) --> extensive elastic laminae, large arteries
Fenestrated capillaries
contains fenestrations in the endothelial cells that allow large volumes of fluid and larger molecules to cross capillary walls (have small holes)
Muscular Artery
control blood flow to organs, regulate blood pressure (distributing artery) --> thick tunica media
Arteriole
control blood flow to tissues, feed capillary beds (smallest artery)--> thin walls, smooth muscle cells, three tunics
Local:
controls blood pressure by amount of water loss in urine affects blood volume increased blood pressure --> atrial cells secrete ANP (kidneys excrete more water & sodium ions= decrease BV= decreased BP) decreased blood pressure--> ADH secretion triggers thirst (increases amount of water retained by kidneys=raise BV=raise BP)
Blood Flow
flows down this pressure gradient from area of higher pressure near heart to area of lower pressure in peripheral vasculature
Sinusoidal capillaries
have a discontinuous sheet of endothelium, irregular basal lamina, VERY LARGE PORES which allow large substances such as cells to cross the capillary walls
Blood Pressure
is highest near the heart and decreases as blood moves further away. Outward force that blood exerts on walls of blood vessels, affected by: CO, peripheral resistance, and BV
What is Coagulation?
it has two pathways intrinsic (inside vessel) 12--> 11--> 9--> +8+ Calcium --> 10 extrinsic (outside vessel) tissue factor --> 7 + Calcium --> 10
Continuous capillariess
least "leaky" their tight junctions between cells permit a narrow range of substance to cross the capillary walls
What is Plasma?
liquid extracellular matrix of blood
Venule
small venules have only a tunica intima, larger ones have all three tunics --> drain capillary beds
Neural factors that affect and regulate blood pressure:
sympathetic axons release norepinephrine and epinephrine which increases HR and contractibility-->increases CO, vasoconstriction of all types of vessels -->increases peripheral resistance. (overall increases BP) Axons of the parasympathetic system release acetylcholine which decreases CO and decrease HR (overall decreases BP) Baroreceptor reflex causes a negative feedback loop that responds to an increase in BP, receptors detect less stretch (Decrease HR, Decrease CO) Effects of chemoreceptor stimulation: peripheral chemoreceptors (oxygen) & central chemoreceptors (pH) --> increases HR, increased CO, increase in vasoconstriction =resistance
Large Vein
thin walled vessels with large lumens, little smooth muscle, and valves-->return blood to the heart
Extrinsic equation:
tissue factor --> 7 & Calcium --> 10
What happens in a vascular spasm?
vessel is injured leaks into extracellular fluid vessel spasms and leaked blood increases tissue pressure which decreases BF and blood loss.
