Human Phys Lecture Chap 11 SG

How does vascular spasm occur?

- Injury to blood vessels causes release of a paracrine from the endothelial lining that causes vasoconstriction - - Inner endothelial surface becomes sticky and opposing ends adhere to each other

What do actin and myosin in platelets do?

Actin-myosin complex within aggregated platelets contracts to tighten plug

What is clot retraction?

Clot retraction: platelets trapped in clot retract, pulling edges of damaged vessel closer together

How does a person's blood type affect their body's response to transfused blood? What happens during a transfusion reaction? If given a donor blood type and a recipient blood type, could you predict whether a transfusion reaction would occur?

A transfusion reaction can happen if the individual is given the wrong type - agglutination and rupturing and clogging of capillaries Antibody interaction with an erythrocyte-bound antigen may result in agglutination (clumping) or hemolysis (rupture) of the attacked RBCs.

what is the color hemoglobin bound to o2? how about without o2?

Hemoglobin alone =Bluish color Hemoglobin + O2 = Reddish color

What is hemostasis? What are the three steps of this process?

Hemostasis: the arrest of bleeding from a broken blood vessel (stopping bleeding) 1. vascular spasm 2. formation of platelet plug 3. blood coagulation

What is the difference between the intrinsic and extrinsic clot pathways?

Intrinsic clot pathway: Triggered at exposure of blood to damaged blood vessel Extrinsic clot pathway: Triggered at exposure of blood to factors in damaged tissue outside of blood vessel (clot that forms on skin, or in body tissue—bruise) (bruse is a fibrin mesh and is darkly colored because it trapps things)

what do the kidneys secrete that affects erythropoiesis? is the secretion in response to low or high o2 level in the blood?

Kidneys secrete hormone erythropoietin this is secreted when O2 is too low in the blood and kidneys detect it

What does activating plasmin do?

Plasmin SLOWLY dissolves fibrin mesh over time (dissolves clot

What is the ultimate step in formation of a blood clot? How does this form a clot?

STEP Ultimate step in clotting is conversion of fibrinogen (plasma protein produced in liver) to fibrin Fibrin form is thread-like, forming a loose mesh that adheres to damaged blood vessel surface and traps red blood cells and aggregating platelets, forming a clot

What is the main function of leukocytes? Where are they produced?

They protect you against illness and disease, main function is in the body outside of blood vessels (Only exist in blood to be transported across body rapidly) produced: in BONE MARROW Exception of the 5: One subtype (lymphocytes) produced in lymphoid tissue

What do platelets consist of?

- vesicles containing cytoplasm of megakaryocyte - contain some organelles and enzymes for energy production and secretion of substances - actin & myosin, which allow them to contract - but NO NUCLEUS

what are the three types of plasma proteins?

1. albumins- these proteins transport substances that are poorly soluble in plasma 2. globulins- transport specific substances or are factors that help in clotting or salt balance 3. fibrinogen- KEY factor in blood clotting

Could you identify the steps of platelet plug formation from a list? EXAM

1. circulating platelets adhere and are activated by exposed collagen at the site of the vessel injury 2. activated platelets release ADP and thromboxane A2 3. these chemical messengers work together to activate other platelets passing by 4. newly activated platelets aggregate onto the growing platelet plug and release even more platelets attracting chemicals 5. normal uninjured endothelium releases prostacyclin and nitric oxide, which inhibit platelet aggregation, so the platelet plug is confined to the site of injury

what are the 4 main constituents of blood? what does plasma contain?

1. erythrocytes (red blood cells) 2. leukocytes (white blood cells) 3. platelets (thrombocytes- which are cell fragments) 4. plasma (has PROTEINS) PLASMA contains water 90% plasma proteins (6-8%) electrolytes 1% by weight organic molecules dissolved gasses o2 and co2

What are the two groups of leukocytes? What are the five subtypes of leukocytes?

1. polymorphonuclear granulocytes - nuclei are segmented into several lobes of diff shapes & have granules that store chemicals 2. mononuclear agranulocytes 1. neutrophils 2. eosinophil 3. basophil 4. monocyte 5. lymphocyte

what is the function of carbonic anhydrase? what contains this enzyme?

an enzyme that assists rapid inter-conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions it is an enzyme that catalyzes erythrocytes (red blood cells) contain carbonic anhydrase

Exposure of what protein in the blood vessel to plasma leads to platelet plug formation?

collagen Following vasoconstriction, exposed collagen from the damaged surface will encourage platelets to adhere, activate and aggregate to form a platelet plug, sealing off the injured area

where does erythropoiesis occur?

generation of new erythrocytes OCCURS in bone marrow of sternum, ribs, pelvis, and upper ends of limb bones

what is the main molecule inside erythrocytes? where does o2 bind within this molecule?

hemoglobin (which carries the oxygen) o2 binds with each Fe atom

what are plasma proteins produced?

in the liver (except antibodies)

why do erythrocytes have a short life span? where are old, fragile erythrocytes removed?

they lack a nucleus and organelles= leads to them having a short life span removed in the SPLEEN

what is the main function of erythrocytes?

to carry oxygen !!!!! Biconcave disc shape provides a large surface area for diffusion of O2

What are megakaryocytes? What hormone stimulates their production and activity?

very large cell in bone marrow that sheds off platelets (cell fragments) hormone thrombopoietin—stimulates increase in number and activity of megakaryoctyes in the bone marrow

constituents of plasma

1. water (90% by weight) 2. plasma protein 3. electrolytes 4. organic molecules- glucose, amino acids, urea, hormones 5. dissolved gases like o2&co2

what is an antigen? how does it relate to the ABO Rh factor blood types?

Antigen: large molecule that triggers immune reponse in the body (bc they are on the surface, they can interact with other things on the surface) (usually protein, glycoprotein, or glycolipid on cell surface) - Those with AB-type blood don't develop antibodies to "A" and "B" because we don't develop antibodies to our own cells - Those with O-type blood develop antibodies to "A" and "B" because their own cells don't express "A" or "B" - A-type blood develops antibodies to "B", and B-type blood develops antibodies to "A" Most important is Rh factor—surface molecule that is either present (+) or absent (−)