Tuesday Week 3 Flashcards
What is in plasma?
albumins, globulins, fibrinogen, and electrolytes, organic nutrients and wastes
what is hematocrit?
percentage of formed elements in the blood
Which cells don’t come from the myeloid stem cell?
Lymphocytes. The rest come from the myeloid stem cell
What cell becomes platelets
magkaryocyte
what is the lifespan of an RBC
120 days
Explain erythropoiesis to the reticulocyte stage
day 1: Myeloid stem cells destined to become RBCs differentiate into pro erythroblasts
Day 2: now we are basophilic erythroblasts, which actively synthesize hemoglobin.
Day 3: now we are polychromatophilic erythroblasts and the nucleus is shrinking
Day 4: Normoblast ejects nucleus to become
Day 5: reticulocyte which enters blood stream
explain the life events of an RBC starting at reticulocyte and ending in complete recycle of components.
pages 632 and 633
Which WBCs can phaygocytize?
Neutrophils, eosinophils & monocytes can undergo phagocytosis
Which WBC’s are granulocytes?
neutrophils, basophils and eosinophils (monocytes and lymphocytes aren’t)
What are the three stages of clotting response?
Vascular phase, platelet phase and coagulation phase
Describe the vascular phase of clotting
This is the initial 30 minutes; the endothelial cells contract and begin releasing factors and hormones. ENDOTHELINS are a hormone that stimulate smooth muscle contraction and promote vascular spasm. The spasm prevents blood loss from the open vessel. Also, the endothelial plasma membranes become sticky.
Describe the platelet phase of clotting
This begins with the attachment of platelets to sticky endothelial surfaces, the basement membrane, and to each other. The activated platelets go on to release other chemicals, including platelet factors and calcium ions.
Describe the extrinsic route to the common pathway of clotting.
This starts when damaged epithelial cells or tissues release TISSUE FACTOR. Tissue factor combines with calcium insane another clotting factor to form an enzyme complex in order to activate FACTOR X to start the common pathway.
Describe the intrinsic pathway to the common pathway.
This begins with the activation of proenzymes exposed to collagen fibers at the injury site. We need PF-3 (released by platelets). After a series of reactions, factors combine to form an enzyme complex capable of activating FACTOR X to start the common pathway of clotting.
Describe the common pathway of clotting, starting with activated FACTOR X.
Activated FACTOR X activates a complex called prothrombin activator. Prothrombin activator convert prothrombin to thrombin. Thrombin then completes the clotting process by converting fibrinogen to fibrin. Fibrin makes a mesh network to trap more cells, making a clot!!
Describe three nutritionally based blood disorders
Iron deficiency can lead to microcytic RBC’s because not enough functional hb is produced.
Vitamin B12- problems with stem cell division leads to pernicious anemia (macrocytic)
Calcium and Vit K deficiency can lead to clotting problems
Describe three congenital blood disorders
Sickle cell anemia -arises in a mutation for a gene coding for Hb
Hemophilia: reduced production of a single clotting factor
Thalassemias: inherited blood disorder, mutation for gene coding for protein subunits of Hb.
Describe three kinds of blood infections
Bacteremia: bacteria circulate in blood, but don’t multiply there. (Viremia for viruses)
Sepsisemia: pathogens are present and multiplying in the blood and spreading throughout the body.
What are two kinds of leukemia?
Myeloid leukemia: abnormal granulocytes
Lymphoid leukemia: lymphocytes and their stem cells are affected
Describe the layers of the arterial wall.
There is an inner layer, known as the tunica intima: this has the endothelial lining and underlying layer of connective tissue with elastic fibers.
There is a middle layer known as the tunica media , which is basically concentric sheets of smooth muscle tissue.
There is an outer layer called tunica external, which is a connective tissue sheath.
How do veinous walls differ from arterial walls?
- They are usually flattened or collapsed, with thinner walls and larger lumens.
- Their tunica intima lacks the internal elastic membrane
- Their tunica media also lack elastic fibers and are much thinner.
- Their tunica external have smooth muscle cells.
How do blood vessels change with distance from the heart?
They get progressively smaller.
What are the “classes” of veins, biggest to smallest?
Large veins (all three layers), medium veins (all three layers), venules (no tunica media), and capillaries.
What is different about capillaries?
They are the only blood vessels whose walls permit exchange between blood and interstitial fluids.
What are the “classes of arteries, biggest to smallest?
Elastic arteries (very resilient), muscular artery (thick tunica media), arterioles (poorly defined tunica externa), and capillaries.
Describe the two kinds of capillaries
Continuous and fenestrated.
Continuous permits passage of water, small solutes, etc across, but permeability is still restricted by tight junctions.
Fenestrated contain pores that penetrate the endothelial lining, which allow solutes as big as peptides to cross into and out of the interstitial fluid.
What are sinusoids?
These are similar to menstruated capillaries, except they are flattened and irregularly shaped. basement membranes are absent, and theses are found in the bone marrow, liver, spleen and endocrine glands.
Describe capillary beds
There is a pre capillary arteriole with pre capillary sprinters to control blood flow. The thorough fare has continuous blood flow across the bed.
What are the two controllers of vasomotion?
sympathetic innervation and cardiovascular centers of the medulla oblongata
Blood pressure in venules and medium sized veins is so low that it can’t overcome gravity on its own. What helps?
Valves and skeletal muscle contraction.
At any given time, where is most of your blood?
In your venous system. 64%
If hemorrhaging occurs, what can the the MO do?
Its vasomotor center stimulates sympathetic nerves to constrict the veins. this helps maintain the volume within the arterial system to near normals despite significant blood loss.
Describe how blood vessels form
Through vasculogenesis and angiogenesis. At about 4 weeks gestation, hemangioblasts form little blood islands. The ones in the center differentiate into hematopoietic stem cells, but the ones in the periphery become angioblases, which become blood vessels.
describe the heart wall
There is a pericardium with a visceral layer (epicardium) and a parietal layer (dense and fibrous). The heart has a myocardial layer and an inner endocardial layer. The endocardial layer has an endothelium and areolar tissue.
What are myocardial bundles
These are parallel muscle patterns that wrap around the heart in the configuration need to squeeze the blood the appropriate direction.
What is the biggest way cardiac muscle tissue is different than skeletal muscle tissue.
Cardiac muscle has intercalated discs. Entwined plasma membranes with gap junctions and desmosomes. On the sarcomeres, they run along the z lines.
What is pericarditis?
An infection of the pericardium. Heart attack-like pain Fever Coughing Friction rub heard by stethoscope