Cardiovascular System: Capillary Beds and Blood Flashcards
Capillary Beds
Groups of interconnected capillaries that facilitate the exchange of gas and solutes between the blood and interstitial fluid.
Made up of endothelial cells that rest on a basement membrane.
beds are groups of interconnected capillaries that facilitate the exchange of gas and solutes between |
3 ways materials/substances pass into capillary beds?
- Diffusion
- Through Intercellular Clefts
- Vesicular Transport
Intercellular clefts
Channels between adjacent endothelial cells.
3 types of capillaries
- Continuous
- Fenestrated
- Sinusoid
Continuous capillary
Capillaries with a nonporous continuous endothelium. Most common type + most IMpermeable.
Fenestrated capillary
Capillaries with pores that increase their permeability; found in kidneys & small intestine.
Sinusoid capillary
Capillaries with a discontinuous endothelium; permits passage of large particles + blood cells.
MOST permeable capillary.
Peripheral Resistance
Resistance of the vessels to the flow of blood due to FRICTION.
Resistance increases = rate of blood flow decreases.
Diameter and length of the vessel + volume and viscosity of the blood affect this.
Blood composition
- Plasma (55%)
- RBC, WBC, platelets
Plasma
Clear straw-colored; made of water, plasma proteins (albumin, antibodies, clotting proteins), carbohydrates, amino acids, lipids, vitamins, salts, gases, hormones, and waste products.
92% is water
Red Blood Cells (RBCs)
Most of the cells in the blood; (AKA erythrocytes). No organelles = hemoglobin
percentage of red blood cells by volume is called hematocrit and averages about 42% for women and |
Hemoglobin
Protein to which oxygen and carbon dioxide can bind.
Hematocrit
Percentage of RBCs by volume.
(42% for women
46% for men)
White Blood Cells (WBCs)
(leukocytes) the only blood cells with nuclei. NOT confined to blood; move in and out of vessels.
Platelets
(thrombocytes) cell fragments that initiate clotting, and outnumber WBCs about 40:1.
Erythropoiesis
The production of red blood cells; occurs in the red bone marrow.
Erythropoietin
Hormone (produced by the kidneys and liver) targets the marrow + stimulates myeloid stem cells to differentiate into erythroblasts.
are low, the hormone erythropoietin (produced by the kidneys and liver) targets the marrow, |
Erythroblasts
Nucleated cell occurring in red marrow as a stage in the development of the red blood cell
Stages of RBC production
Erythropoietin————>stimulate myeloid stem cells————> erythroblasts——————————————->reticulocytes—————————–>erythrocytes are formed
Erythropoiesis (the production of red blood cells) occurs in the red bone marrow. When oxygen levels |
Leukocytes (White Blood Cells)
3 types of Leukocytes (White Blood Cells).
Lymphocytes
Monocyte
Lymphocyte
WBC: 2 types B cells and T cells
Monocyte
WBC. Characterized by a well-defined nucleus. They play important role in the body’s immune response to pathogens. Produced in bone marrow.
Granulocyte
WBC with granules in its cytoplasm. Fight against infections and allergens. There are several types of these kinds of WBCs.
basophils, eosinophils, neutrophils and mast cells. Some categorizations of granulocytes merge mast |
Types of Granulocytes
Basophils, eosinophils, neutrophils and mast cells.
Basophils
Play important role in allergies and allergic reactions, as well as in inflammation
important part in the defense against infection by parasites in addition to responding to allergens by |
Eosinophils
Defend against infection by parasites in addition to responding to allergens by inducing inflammation
Neutrophils
Defend against infection from microorganisms
Blood types
A, B, O, AB
2 Types of Clotting Mechanisms
- Extrinsic
- Intrinsic
Extrinsic clotting mechanism
This type of clotting mechanisms occurs when damaged tissue releases thromboplastin and triggers a reactions resulting in production of enzyme: prothrombin activator.
Intrinsic clotting mechanism
Clotting mechanism involved with Hageman factor: plasma protein that initiates the contact phase of coagulation
Protoporphyrin
Complex organic ring that serves as a critical intermediate in the biosynthesis of heme: the iron-containing component of hemoglobin
Oxyhemoglobin
oxygenated form of hemoglobin
Baroreceptors
Sensory nerve endings located primarily in the walls of large blood vessels, such as the carotid sinus and the aortic arch. They are mechanoreceptors that detect changes in blood pressure by sensing the stretch or tension in the vessel walls.
Renin
Enzyme secreted by the juxtaglomerular cells of the KIDNEYS, playing a critical role in the body’s regulation of blood pressure, blood volume, and sodium balance.
