Topic 4.2: Circulation Flashcards
Describe how blood flow is controlled in each of the three major types of blood vessels.
Blood flow is controlled in arteries by contraction of smooth muscle in artery walls.
Capillary blood flow is affected by the pressure of arterial supply plus the contraction of precapillary sphincters. Venous blood flow is affected by arterial and capillary blood flow, and valves that prevent blood from flowing backward.
List several specific substances that diffuse across capillary walls.
O2, CO2, glucose, amino acids.
List the major components of blood, along with their functions.
Red blood cells (erythrocytes): Transports O2 and helps transport CO2
White blood cells: Fight infection
- Neutrophils: phagocytizes pathogens
- Eosinophils: phagocytizes antigen-antibody complexes and allergens
- Basophils: releases histamine, which promotes blood flow to injured tissues
-Lymphocytes: responsible for specific immunity
- Monocytes: become macrophages that phagocytize pathogens and cellular debris
Platelets (thrombocytes): Aid clotting
Describe the cellular and molecular events that lead to blood clotting.
- Blood vessel is punctured
- Platelets congregate and form a plug
- Platelets and damaged tissue cells release prothrombin activator, which initiates a cascade of enzymatic reactions
- Fibrin threads form and trap red blood cells.
Identify some types of diseases that would be expected to be treatable with stem cell therapy.
Diabetes
Heart disease
Liver disease
Parkinson’s
Alzheimer’s
Predict the effect on the interstitial fluid if the protein content of the blood was greatly reduced.
If the protein content of the blood was reduced, then the osmotic pressure of the blood would be lowered and less water would move from the interstitial fluid into the blood.
Define blood
Fluid circulated by the heart through a closed system of vessels; type of connective tissue.
Define plasma
In vertebrates, the liquid portion of blood; contains nutrients, wastes, salts, and proteins.
Define formed elements
Portion of the blood that consists of erythrocytes, leukocytes, and platelets (thrombocytes).
Define red blood cells
Erythrocyte; contains hemoglobin and carries oxygen from the lungs or gills to the tissues in vertebrates.
Define erythrocyte
Red blood cell; contains hemoglobin and carries oxygen from the lungs or gills to the tissues in vertebrates.
Define hemoglobin
Iron-containing respiratory pigment occurring in vertebrate red blood cells and in the blood plasma of some invertebrates.
Define white blood cells
Leukocyte, of which there are several types, each having a specific function in protecting the body from invasion by foreign substances and organisms.
Define leukocytes
White blood cell, of which there are several types, each having a specific function in protecting the body from invasion by foreign substances and organisms.
Define neutrophils
Granular leukocyte that is the most abundant of the white blood cells; first to respond to infection.
Define basophils
White blood cell with a granular cytoplasm; able to be stained with a basic dye.
Define eosinophil
White blood cell containing cytoplasmic granules that stain with acidic dye.
Define monocytes
Type of agranular leukocyte that functions as a phagocyte, particularly after it becomes a macrophage, which is also an antigen-presenting cell.
Define dendritic cell
Antigen-presenting cell of the epidermis and mucous membranes.
Define macrophages
In vertebrates, large phagocytic cell derived from a monocyte, that ingests microbes and debris.
Define lymphocyte
Specialized white blood cell that functions in specific defense; occurs in two forms—T lymphocytes and B lymphocytes.
Define platelets
Thrombocyte; component of blood that is necessary for blood clotting.
Define thrombocyte
Platelet; component of blood that is necessary for blood clotting.
Define clotting
Also called coagulation, the response of the body to an injury in the vessels of the circulatory system; involves platelets and clotting proteins.