Physiology ch. 13

Describe the functions of the arteries, veins, and capillaries.

Arteries: vessels that carry blood away from the heart. Veins: vessels that return blood toward the heart Capillaries: the thinnest blood vessels that function in passing blood from the arteries to the veins.

vein

a blood vessel that returns blood to the heart

artery

a vessel that carries blood away from the heart

Define the terms interstitial fluid and lymph. How do these fluids relate to blood plasma?

Interstitial fluid is fluid derived from plasma that passes out of capillary walls into the surrounding tissues. Lymph is the fluid in lymphatic vessels that is returned to the venous blood at specific sites after being cleaned by lymph nodes. These fluids relate to blood plasma because they are part of the blood plasma that is forced out of the capillary walls by hydrostatic pressure.

state the components of the circulatory system that function in oxygen transport, in the transport of nutrients from the digestive system, and in protection.

Oxygen transport: Red blood cells contain a protein called hemoglobin that binds oxygen in the lungs. These oxygenated red blood cells are then transported to the cells by vessels for aerobic respiration. Nutrient transport: Nutrients are absorbed through the intestinal wall into the blood and lymphatic vessels. The blood then carries these absorbed products through the liver to the cells of the body. Protection: The clotting mechanism protects against blood loss when vessels are damaged. The immune function of the blood is performed by the leukocytes that protect against many disease-causing agents.

thrombocyte

a blood platelet; a disc-shaped structure in blood that participates in clot formation

megakaryocyte

a bone marrow cell that gives rise to blood platelets

thrombopoietin

a cytokine that stimulates the production of thrombocytes (blood platelets) from megakaryocytes in the bone marrow

platelet

a disc-shaped structure, 2 to 4 micrometers in diameter, derived from bone marrow cells called megakaryocytes. Platelets circulate in the blood and participate (together with fibrin) in forming blood clots.

lymph

a fluid derived from tissue fluid that flows through lymphatic vessels returning to the venous bloodstream

polymorphonuclear leukocyte

a granular leukocyte containing a nucleus with a number of lobes connected by thin cytoplasmic strands. This term includes neutrophils, eosinophils, and basophils.

erythropoietin

a hormone secreted by the kidneys that stimulates the bone marrow to produce red blood cells

monocyte

a mononuclear, nongranular, phagocytic leukocyte that can be transformed into a macrophage

erythrocyte

a red blood cell. Erythrocytes are the formed elements of blood that contain hemoglobin and transport oxygen.

erythrocyte

a red blood cell. erythrocytes are the formed elements of blood that contain hemoglobin and transport oxygen.

fibrinogen

a soluble plasma protein that serves as the precursor of fibrin; also called factor I

lymphocyte

a type of mononuclear leukocyte; the cell responsible for humoral and cell-mediated immunity

albumin

a water-soluble protein produced in the liver; the major component of the plasma proteins

leukocyte

a white blood cell

anemia

an abnormal reduction in the red blood cell count, hemoglobin concentration, or hematocrit, or any combination of these measurements. This condition is associated with a decreased ability of the blood to carry oxygen.

polycythemia

an abnormally high red blood cell count

cytokine

an autocrine or paracrine regulator secreted by various tissues

plasma cells

cells derived from B lymphocytes that produce and secrete large amounts of antibodies. They are responsible for humoral immunity.

granular leukocytes

leukocytes with granules in the cytoplasm. On the basis of the staining properties of the granules, these cells are of three types: neutrophils, eosinophils, and basophils.

serotonin

monoamine neurotransmitter, chemically known as 5-hydroxy-tryptamine, derived from the amino acid L-tryptophan. Serotonin released at synapses in the brain have been associated with the regulation of mood and behavior, appetite, and cerebral circulation.

hemoglobin

the combination of heme pigment and protein within red blood cells that acts to transport oxygen and (to a lesser degree) carbon dioxide. Hemoglobin also serves as a weak buffer within red blood cells.

interstitial fluid

the fluid outside of the cells within a tissue or organ. Interstitial fluid and blood plasma together compose the extracellular fluid of the body. Also called tissue fluid.

plasma

the fluid portion of the blood. Unlike serum (which lacks fibrinogen), plasma is capable of forming insoluble fibrin threads when in contact with test tubes.

serum

the fluid squeezed out of a cell as it retracts; supernatant when a sample of blood clots in a test tube and is centrifuged. Serum is plasma from which fibrinogen and other clotting proteins have been removed as a result of clotting.

hematopoiesis

the formation of new blood cells, including erythropoiesis (the formation of new red blood cells) and leukopoiesis (the formation of new white blood cells)

fibrin

the insoluble protein formed from fibrinogen by the enzymatic action of thrombin during the process of blood clot formation

heme

the iron-containing red pigment that, together with the protein globin, forms hemoglobin

lymphatic system

the lymphatic vessels and lymph nodes

diapedesis

the migration of white blood cells through the endothelial walls of blood capillaries into the surrounding connective tissues

basophil

the rarest type of leukocyte; a granular leukocyte with an affinity for blue stain in the standard staining procedure

hematocrit

the ratio of packed red blood cells to total blood volume in a centrifuged sample of blood, expressed as a percentage

capillary

the smallest vessel in the vascular system. Capillary walls are only one cell thick, and all exchanges of molecules between the blood and tissue fluid occur across the capillary wall.

agranular leukocytes

white blood cells (leukocytes) with cytoplasmic granules that are too small to be clearly visible; specifically, lymphocytes and monocytes