chapter 7 Flashcards
circulatory system
consists of the heart, the blood vessels, and the blood that circulates through them. provide all cells with what we need
blood
specialized connective tissue and cell fragments suspended in a watery solution of molecules and ions. 8% of our body
3 crucial tasks for the body
- Transportation - transport all substances needed anywhere by the body, including oxygen from the lungs, nutrients from the digestive system, and hormones from the endocrine glands.
- Regulation - regulates body tempt, the volume of water in the body and the pH of body fluids
- defense - specialized defense cells that help protect against infections and illness
Plasma
transport medium for blood cells and platelets. 55% of whole blood. mostly water
plasma proteins
largest group of solutes in plasma. serve a variety of functions. important plasma proteins include albumins, globulins and clotting proteins
albumins
serve to maintain the osmotic relationship between blood and the interstitial fluid and ensure proper water balance.
globulins
transport various substances in the blood
clotting proteins
minimizes blood loss and helps maintain homeostasis after injury
red blood cells (RBC) or erythrocytes
carriers of oxygen and carbon dioxide. give blood its color and are the major reason why it is viscous. have short life span
hemoglobin
primary protein in red blood cells and gives blood its oxygen carrying capacity. 4 polypeptide chains folded together.
hematocrit
percentage of blood that consists of red blood cells. measure of the oxygen-carrying capacity of blood
stem cells
all blood cells and platelets originate from cells in the red bone marrow. continually produce immature blood cells
macrophages
old and damaged RBCs are removed from the circulating blood and destroyed in the liver and spleen by large cells
phagocytosis
Macrophages surround, engulf, and digest the red blood cell
erythropoietin
Low oxygen availability signals the cells to secrete a hormone
blood doping
some athletes have a bused commercial erythropoietin by injecting it to increase their RBC production and thus their blood oxygen-carrying capacity
white blood cells (WBCs) or leukocytes
larger than RBCs, more diverse in structure and function. have a nucleus but no hemoglobin. translucent, hard to identify. defend body against disease and injury. The activities of various leukocytes incude participating in the response to tissue injury, producing antibodies, engulfing entire foreign cells, and releasing enzymes to attack foreign organisms too large to be engulfed whole
Neutrophils
60% of WBCs, surround and engulf foreign cells. especially target bacteria and some fungi.
Eosinophils
2-4% of WBCs. defend the body against large parasites such as worms. releasing chemicals that moderate severity of allergic reactions
Basophils
rarest at 0.5% of WBCs, tissues are injured, basophils secrete histamine causing adjacent blood vessels to release blood plasma into the injured area.
monocytes
largest of WBCs 5% of circulating wbc. filter out of the bloodstream and take up residence in body tissues
Lymphocytes
30% of circulating WBCs. found in bloodstream, tonsils, spleen, lymph nodes, and thymus gland.
B lymphoctes
give rise to plasma cells that produce antibodies. defend against foreign invaders
T lymphocytes
target and destroy specific threats
