B4 Blood Review Flashcards
What are 3 functions of blood?
- Transport hormones, gasses and nutrients
- Regulates the concentration of materials
- Temperature regulation
How does blood regulate body temperature?
-Vasodilation: amount of blood going to the arteries increases and heat dissipates across the skin (cools you down)
-vasoconstriction: blood vessels constrict and the amount of heat that dissipates is reduced (preserves heat)
What are other ways the body releases heat?
-Sweating (water evaporates which causes your body to cool)
-breathing
What is blood composed of?
-2 parts
1. Plasma: gases, nutrients, wastes (dissolved soluble stuff) and water (55%)
2. Formed portion: red blood cells, white blood cells and platelets (45%)
Where are blood cells and platelets produced?
-Bone marrow
Describe red blood cells (RBC)
-Erythocytes
-specialized for oxygen transport
-bicarbonate, enucleated (no nucleus), contain hemoglobin (iron)
What is hemoglobin?
-Respiratory pigment that transports oxygen and some carbon dioxide
What is anemia?
-Either too few red blood cells or to little hemoglobin
-results in less oxygen being transported (tired)
-may be caused by an iron deficiency
Describe white blood cells (WBC)
-Leukocytes
-part of the immune system
-granulocytes, monocytes, lymphocytes
What is leukaemia?
-Cancer of the white blood cell
-to many immature white blood cells, they crowd out the red blood cells
Describe platelets
-Fragments of cells that form when larger cells in the bone marrow break apart
-key role in blood clotting
1. Injury triggers enzyme reactions that attract platelets
2. If calcium is present prothrombin (inactive) is converted to thrombin
3. Thrombin and calcium convert fibrinogen into fibrin
What is fibrin?
-Thread like material that creates a mesh which traps blood cells and forms a clot
What is hemophilia?
-Blood will not clot
-caused by missing blood clotting proteins
What are glycoproteins?
-Special markers located on the membrane of some of the RBC
-seen as foreign invaders if put on the wrong blood type (immune response)
-type A has A marker, B has B, type AB has both and O has neither
-markers act as antigens which are substances that stimulate the formation of antibodies
What are antibodies?
-proteins formed within the blood that react with antigens and cause the blood to clump
