Chapter 19 - The Cardiovascular System (Blood) Flashcards
What is blood and what are its 3 functions?
Blood is liquid connective tissue.
The three functions of blood are:
1 - transportation (hormones, nutrients, oxygen, CO2)
2 -regulation (pH, temp)
3- protection (clotting, WBC)
What are the 2 components of blood?
Plasma (55%) and formed elements (cells and fragments - 45%)
What are the substances in blood plasma?
Water (91.5%), proteins (albumins, globulins, fibrogens), as well as electrolytes, gasses, enzymes, hormones, vitamins/minerals, lipids, and waste products, glucose.
What are the formed elements?
WBC, RBC, platelets
Hematocrit
% of total blood volume occupied by RBCs
high or low -er than normal # of RBCs
anemia (low) and polycythemia (high)
hemopoiesis
the formation of new blood cells from hemopoietic stem cells in red bone marrow.
Erythropoietin (EPO) and Thrombopoietin (TPO)
Both are hemopoietic growth factors.
EPO - a hormone that increases the # of RBC.
TPO - a hormone that stimulates the formation of platelets.
Describe the structure and function of RBCs
Also called erthrocytes
Structure - RBCs are biconcave discs + hemoglobin (peptide chains) + heme. RBCs lack a nucleus
Function - transport oxygen and waste (hemoglobin’s job)
RBC and WBC
RBC = erythrocytes WBC = leukocytes
What stem cells give rise to RBCs, platelets, granuloycytes, and monocytes?
Meyloid
What stem cells give rise to lymphocytes?
Lymphoid
RBC lifecycle basics
- Live about 120 days
- Hemoglobin component of cells is recycled with the help of transferrin and ferritin
- New RBC formation is called erythropoesis and occurs in red bone marrow.
- Process is stimulated by hypoxia
- Spleen is involved in the removal of old RBCs
WBC basics
- Nucleated cells w 2 main types - granulocytes and agranulocytes
- General function is to combat inflammation and infection
- WBCs may live for only a few hours or days.
- Normal levels of WBCs are 5000-10,000u/L
3 types of granulocytes and what they do
1- Nutrophils (respond to general infection, stress, inflammation) - most numerous of WBC
2- Eosinophils (respond to histamine reactions) - WBC
3- Basophils (respond to lukemias, hypothyroidism, cancers) - WBC
2 types of agranulocytes and what they do
1- lymphocytes (mediate immune response, may live for years) WBC
2- monocytes (phagyocytosis) - horseshoe shape nucleus - biggest WBC
Platelet basics
Disc shaped cells that splinter from megakaryocytes.
Function is to stop blood loss from damaged vessels by forming platelet plugs.
What involves the removal of red bone marrow from the iliac crest?
Bone marrow transplant
Hemostasis
Stoppage of bleeding.
Steps:
1- Vascular spasam
2- Platelet plug formation
3- Clot formation with fibrin and formed elements
Initiated by extrinsic and intrinsic pathways of clotting.
Requires vit K
Thrombosis
Clotting in an unbroken blood vessel.
A thrombosis that moves from the site of origin is called an embolus.
2 types of blood groups
ABO
Rh
What determines the ABO blood type?
The presence or absence of A and B antigens on the surface of RBCs.
What are the possible Rh classifications?
Rh+, Rh-
Describe hemolytic disease of the newborn
When an Rh- parent is pregnant with an Rh+ fetus
