Chapter 19 Flashcards
Reason blood is classified as connective tissue
Surrounded by liquid matrix (plasma)
White blood body weight percent
8%
Plasma in whole blood percentage
55%
Most abundant component of plasma and some other examples of components
Water, blood plasma, proteins, other solutes
Percent of whole blood made of RBC
45%
Most variable in structure of the 3 types of blood cells
Neutrophils
What blood transports
O2, CO2, nutrients, heat, hormones, waste products
How blood is involved in regulating homeostasis
Regulates all body fluids, pH, body temperature, and water contents of the cell
How blood protects us
Protects against excessive clotting and uses WBCs to protect against infections
Hemopoiesis
Process of producing blood cells (occurs mainly in red bone marrow after birth/throughout life)
Type of blood cells able to live for years
Lymphocytes
Type of blood cells that vary in number
WBC; varies depending on invading pathogens/other foreign antigens
Erythropoiesis
Production of RBC
Erythrocytes
- RBC
- No nucleus
- Contain hemoglobin
- Contains carbonic anhydrase
- Lives ~120 days
- Average number of RBC in healthy adults = 4.8-5.4 million/microliter
Hemoglobin
- Aka respiratory pigment
- Helps carry oxygen to body cells and carbon dioxide to lungs
- Consists of 4 polypeptide chains each with affinity for picking up O2
- Helps regulate blood flow/pressure b/c it releases nitric oxide (causes vasodilation)
Vasodilation
- Caused by nitric oxide
- Improves blood flow
- Enhances O2 delivery
Average number of RBC in healthy adults
4.8-5.4 million/microliter (to maintain this, new RBC enter circulation at rate of 2 million per second)
Leukocyte
- WBC
- Contains nucleus and other organelles
- May be granular or agranular
- Some have ability to live months or years (memory cells)
- Able to leave bloodstream and collect at site of invasion/injury
Granular vs. agranular leukocytes
- Contains granules (vesicles) in cytoplasm
- Appear dark when stained
- Neutrophils, eosinophils, basophils
vs.
- Without granules
- Lymphocytes, monocytes
3 stages of emigration
Rolling, sticking, squeezing b/w endothelial cells
Increase in WBC meaning vs. WBC count meaning
Indicates infection/inflammation
vs.
May result from variety of causes such as drug toxicity, exposure to radiation, vitamin deficiency, etc.
Platelets
- Produced by splitting megakaryocytes into 2000-3000 fragments
- Contain many vesicles but no nucleus
- Function in blood clotting
- Short lived (5-9ish days)
Hemostasis
Sequence of responses that stops bleeding
Stages of hemostasis
- Vascular spasm
» Initial reaction when a blood vessel is damaged
» Smooth muscle in vessel wall contracts immediately, slowing loss of blood - Platelet plug formation
»Platelet adhesion: platelets stick to the damaged blood vessel wall
»Platelet release reaction: platelets release various chemicals
» Platelet aggregation: release of ADP makes the platelets sticky and they begin to adhere to each other (a bunch of them=platelet plug) - Blood clotting (coagulation)
» Complex series of chemical reactions that result in production of fibrin (insoluble protein) which forms a thread-like network that traps blood cells in a clot
