Week 3 (ch. 10 blood and circulatory system) Flashcards
(130 cards)
Functions of the blood
Transport O2 and nutrients
Removes waste
Helps maintain homeostasis
Critical role in immune system
Arteries / arterioles function
Transfer blood away from heart
Veins / Venules function
Return blood back to the heart
Capillaries function
Microcirculation within tissues
Systemic circulation
Exchanges of gas, nutrients and wastes in tissues
Pulmonary circulation
Gas exchange in lungs
Hematocrit
Proportion of cells in blood; indicated viscosity
Cells = erythrocytes, leukocytes and thrombocytes
Plasma
Clear, yellowish fluid remaining if cells removed, plasma proteins
Serum
Fluid and solutes left after cell and fibrinogen removed
Where are all cells made
Bone marrow
What do blood cells develop from
Single stem cell
What is hemotopoesis
production of blood cells and platelets which occurs in bone marrow
Dyscrasia
Disorder involving irregular components of blood
Erythrocytes structure
Biconcave flexile disc, similar to a donut with thin center instead of the hole
Erythrocyte life span
~ 120 days
Erythropoietin
Hormone
- originates in the kidney
- stimulates erythrocyte production in red bone marrow in response to hypoxia
It is important to recognize that the erythropoietin stimulates the production of RBC in response to hypoxia - not that bone marrow is stimulated
Where is hemoglobin found?
In erythrocytes
What does hemoglobin consist of?
Globin, amino acid chains, heme groups which contain ferrous iron atom
— O2 molecule attaches to the ferrous iron atom
Where does hemoglobin become fully oxygenated
Lungs
What is the small portion of CO2 carried in hemoglobin transported in the blood as?
Bicarbonate ion
Describe the hemoglobin aging process
- Phagocytosis in spleen in liver
- Broken into globin and heme
— globin becomes amino acids, iron ruptured to bone marrow for reuse
— excess iron stored as ferritin in liver, blood and tissues - Heme converted to bilirubin and sent to the liver
— in the liver, combines with glucuronide
— excreted in bile
Hemolysis
Destruction of RBC
What does excessive hemolysis lead to?
Elevated serum bilirubin - results in jaundice
Lymphocytes
T and B lymphocytes - immune response