Unit 8: Blood Flashcards
3 general functions of blood
Transport function: Transport dissolved/suspended materials like nutrients, wastes, gases, and hormones from one place in the body to another
Regulatory function: Regulate body temperature, blood pressure, and pH
Protective function: Contains white blood cells which are part of the immune system, prevents blood loss by clotting
Two components of blood
Plasma: Liquid protein of the blood, made up of mostly water with proteins and dissolved/suspended materials
55% of the total volume of blood
Formed elements: Blood cells and cell fragments that make up the rest of the blood: Erythrocytes (red blood cells), Leukocytes (white blood cells), and Thrombocytes (platelets)
45% of the total volume of blood
Plasma composition: Water (function and source)
Makes up 90% of the plasma
Function: maintenance of blood volume, transport of cells and dissolved/suspended materials
Source: Absorbed from the large intestine
Plasma composition: Plasma (blood) proteins (function and source)
Makes up 7-8% of the plasma General function: Help maintain osmotic pressure in the blood Specific functions: 1. Albumin: Transport bilirubin 2. Fibrinogen: Blood clotting 3. Globulins: Fight infection Source: Produced in the liver
Plasma composition: Salts (function and source)
Function: Maintains blood osmotic pressure, helps in metabolism
Source: Absorbed from the intestine
Plasma composition: Gases (function and source)
Oxygen and Carbon dioxide
Function: Oxygen is for cellular respiration, carbon dioxide is waste product of cellular respiration
Source: Lungs produces oxygen, Tissue cells give off CO2 as waste
Plasma composition: Nutrients (function and source)
Amino acids, glucose, lipids
Function: Energy source for the repair and growth of the body
Source: Absorbed in the small intestine
Plasma composition: Nitrogenous wastes (function and source)
Urea (major component of urine) and uric acid
Function: These wastes are the products of cellular metabolism in the liver, excreted by the kidneys
Source: Produced in the liver
Plasma composition: Vitamins (function and source)
Function: Function as coenzymes or precursors to coenzymes, aiding metabolism
Source: Absorbed in the intestine
Plasma composition: Hormones (function and source)
Function: Regulate growth, development and metabolism
Source: Endocrine glands
How do blood proteins maintain blood volume?
Their size prevents them from readily passing through the tiny, capillary walls. This causes capillaries to always have a lower water concentration compared to tissue fluids, allowing water to diffuse into capillaries automatically.
Red blood cells: Shape, Structure, Origin, Function
Shape: Small, no nucleus, biconcave disc shape
Structure: Contains many molecules of hemoglobin, a respiratory pigment that combines with oxygen. Hemoglobin is a four polypeptide molecule with each chain containing iron that gives blood its red color once oxygenated
Origin: Produced in the red bone marrow found in the skull, ribs, vertebrae, and long bones
Function: Allows the blood to remain in liquid form so the heart does not have to work as hard, carries oxygen to tissue cells and carry back carbon dioxide as waste
Effect of altitude on red blood cells
There are fewer oxygen molecules per volume of air in high altitudes, meaning there is less oxygen being delivered than what the cells require. To compensate, erythropoietin, one of body’s hormone trigger an increase in the production of red blood cells to aid in oxygen delivery.
White blood cells: Shape, origin, function
Shape: Larger than RBC, has a nucleus, spherical or ameboid in shape
Origin: Produced in red bone marrow
Function: Fight infection and develop immunity
5 types of white blood cells
Neutrophils (40-70%): Most common, phagocytize pathogens
Eosinophils (1-4%): Phagocytize antigen-antibody complexes and allergens
Basophils (0-1%): Releases histamine, which promotes blood flow to injured tissues
Lymphocytes (20-45%): Responsible for specific immunity, produce antibodies
Monocytes (4-8%): Become macrophages that phagocytize pathogens and cellular debris
Platelets: Shape, origin, function
Shape: Irregular shape with no nucleus
Origin: They are broken fragments of larger blood cells called megakaryocytes, in the red bone marrow.
Function: Clumps at a site of blood “leak” and forms a plug
Sequence of blood clotting (6)
Requires the following: Prothrombin, Fibrinogen, and Platelets
- Platelets clump at damaged blood vessel site and partially seal the leak
- Clotting factors promote the release of prothrombin activator from blood vessel, damaged tissue cells release thromboplastin, which stimulates further production of prothrombin activator
- Prothrombin activator converts prothrombin to thrombin (requires calcium ions Ca2+)
- Thrombin converts fibrinogen into fibrin (requires Ca2+)
- Fibrin wrap around the platelets plug, forming a temporary clot
- As soon as vessel repair is initiated, enzyme called plasmin destroys the fibrin network and restores the fluid nature of plasma
Vitamin K and blood clotting
Necessary for the production of prothrombin, which later activates to convert fibrinogen into fibrin.
Exchange of materials in capillary beds (3 stages)
Two forces control the movement of fluids: osmotic pressure and blood pressure. Osmotic pressure tend to move water from tissue fluid to blood, and blood pressure tend to move water in the opposite direction.
At the arteriole end: Blood pressure is greater than osmotic pressure, water diffuses out of the capillaries into tissue fluid.
Midway: Blood and osmotic pressure is equal; no movement of water. Instead, amino acids/glucose/oxygen will diffuse out of capillaries and CO2/nitrogenous wastes will diffuse into the capillaries due to the concentration gradients.
At the venule end: Osmotic pressure is greater than blood pressure, water moves back into the capillaries. However, some of the tissue fluid is absorbed by the lymph capillaries to be returned to the cardiovascular system via the lymphatic system.
What is an antigen
any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off.
Structure of antibody and how it interacts with antigens
Y-shaped molecule with two arms. Each arm has a heavy (long) polypeptide chain and a light (short) chain. Each chains have a variable and a constant region, where the variable regions make up the “tips” of the Y. The variable regions form anti-gen binding sites for a particular antigen. The antigen combines with the antibody at the binding site in a lock-key manner.
Now an antigen-antibody complex is formed, which marks the antigens for destruction.
Blood types (antigen and antibody)
Each blood type corresponds to the attached antigen, and there are antibodies within the body for antigens that the individual does not have.
Type A: antigen A on RBC, anti-B in plasma
Type B: antigen B on RBC, anti-A in plasma
Type AB: antigen A and B on RBC, no antibody
Type O: no antigen on RBC, anti-A and anti-B in plasma
Transfusion of blood according to blood types
Individual can receive blood from other with the same blood type or from type O as it has no surface antigens. (A-A,O; B-B,O; AB-A,B,AB,O; O-O)
If the wrongly-compatible blood is mixed, agglutination occurs. The antigen and antibody interact to from an antibody-antigen complex which can block blood flow, leading to organ damage/death.
Rh system and pregnancy
Rh system is another way of blood typing, where RBC may or may not contain antigen D. This categorizes the blood from Rh+ (have antigen) and Rh-(no antigen).
During pregnancy, an Rh- mother may carry a baby that is Rh+. There is possibility of exposure of the baby’s Rh+ blood to the mother, in which the mother will react by producing Rh+ antibodies. The first baby will not be affected, but a second Rh+ baby may trigger the Rh+ antibody from the mother to start destroying the baby’s RBC. This is hemolytic disease.
Hemolytic disease prevention
Mother can be injected with a globulin called RhoGAM during pregnancy or within 72 hours of birth. This globulin will destroy the baby’s RBC in the mother’s system so the mother will not produce any Rh+ antibody.
