Lesson 3 - Blood Physiology Flashcards
How many liters of blood is in the human body?
Approximately 5 L
This is made up of cellular and extracellular elements
Blood
What are the functions of blood?
- Carries oxygen and nutrients to living cells and removes waste products
- Immunity
- Homeostasis
- Distribution of heat
What are the colors of blood?
Oxygenated - Bright red
Deoxygenated - Dark red
What is the normal pH range of blood?
pH 7.35 - pH 7.45
True or False: Blood contains numerous buffers to help regulate pH
True
This occurs in the red marrow within the spaces of cancellous (spongy) bone tissue
Hematopoiesis
In children, where does hematopoiesis occur?
Medullary cavity of long bones
Where does extra-medullary hematopoiesis occur?
Outside the medullary cavity
What organs maintain their ability to generate the formed elements throughout adulthood?
Liver and spleen
All of the formed elements of blood originate from this specific type of cell
Hematopoietic stem cell
These induce the HSC to divide and differentiate
Hematopoietic growth factors
What are the two types of hematopoietic stem cells?
- Lymphoid stem cells
- Myeloid stem cells
What do lymphoid stem cells give rise to?
Lymphocytes
Lymphocytes include what type of cells?
T cells, B cells, and Natural Killer (NK) Cells
What do Myeloid stem cells give rise to?
Formed elements: Erythrocytes, Megakaryocytes, Granular Leukocytes, and Monocytes
What are the three granular leukocytes?
Neutrophils, Eosinophils, and Basophils
This is the liquid component of blood
Plasma - 55%
The most abundant of the plasma proteins
Albumin
Most common formed element which functions to carry hemoglobin
Erythrocytes
Describe the erythrocytes
Biconcave in shape due to the lack of organelles which allows them to squeeze through capillaries and facilitate gas exchange
The volume of red blood cells relative to whole blood
Hematocrit
A major component of the body’s defenses against disease
Leukocytes
True or false: Erythrocytes have shorter lifespan than leukocytes
False - Leukocytes have shorter lifespan than that of erythrocytes
Defensive functions in the body’s tissues
- Margination - move towards endothelial wall
- Rolling - rolling motion towards site of injury
- Adhesion - attachment to the endothelium
- Diapedesis - leaving the capillaries
- Chemotaxis - movement to the site of injury
What are the two groups of leukocytes?
Granular leukocytes and agranular leukocytes
This type of leukocyte is a rapid responder to the site of infection and is an efficient phagocyte with a preference for bacteria
Neutrophils
This type of leukocyte includes antihistamine molecules and is also capable of phagocytosis
Eosinophils
This type of leukocyte plays a role in allergic reactions and contains histamine
Basophils
This is essential for the repair of blood vessels when damage has occured
Thrombocytes or platelets
These mature into platelets
Megakaryocytes
How many days to platelets remain before they get phagocytized by macrophages?
10 days
What are the 4 steps in the physiological mechanisms that stop bleeding?
- Vasoconstriction
- Primary Hemostasis/Formation of Loose Platelet Plug
- Secondary Hemostasis/Blood Coagulation
- Resolution
What triggers vasoconstriction?
Myogenic spasm and the production of Endothelin-1
Mediated by vWF of ruptured blood vessels and Gp1b of platelets
Platelet Adhesion
Platelets change shape
Platelet Activation
Mediated by fibrinogen and Gp2b-3a of platelets
Platelet Aggregation
At which factors do the intrinsic and extrinsic pathways begin?
Factor 12 and factor 7, respectively.
What is the common pathway?
Factor X
Has A antigens with anti-B antibodies
Blood Group A
Has no antigens, but both anti-A and anti-B antibodies
Blood Group O
Has B antigens with anti-A antibodies
Blood Group B
Has both A and B antigens with no antibodies
Blood Group AB
