Blood Components, Functions & Types Flashcards
What does mainly blood consist of?
- Plasma (55%)
- Red blood cells (RBC)
- White blood cells (WBC)
- Platelets
What is another name for red blood cells?
Erythrocytes
What are red blood cells? What are their the purpose?
RBCs are blood cells that are formed bone marrow and have no nucleus. They carry oxygen from the lungs to all parts of the body through the use of hemoglobin
What is hemoglobin?
It is an iron-containing protein found inside RBCs that allows large amounts of oxygen to bind to it (and some CO2)
What determines the production of red blood cells?
The amount of oxygen available
What does an individual’s oxygen-carrying capacity depend on?
The number of red blood cells (RBC) and amount of hemoglobin
What is the role of the spleen?
Filters blood and destroys worn out RBC, and stores about 150mL of RBC for emergent situations
What is the lifespan of an RBC?
100 - 120 days
What is another name for white blood cells?
Leukocytes
What are white blood cells? What are their the purpose?
White blood cells originate from the bone marrow and thymus gland, and are part of the body’s immune system. They help the body fight infection and other diseases.
What are the three main types of WBCs?
- Granulocytes
- Monocytes
- Lymphocytes
What are granulocytes? What is their role?
A type of white blood cell that has small granules that contain proteins: neutrophils, eosinophils, and basophils. Granulocytes stay in the bloodstream and help the body fight bacterial infections by engulfing and destroying bacteria and foreign bodies
What are monocytes? What is their role?
These are blood cells that can exit the bloodstream and become specialized macrophages. They engulf and destroy bacteria and foreign bodies
What are platelets? What is their role?
Fragments of cells that form when cells and bone marrow break apart. They play a key role in blood clotting.
What are the steps of blood clotting?
- Injury exposes collagen fibers to blood stream, which attracts platelets like magnets
- When platelets arrive at rough surface, they rupture and release a protein, thromboplastin
3.Thromboplastin combines with calcium ions and activates a protein prothrombin (made by liver) - Prothrombin ——-> thrombin enzyme
- Thrombin + fibrinogen = fibrin
- Fibrin forms a mesh of fibres, closing the wound and creating a clot
How does blood transport nutrients, gasses, and other materials like waste?
Digestion - capillaries in the wall of the small intestinal absorb nutrients
Respiration - capillary beds in lungs allow for gas (and other chemical) exchange
Urinary - Metabolic wastes, mineral ions, and other waste products are carried by blood to kidneys for excretion
What is vasodilation and what does it cause?
When the nervous system signals blood vessels to dilate, causing increased blood flow and heat loss (ex. your face turns red during exercise)
What is vasoconstriction and what does it cause?
Constriction of the vessels near the skin which decreases blood flow and heat loss (e.g. looking pale when sick/ scared)
How does blood regulate homeostasis?
Through heat gradients formed by a difference in temp between the blood coming to the skin and the skin itself. Regulated by blood pressure and metabolic activity.
What occurs when the body is too cold?
Vasoconstriction occurs:
- Hypothalamus signals blood vessels through nerves
- Blood vessels constrict and the body stops sweating
- Blood temperature increases
What occurs when the body is too hot?
Vasodilation occurs:
- Hypothalamus signals blood vessels through nerves
- Blood vessels dilate and the body begins to sweat
- Blood temperature decreases
What are capillary beds? What do they do?
A vast network of capillaries that exchange nutrients, waste, and gas, throughout the body
How do capillaries exchange substances?
By diffusing the substances through the capillary walls via interstitial fluid, when there is slow blood flow
What is interstitial fluid?
The fluid surrounding cells and capillaries; any material exchanged between capillaries and cells must pass through this
