Blood and Blood Vessels (lesson nine) Flashcards
Blood Vessels
- You have an expansive network of tubes inside your body designed to transport blood to and from the body and lungs
- This network allows transport of materials to and from every cell in the body
Arteries
- A blood vessel that carries blood away from the heart towards the body tissues is called an artery
- a for away
true or false
all arteries carry oxygenated blood
false
- Most of the time, arteries are therefore carrying oxygenated blood
- The one exception to this rule is your pulmonary artery because it carries deoxygenated blood from the right atrium to the lungs
where is the largest artery?
The largest artery in your body is the aorta, which is attached to your heat and branches off into all other arteries
what are the three layers of tissue that arteries are made of
- An outer layer of connective tissue
- A middle layer of smooth muscle
- An inner layer of epithelial cells
Arterioles
- As arteries branch off, they get smaller and smaller along the way these smaller vessels are called arterioles
Capillaries
- When an arteriole reaches the body tissue, it branches into the smallest vessels called capillaries, which connect the arteries with the veins
- These are the vessels that provide oxygen and nutrients to every cell in the body
- They are often found in networks called capillary beds
how thick are capillaries walls?
- The walls of capillaries are only one cell layer thick and wide
Venules
- After the oxygen has diffused out of and the carbon dioxide has diffused into the blood, it needs to return to the heart and lungs
- After the capillary bed, it will enter small vessels called venules which will connect to larger vessels called veins
Veins
- Veins almost always carry deoxygenated blood away from the tissues and towards the heart
- Most veins contain valves that can open and close
do veins always carry deoxygenated towards the heart?
The one exception is the pulmonary vein because it carries oxygenated blood away from the lungs and towards the heart (i.e. the left atrium)
veins thickness?
- Veins have the same three-layer structure as arteries but have a thinner layer of muscle and a wider opening
- Valves and skeletal muscle contractions help the blood fight gravity and push back toward the heart
Blood
- Its main function is to act as the fluid in our body’s transport system
- It has many other functions though, including being a key player in our body’s defence system
Red Blood Cells shape
- Red blood cells, or erythrocytes, are biconcave disk-shaped cell
- This cell shape is advantageous because it increases the surface area which allows for more gas exchange
Red Blood Cells function
- Their main function is to carry oxygen from the lungs to the body and carbon dioxide from the body back to the lungs
- Oxygen attaches to a special molecule called hemoglobin
where are red blood cells formed?
- Red blood cells are formed in stem cells in the marrow of the vertebrae, ribs, breastbone, skull, and arm and leg bones
- After about 120 days in circulation, they will die and will be removed from the body by the liver or spleen
White Blood Cells
- White blood cells, or leukocytes, are your body’s first line of defence against harmful bacteria, viruses and organisms
- These cells are also formed in the bone marrow
phagocytosis
When leukocytes come across something they want to destroy, they engulf and destroy the target through a process called phagocytosis
Platelets
- Platelets are small cell fragments that are also produced from stem cells in the bone marrow
- They are essential in the blood clotting
- When a blood vessel is broken, the platelets form a clot so that too much blood isn’t lost
Plasma
- Plasma is a protein-rich liquid in which blood cells and platelets are suspended
- It is yellow and will rise to the top if you were to centrifuge a blood sample
Blood Composition
- 55% Plasma
- 40-45% Red Blood Cells
- 0.7-1% White Blood Cells
- Less than 1% of Platelets
Counting Blood Cells
A complete blood count, or CBC, is a blood test that measures many different parts and features of your blood, including Red blood cells, which carry oxygen from your lungs to the rest of your body.
difference between a/b/ab/0 blood types?
- There are two markers: A and B. Type A blood has the A marker, and type B blood has the B marker.
- Individuals with both markers present have type AB blood and individuals
with neither marker having type O blood.
rhesus factor
The rhesus factor is an antigen on erythrocyte membranes that produces
an antibody reaction
Blood Substitutes and Artificial Blood
Research has focused on two types of artificial blood: hemoglobin-based oxygen carriers (HBOCs) andperfluorocarbon emulsions (PFCEs)
