function and formation of blood Flashcards
week 2
blood serves as a “transport vehicle” for —, —, —, and —
nutrients; gases; hormones; waste
what is the general pathway of blood circulating in the human body?
- The heart pumps blood to start circulation.
- Oxygen-rich blood is pumped from the heart into arteries.
- Arteries branch into smaller vessels until they become capillaries.
- At the capillaries, oxygen and nutrients leave the blood and enter tissues, while carbon dioxide and waste enter the blood.
- Oxygen-poor blood flows into veins, which join together.
- The oxygen-poor blood returns to the heart, travels to the lungs, and then comes back to the heart.
- Finally, oxygen-rich blood exits the heart again through arteries.
blood transports —, —, and —
O2; waste; hormones
what three things does blood maintain?
- appropriate body temperature,
- normal pH in body tissues (~7.35 to 7.45)
- necessary fluid volume to adequately perfuse body tissues
what two things does blood prevent and how?
- blood loss through clotting
- infection by defending against foreign invaders
Blood is the ONLY fluid tissue in the human body – what type of tissue is it?
connective tissue
true or false: blood only has liquid components
blood has BOTH cellular and liquid components
erythrocytes are — blood cells that make up about —% of blood volume (BV).
red; 45%
leukocytes are — blood cells that make up less than —% of blood volume (BV).
white; 1%
— are cell fragments that make up less than —% of blood volume (BV).
platelets; 1%
The non-living fluid matrix of blood is called —, and it makes up about —% of blood volume (BV).
plasma; 55%
— is the % of blood made up by erythrocytes
hematocrit
— is the % of blood made up by leukocytes and platelets
buffy coat
blood is slightly — (pH 7.35–7.45), — than body temperature, and 5 times more thick than water, with its thickness determined by — levels.
alkaline; warmer; hematocrit
what is the average blood volume in adult males and females?
- males are about 5 to 6 liters (1.3 to 1.6 gallons)
- females are about 4 to 5 liters (1.1 to 1.3 gallons)
blood accounts for —% of body weight
8%
— is the liquid part of blood
plasma
plasma is light yellow and —% water
90%
out of the three formed elements (erythrocytes, leukocytes, platelets), only — are true cells
leukocytes
— vastly outnumber the other types of formed elements
erythrocytes
a erythrocytes typically die within — days
120
erythrocytes are replaced through a process known as —, which primarily occurs in the red bone marrow.
erythropoiesis
hematopoiesis is the creation of ALL —
blood cells
where does hematopoiesis take place?
within the red bone marrow of the bones and girdles of the axial skeleton
all blood cells come from a hematopoietic stem call called a —
hemocytoblast
true or false: once a blood cell has fully developed into its specific type (like a red blood cell or white blood cell), it can’t change into another type
true
what are the three main reasons erythrocytes are efficient at carrying oxygen?
- High Hemoglobin Content: Hemoglobin binds to oxygen in the lungs and releases it in tissues, allowing red blood cells to transport a large amount of oxygen.
- Biconcave Shape: The biconcave shape increases the surface area for gas exchange, making it easier for oxygen to diffuse in and out of the cell.
- No Nucleus or Organelles: Without a nucleus and organelles, erythrocytes have more space for hemoglobin, maximizing their ability to carry oxygen without using any for themselves.
what is the function of erythrocytes?
to carry Oxygen to the body’s working tissues, carry some CO2 out of tissues to lungs
what is Hemoglobin (Hb)?
iron-containing protein that binds Oxygen to the RBC. (gives metallic taste to blood)
what is spectrin?
deformable protein that allows RBCs to temporarily change and regain their shape as they squeeze through tiny capillaries
there are more — blood cells than — blood cells. the ratio is 1,000:1
red; white
the normal values of hemoglobin in males is —g/100mL and in females its —g/100mL
13-18g; 12-16g
how much Oxygen can be transported by each erythrocyte?
1 bilion O2 molecules
what are the 8 stages of erythropoiesis?
- Hemocytoblast
- Proerythroblast
- Basophilic Erythroblast
- Polychromatic Erythroblast
- Orthochromatic Erythroblast
- Nuclear Extrusion
- Reticulocyte
- Red Blood Cell short description for each stage
what happens during the 1st stage (hemocytoblast) of erythropoiesis?
the stem cell that can become any blood cell. It starts the process of becoming a red blood cell.
what happens during the 2nd stage (proerythroblast) of erythropoiesis?
the cell begins to commit to becoming a red blood cell and starts making hemoglobin.
what happens during the 3rd stage (basophilic erythroblast) of erythropoiesis?
the cell produces more hemoglobin, and its cytoplasm turns blue due to ribosome activity.
what happens during the 4th stage (polychromatic erythroblast) of erythropoiesis?
hemoglobin continues to build up, and the cytoplasm shows both blue and red (from hemoglobin).
what happens during the 5th stage (orthochromatic erythroblast) of erythropoiesis?
the cell is filled with hemoglobin, and the nucleus shrinks and condenses.
what happens during the 6th stage (nuclear extrusion) of erythropoiesis?
the cell ejects its nucleus, leaving an enucleate (nucleus-free) cell.
what happens during the 7th stage (reticulocyte) of erythropoiesis?
the cell is now an immature red blood cell with some leftover RNA and is released into the bloodstream.
what happens during the 8th stage (red blood cell) of erythropoiesis?
The mature red blood cell, with no nucleus, fully functional to carry oxygen and carbon dioxide.
Too few erythrocytes leads to — – O2 deprivation
tissue hypoxia
Too many erythrocytes leads to excessive — and —
blood viscosity (thickness);
blood clots
— is a hormone that stimulates erythrocyte formation, its produced in the — and —
erythropoietin (EPO); kidneys; liver
what are three events that may trigger release of erythropoietin (EPO)?
- Low red blood cell count (e.g., after bleeding).
- Low hemoglobin levels (e.g., due to iron deficiency).
- Low oxygen levels (e.g., at high altitudes or during respiratory illness).
EPO stimulates more rapid production of —
erythrocytes
— enhances the kidneys’ production of EPO
testosterone
Erythrocytes cannot —, —, or — once they mature.
create proteins; grow; divide
as erythrocytes age, they lose —, and — begins to degenerate.
flexibility; hemoglobin
aging erythrocytes become trapped in small vessels and are engulfed by — for recycling.
macrophages
the heme part of hemoglobin is converted into —, a yellow pigment, which is then processed and — by the body.
bilirubin; eliminated
what is anemia?
a condition where there is a decrease in the blood’s ability to carry oxygen due to a reduction in the number of red blood cells (RBCs) or insufficient hemoglobin.
what are four symptoms of anemia?
fatigue, pallor (pale skin), feeling cold, shortness of breath
what are the three causes of anemia?
chronic blood loss, low RBC production, excess RBC destruction
the causes of low RBC production include deficiency of —, —, —, or —
iron, B12, EPO, or red bone marrow
what is sickle cell disease?
a genetic disorder where abnormal hemoglobin causes RBCs to become sickle-shaped, leading to RBC destruction, pain, and organ damage.
what are two symptoms of sickle cell disease?
shortness of breath and extreme pain
what is the cause of sickle cell disease?
its a genetic mutation in the hemoglobin gene. In normal hemoglobin the gene is HbA but in sickle hemoglobin its HbS
what is polycythemia?
excessive or abnormal increase in the number of red blood cells (RBCs) in the bloodstream.
what are three causes of polycythemia?
bone marrow cancer, living at high altitude, “blood doping”
what are four symptoms of polycythemia?
headaches, dizziness, fatigue, shortness of breath
what is blood doping?
the practice of increasing red blood cell count through blood transfusions, EPO injections, or synthetic oxygen
how would blood doping benefit competitors in aerobic sports?
by increasing the number of red blood cells, which enhances oxygen delivery to muscles, improving endurance and performance.
