formed platlets

Question 1

what has the most amount of cells

Answer 1

Under a microscope, you can see red blood cells (erythrocytes), white blood cells (leukocytes), and platelets. Among them, erythrocytes are the most abundant—they make up about 99% of all formed elements in the blood. Their main job is to carry oxygen throughout the body.

Question 2

erythrocytes

Answer 2

Erythrocytes (Red Blood Cells – RBCs)
Main function: To carry oxygen to all the cells in the body.

They show a great example of structure matching function.

🔬 Unique Features of RBCs:
They are anucleate, meaning they have no nucleus.

They also have very few organelles, so there’s more room for hemoglobin.

Mature red blood cells are basically “bags of hemoglobin” floating in the blood.

🧪 Hemoglobin (Hb):
It’s an iron-containing protein inside RBCs.

It binds to oxygen in the lungs and releases it where the body needs it.

Hemoglobin can also carry a small amount of carbon dioxide, but on a different site than where oxygen binds.
Erythrocytes don’t have mitochondria, so they make ATP without using oxygen (this is called anaerobic respiration).
Because of this, they don’t use up any of the oxygen they carry—which makes them very efficient at delivering oxygen to the body’s tissues.

Red blood cells are small and have a unique biconcave disc shape (they’re round and flattened in the middle). This shape gives them a large surface area compared to their volume, which makes them perfect for gas exchange—allowing oxygen and carbon dioxide to move in and out quickly and efficiently.

Question 3

what makes blood viscous

Answer 3

Erythrocytes (red blood cells) are the main reason blood is thick (viscous).

More erythrocytes = thicker blood

Fewer erythrocytes = thinner blood

Also, erythrocytes outnumber white blood cells by about 1,000 to 1, but their number can vary depending on the body’s needs.

Question 4

erythocytes and the importance of hemoglobin

Answer 4

The amount of oxygen transported depends on how much hemoglobin is in the red blood cells.

If there’s less hemoglobin, the RBCs carry less oxygen.

Each RBC usually contains about 250 million hemoglobin molecules.

Each hemoglobin molecule can bind 4 oxygen molecules, so one RBC can carry about 1 billion oxygen molecules.

Typically, men have slightly more hemoglobin in their blood than women.

Question 5

doe rbcs carry anything else

Answer 5

The main job of red blood cells (RBCs) is to transport oxygen (and a small amount of carbon dioxide), but they don’t really transfer many other substances.

Here’s a quick breakdown:

Primary function: Carry oxygen from the lungs to body tissues using hemoglobin.

Also carry: A small amount of carbon dioxide from tissues back to the lungs (but most CO2 is transported dissolved in plasma or as bicarbonate).

Other substances: RBCs don’t carry nutrients, hormones, or wastes—those travel mostly dissolved in plasma.

Question 6

anemia

Answer 6

A decrease in the oxygen-carrying ability of the blood, whatever the reason, is called anemia (ah-ne′me-ah; “lacking blood”). Anemia may be the result of (1) a lower-than-normal number of RBCs or (2) abnormal or deficient hemoglobin content in the RBCs. There are several types of anemia (classified and described briefly in Table 10.1), but one of these, sickle cell anemia, deserves a little more attention because people with this genetic disorder are frequently seen in hospital emergency rooms.

Question 7

sickle cell anemia

Answer 7

Anemia Overview
Anemia means a decrease in the blood’s ability to carry oxygen.

Causes of anemia:

Too few red blood cells (RBCs)

Abnormal or low hemoglobin content in RBCs

Sickle Cell Anemia (SCA)
In SCA, abnormal hemoglobin is produced instead of normal hemoglobin.

This abnormal hemoglobin becomes spiky and sharp when oxygen levels drop.

It causes RBCs to become sickle-shaped (crescent-shaped).

These sickled cells:

Rupture easily (breaking apart)

Block small blood vessels, causing pain and poor oxygen delivery.

SCA symptoms include extreme pain and trouble breathing.

Genetics & Malaria Connection
SCA mostly affects dark-skinned people in the malaria belt of Africa and their descendants.

The sickle cell gene helps protect carriers from malaria by making infected RBCs stick to capillaries and lose potassium, preventing parasite growth.

People with two copies of the defective gene have sickle cell anemia (show symptoms).

People with one copy have sickle cell trait (SCT) — usually no symptoms but can pass the gene to children.

Key points for nursing tests:
Anemia = low oxygen-carrying capacity.

SCA is caused by abnormal hemoglobin that changes RBC shape.

SCA causes vessel blockage and pain.

SCT carriers usually don’t show symptoms but carry the gene.

Question 8

polycythemia

poly=alot
cyte=cell
themia=blood site

Answer 8

Polycythemia is when there are too many red blood cells in the blood.
It can happen because of:

Bone marrow cancer (polycythemia vera)

Living at high altitudes where there’s less oxygen (secondary polycythemia)

Athletes doing blood doping to boost oxygen capacity

Too many RBCs make blood thicker and flow sluggishly, which can impair circulation and cause problems.

Question 9

white bllod cells

Answer 9

Leukocytes (White Blood Cells – WBCs)
Much fewer than red blood cells — only about 4,800 to 10,800 WBCs per mm³ of blood.

They make up less than 1% of total blood volume.

Despite their low numbers, they are essential for body defense (immune system).

WBCs are the only complete cells in blood because they:

Have a nucleus

Contain organelles

🧠 Key Point for Exams:
Unlike RBCs (which are anucleate), WBCs are fully functional cells and play a key role in fighting infections.

Question 10

transportation of white blood cells

Answer 10

Leukocytes (White Blood Cells): Defense Army of the Body
WBCs act like a mobile defense army, protecting the body from:

Bacteria

Viruses

Fungi

Parasites

Tumor cells

Unlike red blood cells (which stay inside blood vessels), white blood cells can leave the bloodstream.

Key Term: Diapedesis
Diapedesis means WBCs can “leap across” or move through blood vessel walls.

This lets them reach areas of infection, inflammation, or injury in the tissues.

🧠 Important to remember:

The circulatory system is just transportation for WBCs.

Their real work happens in the tissues, not in the blood itself.

Want to go over how WBCs know where to go during infection (chemotaxis)?

“Dia” = through

“Pedesis” comes from Greek paidein, meaning to leap or step.

So diapedesis literally means “leaping through” — like WBCs squeezing through a small hole in the vessel wall to enter tissues.

Question 11

white blood cells movement

Answer 11

🧠 How WBCs Find Infection or Damage
Positive Chemotaxis

WBCs are attracted to chemicals released by damaged or infected tissues.

These chemicals act like a “scent trail” that the WBCs follow.

That movement toward the chemicals is called positive chemotaxis.

Amoeboid Motion

WBCs move by changing shape — they create flowing extensions of their cytoplasm to “crawl” through tissues.

This is called amoeboid motion, like how an amoeba moves.

What Happens Next

Once WBCs reach the damaged site, they gather in large numbers.

They kill microbes, clean up dead cells, and help heal the tissue.

Question 12

low and high wbcs

Answer 12

When WBCs Go to Action:
When the body needs more defense (like fighting an infection), it speeds up producing white blood cells.

The WBC count can double within a few hours.

Leukocytosis:
Means: High WBC count (above 11,000 cells/mm³).

Usually a sign that the body is fighting a bacterial or viral infection.

The suffix “-cytosis” means “increase in cells.”

Leukopenia:
Means: Low WBC count (lower than normal).

Can be caused by certain drugs, like corticosteroids or chemotherapy.

The suffix “-penia” means “deficiency.”

Question 13

the disease in leukomenia

Answer 13

Leukocytosis:
A normal and good response when your body is fighting an infection.

Your body makes more white blood cells (WBCs) to protect you.

Leukemia:
A cancer of the bone marrow where it makes huge numbers of immature and abnormal WBCs.

These immature WBCs can’t fight infections properly.

Because the bone marrow is busy making these faulty cells, it crowds out other important blood cells, leading to:

Severe anemia (low red blood cells)

Bleeding problems (low platelets)

So, even though the WBC count is high, the body’s defense is actually weaker.