MT 30 (LEC): the largest cell in the human body

How many cells are estimated to be in the human body?

Over 100 trillion cells.

What do cells form that leads to organs in the human body?

Tissues.

What is the largest human cell known as?

Female Ovum (Egg Cell).

How large is the female ovum in diameter?

About 120 micrometers.

How many eggs do women typically have at birth?

Approximately 1 million eggs.

How many eggs usually remain at puberty?

Around 300,000 eggs.

How often is an egg released during ovulation?

One egg per month.

What is the smallest human cell?

Male Sperm.

What are the dimensions of a sperm head and tail?

Head: ~4 micrometers long; Tail: ~50 micrometers long.

How many sperm cells can a fertile man produce?

Between 40 million and 1.8 million sperm cells.

In what type of environment do sperm cells survive?

Warm environments.

What shape are platelets?

Tiny disc-shaped fragments.

What is the diameter range of platelets?

1-4 micrometers.

What is the role of platelets in the body?

Blood clotting and tissue repair.

Where are platelets produced?

In the bone marrow from megakaryocytes.

What hormone regulates platelet production?

Thrombopoietin (TPO).

What is the lifespan of platelets?

5-9 days.

What do platelets do when activated?

Change shape and extend filaments to form a clot.

What condition is caused by low platelet count?

Thrombocytopenia.

What is thrombocythemia?

Overproduction of platelets.

What type of blood cell are macrophages?

White blood cell (leukocyte).

What is a key function of macrophages?

Engulf bacteria and remove dead cells.

What do neutrophils respond to?

Infections.

What percentage of white blood cells are eosinophils?

Less than 5%.

What do basophils release for allergic reactions?

Histamine.

What is the largest white blood cell?

Monocyte.

What do monocytes mature into?

Macrophages.

What is the lifespan of monocytes?

Approximately 3 days.

What are the most abundant blood cells?

Red Blood Cells (Erythrocytes).

How many red blood cells are present per microliter?

About 5 million.

What protein is found in red blood cells for oxygen transport?

Hemoglobin.

What is the shape of red blood cells?

Biconcave.

What is the lifespan of red blood cells?

Around 120 days.

What condition results from a low red blood cell count?

Anemia.

What are common symptoms of anemia?

Pale skin, fatigue, rapid heart rate.

What causes iron deficiency anemia?

Inadequate iron intake or absorption.

What is essential for red blood cell formation?

Vitamin B12.

In which foods can Vitamin B12 be found?

Meat, dairy, eggs, and fortified cereals.

What can cause Vitamin B12 deficiency?

Poor diet, alcohol use, or digestive issues.

What are important functions of red blood cells?

Transporting oxygen and removing carbon dioxide.

Which blood cells are primarily responsible for immune response?

White blood cells (leukocytes).

What are the two main types of white blood cells?

Granulocytes and agranulocytes.

How do platelets help in injury sites?

They stick to vessel walls and each other to form clots.

What are the smallest blood cells in the human body?

Platelets (thrombocytes).

What is a crucial aspect of red blood cell shape?

Increased surface area for gas exchange.

What do macrophages stimulate?

The immune system.

What is a potential consequence of thrombocytopenia?

Excessive bleeding.

What is the fate of sperm cells outside the body?

They die quickly.

What happens to platelets when they are activated at a site of injury?

They extend filaments to form a clot.

What percentage of blood cells do neutrophils represent?

50-70% of white blood cells.

What is the primary role of red blood cells?

Carrying oxygen from the lungs to the body tissues.

How are red blood cells produced?

In the bone marrow.

What can excessive platelet counts lead to?

Increased risk of blood clots.

What is the origin of macrophages in the human body?

They mature from monocytes produced in the bone marrow.