Login

Functions of Red Blood Cells, White Blood Cells & Platelets

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Fibrous Connective Tissue: Function & Types

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:06 Blood Connective Tissue
  • 0:38 Red Blood Cells
  • 1:48 White Blood Cells
  • 3:58 Remembering White Blood Cells
  • 4:10 Platelets
  • 4:28 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Laura Enzor

Laura has a Master's degree in Biology and is working on her PhD in Biology. She specializes in teaching Human Physiology at USC.

Blood is a connective tissue vital to our body's survival. In this lesson, we will explore the three functions of blood by delving into red blood cells, white blood cells and platelets - the three individual components that make up blood as a whole.

Blood, A Connective Tissue

Types of living cells in the blood
Blood Cell Types

In the human body, one of the most important connective tissues is blood. Blood is considered a connective tissue because it consists of a non-living fluid in which living cells are suspended. The blood matrix surrounding the cells is known as plasma, which accounts for about 55% of our blood volume. There are three types of living cells in blood: red blood cells (or erythrocytes), white blood cells (or leukocytes) and platelets (or thrombocytes). These make up the remaining 45% of our blood volume.

Red Blood Cells

Blood has three main functions: transportation, regulation and protection.

Our erythrocytes, or red blood cells, are the most abundant cell type in the human body. Additionally, erythrocytes are anucleated, which means they don't have a nucleus. This extra room allows for more hemoglobin to be stored in our red blood cells. Hemoglobin is a respiratory pigment, which binds to either oxygen or carbon dioxide. This allows oxygen to be transported around our body to our tissues and organs (and carbon dioxide to be taken away). Hemoglobin is largely comprised of iron, which when combined with oxygen, gives blood its red color. Additionally, blood helps cycle nutrients and hormones throughout our bodies.

Process of transporting oxygen throughout the body
Oxygen Transportation

Blood also helps us maintain homeostasis by regulating our internal body pH and temperature as well as how much water is in our bodies at a given time. Plasma, our connective tissue matrix, is about 90% water. Blood is also vital in protecting our bodies. Blood loss is controlled with clotting mechanisms, and white blood cells provide immune response. Let's examine this function in more detail.

White Blood Cells

The types of leukocytes in the blood
White Blood Cell Types

There are five different types of white blood cells, or leukocytes, in our bodies, and we can break them up into two main categories. These are granulocytes and agranulocytes. These terms simply refer to how these cells look when stained. Granulocytes have visible granules in their cell bodies, and agranulocytes do not. There are three types of granulocytes. They are neutrophils, eosinophils and basophils.

Granulocytes

Neutrophils

Neutrophils are the most abundant type of white blood cell in our body. These are primarily responsible for killing off foreign bacteria. Neutrophils are the first responders when we are injured or sick, and they help keep us healthy by phagocytizing (or consuming) bacteria in our bodies.

Eosinophils

Eosinophils are responsible for fighting infections of parasitic worms. These cells release toxins that kill the worms and are also involved in the inflammatory response when we have an allergic reaction.

Basophils

Basophils release two chemicals, histamine and heparin. Histamine is also involved in allergic reactions, and heparin is an anticoagulant. Anticoagulants keep blood from clotting, which helps bring more blood to a damaged area in our body, which, in turn, helps promote healing.

Agranulocytes

The two remaining types of leukocytes are agranulocytes. These are monocytes and lymphocytes.

Monocytes

Monocytes are the largest of the white blood cells. These are the cells that 'clean up' our blood the most. Monocytes also employ phagocytosis to 'eat' foreign particles, bacteria and dead neutrophils.

Lymphocytes

Lymphocytes are broken down into two main types, B-lymphocytes, which produce antibodies, and T-lymphocytes, which are responsible for cell-mediated resistance to infections. Lymphocytes are the 'last responders' in our immune system and allow for long-term resistance.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support