Circulatory System

Biology 11

Video

PBS: Mysterious Human Heart

Open vs. Closed

Open Circulatory System: Blood is not contained in vessels, bathes tissues and organs directly.

Example: Arthropods and most mollusks

Closed Circulatory System: Blood is contained in vessels.

Example: Vertebrates and earthworms

Human Circulatory System

3 main parts:

Heart

Blood

Vessels

Function of Circulatory System

The circulatory system transports oxygen and carbon dioxide, nutrients, wastes and hormones throughout the body.

Blood

Normally, 7-8% of human body weight is from blood. 

This essential fluid carries out the critical functions of transporting oxygen and nutrients to our cells and getting rid of carbon dioxide and other waste products. 

In addition, it plays a vital role in our immune system and in maintaining a relatively constant body temperature.

Whole Blood Sample

Sample Placed in Centrifuge

Plasma

Platelets

White blood cells

Red blood cell

Blood Sample That Has Been Centrifuged

Blood Composition

Components of Blood

4 Main components: Red blood cells White blood cells Platelets Plasma

Red Blood Cells

Red blood cells, or erythrocytes, are relatively large microscopic cells without nuclei. 

They transport oxygen from the lungs to all of the living tissues of the body and carry away carbon dioxide.

Hemoglobin is the gas transporting protein molecule that makes up 95% of a red cell. 

*FYI: Each red cell has about 270,000,000 iron-rich hemoglobin molecules.

White Blood Cells

White blood cells, or leukocytes, exist in variable numbers and types but make up a very small part of blood's volume-normally only about 1%.

White cells are a major part of the immune system.  They also have the function of getting rid of invaders

(such as viruses and bacteria), old unneeded blood cells as well as foreign matter such as dust and asbestos.

Platelets

Platelets, or thrombocytes, are cell fragments that clot blood at the site of wounds. 

Plasma

Plasma is the relatively clear liquid protein and salt solution which carries the red cells, white cells, and platelets. 

About 95% of plasma consists of water. 

Blood Type

Q: What causes a bruised bone?

A: Two types…

Sub-periosteal Hematoma:Collection of blood located underneath the protective membranous layer on bones called the periosteum. Tends to occur as a result of direct force trauma against a bone, usually in a leg.

Inter-osseus:Occurs from compressive forces being applied to a bone that cause internal injury to the bone marrow. Professional athletes, such as football and basketball players as well as runners, are at higher risk for these injuries.

Anatomy of the Human Heart

PBS: Nova interactive

The Heart

Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium

Right Atrium

Superior Vena Cava:

The Heart

Bring oxygen-rich blood from each of the lungs to the left atrium

Left Atrium

Pulmonary Veins:

The Heart

Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery.

Right Atrium

Pulmonary ArteriesPulmonary Valve:

The Heart

Prevents blood from flowing back into the right atrium after it has entered the right ventricle

Right Atrium

Tricuspid Valve:

The Heart

Vein that brings oxygen-poor blood from the lower part of the body to the right atrium.

Right Atrium

Inferior Vena Cava:

The Heart

Mitral Valve: Prevents blood from flowing back into the left atrium after it has entered the left ventricle

Left Atrium

Left Ventricle

The Heart

Aortic Valve: Prevents blood from flowing back into the left ventricle after it has entered the aorta

Left Atrium

Left Ventricle

Aorta

The Heart

Bring oxygen-poor blood to the right or left lung

Pulmonary Arteries:

The Heart

Brings oxygen-rich blood from the left ventricle to the body

Aorta:

Septum

The septum divides the right side of the heart from the left.

It prevents the mixing of oxygen-poor and oxygen-rich blood.

Blood Flow

Pulmonary Circulation:

Circulates blood between the heart and the lungs.

In the lungs, carbon dioxide leaves the blood and oxygen is absorbed. The oxygen-rich blood returns to the heart.

Blood Flow

Systemic Circulation:Circulates blood between the heart and the rest of the body.

After returning from the lungs, the oxygen-rich blood is pumped to the rest of the body.

3 Types of Blood Vessels

Arteries: Carry blood away from the heart

Veins: Return blood back to the heart

Capillaries: Tiny blood vessels that allow for gas exchange and diffusion.

Q: How / why does nitroglycerine work?

A: It dilates blood vessels, therefore decreasing blood pressure during an angina attack (chest pain).

Blood flow…

The “rules”

Left side of heart oxygen rich blood Right side of heart oxygen poor blood

Atria receive blood Ventricles pump blood

Arteries flow away from heart Veins flow towards heart

Pulmonary = lungs

Trace a RBC…

Right atrium right ventricle pulmonary arteries arterioles capillary bed (in lung) venule pulmonary veins left atrium left ventricle aorta arterioles capillary bed (body / organs) venule inferior or superior vena cava right atrium…

Exam Prep

Study Skills

Textbook Review

Read Pages 242-258 Questions 1-2 page 243 Questions 1-8 page 246 Questions 1-4 page 253 Question 1-2 page 258

What is this???

Crane video

PBS: Nova Science Now

Growing Hearts?