Chapter 14 Circulation and Respiration Section 1: The Body’s Transport System What are the functions of the cardiovascular system? What is the function.

Chapter 14 Circulation and Respiration

Section 1: The Body’s Transport System

What are the functions of the cardiovascular system?What is the function and structure of the heart?What path does blood take through the cardiovascular system?What are the functions and structures of arteries, capillaries, and veins?


The Cardiovascular System

The cardiovascular system has 3

main jobs.



#1: Delivering Needed Materials

Transports oxygen, hormones, and glucose (food) to all of your cells.



#2: Removing Waste Products

Transports toxins and other “trash” to the lungs and kidneys, where they are properly disposed.



#3: Helps Fight Disease

Transports white blood cells to areas of the body that are sick or injured.


The Heart

The heart is a hollow, muscular organ that pumps blood throughout the body.


The Heart

The right side of the heart is completely separated from the left side by a wall of tissue called the septum.


The Heart

Each side has an upper chamber, or atrium, and a lower chamber, or ventricle.


The Heart Valves

As blood flows out of the heart and toward the lungs, it passes through a valve. Valves prevent blood from flowing backwards and re-entering the heart.


Two Loop System

Blood circulates through the body in two loops, with the heart at the center.


Two Loop System

In the first loop, blood travels from the heart to the lungs and then back to the heart.


Two Loop System

In the second loop, blood is pumped from the heart throughout the body and then returns to the heart.


Blood Vessels

The walls of arteries and veins have three layers.

The walls of capillaries are only one cell thick.


Artery and Vein

The walls of an artery are very thick.

They consist of 3 separate layers:

• Layer of Epithelial Cells (smooth inner layer that allows blood to flow freely)

• Smooth Muscle (muscular middle layer that controls the amount of blood that flows to an area)

• Connective Tissue (strong outer layer that protects the artery from bursting from the blood pressure)

Artery

Vein


Artery and Vein

The walls of a vein are thinner than an artery.

They also consist of the same 3 layers found in arteries, only thinner.

Blood pressure in the veins is much lower (because they’re farther from the heart), so there are 3 methods that compensate for this:

• Contracting skeletal muscles squeeze the veins.

• Valves (similar to the ones in your heart) prevent blood from flowing backwards.

• Breathing movements cause the veins in your chest to squeeze blood into the heart.

Artery

Vein


Blood Pressure


Blood Pressure

Sphygmomanometers are used to measure blood pressure.

A typical blood pressure is 120/80 or lower.

The first number represents the pressure in your arteries when the heart’s ventricles contract.

The second number represents the pressure when your ventricles relax.


Blood Pressure

Like a garden hose, too much blood pressure in your arteries is a bad thing.


End of Section: The Body’s

Transport System


Section 2: Blood and LymphWhat are the components of blood?What determines the type of blood that a person can receive in a transfusion?What are the structures and functions of the lymphatic system?


Blood

Blood consists of liquid plasma and three kinds of cells—red blood cells, white blood cells, and platelets.


Plasma

About 55% of your blood is made up of a yellowish watery liquid called “plasma”.

Plasma is 90% water and 10% protein molecules.

Plasma carry nutrients such as glucose, fats, vitamins, and minerals. Can also carry carbon dioxide (CO2).


Red Blood Cells

Red blood cells (also called “RBCs”) make up about 45% of your blood.

RBCs are made up of a protein called hemoglobin. This protein is made up of iron, and it is what allows oxygen (O2) to stick to it.

Have no nuclei, therefore they can NOT perform mitosis and make copies of themselves. RBCs can only be made in red marrow found in bones.

Only live 120 days, so your body must make at least 2 million RBCs every second.


White Blood Cells

White blood cells (also called “WBCs”) fight off diseases such as bacteria and viruses. Some WBCs alert the body of the invasion, some make chemicals that kill the disease, and others simply surround and digest the disease.

WBCs are rare: for every 1 WBC, there are 500-1,000 RBCs.WBCs make up less than 1% of your blood.

WBCs have nuclei, but they still do not perform mitosis.Like RBCs, WBCs are made in red bone marrow.

WBCs can live for months, even years.


Platelets

Platelets are made up of broken pieces of cells.

Platelets make up less than 1% of your blood.

They only live for 5-9 days.

When you bleed, platelets release chemicals that form a protein called fibrin. Fibrin looks like tiny fibers, and these fibers form a net to stop the bleeding and form a scab.


Blood Types

The marker molecules on your red blood cells determine your blood type and the type of blood that you can safely receive in transfusions.


Rh factor

Besides the “A” and “B” marker proteins, there is another protein in blood called the Rh factor.

85% of people have this Rh factor protein (Rh +). If you have this protein, you can receive blood with the Rh protein (Rh +) or without it (Rh -).

15% of people do not have the Rh factor protein (Rh -). If you receive blood that is Rh +, you can develop serious problems.


Blood Type Distribution

The circle graph shows the percentage of each blood type found in the U.S. population.


Blood Types

O-type = “universal DONOR”

AB-type = “universal RECEIVER”


The Lymphatic System

The lymphatic system is a network of veinlike vessels that returns the fluid to the bloodstream.


End of Section: Blood and Lymph


Section 3: The Respiratory System

What are the functions of the respiratory system?What structures does air pass through as it travels to the lungs?What happens during gas exchange and breathing?


Respiratory System Functions

Oxygen from the air and glucose from digested food are both carried to the cells by the blood. During cellular respiration, oxygen reacts with glucose to release energy.


The Path of Air

As air travels from the outside environment to the lungs, it passes through the following structures: nose, pharynx, trachea, and bronchi.


Gas ExchangeAfter air enters an alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood. Carbon dioxide and water pass from the blood into the alveoli.


How You Breathe

When you breathe, the actions of your rib muscles and diaphragm expand or contract your chest. As a result, air flows in or out.


Breathing and Speaking

Two vocal cords, folds of connective tissue that produce your voice, stretch across the opening of the larynx. Air moving over the vocal cords causes them to vibrate and produce sound.


End of Section: Cardiovascular and

Respiratory Diseases


Section 4: Cardiovascular and

Respiratory DiseasesWhat are some diseases of the cardiovascular system?How may tobacco smoke affect the body?What are some respiratory diseases that result from infections or other physical conditions?


Health Problems and Smoking

Tobacco smoke damages the respiratory system and strains the circulatory system, resulting in such diseases as emphysema, cancer, and chronic bronchitis.


Respiratory Diseases

During an asthma attack, air passages narrow and breathing is more difficult.


Sickle-Cell Disease

A genetic disease of the hemoglobin that causes some blood cells to form a rigid, sickle shape.

People with SCD have an average life expectancy of 45 years.

Since the RBCs are harder and have a curved shape, it makes it difficult for oxygen to stick, so people with SCD get tired easily.


End of Section: The Respiratory System

Chapter 14 Circulation and Respiration Section 1: The Body’s Transport System What are the functions of the cardiovascular system? What is the function.

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