Chapter 23 Circulation and Respiration



Chapter 23 Circulation, Lymphatic and Respiration

GPS: S7L2 - Students will describe the structure and function of cells, tissues, organs, and organ systems (a-e).

Section 1 The Cardiovascular System

The heart and blood vessels are the main components to this system. Your heart is made of cardiac muscle. Cardio means heart, vascular means vessels, so the cardiovascular system contains the heart and the blood vessels. The function of the cardiovascular system is to transport nutrients and oxygen to your cells while removing the wastes products from the cells.

We have about 5 liters (5L) of blood in our bodies. Blood is a connective tissue made up of two types of cells, cell parts, and plasma. The blood is a mixture of water, minerals, nutrients, sugars, proteins and other substances. Red blood cells, white blood cells and platelets float in the plasma.

Red Blood Cells (RBC’s)

Red blood cells are round and concave and the most abundant cells in blood. The red blood cells are responsible for supplying our cells with the oxygen needed to carry out cellular respiration. The red blood cells have a special protein called hemoglobin. The hemoglobin gives the red blood cells the red coloration. The hemoglobin also binds with the oxygen we breathe in and transport oxygen throughout the body. The shape of the red blood cell shape (concave on both sides) increases the surface area, which in turn allow the red blood cell to carry more oxygen than if it were a perfect sphere.

Recall, the red blood cells are produced in the red bone marrow. Before the red blood cells enter the bloodstream, they lose their nucleus and organelles. Without the nucleus, the red blood cells cannot carry out mitosis and must be replaced when they become worn out. The RBC’s are replaced about every 4 months due to this.

White Blood Cells (WBC’s)

These blood cells have a nucleus and are phagocytic, which means they are capable of engulfing foreign materials (bacteria, viruses and other potential pathogens). Pathogens are materials or organisms that can make us sick. Some white blood cells produce antibodies that fight against pathogens to protect us from foreign invaders. Another function of the WBC’s is to engulf body cells that died or become damaged. WBC’s are also made in the bone marrow.

Platelets

Platelets are pieces of larger cells found in the bone marrow and break off of these larger cells. Platelets function in clotting blood when an injury causes bleeding. The platelets clump together and form a plug on the area that is bleeding in order to reduce blood loss. Platelets also release chemicals that activate proteins in the plasma that will form tiny fibers that ultimately create a blood clot.

The Heart

Your heart is made up of cardiac muscle tissue and is about the size of your fist. It is located in the center of your chest beneath your ribs. The function of the heart is to pump oxygen rich blood to all parts of the body and oxygen poor blood to your lungs where the blood will pick up oxygen.

All mammals (humans included) have a four chambered heart. The heart is divided into a left and right side. The left side of the heart is on the left side of your body, but if you are looking at someone and referring to their heart, the left side would be on your right. THINK ABOUT IT. GOOD!. This orientation is known as the anatomical position which keeps everyone “on the same level” so to speak. All doctors and medical personnel recognize body orientation based on the anatomical position. You would not want surgery on the wrong side of your heart or any other part of your body.

Each upper chamber is called an atrium and each lower chamber is called a ventricle. We have a left and right atrium and ventricle. Between the ventricle and atria you find a valve. The valves prevent the backflow of blood. When a medical person listens to your heart with a stethoscope, they are listening to the valves closing (lubb-dubb). If the sound has a hiss to it, it can indicate a leaking valve.

Blood Flow Through The Heart

Blood enters the left atria from the lungs with oxygen rich blood, while at the same time the right atria is receiving blood that is oxygen poor from the rest of the body.

As the atria contract, the blood is forced into the ventricles. While the atria relax, the ventricles contract and the blood from the right ventricle the blood goes to the lungs and the blood from the left ventricle goes to the rest of the body.

Essentially, the atria contract to send blood to the ventricles, and then the atria relax. Next, the ventricles contract to send blood out.

If we followed one drop of blood through the heart we would see the following path. Coming from the body the blood enters into the right atria, through a valve into the right ventricle. From the right ventricle, the blood would go to the lungs. From the lungs the blood would enter the left atria and pass through a valve into the left ventricle. From the left ventricle, the blood would be sent to all parts of the body to begin the cycle over again.

Blood Vessels

Our blood travels through our body through our blood vessels. A blood vessel is a hollow tube that transports blood. There are three types of vessels – arteries, capillaries and veins.

Remember: Arteries always carry blood away from the heart and Veins always carry blood to the heart.

Large arteries will become smaller and branch into even smaller arteries until they join capillaries. The capillaries are only large enough for one red blood cell at a time to pass. This is where nutrients are released to cells and wastes are picked up. This is also where oxygen is dropped off to cells and carbon dioxide is picked up. Once the capillaries start merging and getting larger, they enter veins which carry the blood back to the heart.

Arteries

Arteries carry blood away from the heart. They have thick elastic walls that contain a layer of smooth muscle. The thick walls and arteries that can withstand the high pressure created when the ventricles contract and force blood through the arteries. The rhythmic change in blood pressure is what creates the pulse. When the ventricles contract, we can feel certain arteries enlarge, this is the pulse. Most arteries that we are able to feel a pulse on must cross over a bone for us to identify the pulse readily (wrist and carotid arteries are the most often used to take one’s pulse).

Capillaries

Capillaries are the smallest blood vessels in the human body as well as other mammals. They often form capillary beds, which function to deliver oxygen and nutrients to cells and transport wastes and carbon dioxide away from the cells. Capillaries are so small in fact that only one red blood cell can pass through them at a time. One strand of hair is about 10X wider than a capillary (wow that is small). Due to the fact that the capillaries are so small, diffusion can easily occur across the capillary wall. Capillaries are also so small that no cell is over three or four cells away from a capillary.

Veins

When the blood picks up the waste and carbon dioxide and leaves the capillaries, it enters veins and begins traveling back to the heart. Veins are different from arteries in that they have valves that prevent the blood from flowing backward. The heart does not actually provide enough pressure to push blood through veins. Skeletal muscles are responsible for helping the blood through the veins. As the skeletal muscles contract, they squeeze the veins and this helps push the blood through them.

The flow of blood from the heart and to all parts of the body is called systemic circulation. We also have blood flowing from the heart to the lungs, we call this pulmonary circulation.

Remember: Oxygen poor blood is sent from the body to the heart, then to the lungs to pick up a “fresh supply” of oxygen. After the lungs provide the fresh oxygen, the blood is sent to the heart again to be pumped to all parts of the body.

Blood Flow Pathway through the Systemic and Pulmonary Circulation

As the blood comes from areas of the body other than the lungs, it enters the right atrium. From the right atrium, the blood passes through a one way valve and enters the right ventricle. From the right ventricle, the blood enters the pulmonary artery and goes to the lungs. Once in the lungs, fresh oxygen is picked up and carbon dioxide is taken out of the blood. Now, the blood leaves the lungs by way of the pulmonary veins and goes to the left atrium of the heart. From the left atrium, the blood passes through a one way valve into the left ventricle. Next, the blood leaves the left ventricle and enters the aorta artery to be sent to all areas of the body.

Blood Pressure

The force that is exerted on the walls of the vessels is called blood pressure. Blood pressure is reported in millimeters of mercury (Hg). When someone has a blood pressure of 120 over 80 (written 120/80) it means that the systolic pressure is 120 and the diastolic pressure is 80. Systolic pressure is the pressure exerted on the artery wall when the ventricles contract. Diastolic pressure is the pressure exerted when the ventricles are relaxed. A blood pressure of 120/80 is considered to be “normal”.

Exercise and Blood Flow

When we exert ourselves (like exercising) our muscles need more oxygen than they require at rest. Our muscles also need more nutrients during periods of exercise. The way that our muscles get the oxygen and nutrients they need is by having our heart pump faster. If our heart cannot supply our muscles with the oxygen and nutrients they need, (RECALL) fermentation occurs and our muscles begin to ache because the glucose is being broken down partially and in the absence of oxygen.

During exercise, some organs do not need as much blood flowing to them and so more blood can be sent to the skeletal muscles, heart, brain and lungs. This is like turning some water faucets off in order to allow more water to other faucets (so to speak). If you have ever been using a faucet and someone else in the house turns another faucet on, you may have noticed the water pressure decrease. When the other person turns their water faucet off, your water pressure increases and more water flows out of the faucet you are using.

Blood Type

There are 4 types of blood that humans have. Humans have one of the following types A, B, AB, or O. These are based on the type of antigens found on the surface of the red blood cells. Type A has A antigens on the surface of the red blood cells, type B has B antigens, type AB has A and B antigens on the surface of the red blood cell, and people with type O have neither A or B antigens on the surface of the red blood cell.

Blood Antibodies.

Antibodies “fight” against antigens. A person with type A blood antigens will have type B antibodies, a person with type B antigens will have type A antibodies, a person with type AB antigens will not have any A or B antibodies, and a person with type O blood will have type A and B antibodies. If we give someone the wrong type of blood, their antibodies can attack the antigens on the blood cells and the person may die from this process.

Mixing Blood for Medical Reasons

When someone has had a serious accident and has had a loss of blood, it may be necessary to give the injured person a blood transfusion (giving blood taken from one person and injected “transfused” into a person needing the blood). This process “blood transfusion” can save someone’s life when properly done.

In order to have a safe transfusion doctors try to give the same type of blood to the person needing the blood. Example if the person needing blood has type A, the blood type the doctor wants to transfuse would be type A.

However, since a person with type O blood does not have any antigens on the red blood cell surface that would react with antibodies, a person with type O blood is known as the universal donor. A person with type AB blood would not have any antibodies, so they are considered the universal recipient.

Cardiovascular problems

When someone has cardiovascular problems, the person will have health problems because the heart and blood vessels are affected. Cardiovascular problems can be caused by smoking, high levels of cholesterol, heredity, over-weight, stress and other factors

Atherosclerosis

This is the leading cause of death in the United States. Atherosclerosis occurs when fatty materials like cholesterol build up on the inside of the blood vessels. This decreases the amount of blood flow to the body. If it decreases the blood flow to the heart, the heart muscle can die and the result is a heart attack.

Hypertension

Hypertension is often detected when someone has abnormally high blood pressure. This makes it harder for the heart to pump the blood through the body. If a blood vessel is weak in one area, the high blood pressure can cause the vessel to rupture (called an aneurism). If this occurs in the brain we call it a stroke. Strokes can lead to death.

Must Know Items

1. Blood flow through the heart and to the body and lungs.

Coming from all part of the body, the blood enters the right atrium from the inferior and superior vena cave veins, and then passes through a valve into the right ventricle. From the right ventricle the blood flows into the pulmonary artery and is carried to the blood where the carbon dioxide is released and oxygen is picked up. From the lungs the blood enters into the pulmonary veins traveling back to the heart. The blood enters into the left atrium and passes through a valve into the right ventricle. The blood then leaves the right ventricle and enters the aorta, which will branch to form the other blood vessels that carry the blood to all parts of our body.

2. Know the differences between arteries, veins and capillaries.

3. The difference between pulmonary and systemic circulation.

4. What is blood pressure? Systolic vs. Diastolic pressure.

5. How does exercise affects blood flow?

6. Blood types and transfusion.

7. Atherosclerosis and Hypertension.

The Lymphatic System

When blood pumps through our body, some fluid leaks out and combines with the fluid that surrounds our cells. Most of the fluid is reabsorbed by capillaries, the rest is collected by the lymphatic system which carries the fluid back to a vein near the heart where it empties the fluid back into the blood. This system is called the lymphatic system. Your lymphatic system also helps your body fight pathogens, Pathogens are microscopic organisms and viruses that can make you sick.

Lymphatic vessels

The smallest vessels in the lymphatic tissue are called lymphatic capillaries. These are located between cells and absorb fluid and any particles too large to enter the blood capillaries. Some of these particles are dead cells or cells that are foreign to our body. All of the fluid that drains into the lymphatic system is called lymph.

The lymphatic system relies on the contraction of skeletal muscles to push the lymph through the lymph vessels.

Lymphatic Organs

Lymph nodes are small bean shaped organs where particles, such as pathogens and dead cells, are removed from the fluid. Lymph nodes have many white blood cells (WBC’s) which “eat” these pathogens. Some of the white blood cells mark the pathogens to be destroyed. When the body becomes infected by bacteria or viruses, the WBC’s multiply and the nodes will become swollen (this is what the doctor is feeling of when they touch your neck). Sometimes the lymph nodes become swollen and very painful.

Thymus gland: this lymphatic organ is located just above your heart and releases White Blood Cells that will travel to other areas of the lymphatic system to fight infections.

Spleen: The spleen is the largest lymphatic organ and is located in the upper left side of your abdomen (just below your diaphragm). Your spleen filters blood and releases WBC’s. As the red blood cells pass through the spleen, some of them are old and fragile, which become ruptured. These red blood cells and some of their parts are recycled and reused. Some people think the spleen could be called the red blood cell recycling center.

Tonsils: Your tonsils are made up of groups of lymphatic tissue located in the back of your nasal cavity in the back of your throat behind your tongue. Sometimes they can become infected and surgery is required to remove them. If they are not removed, the infection may spread to other areas of the body.

The Respiratory System

In order for us to survive, our cells need a fresh supply of oxygen and a way to remove the waste (carbon dioxide and water). The respiratory system is responsible for this.

The oxygen is needed in our cells to obtain energy from the food we eat. When you inhale “breathe in” we take oxygen into our lungs where it enters the capillaries and travels into the blood stream. When we exhale, the waste (carbon dioxide and water) is released.

Many people think the process of breathing and respiration are the same, but they are not. Breathing involves taking air into our lungs and respiration involves gas exchange at the cellular level. Respiration is the entire process of taking in oxygen and releasing carbon dioxide and water. Again, breathing involves inhaling and exhaling. Cellular respiration involves the exchange of oxygen and carbon dioxide at the cells themselves and the chemical reactions in the cell that take place to obtain energy from the food we eat.

The respiratory system consists of the lungs, throat, and passageways that lead to the lungs. Most people inhale and exhale through their nose, therefore our nose is the major passageway into and out of our respiratory system.

Pharynx: as the air you inhale enters passes through your nose, it enters the pharynx. This is located behind your tongue. Look into a mirror and stick your tongue out and say AAHHH! The area you see behind your tongue is the pharynx. The pharynx branches into two tubes 1: the esophagus (carries food to the stomach) 2: the larynx which leads to the lungs.

Larynx: It is located on the front of your throat. You can feel the larynx by gently passing your fingers down the outside of you neck in the front of your throat. The ridges or elevated portion is the larynx. The larynx is also called the voice box because it contains the vocal cords that allow us to talk. When the vocal cords are pulled tight by the muscles it changes the pitch of the sounds we make (different sounds).

Trachea: the larynx is located “on top of” the trachea (also called the windpipe). The trachea is the passageway for air from the larynx to the lungs.

Bronchi: as the trachea makes its way to the lungs, it splits into two tubes called bronchi (one goes to each lung). As the bronchi pass further into the lungs, they branch into bronchioles that enter the air sacs (alveoli) of our lungs.

Lungs: two large organs in your chest cavity (thoracic cavity) made up of thousands of tiny air sacs called alveoli. The alveoli have capillary beds where the gas exchange (oxygen and carbon dioxide) takes place.

Breathing is the Job for the Diaphragm: our lungs “sit” on top of a broad “sheet” of muscle called the diaphragm. The diaphragm contracts and flexes down and causes the process of inhaling air into our lungs. When the diaphragm contracts, some of the rib muscles also contract, this helps lift the ribs and aids in the process of taking in air (inhalation) also. When the diaphragm relaxes it flexes back into an upward arch and forces the air out of our lungs. The rib muscles also relax and this helps force the air out of the lungs also.

Oxygen’s Job: at the level of cellular respiration, the oxygen is used to release the energy stored in the proteins, fats and carbohydrates we consume. When this happens (recall) we produce carbon dioxide and water as the waste product, which is diffused into the bloodstream to be taken to the lungs for removal during exhalation (breathing out).

Respiratory Problems: many people have respiratory problems. You may have heard of some: asthma, bronchitis (inflammation or infection in the bronchi), pneumonia (infection in the alveoli from the bacterium pneumococcus), and emphysema (where the alveoli walls collapse or deteriorate and the gas exchange process is greatly reduced because the surface are of alveoli has decreased to a great extent).

Smoking and our Respiratory System: Smoking causes emphysema and lung cancer. Both of these diseases reduces a person’s ability to carry out proper respiration and the individual may feel as if they cannot ever get enough air to into their lungs for respiration purposes. In reality, they cannot get enough to breathe and they actually suffocate to death in severe cases. Both of these diseases cause the lung tissue to deteriorate.

Worksheet for Chapter 23 Section 1

1. The main components to the cardiovascular system are the h and the b v .

2. Cardio means h .

3. Vascular means v .

4. Cardiovascular must mean the system contains the h and the blood v .

5. The function of the cardiovascular system is to p b and

n to your cells while removing the w____________ products from the cells.

6. . Blood is a c tissue made up of two types of cells, cell parts, and plasma.

7. There are two major types of blood cells, one type is the r blood cell and the other type is the w blood cell.

8. Red blood cells are c in shape and this allows for them to transport more o , which is a major responsibility of theirs.

9. The red blood cells have a special protein called h .

Chapter 23 Section 2 Lymphatic System Review Guide/Study Sheet

1. The fluid and particles absorbed into the lymphatic capillaries is known as l .

2. The system that collects all of the “excess” fluid that has been lost from capillary beds and blood vessels is the l system.

3. The small “bean-shaped” lymphatic organs that filter pathogens and dead cells are l n .

4. When the body is infected with bacteria or viruses, w blood cells multiply in order to combat “fight” the infection.

5. The lymphatic organ located “right above” your heart that releases WBC’s is the t .

6. The s is the largest lymphatic organ that stores WBC’s and filters red blood cells. Sometimes the broken down blood cell parts may be recycled.

7. The t are lymphatic organs located in the back of your throat at the rear of your nasal cavity. They can become so infected that they need to be removed surgically. (Many children have this done and eat a lot of ice cream to ease the pain).

8. When lymph leaves the lymphatic system it enters back into the

b .

9. How can lymph nodes be similar to our spleen?

10. How is lymph “forced” through the lymphatic system?

Chapter 23 Section 3 The Respiratory System Study Guide

1. The process by which the body obtains and uses oxygen and gets rid of carbon dioxide and water is called r .

2. The respiratory system consists of the l , throat, and all of the passageways that lead into the lungs.

3. Taking air into the lungs and exhaling air from the lungs is called

b . (Not at the cellular level).

4. Most people use their n as the primary passageway for air into the respiratory system.

5. If you look into a mirror and open your mouth, stick out your tongue and say AHHH! What part of the respiratory system would you be seeing in the mirror? P .

6. This part of the respiratory passageway contains the “voice box”. What part are we talking about? L .

7. The t is sometimes referred to as our windpipe, which carries the air from the larynx to the bronchi.

8. When the trachea branches into two passageways, it is called

b .

9. If we looked at the tissue from this respiratory system organ, we would see thousands of tiny sacs called alveoli. What organ are we talking about? (We have two of these) L .

10. The large flat muscle right below our lungs that flexes down when it contracts and forces us to inhale is called the d .

11. In c r oxygen is used to obtain the energy contained in the proteins, fats, and carbohydrates we eat.

12. When someone secretes large amounts of mucus due to the area of the bronchi or lungs, they may have a which makes if difficult for them to “catch their breath”. (Some children grow out of this disorder).

13. S can cause emphysema or lung cancer.

14. When someone has e , the alveoli erode or break down and gas exchange is not as efficient and the person can literally smother to death.

15. Give the proper pathway for air entering our lungs, going to all parts of the body and then back out of our lungs to the atmosphere. N ,

P , L , T ,

B , and L .

16. What is pneumonia?

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