1. Chapter 8
Body Systems

2. Body Systems Our bodies are made up of trillions of cells.
Cells – the basic unit of all living things.
Different kinds of cells make up different parts of the body.
Nerve cell is different than a muscle cell.
The differences allow each type of cell to do a different job in the body.
Tissue – a group of similar cells working together.
Muscle cells make up muscle tissue, nerve cells make up nerve tissue.
Organ – a group of tissues that work together.
The heart is an organ made up of muscle tissue
Each organ is responsible for a particular job. The hearts job is to pump blood but the heart depends on help from other organs to send blood through the body.
Body System – A group of organs working together to complete a task.

3. Body Systems Working Together
Homeostasis – the condition in which the body’s internal conditions are at a stable state.
A person will use oxygen more quickly during exercise so when the body’s level of oxygen decreases, the respiratory and circulatory systems work together to supply more oxygen. These systems work together to supply more oxygen to keep the body at a healthy level.
The body systems constantly work together.
For the body to do anything, several body systems MUST work together.
When a person runs, the respiratory system moves air in and out of the body. The muscle system moves the arms and legs. The skeletal system provides support for the entire body. And none of the systems could function without the direction of the nervous or energy provided by the digestive and circulatory systems.
*The body systems depend on the other. If any one of the system is not working properly, it affects other body systems. Caring for each system helps protect the others and improves your health.

4. 6 Body Systems Skeletal System Muscular System Digestive System
Circulatory System
Respiratory System
Nervous System

5. The Skeletal System
*The skeletal system includes the bones and joints of the body. - support of the body. - protects internal organs. - works with the muscular system to allow movement. - stores minerals, such as a calcium and phosphorus. - produces blood cells. Bones – an organ of the skeletal system. Bone Marrow – soft tissue that is inside the bone that makes blood cells and stores fat. Joint - a place where two or more bones meet. Ligaments – tissue that holds bones together at a joint. These allow the body to move in controlled ways. Tendons – tissue that attaches muscle to bones. When muscles move, tendons cause the muscle to move too.

6. Bone and Joint Development
Before birth, most bones in a baby’s body are made of cartilage.
Cartilage – is a soft, flexible tissue that starts changing to bone before a baby is born. This change does not finish until a person is around 18 years old.
Some cartilage still remains in the body such as joints, nose and ears for flexible supports and shapes.
Healthy bones stay strong and solid for many years. However, as we age, the skeletal system may develop problems.
Osteoporosis – a disease in which the bones become weaker. This will increase a person’s risk of breaking bones.
Arthritis – an irritation of the joints. This can occur in young and older people. Pain is felt every time the joint is moving.

7. Skeletal Diagram

8. Muscular System Muscles system includes all the muscles in the body.
Provides stability and support to the body.
Works with the skeletal system to allow movement.
Helps maintain posture.
Produces heat to help maintain body temperature.
Aids in respiration, blood circulation, food movement, emptying the bladder, and functions of the reproductive system.
Muscles cause movement and support by contracting.
contracting – when a joint moves, the muscle shortens in length.

9. Types of Muscle Tissue
Skeletal Muscle – the muscle that attaches to the bones.
Smooth Muscle – the muscle that forms some internal organs. The stomach is a smooth muscle as it contracts it moves material through the organ.
Cardiac Muscle – the muscle that forms the heart. When it contracts it pumps blood through the body.
When muscle contract, they pull on bones. The two ends of a muscle pull to the center to cause the bone and joint to pull towards the body. To return to the original position, a different muscle must pull the bone in the other direction.

10. Muscles

11. The Digestive System
As soon as food hits the mouth, the digestive system begins digesting it.
Digestion – The process of breaking down food into a form the body can use.
Most digestion occurs in the stomach and small intestines.
Digestion frees the nutrients from food into the blood stream and delivered to the cells so that they can be used by the body.
Eliminates solid waste products from the body.
Stores and releases nutrients.
Nutrients – the substance in food that the body needs to work properly.
After foods are digested, the blood absorbs the nutrients to cells throughout the body.
Cells use nutrients to grow, repair themselves and get energy.

12. Digestive Process
Mouth – food is chewed and swallowed here. Little digestion.
Pharynx & Esophagus – food passes here. No digestion.
Stomach – food enters and mixes with juices. Some digestion.
Small Intestines – food enters and most nutrients are absorbed. Digestion is completed here.
Large intestines – food waste enters here and water and salts are absorbed. Any remain food leaves the body through the anus.

13. Solid Waste vs. Non-digestive Waste Removal
Solid waste is part of food that the body cannot use. This leaves the body through the large intestines and out the anus. The large intestines are to remove all the water and salt from the remain food material. This process takes water from our system. If someone is dehydrated, it can cause many problems.
Non-digestive waste occurs when the body uses nutrients to get energy. 1. The blood carries some of these wastes to the kidneys. The kidneys mixes waste with water to form Urine. 2. Respiratory waste occurs when carbon dioxide is released form the body when you breathe. The blood carries the gas to the lungs, where it is released into the air. 3. The skin also helps remove waste from the body by sweating. Sweat glands remove salt and water by sweating.

14. The Circulatory System
Transports and distributes oxygen, nutrients, and hormones throughout the body.
collects and transports waste products
Transports materials that help fight and prevent disease and that help injuries.
BLOOD:
The circulatory system carries important materials in the blood to the body to carry out normal body functions.
Oxygen is one of many materials that blood carries through the body.
Nutrients are also carried through the body from the stomach and intestines to the body’s cells.
Carries waste products, such as carbon dioxide, away from the cells.
Blood is made up of plasma, platelets, white blood cells and red blood cells. Each part has an important role in the circulatory system.
DEFINITIONS:
Plasma – is liquid made up of mostly water that the body’s cell absorbs.
Platelets – help the blood clot if a blood vessel is injured.
White Blood Cells – helps fight infection and prevent disease.
Red Blood Cells – carry oxygen throughout the body.
Blood Vessels – hollow tubes of tissue that blood moves through.
Artery – The blood vessel that carries blood away from the heart.
Vein – A blood vessel that carries blood to the heart.
Capilary – a tiny blood vessel that carries blood from arteries to veins.

15. The Circulatory System
HEART: a muscle that contracts to pump blood through the blood vessels.
4 Chambers of the heart:
* Upper Chambers: Right and Left Atrium
* Lower Chambers: Right and Left Ventricle
Flow of blood to and from the heart:
1. Right Ventricle pumps blood to the lungs (blood exchanges carbon dioxide for oxygen)
2. Blood then flows to the left atrium
3. Left atrium pumps the blood to the left ventricle
4. The left ventricle then pumps the blood to all parts of the body.
5. The body absorbs oxygen from the blood and releases it into the blood.
6. This blood then flows to the right atrium.
7. The right atrium then pumps the blood back to the right ventricle.

16. Respiratory System
The respiratory system moves air into and out of the body.
Exchanges air between the environment and the lungs.
Exchanges oxygen and carbon dioxide between lungs and blood.
Warms and moisturizes air as it comes into the lungs.
Filters materials from the air before it enters the lungs.
Flow of air:
1. Air enters the body through the nose and the mouth.
2. Pharynx – the throat that air enters into after going through the nose and mouth.
3. Larynx – the voice box where air moves into after going through the pharynx.
4. Trachea – the pipe that carries air deep into the body after going through the larynx.
5. Bronchi – the lower end of the trachea that splits into two branches and carries air to and from the two lungs.
6. Lungs – Sponge-like organ that allows gases to pass between blood and air.
7. Bronchiolies – smaller tubes in the lungs that branch off of the bronchi.
8. Alveoli – the tiny air sacs at the ends of the bronchioles that are surrounded by capillaries.

17. Respiratory System Gas Exchange Breathing Process
1. The lungs and blood exchange oxygen and carbon dioxide in the alveoli.
2. Air enters the alveoli, oxygen enters the blood through the capillaries.
3. Blood carries oxygen to the body’s cells.
4. Cells use oxygen to release the energy in nutrients. This process produces the waste gas, carbon dioxide.
5. The blood carries carbon dioxide from the cells to the alveoli and leaves the blood through the capillaries.
6. Carbon dioxide leaves the body with air released from the lungs.
Breathing Process
Air must move in and out of the lungs for gas to be exchanged in the lungs.
Breathing – moving air in and out of the lungs. We Inhale (air enters lungs) and we exhale (air exits the lungs).
When we inhale the Diaphragm, a muscle that separates the chest from the abdomen, contracts and the rib cage expands.
When the diaphragm relaxes, it works with other muscles to force air out of the lungs.

18. The Nervous System
The nervous system controls all of the body’s activities.
Allows for communication between parts of the body.
Allows for the body to respond to changes in the environment.
This system allows different parts of the body to exchange information and helps people sense changes inside and outside the body.
Brain – major organ in the nervous system.
Controls many body functions such as movement, memory, learning, speaking, and five senses (see, hear, smell, taste, and feel your surroundings.
Spinal Cord – organ that carries messages to and from the brain.
Nerves – a bundle of cells that conducts messages from one part of the body to another.
Message from the brain go through the spinal cord to the nerves that reach other parts of the body. Nerves through the body send messages to the brain through the spinal cord.

19. The Nervous System The nervous system responds to changes
Stimuli – changes that cause a reaction.
The eyes, ears, tongue, nose and skin sense stimuli outside the body and send messages to the brain and spinal cord through nerves.
Nerves throughout the body also carry messages about stimuli that occur inside the body.
Reactions to stimuli:
1. Think about how to respond
In this response, the brain sends messages through the spinal cord to tell the body how to react. Example… if you want to swat a fly the brain sends a message to the arm muscle to contract.
2. Automatic Response
In this response, we call it a reflex – an automatic response to a stimuli. Example…a person drops a hot pan before you realize its hot or your heart rate increases when you exercise.
These reflex reactions send messages to the spinal cord and then sends a fast response even before the original message reaches the brain.

20. Taking Care of Your Body Systems
1. Getting Exercise
Your body needs frequent exercise to function properly.
Exercise keeps bones, joints and muscle stay strong and prevent osteoporosis, increase flexibility, decrease risk of arthritis, work harder for a longer time, do more things and do things much easier.
Exercise strengthens the heart. A stronger heart can pump blood through the body more easily.
Exercise strengthens the lungs which will allow for breathing to be easier at rest and during exercise.

21. Taking Care of Your Body Systems
2. Eating Healthy Foods
The body uses nutrients to grow, get energy, and stay healthy.
Eating a variety of foods will provide your body with the right nutrients.
Vitamins and minerals from fruits and veggies help a person grow and function properly.
Protein from meat and dairy products helps build strong muscles and tissues.
Carbohydrates from grains are a good source of energy.
Proper diet can even help prevent so illnesses.
Eating dairy products and green leafy vegetables is a way to get calcium – a mineral that makes the bones strong and healthy.
Proper nutrition allows all body systems to function properly and when the systems are healthy the body has the strength to fight diseases.

22. Taking Care of Your Body Systems
3. Avoiding Tobacco and Other Drugs
Tobacco products, alcohol and illegal drugs can harm every system in your body.
Smoking and chewing tobacco damages the respiratory, circulatory, digestive and nervous systems.
Tobacco products increase the risk of getting lung, mouth, throat, and pancreatic cancers.
Drugs can damage how the nervous system works. And affect the entire body.
Drugs can alter the chemicals in the brain, changing how the brain functions.
Drugs can cause the brain to send dangerous messages throughout the body. Sometime these messages cause permanent damage or even death.

23. Taking Care of Your Body Systems
4. Getting Enough Sleep
Sleep is necessary for both physical and mental health.
A person deprived of sleep would die more quickly than a person deprived of food.
Sleep – a period of reduced awareness during which many body systems rest or slow down.
The body repairs and heals injured parts of the body during sleep.
Without enough sleep, many organs-especially the brain- will not function correctly.
Scientist do not know exactly what happens to the body when it sleeps.
They do know it helps the body repair itself.
Good sleep requires a comfortable place to rest and a comfortable bed in a dark, quiet room without being disturbed.

24. Taking Care of Your Body Systems
5. Drinking Water
Water makes up more than half the weight of a human body.
Water helps the body systems function. Without enough water, the body systems cannot do their jobs.
The circulatory system depends on water as the major part of blood. A lack of water could decrease the amount of blood in the body.
The digestive system depends on water in the process of getting nutrients from food. A lack of water could decrease the amount of food that is digested
When less food is digested, fewer nutrients will reach the body’s cells and the body cannot get as much needed energy.
Drinking enough water can prevent many health problems.
The body loses water during urination, breathing, and sweating. When we sweat a lot we need to drink extra water.