Human Body Systems Technology Project. by R. Leonard. Human Body Systems THE DR. I.I.L. M C SNEER WAY. D igestive R espiratory I ntegumentary I mmune L ymphatic M uscular C irculatory S keletal N ervous E ndocrine E xcretory R eproductive. And Levels of Organization.
by R. Leonard
And Levels of Organization
This slide presentation is meant to help you study the major systems of the human body.
Use it as an introduction or as a review. Follow the instructions as you move along to explore and learn. You can go through the entire program slide by slide, or you skip to focus on any one system.
Well, at least your body is!
Answers to previous slide: cell, tissue, organ (small intestine).
(It’s Your Skin!)
Your skin covers your body and prevents the loss of water. It protects the body from injury and infection. The skin also helps to regulate body temperature, eliminate wastes, gather information about the environment, and produce vitamin D. The skin is organized into two main layers, the epidermis and the dermis.
Botox is the commercial name given to a toxin which is produced from botulism toxin. a medical protein that is injected into a muscle to cause temporary (months) paralysis of that muscle. This helps prevent the appearance of wrinkles.
Your skeleton has five major functions. It provides shape and support, enables you to move, protects your internal organs, produces blood cells, and stores certain materials until your body needs them
Many bones have the same basic structure. A thin, tough membrane covers all of a bone except the ends. Blood vessels and nerves enter and leave the bone through the membrane. Beneath the membrane is a layer of compact bone, which is hard and dense, but not solid. Small canals run through the compact bone, carrying blood vessels and nerves from the bone’s surface to the living cells within the bone. Just inside the compact bone is a layer of spongy bone, which has many small spaces within it.
Cartilage provides a smooth surface between bones or sometimes a more flexible extension of bone, as in the tip of your nose. As an infant, much of your skeleton was cartilage. By the time you stop growing, most of the cartilage will have been replaced with hard bone tissue.
A joint is a place in the body where two bones come together. Joints allow bones to move in different ways. Immovable joints connect bones in a way that allows little or no movement. Movable joints allow the body to make a wide range of movements. Movable joints include ball-and- socket joints, pivot joints, hinge joints, and gliding joints. The bones in movable joints are held together by a strong connective tissue called a ligament.
A combination of a balanced diet and regular exercise can start you on the way to a lifetime of healthy bones. As people become older, their bones begin to lose some minerals. Mineral loss can lead to osteoporosis, a condition in which the body’s bones become weak and break easily. Regular exercise and a diet rich in calcium can help prevent osteoporosis.
Fill in the blanks on the next slide or on your handout, and check the following slide for the answers.
Osteoporosis is a disease in which bones become fragile and more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly until a bone breaks.
Your body has three types of muscle tissue—skeletal muscle, smooth muscle, and cardiac muscle.
Skeletal muscles are attached to the bones of your skeleton. Because you have conscious control of skeletal muscles, they are classified as voluntary muscles. These muscles provide the force that moves your bones. Skeletal muscles react quickly and tire quickly. At the end of a skeletal muscle is a tendon. A tendon is a strong connective tissue that attaches muscle to bone. Note- ligaments connect bones together.
Smooth muscles are called involuntary muscles because they work with your conscious effort.
Cardiac muscles are involuntary muscles found only in the heart. Cardiac muscles do not get tired.
A Cardiac Muscle Cell
The muscles that are under your direct control are called voluntary muscles. Smiling and turning the pages in a book are actions of voluntary muscles
The muscles that are not under your conscious control are called involuntary muscles. Your colon (left) is lined with smooth muscle, and your heart (right) is comprised of cardiac muscle which works automatically pumping blood around your body.
Muscles work by contracting, or becoming shorter and thicker. Because muscle cells can only contract, not extend, skeletal muscles must work in pairs. While one muscle contracts, the other muscle in the pair returns to its original length. For example, in order to move the lower arm, the biceps muscle on the front of the upper arm contracts to bend the elbow. This lifts the forearm and hand. As the biceps contracts, the triceps on the back of the upper arm returns to its original length. To straighten the elbow, the triceps muscle contracts while the biceps returns to its original length.
Your nervous system receives information about what is happening both inside and outside your body. It also directs the way in which your body responds to this information. In addition, the nervous system helps maintain homeostasis. A stimulus is any change or signal in the environment that can make an organism react
Your nervous system consists of the central and peripheral systems. The central nervous system (CNS), includes the brain and spinal cord; the peripheral system includes the nerves to the rest of the body.
Homeostasis and Negative Feedback
Homeostasis is one of the fundamental characteristics of living things. It refers to the maintenance of the internal environment within tolerable limits. All sorts of factors affect the suitability of our body fluids to sustain life; these include properties like temperature, salinity, acidity, and the concentrations of nutrients and wastes. Because these properties affect the chemical reactions that keep us alive, we have built-in physiological mechanisms to maintain them at desirable levels. When a change occurs in the body, there are two general ways that the body can respond. In negative feedback, the body responds in such a way as to reverse the direction of change. Because this tends to keep things constant, it allows us to maintain homeostasis. On the other hand, positive feedback is also possible. This means that if a change occurs in some variable, the response is to change that variable even more in the same direction. This has a de-stabilizing effect, so it does not result in homeostasis. Positive feedback is used in certain situations where rapid change is desirable (see Positive Feedback for an example).
To illustrate the components involved in negative feedback, we can use the example of a driver trying to stay near the speed limit. The desired value of a variable is called the set point. Here, the set point is a speed of 55 mph; in controlling body temperature, the set point would be 98.6 degrees. The control center is what monitors the variable and compares it with the set point. Here, the control center is the driver; for body temperature, it would be the hypothalamus of the brain. If the variable differs from the set point, the control center uses effectors to reverse the change. Here, the effector is the foot on the accelerator pedal; in controlling body temperature, it would include the glands that sweat and the muscles that shiver.
Web Sources and Resources: http://www.colorado.edu/epob/academics/web_resources/cartoons/gas.html
The cells that carry information through your nervous system are called neurons, or nerve cells. The message that a neuron carries is called a nerve impulse. A neuron has a large cell body that contains the nucleus. The cell body has threadlike extensions. One kind of extension, a dendrite, carries impulses toward the cell body. An axon carries impulses away from the cell body. Axons and dendrites are sometimes called nerve fibers. A bundle of nerve fibers is called a nerve.
The yellow parts are CNS parts and the purple are parts of your peripheral nervous system.
The knee jerk reflex (seen in the figure to the above) is called a monosynaptic reflex. This means that there is only 1 synapse in the neural circuit needed to complete the reflex. It only takes about 50 milliseconds of time between the tap and the start of the leg kick...that is fast. The tap below the knee causes the thigh muscle to stretch. Information is sent to the spinal cord. After one synapse in the ventral horn of the spinal cord, the information is sent back out to the muscle...and there you have the reflex.
The human brain is a complex organ that allows us to think, move, feel, see, hear, taste, and smell. It controls our body, receives information, analyzes information, and stores information (our memories).
The brain produces electrical signals, which, together with chemical reactions, let the parts of the body communicate. Nerves send these signals throughout the body.
The average human brain weighs about 3 pounds. At birth, the human brain weighs less than a pound. As a child grows, the number of cell remains relatively stable, but the cells grow in size and the number of connections increases. The human brain reaches its full size at about 6 years of age.
TRY IT!- The famous "Stroop Effect" is named after J. Ridley Stroop who discovered this strange phenomenon in the 1930s. Here is your job: name the colors of the following words. Do NOT read the words...rather, say the color of the words. For example, for the word BLUE, you should say "RED". Say the colors as fast as you can. It is not as easy as you might think!
Alzheimer's disease attacks the brain; it is not a normal part of aging. People with AD have a gradual memory loss and difficulties with language and emotions.
The progressive loss of intellectual abilities is termed dementia. As the disease advances, the person may need help in all aspects of life: bathing, eating, and using the restroom.
Because of this round-the-clock care, families and friends of people with AD are greatly affected. The disease is irreversible and there is currently no cure.
Sight, Taste, Touch, Hearing, Smell
Web Sources and Resources: Usborne Science Encyclopedia pgs. 370-375 and Quicklink Images
How well do you know your own nervous system? Fill in the blanks on the slides that follow. Then go back and check your work if needed.
Your respiratory system moves oxygen from the outside environment into your body. It also removes carbon dioxide and water from your body (this image shows all the tiny bronchioles that carry air into your alveoli for gas exchange).
Please label the parts of your respiratory system on your handout. Can you describe the path that air takes as it enters and leaves your body?
Working together the respiratory and circulatory systems form the cario-pulmonary system, which is an integral connection between the heart and lungs.
Pneumonia is an inflammation or infection of the lungs most commonly caused by a bacteria or virus. Pneumonia can also be caused by inhaling vomit or other foreign substances.
Web Sources and Resources
The cancerous lung (right) shows how much damage smoking can do over time to your respiratory system.
Web Sources and Resources
Web Sources and Resources:
Usborne Science Encyclopedia pgs. and Quicklink Images
Web Sources and Resources Usborne Human Body: Quicklinks
Blood is the fluid of life, transporting oxygen from the lungs to body tissue and carbon dioxide from body tissue to the lungs.
Because it contains living cells, blood is alive. Red blood cells and white blood cells are responsible for nourishing, cleansing, and protecting the body. Since the cells are alive, they too need nourishment. Vitamins and Minerals keep the blood healthy. The blood cells have a definite life cycle, just as all living organisms do.
Approximately 55 percent of blood is plasma, a straw-colored clear liquid. The liquid plasma carries the solid cells and the platelets which help blood clot. Without blood platelets, you would bleed to death.
When the human body loses a little bit of blood through a minor wound, the platelets cause the blood to clot so that the bleeding stops. Because new blood is always being made inside of your bones, the body can replace the lost blood. When the human body loses a lot of blood through a major wound, that blood has to be replaced through a blood transfusion from other people.
Your Heart is a Very Muscular Organ!
The action of the artificial heart is entirely similar to the action of the natural heart. There is, however, one huge difference: the natural heart is living muscle, while the artificial heart is plastic, aluminum, and Dacron polyester. As a result, the artificial heart needs some external source of "life." An external power system energizes and regulates the pump through a system of compressed air hoses that enter the heart through the chest. Since the system is cumbersome and open to infection, the use of an artificial heart is meant to be temporary.
…breaks down food into molecules the body can absorb.
…passes these molecules into the blood to be carried throughout the body.
…works to eliminate solid wastes from the body.
How well do you know them?
Digestion begins in your mouth with action of your teeth and tongue (mechanical digestion) and your salivary glands (chemical digestion).
The salivaryglands produce enzymes that are mixed with the food, breaking down the starches. Peristalsis is the muscular action that moves the food through the esophagus and into your stomach after you swallow.
The food moves into your stomach, which contains chemicals such as hydrochloric acid and pepsin. Pepsin breaks proteins, and other enzymes break down fat. Your stomach gradually releases these materials into the upper small intestine (duodenum), where digestion is completed. Your stomach also has a thick coating of mucus to protect it form the acids and to keep it from digesting itself!
Located in the upper portion of your abdomen, your liver is the largest and heaviest organ of your body. It is like a busy chemical factory that plays many roles. For example, your liver breaks down many substances and toxins, and produces bile- a substance that helps break down fat. The bile flows from the liver into the gall bladder, where it is stored until needed. The pancreas lies between the stomach and the duodenum and produces enzymes that flow into the small intestines, helping to break up complex starches, proteins, and fats.
After the solid food has been digested the fluid remaining is called chyme When it is thoroughly digested it passes through an opening (called the pylorus sphincter) into the small intestines. In the small intestines all the nutrients are absorbed leaving undigestible wastes. These wastes pass into the large intestines, where water is removed. Then the wastes are stored in the rectum until they are released by the anus.
The Villi add surface area to increase absorption of food and nutrients. On the left you see how the villi line your small intestines, and on the left you see 1 villi with its capillaries.
The human large intestine, or colon, is home to many microorganisms, such as the bacterium Escherischia coli (E. coli). Certain foods contain large amounts of carbohydrates that our digestive enzymes cannot break down.
When these carbohydrates reach the large intestine, our gut microbes respond by "having a party“ (reproducing rapidly, giving off gases such as methane and hydrogen sulfide as natural by-products of their activities). This is the cause of the discomfort and flatulence associated with eating beans, cabbage, and other gas-promoting foods.
Fortunately for gas sufferers, the enzymes that enable our microbes to break down complex carbohydrates are now available in pill form. If these are taken before a meal, the enzymes break down the carbohydrates in the small intestine so that they can be absorbed by the body before they reach the hungry throngs of bacteria living in the colon.
Web Sources and Resources: http://www.colorado.edu/epob/academics/web_resources/cartoons/gas.html
Your excretory system collects wastes produced by cells and removes these wastes from your body. The removal process is known as excretion. The two kidneys are the major organs of the excretory system. The kidneys filter your blood and remove urea, excess water, and some other waste materials from your blood. Urea is a chemical that comes from the breakdown of proteins. The filtering process produces a watery fluid called urine. Each kidney contains about a million nephrons.
The kidneys regulate the body fluids, maintaining desirable levels of acids and bases, salts, nutrients and wastes. Each kidney is made up of over a million tiny tubes known as nephrons, or kidney tubules. The tubules act in parallel to filter the blood and produce the urine. As the blood filtrate passes along the tubule, the composition of the fluid is changed in complex ways. In some ways the tubule resembles an industrial processing plant, and the cells lining the walls of the tubule can be thought of as technicians who modify the filtrate as it passes by. The first step in urine production is called filtration. This occurs at the glomerulus, which is really a ball of capillaries that makes close contact with the end of the nephron. Driven by the beating of the heart, blood plasma (the fluid component of blood) is forced out of the capillaries and into the nephron. Because this transfer occurs through narrow spaces (represented by a sieve in the cartoon), the larger molecules (mainly proteins) are left behind in the blood. Blood cells (not shown in the cartoon) are many times larger still, and are also left behind.
Finally, the tubule empties its contents into one of the many collecting ducts. The urine now contains a concentrated solution of whatever the body currently considers to be "wastes." Water continues to be reabsorbed in the collecting duct, so that little water is wasted in the process of excretion (elimination of wastes). Finally, all the urine collects together in the kidney and is passed out through the ureter, and from there to the bladder.
Web Sources and Resources:http://www.colorado.edu/epob/academics/web_resources/cartoons/gas.html
Kidney stones are created when certain substances in urine -- including calcium and uric acid -- crystallize and the crystals clump together. Usually, they form in the center of the kidney, where urine collects before flowing into the ureter, the tube that leads to the bladder. Small stones are able to pass out of the body in the urine and often go completely unnoticed. But larger stones irritate and stretch the ureter as they move toward the bladder, causing excruciating pain and blocking the flow of urine. Rarely, a stone can be as large as a golf ball, in which case it remains lodged in the kidney, creating a more serious condition
Your Immune system protects you from foreign invaders. Special cells react to each kind of pathogen with a defense targeted specifically at that pathogen.
White blood cells that target specific pathogens are called lymphocytes. There are two major kinds of lymphocytes—T cells and B cells.
A major function of T cells is to identify pathogens by recognizing their antigens. Antigens are molecules that the immune system recognizes as either part of your body, or as coming from outside your body. B cells produce chemicals called antibodies.
Our immune system protects us against threats. These include viruses, bacteria and parasites causing infectious diseases, from ordinary flu to full-blown malaria. The white blood cells of the defense system are produced in the marrow of our bones. The cells are carried in the blood to specialized organs, where they develop and communicate to launch immune responses against infections.
Your lymphatic system and the cardiovascular system are closely related structures that are joined by a capillary system. The lymphatic system is important to the body's defense mechanisms. It filters out organisms that cause disease, produces certain white blood cells and generates antibodies. It is also important for the distribution of fluids and nutrients in the body, because it drains excess fluids and protein so that tissues do not swell up.
The endocrine system is a collection of special organs in the body that produce hormones. These organs are usually called the "glands." They are located in different parts of the body. For example, the pituitary is in the brain, the thyroid is in the neck, the adrenal glands are just alone the kidneys and the sexual glands (ovaries and testes) are located in the sexual organs. Each gland produces a hormone into the blood, which travels all through the body. Hormones regulate our body activities, for example growth, sleep, sudden actions, feelings and blood sugar for energy.