Human Physiology

The Human Physiology curriculum offers rigorous study of human physiology across the molecular/cellular, systems, organism, and behavioral levels. At the undergraduate level this study begins with foundation courses in mathematics, statistics, biology, chemistry, and physics, continues with core courses in anatomy and physiology, and is capped by elective courses that provide for in-depth study across a broad range of topics in human physiology, including those related to health and disease. Undergraduates can also pursue laboratory-based original research under the mentorship of faculty. The undergraduate curriculum provides an excellent preparation for students with career interests in the health professions and/or biomedical research. The graduate curriculum is designed to provide more focused study of human physiology to prepare students for research as independent investigators, and for college teaching careers.

Degree

• Bachelor of Science (BS) in Human Physiology

Career Options

Students in the area of Human Physiology often continue their studies in health professional programs to become physicians/surgeons, physical therapists, physician assistants, dentists, optometrists, podiatrists, or similar professionals. Others pursue graduate degrees (MS and/or PhD) in the biomedical or physiological sciences to prepare for careers in research and/or college teaching. Students who choose not to pursue advanced degrees are well qualified for employment in research or clinical laboratories.

Systems of the Human Body

Systems of the Human Body

CONTEXT

At this level, children can begin to view the body as a system, in which parts do things for other parts and for the organism as a whole. Through the use of an online interactive activity, children learn about the concept of separate components working together to build a body system. In addition, this lesson focuses on activities to help students learn that body systems work together to build the functioning human body. This lesson could be used in conjunction with instruction on the human body and/or systems.

In order to be able to do this lesson, students should understand that most items are composed of different parts and that an item may not work if its parts are missing. Also, they should know that an assembly of parts can perform functions that the single parts cannot perform alone. More specific to the human body, students at this level should realize that the human body has parts that help it seek and take in food when it feels hunger. They should understand that the brain is the part of the body that enables humans to think and it communicates with the other parts of the body.

This prerequisite knowledge should help elementary-school students understand that parts within a system usually influence one another and that a system may not work as well, or at all, if a part is missing, broken or worn out, or misconnected. In addition, they should be able to make correlations about systems in general to systems of the human body. Specific to the human body, students should understand the following: by eating food, humans obtain energy and materials for body repair and growth; by breathing, humans take in the oxygen they need to live; by communicating with all parts of the body, the brain understands what is going on at different parts throughout the body; and the skeleton provides the body with structure and protection.

Research indicates that elementary students may believe that a system of objects must be doing something (interacting) in order to be a system and/or that a system that loses a part of itself is still the same system. (Benchmarks for Science Literacy, p. 355.) Research shows that student misconceptions about systems arise from their difficulty in recognizing that a natural phenomenon (e.g., the human body) occurs by systems working independently and together (e.g., circulatory, respiratory, nervous, digestive). Studies of student thinking show that, at all ages, they tend to interpret phenomena by noting the qualities of separate objects rather than by seeing the interactions between the parts of a system.

For upper elementary-school students, research specific to the human body indicates that, in terms of internal bodily organs, upper elementary students are able to list a large number of organs. In terms of the nervous system, they know the brain helps the body parts but do not always realize the converse (that the body helps the brain). They do know, however, that nerves conduct messages, control activity, and stabilize the body. Upper elementary students do not understand the brain's role in controlling involuntary behavior. In terms of the digestive system, once students reach the fifth grade, they know that food undergoes a transformation process in the body. In terms of therespiratory system, they associate the lungs' activities with breathing. Further, they may have some knowledge about the exchange of gases in the lungs and understand that air goes to all parts of the body. In terms of the circulatory system, upper elementary-school students realize that the heart is a pump, but they do not realize that the blood returns to the heart. (Benchmarks for Science Literacy, pp. 344-345.)

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MOTIVATION

Questions about familiar body systems can be useful in getting students to start thinking about systems in general. This process can initiate the understanding that each organ affects and is affected by others.

Hold up an apple (or some other healthy snack). Ask students:

• What am I holding in my hand?
• If I were going to eat this apple, what parts of my body would I use?

Have students discuss the body parts we use when biting, chewing, swallowing, and digesting an apple. You may want to create a chart on the blackboard or a large sheet of paper to record students' ideas. If so, you can use these categories to help you organize the information:

• Body Parts for Biting
• Body Parts for Chewing
• Body Parts for Swallowing
• Body Parts for Digesting

Now ask students:

• How do the different parts work together? (Each part plays a special role, so once one task is accomplished, then the next part can perform it's role.)
• What happens if one of the parts is missing? (For example, if the teeth were missing, then it would be difficult if not impossible to chew some foods, and if one couldn't chew something large to get it small enough to pass through the esophagus, then they could choke.)

Continue to guide student understanding of systems by asking:

• Who remembers what it's called when a number of different parts work together to make something happen or function? (Guide students so that they come up with system as an answer.)
• Can you think of an example of a system? (Some possible examples are a bicycle, a computer, a school, or a bus.)
• For the system you picked, write down any parts that belong to that system. (For example, some parts that are necessary for a bicycle are two wheels, gears, brakes, foot pedals, and handles.)

Anatomy of the human body internal organs.

Digestive Disorders Health Center

The abdomen (commonly called the belly) is the body space between the thorax (chest) and pelvis. The diaphragm forms the upper surface of the abdomen. At the level of the pelvic bones, the abdomen ends and the pelvis begins.

The abdomen contains all the digestive organs, including the stomach, small and large intestines, pancreas, liver, and gallbladder. These organs are held together loosely by connecting tissues (mesentery) that allow them to expand and to slide against each other. The abdomen also contains the kidneys and spleen.

Many important blood vessels travel through the abdomen, including the aorta, inferior vena cava, and dozens of their smaller branches. In the front, the abdomen is protected by a thin, tough layer of tissue called fascia. In front of the fascia are the abdominal muscles and skin. In the rear of the abdomen are the back muscles and spine.

Abdomen Conditions

• Peritonitis: Inflammation of the covering of the abdominal structures, causing rigidity and severe pain. Usually, this is due to a ruptured or infected abdominal organ.
• Acute abdomen: A medical phrase doctors use to suggest that peritonitis or some other emergency is present and surgery is likely needed.
• Appendicitis: Inflammation of the appendix, in the lower right colon. Usually, an inflamed appendix must be removed by surgery.
• Cholecystitis: Inflammation of the gallbladder, causing severe right-sided abdominal pain. A gallstone blocking the duct exiting the gallbladder is usually responsible.
• Dyspepsia: The feeling of an upset stomach or indigestion. Dyspepsia can result from benign or more serious conditions.
• Constipation: Having fewer than three bowel movements per week. Diet and exercise may help but many people will need to see their health care providers.
• Gastritis: Inflammation of the stomach, often causing nausea and/or pain. Gastritis can be caused by alcohol, NSAIDs, H. pylori infection, or other factors.
• Peptic ulcer disease: Ulcers are erosions and peptic refers to acid. Peptic ulcers are ulcers in the stomach and duodenum (the first part of the small intestine). The usual cause is either an infection with H. pylori or taking anti-inflammatory medications like ibuprofen.
• Intestinal obstruction: A single area of the small or large intestine can become blocked or the entire intestine may stop working. Vomiting and abdominal distension are symptoms.
• Gastroparesis: The stomach empties slowly due to nerve damage from diabetes or other conditions. Nausea and vomiting are symptoms.
• Pancreatitis: Inflammation of the pancreas. Alcohol and gallstones are the most common causes of pancreatitis. Other causes include drugs and trauma; about 10% to 15% of cases are from unknown causes.
• Hepatitis: Inflammation of the liver, usually due to viral infection. Drugs or immune system problems can also cause hepatitis.
• Cirrhosis: Scarring of the liver caused by chronic inflammation. Heavy drinking or chronic hepatitis are the most common causes.
• Ascites: Abdominal fluid buildup often caused by cirrhosis. Ascites may cause the abdomen to protrude impressively.
• Abdominal hernia: A weakening or gap in the abdominal fascia allows a section of the intestine to protrude.
• Abdominal distension: Swelling of the abdomen, usually due to an increased amount of intestinal gas.
• Abdominal aortic aneurysm: A weakening of the aorta's wall creates a balloon-like expansion of the vessel that grows over years. If abdominal aortic aneurysms grow large enough, they may burst.

The Spermatozoön

http://www.bartleby.com/ The Spermatozoön

The spermatozoa or male germ cells are developed in the testes and are present in enormous numbers in the seminal fluid. Each consists of a small but greatly modified cell. The human spermatozoön possesses a head, a neck, a connecting piece or body, and atail	1
FIG. 6– Human spermatozoön. Diagrammatic. A. Surface view. B. Profile view. In C the head, neck, and connecting piece are more highly magnified. (See enlarged image)
The head is oval or elliptical, but flattened, so that when viewed in profile it is pear-shaped. Its anterior two-thirds are covered by a layer of modified protoplasm, which is named the head-cap. This, in some animals, e. g., the salamander, is prolonged into a barbed spear-like process or perforator, which probably facilitates the entrance of the spermatozoön into the ovum. The posterior part of the head exhibits an affinity for certain reagents, and presents a transversely striated appearance, being crossed by three or four dark bands. In some animals a central rodlike filament extends forward for about two-thirds of the length of the head, while in others a rounded body is seen near its center. The head contains a mass of chromatin, and is generally regarded as the nucleus of the cell surrounded by a thin envelope.	2
The neck is less constricted in the human spermatozoön than in those of some of the lower animals. The anterior centriole, represented by two or three rounded particles, is situated at the junction of the head and neck, and behind it is a band of homogeneous substance.	3
The connecting piece or body is rod-like, and is limited behind by a terminal disk. Theposterior centriole is placed at the junction of the body and neck and, like the anterior, consists of two or three rounded particles. From this centriole an axial filament,surrounded by a sheath, runs backward through the body and tail. In the body the sheath of the axial filament is encircled by a spiral thread, around which is an envelope containing mitochondria granules, and termed the mitochondria sheath.	4
The tail is of great length, and consists of the axial thread or filament, surrounded by its sheath, which may contain a spiral thread or may present a striated appearance. The terminal portion or end-piece of the tail consists of the axial filament only.	5
FIG. 7– Scheme showing analogies in the process of maturation of the ovum and the development of the spermatids (young spermatozoa). (See enlarged image)
Krause gives the length of the human spermatozoön as between 52μ and 62μ, the head measuring 4 to 5μ, the connecting piece 6μ, and the tail from 41μ to 52μ.	6
By virtue of their tails, which act as propellers, the spermatozoa are capable of free movement, and if placed in favorable surroundings, e. g., in the female passages, will retain their vitality and power of fertilizing for several days. In certain animals, e. g., bats, it has been proved that spermatozoa retained in the female passages for several months are capable of fertilizing.	7

Your Body's Systems

www.factmonster.com

Circulatory System

The circulatory system is the body's transport system. It is made up of a group of organs that transport blood throughout the body. The heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta. The aorta branches into smaller arteries, which then branch into even smaller vessels that travel all over the body. When blood enters the smallest blood vessels, which are called capillaries, and are found in body tissue, it gives nutrients and oxygen to the cells and takes in carbon dioxide, water, and waste. The blood, which no longer contains oxygen and nutrients, then goes back to the heart through veins. Veins carry waste products away from cells and bring blood back to the heart , which pumps it to the lungs to pick up oxygen and eliminate waste carbon dioxide.

Digestive System

The digestive system is made up of organs that break down food into protein, vitamins, minerals, carbohydrates, and fats, which the body needs for energy, growth, and repair. After food is chewed and swallowed, it goes down the esophagus and enters the stomach, where it is further broken down by powerful stomach acids. From the stomach the food travels into the small intestine. This is where your food is broken down into nutrients that can enter the bloodstream through tiny hair-like projections. The excess food that the body doesn't need or can't digest is turned into waste and is eliminated from the body.

Endocrine System

The endocrine system is made up of a group of glands that produce the body's long-distance messengers, or hormones.Hormones are chemicals that control body functions, such as metabolism, growth, and sexual development. The glands, which include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, thymus gland, pineal body, pancreas, ovaries, and testes, release hormones directly into the bloodstream, which transports the hormones to organs and tissues throughout the body.

Immune System

The immune system is our body's defense system against infections and diseases. Organs, tissues, cells, and cell products work together to respond to dangerous organisms (like viruses or bacteria) and substances that may enter the body from the environment. There are three types of response systems in the immune system: the anatomic response, the inflammatory response, and the immune response.

• The anatomic response physically prevents threatening substances from entering your body. Examples of the anatomic system include the mucous membranes and the skin. If substances do get by, the inflammatory response goes on attack.
• The inflammatory system works by excreting the invaders from your body. Sneezing, runny noses, and fever are examples of the inflammatory system at work. Sometimes, even though you don't feel well while it's happening, your body is fighting illness.
• When the inflammatory response fails, the immune response goes to work. This is the central part of the immune system and is made up of white blood cells, which fight infection by gobbling up antigens. About a quarter of white blood cells, called the lymphocytes, migrate to the lymph nodes and produce antibodies, which fight disease.
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Lymphatic System

The lymphatic system is also a defense system for the body. It filters out organisms that cause disease, produces white blood cells, and generates disease-fighting antibodies. It also distributes fluids and nutrients in the body and drains excess fluids and protein so that tissues do not swell. The lymphatic system is made up of a network of vessels that help circulate body fluids. These vessels carry excess fluid away from the spaces between tissues and organs and return it to the bloodstream.

Muscular System

The muscular system is made up of tissues that work with the skeletal system to control movement of the body. Some muscles—like the ones in your arms and legs—are voluntary, meaning that you decide when to move them. Other muscles, like the ones in your stomach, heart, intestines and other organs, are involuntary. This means that they are controlled automatically by the nervous system and hormones—you often don't even realize they're at work.

The body is made up of three types of muscle tissue: skeletal, smooth and cardiac. Each of these has the ability to contract and expand, which allows the body to move and function. .

• Skeletal muscles help the body move.
• Smooth muscles, which are involuntary, are located inside organs, such as the stomach and intestines.
• Cardiac muscle is found only in the heart. Its motion is involuntary

Nervous System

The nervous system is made up of the brain, the spinal cord, and nerves. One of the most important systems in your body, the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body. These nerve impulses tell your muscles and organs what to do and how to respond to the environment. There are three parts of your nervous system that work together: the central nervous system, the peripheral nervous system, and the autonomic nervous system.

• The central nervous system consists of the brain and spinal cord. It sends out nerve impulses and analyzes information from the sense organs, which tell your brain about things you see, hear, smell, taste and feel.
• The peripheral nervous system includes the craniospinal nerves that branch off from the brain and the spinal cord. It carries the nerve impulses from the central nervous system to the muscles and glands.
• The autonomic nervous system regulates involuntary action, such as heart beat and digestion.

Reproductive System

The reproductive system allows humans to produce children. Sperm from the male fertilizes the female's egg, or ovum, in the fallopian tube. The fertilized egg travels from the fallopian tube to the uterus, where the fetus develops over a period of nine months.

Respiratory System

The respiratory system brings air into the body and removes carbon dioxide. It includes the nose, trachea, and lungs. When you breathe in, air enters your nose or mouth and goes down a long tube called the trachea. The trachea branches into two bronchial tubes, or primary bronchi, which go to the lungs. The primary bronchi branch off into even smaller bronchial tubes, or bronchioles. The bronchioles end in the alveoli, or air sacs. Oxygen follows this path and passes through the walls of the air sacs and blood vessels and enters the blood stream. At the same time, carbon dioxide passes into the lungs and is exhaled.

Skeletal System

The skeletal system is made up of bones, ligaments and tendons. It shapes the body and protects organs. The skeletal system works with the muscular system to help the body move. Marrow, which is soft, fatty tissue that produces red blood cells, many white blood cells, and other immune system cells, is found inside bones.

Urinary System

The urinary system eliminates waste from the body, in the form of urine. The kidneys remove waste from the blood. The waste combines with water to form urine. From the kidneys, urine travels down two thin tubes called ureters to the bladder. When the bladder is full, urine is discharged through the urethra.

The heart and circulation.

The heart and circulation.

The heart is the body's engine room, responsible for pumping life-sustaining blood via a 60,000-mile-long (97,000-kilometer-long) network of vessels. The organ works ceaselessly, beating 100,000 times a day, 40 million times a year—in total clocking up three billion heartbeats over an average lifetime. It keeps the body freshly supplied with oxygen and nutrients, while clearing away harmful waste matter.

The fetal heart evolves through several different stages inside the womb, first resembling a fish's heart, then a frog's, which has two chambers, then a snake's, with three, before finally adopting the four-chambered structure of the human heart.

About the size of its owner's clenched fist, the organ sits in the middle of the chest, behind the breastbone and between the lungs, in a moistened chamber that is protected all round by the rib cage. It's made up of a special kind of muscle (cardiac muscle) that works involuntarily, so we don't have to think about it. The heart speeds up or slow downs automatically in response to nerve signals from the brain that tell it how much the body is being exerted. Normally the heart contracts and relaxes between 70 and 80 times per minute, each heartbeat filling the four chambers inside with a fresh round of blood.

These cavities form two separate pumps on each side of the heart, which are divided by a wall of muscle called the septum. The upper chamber on each side is called the atrium. This is connected via a sealing valve to the larger, more powerful lower chamber, or ventricle. The left ventricle pumps most forcefully, which is why a person's heartbeat is felt more on the left side of the chest.

When the heart contracts, the chambers become smaller, forcing blood first out of the atria into the ventricles, then from each ventricle into a large blood vessel connected to the top of the heart. These vessels are the two main arteries. One of them, the pulmonary artery, takes blood to the lungs to receive oxygen. The other, the aorta, transports freshly oxygenated blood to the rest of the body. The vessels that bring blood to the heart are the veins. The two main veins that connect to the heart are called the vena cava.

Blood Delivery

Since the heart lies at the center of the blood delivery system, it is also central to life. Blood both supplies oxygen from the lungs to the other organs and tissues and removes carbon dioxide to the lungs, where the gas is breathed out. Blood also distributes nourishment from the digestive system and hormones from glands. Likewise our immune system cells travel in the bloodstream, seeking out infection, and blood takes the body's waste products to the kidneys and liver to be sorted out and trashed.

Given the heart's many essential functions, it seems wise to take care of it. Yetheart disease has risen steadily over the last century, especially in industrialized countries, due largely to changes in diet and lifestyle. It has become the leading cause of death for both men and women in the United States, claiming almost 700,000 lives a year, or 29 percent of the annual total. Worldwide, 7.2 million people die from heart disease every year.