Human Anatomy And Physiology Essential Concepts

Human Anatomy and Physiology Essential Concepts Obj 1 Define the terms anatomy and physiology

An organism's anatomy is its structure -- a description of its parts. Physiology refers to the functions and activities of an organism or any of its parts. In this unit you will study eleven major systems that make up a human and how these systems work.

1. Skeletal system 5. Circulatory system 9. Endocrine system 2. Muscular system 6. Respiratory system 10.Reproductive system 3. Integumentary system 7. Excretory system 11.Immune system 4. Digestive system 8. Nervous system

------SKELETAL SYSTEM ------

Obj 2 Describe the components of the skeletal system and their functions.

The skeletal system is made up of bones, cartilage, joints, and connective tissue. The system provides the framework for the attachment of muscles and other body parts, stores minerals, makes blood cells, and protects internal organs.

Obj 3 Compare and contrast ligaments and tendons.

Ligaments and tendons are connective tissues and are thus part of the skeletal system. Ligaments connect bones to other bones. Tendons attach muscles to bones.

------MUSCULAR SYSTEM ------

Obj 4 Describe the functions of the muscle system.

The muscular system enables the movement of internal body parts as well as the movement of the whole body, and produces body heat.

Obj 5 Contrast the three types of muscle.

1. Skeletal muscles enable the body to move and are under conscious control and are thus considered voluntary. 2. Smooth muscles regulate the width of blood vessels, the contractions of the digestive system, and cause pupils to contract in bright light. They are involuntary (that is, their movement is not under conscious control). 3. Cardiac muscle makes up the heart. This muscle contracts and relaxes throughout life to move blood through the body. It is under involuntary control. ------INTEGUMENTARY SYSTEM ------

Obj 6 Describe the components of the integumentary (in TEG-yoo-MEN-tuh-ree) system and its functions.

The integumentary system is made up of skin, hair, nails, and glands in the skin. It functions to forms a waterproof barrier between the body and the environment. It protects the body from infection, secretes certain wastes, and helps regulate temperature.

Obj 7 Describe the structure and function of skin

The skin is the largest organ of the body and has three main functions:  to protect the body,  to regulate its internal temperature, and  to serve as a sense organ.

Skin is composed of two main layers:  the epidermis (the thin outer layer of skin), and  the dermis (the thick inner layer of skin), which contains nerve endings, blood vessels, hair follicles, and sweat glands.

------DIGESTIVE SYSTEM ------

Obj 8 List the components of the digestive system and describe its function.

The digestive system is made up of the mouth, pharynx (also called the throat, which connects the nose and mouth to the digestive and respiratory tracts), esophagus (leads from the pharynx to the stomach), the stomach, the small intestine, and the large intestine. These are part of the digestive tract (the organs through which food moves). The digestive system also includes the liver, gallbladder and pancreas (food does not pass through these organs but they are important for digestion). The function of the digestive system is to break down food and absorb nutrients.

Obj 9 Contrast the functions of the small and large intestines.

The small intestine is connected to the stomach. It digests carbohydrates and fats, completes the digestion of proteins, and absorbs digested nutrients. An adult's small intestine is about 7 m (22 feet) long. The large intestine (also called the colon) is about 1.5 m (5 feet) long, but is wider than the small intestine. Undigested material is passed from the small intestine to the large intestine, where water and water-soluble vitamins are absorbed before the material (feces) leaves the body through the rectum (the last few inches of the large intestine) and out the anus. Obj 10 Identify the functions of the liver, the gallbladder, and the pancreas in digestion and other processes.

Food does not pass through these organs, but they produce digestive fluids that are delivered to the digestive tract. These organs also perform many other vital body functions.

 The liver is the largest organ inside the human body and serves as the body's primary storage place, as well as its main chemical factory and detoxification site. It actually carries out more than 500 functions.  The gallbladder stores bile made by the liver. Bile is released into the small intestine to dissolve cholesterol.  The pancreas is a gland that secretes enzymes and sodium bicarbonate into the intestine, and secretes hormones into the blood.

------CIRCULATORY SYSTEM ------

Obj 11 List the function of the circulatory system.

The circulatory system delivers oxygen, nutrients, and other needed substances to the cells of the body and picks up carbon dioxide and other wastes for removal. The main organ of the circulatory system is the heart.

Obj 12 Identify the components of blood and the role of each.

 Plasma: the yellowish liquid in which blood cells are suspended  Red blood cells (erythrocytes): contains the protein hemoglobin which can carry oxygen to all cells of the body and pick up carbon dioxide waste.  White blood cells (leukocytes): help the body fight diseases  Platelets: cell fragments that form blood clots to prevent excess loss of blood

Obj 13 Contrast arteries, capillaries, and veins

 Arteries: carry blood away from the heart  Capillaries: very thin vessels where gas exchange takes place (oxygen is traded for carbon dioxide by cells throughout the body).  Veins: return blood to the heart.

Obj 14 Explain the functions of the lymphatic system

A network of vessels, nodes, and organs collect intercellular fluid (the fluid between cells), cleans it, and returns it to the circulatory system. This fluid is called lymph. ------RESPIRATORY SYSTEM ------

Obj 15 Describe the functions and parts of the respiratory system

The respiratory system brings oxygen into the body and gets rid of carbon dioxide.

 Nose: filters air taken in  Pharynx (throat)  Larynx (voicebox): contains a flap to control the passage into either the esophagus (which leads to the stomach) or the trachea (which leads to the lungs).  Trachea (windpipe): tube that leads from the larynx to the lungs  Lungs: sites where oxygen from air is absorbed and dissolved carbon dioxide from blood is released.

------EXCRETORY SYSTEM ------

Obj 16 Explain the function of the excretory system.

The function of the excretory system is to rid the body of waste.

Obj 17 Describe the function of the kidneys

The kidneys remove wastes from the blood. They process wastes, medications, and toxins into the urine.

------NERVOUS SYSTEM ------

Obj 18 Identify and compare the roles of the two main parts of the nervous system.

The nervous system enables the body to gather information and respond quickly. The two main parts are:  Central nervous system (brain and spinal cord)  Peripheral nervous system (nerves throughout the body)

______ENDOCRINE SYSTEM ------

Obj 19 Explain what an endocrine gland is and the function of hormones

Endocrine glands are ductless hormone glands (they don't release hormones directly to their targets, but instead release them into the blood). Hormones are chemicals made in one part of the body that affect cells in another part of the body. Example: insulin is a hormone that stimulates cells to take up sugar from the blood. Other hormones affect most aspects of sexual development and reproduction.

------REPRODUCTIVE SYSTEM ------

Obj 20 Identify the structures of the male reproductive system and describe their functions.

The function of the male reproductive system is to produce sperm cells and deliver them to the female reproductive system.

 Testes (singular, testis): the male organs, located in the scrotum, that produce sperm and the hormone testosterone.  Testosterone: a hormone whose production increases at puberty and starts sperm production and the development of secondary sex characteristics (body hair, defined muscles, etc.)  Penis: the male organ that delivers sperm during sexual intercourse. Prior to intercourse, the tissues in the penis fill with blood, causing the penis to become erect. Sperm are released from the body in a fluid called semen during a process called ejaculation. A single drop of semen may contain as many as 5 million sperm.

Obj 21 Identify the structures of the female reproductive system and describe their functions.

 Ovaries: the female organs that produce eggs and the hormones estrogen and progesterone.  Fallopian tube: provides a pathway through which eggs from the ovary can travel to the uterus.  Uterus: an organ with muscular walls in which a fetus develops.  Cervix: at the base of the uterus, connects the uterus with the vagina.  Vagina (also called the birth canal): a muscular, tube-shaped organ into which sperm are deposited during sexual intercourse.

------IMMUNE SYSTEM ------

Obj 22 State the function of the immune system

The immune system protects the body from invasion by other organisms. Obj 23 Describe the body's defenses against pathogens (bacteria and virus that cause disease).

Nonspecific defenses (protection against many different disease-causing agents)

 Skin and mucus. The skin provides a barrier against most pathogens and the mucus of the nose and respiratory organs serves to trap pathogens.  Inflammatory response. When tissue is damaged, more blood flows to the site of injury and more plasma leaks into the intercellular fluid, causing the area to swell. The plasma contains white blood cells that engulf and destroy pathogens.  Interferon, a protein that interferes with the replication of viruses, is released by cells that have been invaded by viruses.  Natural killer cells, which also defend the body against viruses, are contained in blood and lymph. Natural killer cells attack our own body cells that have been infected by viruses.  (Interferon and natural killer cells also fight against cancer cells.)

Specific defenses (responses to specific pathogens), also known as immune response.

 Lymphocytes: white blood cells that activate the immune response recognize invaders that do not belong in the body (called antigens).  Antibodies: a disease-fighting protein produced in response to a specific pathogen.  B lymphocytes, or B cells: white blood cells that produce antibodies  T lymphocytes, or T cells: white blood cells that attack and destroy foreign or dangerous cells.