Human Biology Chapter 4 Vocabulary

which includes areolar and reticular connective tissue, supports epithelium and many internal organs. Its presence in lungs, arteries, and the urinary bladder allows these organs to expand. It forms a protective covering enclosing many internal organs, such as muscles, blood vessels, and nerves.

is a special type of loose connective tissue in which the cells enlarge and store fat

are crowded, and each is filled with liquid fat.  The body uses this stored fat for energy, insulation, and organ protection. Adipose tissue also releases a hormone called leptin, which regulates appetite-control centers in the brain. Adipose tissue is primarily found beneath the skin, around the kidneys, and on the surface of the heart.

contains many collagen fibers packed together. This type of tissue has more specific functions than does loose connective tissue. For example, dense fibrous connective tissue is found in tendons, which connect muscles to bones, and in ligaments, which connect bones to other bones at joints.

Includes ground substance and fibers

the most common type of cartilage, contains only fine collagen fibers. The matrix has a glassy, translucent appearance. Hyaline cartilage is found in the nose and at the ends of the long bones and the ribs, and it forms rings in the walls of respiratory passages. The fetal skeleton also is made of this type of cartilage. Later, the cartilaginous fetal skeleton is replaced by bone.

has more elastic fibers than hyaline cartilage does. For this reason, it is more flexible and is found, for example, in the framework of the outer ear.

has a matrix containing strong collagen fibers. Fibrocartilage is found in structures that withstand tension and pressure, such as the disks between the vertebrae in the backbone and the cushions in the knee joint.

are responsible for forming the matrix in bone tissue.

Osteons, roughly cylindrical structures that are typically several millimeters long and around 0.2 mm in diameter. Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surrounds a central canal, the Haversian canal. The Haversian canal contains the bone's nerve and blood supplies.

a cavity or depression, especially in bone.

Consists of formed elements and plasma

Fluid that surrounds the body's cells; consists of dissolved substances that leave the capillaries of the circulatory system by diffusion and filtration.  Bathes the body's cells and removes carbon dioxide and other wastes.

are small, biconcave, disk-shaped cells without nuclei.  Red Blood cells transport oxygen.

Phagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel".

Have a nucleus.  These are phagocyticcells, because they engulf infectious agents, such as bacteria

they are fragments of giant cells present only in bone marrow. When a blood vessel is damaged, platelets form a plug that seals the vessel, and injured tissues release molecules that help the clotting process.

Voluntary Muscle.  It is composed of cells called muscle fibers, which contain actin and myosin filaments

Having bands; in cardiac and skeletal muscle, alternating light and dark crossbands produced by the distribution of contractile proteins.

Smooth muscle is found in the walls of viscera (intestine, bladder, and other internal organs) and blood vessels

is found only in the walls of the heart.  Cardiac muscle cells also differ from skeletal muscle cells in that they usually have a single, centrally placed nucleus.

consists of nerve cells, called neurons, and neuroglia, the cells that support and nourish the neurons

is a specialized cell that has three parts: dendrites, a cell body, and an axon

A dendrite is an extension that receives signals from sensory receptors or other neurons.

An axon is an extension that conducts nerve impulses. Long axons are covered by myelin, a white, fatty substance.

conduct signals from sensory receptors to the spinal cord and the brain, where integration, or processing, occurs.  Nerves also conduct signals from the spinal cord and brain to muscles, glands, and other organs.

are cells that outnumber neurons nine to one and take up more than half the volume of the brain.  Although the primary function of neuroglia is to support and nourish neurons, research is being conducted to determine how much they directly contribute to brain function

Microglia, in addition to supporting neurons, engulf bacterial and cellular debris

Astrocytes provide nutrients to neurons and produce a hormone known as glial-derived neurotrophic factor (GDNF)

form the myelin sheaths around fibers in the brain and spinal cord.

consists of tightly packed cells that form a continuous layer.  Epithelial tissue covers surfaces and lines body cavities

the basement membrane is a thin layer of various types of carbohydrates and proteins that anchors the epithelium to underlying connective tissue.

composed of flattened cells, is found lining the air sacs of lungs and walls of blood vessels.  Oxygen–carbon-dioxide exchange occurs in the lungs, and nutrient-waste exchange occurs across blood vessels in the tissues.

Lining of kidney tubules, various glands.  Absorbs molecules

Lining of small intestine, uterine tubes.  Absorbs nutrients.

Lining of trachea.  Sweeps impurities toward throat.

Lining of nose, mouth, esophagus, anal canal, vagina.  Protects.

consists of a single layer of cube-shaped cells. This type of epithelium is frequently found in glands, such as the salivary glands, the thyroid, and the pancreas

has cells resembling rectangular pillars or columns, with nuclei usually located near the bottom of each cell. This epithelium lines the digestive tract, where microvilli expand the surface area and aid in absorbing the products of digestion

The lining of the windpipe, or trachea, is pseudostratified ciliated columnar epithelium. A secreted covering of mucus traps foreign particles. The upward motion of the cilia carries the mucus to the back of the throat, where it may either be swallowed or expectorated (spit out)

Epithelial cell or a group of epithelial cells specialized to secrete a substance.

Glands that secrete its product to an epithelial surface directly or through ducts

Stratified epithelia have layers of cells piled one on top of the other.  Only the bottom layer touches the basement membrane. The nose, mouth, esophagus, anal canal, outer portion of the cervix (adjacent to the vagina), and vagina are lined with stratified squamous epithelium

is an organ comprising all four tissue types: epithelial, connective, muscular, and nervous tissue.  The skin has numerous functions. It protects underlying tissues from physical trauma, pathogen invasion, and water loss. It also helps regulate body temperature

Organ system consisting of skin and structures, such as nails, found in skin.

A waterproof protein.

macrophages, white blood cells that phagocytize infectious agents and then travel to lymphatic organs. There they stimulate the immune system to react to the pathogen

lying deep in the epidermis, produce melanin, the main pigment responsible for skin color

is a region of dense fibrous connective tissue beneath the epidermis.  The dermis contains collagen and elastic fibers. The collagen fibers are flexible but offer great resistance to overstretching. They prevent the skin from being torn. The elastic fibers maintain normal skin tension but also stretch to allow movement of underlying muscles and joints

The thoracic cavity contains the lungs and the heart and esophagus.

The stomach, liver, spleen, pancreas, and gallbladder and most of the small and large intestines are in the abdominal cavity

The pelvic cavity contains the rectum, the urinary bladder, the internal reproductive organs, and the rest of the small and large intestines.

Contains the brain

Contains the spinal cord

line the tubes of the digestive, respiratory, urinary, and reproductive systems. They are composed of an epithelium overlying a loose fibrous connective tissue layer. The epithelium contains specialized cells that secrete mucus. This mucus ordinarily protects the body from invasion by bacteria and viruses. Hence, more mucus is secreted and expelled when a person has a cold and has to blow his or her nose. In addition, mucus usually protects the walls of the stomach and small intestine from digestive juices

line and support the lungs, the heart, and the abdominal cavity and its internal organs (Fig. 4.14b). They secrete a watery fluid that keeps the membranes lubricated. Serous membranes support the internal organs and compartmentalize the large thoracic and abdominal cavities.

composed only of loose connective tissue line the cavities of freely movable joints. They secrete synovial fluid into the joint cavity. This fluid lubricates the ends of the bones, so that they can move freely

are membranes within the dorsal cavity. They are composed only of connective tissue and serve as a protective covering for the brain and spinal cord

is the body’s ability to maintain a relative constancy of its internal environment by adjusting its physiological processes

Blood delivers oxygen and nutrients to the tissues and carries away carbon dioxide and wastes

Interstitial fluid, not blood, bathes the body’s cells. Therefore, interstitial fluid is the medium through which substances are exchanged between cells and blood.  Oxygen and nutrients pass through interstitial fluid on their way to tissue cells from the blood. Then carbon dioxide and wastes are carried away from the tissue cells by the interstitial fluid and are brought back into the blood. The cooperation of body systems is required to keep these substances within the range of normalcy in blood and interstitial fluid.

Regulates and coordinates the activities of all the other systems.  It responds quickly to internal and external stimuli.

Endocrine glands secrete hormones, which also regulate and coordinate the activities of other systems.  Works more slowly than the nervous system.

Supplies blood with oxygen for tissue cells and rids blood of carbon dioxide.  Helps regulate the acid-base balance of the blood.

Transports oxygen and nutrients to tissue cells and transports wastes away from cells.  Also transports hormones secreted by the endocrine glands.

Excretes nitrogenous and other wastes.  Regulates water-salt balance of the blood.  Helps regulate the acid-base balance of the blood.

Supplies blood with nutrients and water for tissue cells.  Rids the body of nondigestible remains.

Helps maintain blood volume by collecting excess interstitial fluid and returning it via lymphatic vessels to the cardiovascular veins.  Defends against disease.

Produces heat that maintains body temperature.  Protects and supports internal organs.

Helps maintain body temperature and protects internal organs.

Mechanism of homeostatic response in which a stimulus initiates reactions that reduce the stimulus.