Chapter 2 - The Human Body in Health and Disease

Chapter 2 - The Human Body in Health and Disease Word Parts                aden/o - gland adip/o -fat anter/o - before, front caud/o - lower part of body, tail cephal/o - head cyt/o, - cytecell end-, endo-in, within, inside exo-out of, outside, away from hist/o - tissue -ologist - specialist -ology - the science or study of path/o, -pathy - disease, suffering, feeling, emotion plas/i, plas/o, -plasia - development, growth, formation poster/o - behind, toward the back -stasis, -static - control, maintenance of a constant level Medical Terms               abdominal cavity(ab-DOM-ih-nal) - contains the major organs of digestion. This cavity is frequently referred to simply as the abdomen. adenectomy(ad-eh-NECK-toh-mee) - the surgical removal of a gland. adenocarcinoma(ad-eh-noh-kar-sih-NOH-mah) - a malignant tumor that originates in glandular tissue. Malignant means harmful, capable of spreading, and potentially life threatening. adenoma(ad-eh-NOH-mah) - a benign tumor that arises in or resembles glandular tissue. adenomalacia(ad-eh-noh-mah-LAY-shee-ah) - the abnormal softening of a gland. adenosclerosis(ad-eh-noh-skleh-ROH-sis) - the abnormal hardening of a gland; the opposite of adenomalacia. anaplasia(an-ah-PLAY-zee-ah) - a change in the structure of cells and in their orientation to each other. anatomy(ah-NAT-oh-mee) - the study of the structures of the body. anomaly(ah-NOM-ah-lee) - a deviation from what is regarded as normal. anterior(an-TEER-ee-or) - means situated in the front. It also means on the front or forward part of an organ;the opposite of posterior. aplasia(ah-PLAY-zee-ah) - the defective development, or the congenital absence, of an organ or tissue. bloodborne transmission - the spread of a disease through contact with infected blood or other body fluids that are contaminated by infected blood. caudal(KAW-dal) - toward the lower part of the body.                            cell membrane - the tissue that surrounds and protects the contents of a cell from the external environment. cephalic(seh-FAL-ick) - toward the head;the opposite of caudal. chromosome(KROH-moh-sohme) - a genetic structure located within the nucleus of each cell. communicable disease(kuh-MEW-nih-kuh-bul) - also known as a contagious disease, is any condition that is transmitted from one person to another either directly or by indirect contact with contaminated objects. congenital disorder(kon-JEN-ih-tahl) - an abnormal condition that exists at the time of birth. cranial - pertaining to the skull. cytology - the study of the anatomy, physiology, pathology, and chemistry of the cell. cytoplasm(SIGH-toh-plazm) - the material within the cell membrane that is not part of the nucleus. distal(DIS-tal) - situated farthest from the midline or beginning of a body structure. dorsal(DOR-sal) - refers to the back of the organ or body. dysplasia(dis-PLAY-see-ah) - the abnormal development or growth of cells, tissues, or organs. endemic(en-DEM-ick) - refers to the ongoing presence of a disease within a population, group, or area. endocrine glands(EN-doh-krin) - which produce hormones, do not have ducts. These hormones are secreted directly into the bloodstream and are then transported to organs and structures throughout the body. epidemic(ep-ih-DEM-ick) - a sudden and widespread outbreak of a disease within a specific population group or area. epigastric region(ep-ih-GAS-trick) - located above the stomach. etiology(ee-tee-OL-oh-jee) - the study of the causes of diseases. exocrine glands(ECK-soh-krin) - secrete chemical substances into ducts that lead either to other organs or out of the body, such as sweat glands. functional disorder - produces symptoms for which no physiological or anatomical cause can be identified. genetic disorder geriatrician(jer-ee-ah-TRISH-un) - a physician who specializes in the care of older people. hemophilia(hee-moh-FILL-ee-ah) histology(hiss-TOL-oh-jee) - the microscopic study of the structure, composition, and function of tissues. homeostasis(hoh-mee-oh-STAY-sis) - the processes through which the body maintains a constant internal environment. hyperplasia(high-per-PLAY-zee-ah) - the enlargement of an organ or tissue because of an abnormal increase in the number of cells in the tissues. hypertrophy(high-PER-troh-fee) - a general increase in the bulk of a body part or organ that is due to an increase in the size, but not in the number, of cells in the tissues. hypogastric region(high-poh-GAS-trick) - located below the stomach.                           hypoplasia(high-poh-PLAY-zee-ah) - the incomplete development of an organ or tissue usually due to a deficiency in the number of cells. iatrogenic illness(eye-at-roh-JEN-ick) - an unfavorable response due to prescribed medical treatment. idiopathic disorder(id-ee-oh-PATH-ick) - an illness without known cause. infectious disease(in-FECK-shus) - an illness caused by living pathogenic organisms such as bacteria and viruses. inferior - uppermost, above, or toward the head. inguinal(ING-gwih-nal) -relating to the groin, refers to the entire lower area of the abdomen. This includes the groin, which is the crease at the junction of the trunk with the upper end of the thigh. lateral - the direction toward, or nearer, the side of the body, away from the midline. Bilateral means relating to, or having, two sides. medial(MEE-dee-al) - the direction toward, or nearer, the midline;the opposite of lateral. mesentery(MESS-en-terr-ee) - a fused double layer of the parietal peritoneum that attaches parts of the intestine to the interior abdominal wall. midsagittal plane(mid-SADJ-ih-tal) - the sagittal plane that divides the body into equal left and right halves. nosocomial infection(nahs-oh-KOH-mee-al in-FECK-shun) - a disease acquired in a hospital or clinical setting. pandemic(pan-DEM-ick) - refers to an outbreak of a disease occurring over a large geographic area, possibly worldwide. pelvic cavity(PEL-vick) - the space formed by the hip bones and contains the organs of the reproductive and excretory systems. peritoneum(pehr-ih-toh-NEE-um) - a multilayered membrane that protects and holds the organs in place within the abdominal cavity. peritonitis(pehr-ih-toh-NIGH-tis) phenylketonuria(fen-il-kee-toh-NEW-ree-ah) physiology(fiz-ee-OL-oh-jee) - the study of the functions of the structures of the body. posterior(pos-TEER-ee-or) - means situated in the back. It also means on the back part of an organ. proximal(PROCK-sih-mal) - situated nearest the midline or beginning of a body structure;the opposite of distal. retroperitoneal(ret-roh-pehr-ih-toh-NEE-al) - located behind the peritoneum. stem cells - unspecialized cells that are able to renew themselves for long periods of time by cell division. This is in contrast to other types of cells that have a specialized role and die after a determined life span. superior - uppermost, above, or toward the head;the opposite of inferior. thoracic cavity(thoh-RAS-ick) - also known as the chest cavity or thorax, surrounds and protects the heart and the lungs. The diaphragm is a muscle that separates the thoracic and abdominal cavities. transverse plane(trans-VERSE) - is a horizontal plane that divides the body into superior (upper) and inferior (lower) portions. umbilicus(um-BILL-ih-kus) - commonly known as the belly button or navel. vector-borne transmission - the spread of certain disease due to the bite of a vector.  ventral(VEN-tral) - refers to the front, or belly side, of the organ or body; the opposite of dorsal. EX. of a Body Plane ( - imaginary vertical and horizontal lines used to divide the body into sections for descriptive purposes ) The Vertical Planes A vertical plane is an up-and-down plane that is at a right angle to the horizon.  A sagittal plane(SADJ-ih-tal) is a vertical plane that divides the body into unequal left and right portions.  A frontal plane is a vertical plane that divides the body into anterior (front) and posterior (back) portions. Also known as the coronal plane, it is located at right angles to the sagittal plane. Body directions : Cephalic means toward the head, and caudal means toward the feet. Anterior means toward the front, and the front of the body is known as the ventral surface. Posterior means toward the back, and the back of the body is known as the dorsal surface. Body directions : Proximal means situated nearest the midline, and distal means situated farthest from the midline. Medial means toward or nearer the midline, and lateral means toward the side and away from the midline. The major body cavities The Dorsal Cavity The dorsal cavity, which is located along the back of the body and head, contains organs of the nervous system that coordinate body functions and is divided into two portions:   The cranial cavity, which is located within the skull, surrounds and protects the brain. Cranial means pertaining to the skull. The spinal cavity, which is located within the spinal column, surrounds and protects the spinal cord. There is no physical division between the abdominal and pelvic cavities. The term abdominopelvic cavity (ab-dom-ih-noh-PEL-vick) refers to these two cavities as a single unit. Regions of the Thorax and Abdomen Regions of the thorax and abdomencomprise a descriptive system that divides the abdomen and lower portion of the thorax into nine parts.    The right and left hypochondriac regions(high-poh-KON-dree-ack)are covered by the lower ribs (hypo-means below, chondr/imeans cartilage, and -acmeans pertaining to). As used here, the term hypochondriacmeans below the ribs. This term also describes an individual with an abnormal concern about his or her health. The right and left lumbar regions(LUM-bar)are located near the inward curve of the spine (lumbmeans lower back, and -armeans pertaining to). The term lumbardescribes the part of the back between the ribs and the pelvis. The right and left iliac regions(ILL-ee-ack)are located near the hip bones (ilimeans hip bone, and -acmeans pertaining to)   The parietal peritoneum (pah-RYE-eh-tal pehr-ih-toh-NEE-um) is the outer layer of the peritoneum that lines the interior of the abdominal wall. Parietal means cavity wall. The visceral peritoneum (VIS-er-al pehr-ih-toh-NEE-um) is the inner layer of the peritoneum that surrounds the organs of the abdominal cavity. Visceral means relating to the internal organs. A basic cell and DNA molecule. Adult stem cells, also known as somatic stem cells, are undifferentiated cells found among differentiated cells in a tissue or organ. Normally the primary role of these cells is to maintain and repair the tissue in which they are found. The term undifferentiated means not having a specialized function or structure. In contrast, the term differentiated means having a specialized function or structure. Stem cells potentially have many therapeutic uses, including being transplanted from one individual to another. Cells for this purpose are harvested from the hemopoietic (blood forming) tissue of the donor’s bone marrow. However, unless there is an excellent match between the donor and recipient, there is the possibility of rejection, known as graft-versus-host disease. Embryonic stem cells (em-bree-ON-ik) are undifferentiated cells that are unlike any specific adult cell; however, they have the important ability to form any adult cell. Embryonic means referring to an embryo, a developing child during in its first eight weeks in the womb ( embry/o means fertilized ovum, and -nic means pertaining to).  These cells can proliferate (grow rapidly) indefinitely in a laboratory and could therefore potentially provide a source for adult muscle, liver, bone, or blood cells.    Because these cells are more primitive than adult stem cells, an embryonic stem cell transplant does not require as perfect a match between the patient and donor as the transplantation of adult stem cells. Embryonic stem cells come from the cord blood found in the umbilical cord and placenta of a newborn infant. Embryonic stem cells from cord blood can be harvested at the time of birth without danger to mother or child. These cells are kept frozen until needed for treatment purposes. Embryonic stem cells can also be obtained from surplus embryos produced by in vitro (test tube) fertilization. With the informed consent of the donor couple, stem cells obtained in this manner can be used for medical and scientific research. Dominant and Recessive Genes Each newly formed individual receives two genes of each genetic trait: one from the father and one from the mother.        DNA When a dominant gene is inherited from either parent, the offspring will inherit that genetic condition or characteristic. For example, freckles are a physical trait that is transmitted by a dominant gene. So, too, is the hereditary disorder Huntington’s disease. When the same recessive gene is inherited from both parents, the offspring will have that condition. For example, sickle cell anemia is a group of inherited red blood cell disorders that are transmitted by a recessive gene. When this gene is transmitted by both parents, the child will have sickle cell anemia. When a recessive gene is inherited from only one parent, and a normal gene is inherited from the other parent, the offspring will not have the condition. Although this child will not develop sickle cell anemia, he or she will have the sickle cell anemia trait. People with this trait can transmit the sickle cell gene to their offspring. A somatic cell is any cell in the body except the gametes (sex cells). Somatic means pertaining to the body in general. Somatic cells contain 46 chromosomes arranged into 23 pairs. There are 22 identical pairs of chromosomes, plus another pair. In a typical female, this remaining pair consists of XX chromosomes. In a typical male, this pair consists of an XY chromosome pair. This chromosome pair determines the sex of the individual. A gamete (sperm or egg), also known as a sex cell, is the only type of cell that does not contain 46 chromosomes. Instead, each ovum (egg) or sperm has 23 single chromosomes. In a female, one of these will be an X chromosome. In a male, one of these will be either an X or a Y chromosome. When a sperm and ovum join, the newly formed offspring receives 23 chromosomes from each parent, for a total of 46. It is the X or Y chromosome from the father that determines the gender of the child. A defect in chromosomes can lead to birth defects. For example, individuals with Down syndrome have 47 chromosomes instead of the usual 46.     DNA is packaged in a chromosome as two spiraling strands that twist together to form a double helix. A helix is a shape twisted like a spiral staircase. A double helix consists of two of these strands twisted together. DNA, which is an abbreviation for deoxyribonucleic acid, is found in the nucleus of all types of cells except erythrocytes (red blood cells). The difference here is due to the fact that erythrocytes do not have a nucleus. The DNA for each individual is different, and no two DNA patterns are exactly the same. The only exception to this rule is identical twins, which are formed from one fertilized egg that divides. Although their DNA is identical, these twins do develop characteristics that make each of them unique, such as fingerprints. A very small sample of DNA, such as from human hair or tissue, can be used to identify individuals in instances such as criminal investigations, paternity suits, or genealogy research. Genetic mutation    A somatic cell mutation is a change within the cells of the body. These changes affect the individual but cannot be transmitted to the next generation. A gametic cell mutation is a change within the genes in a gamete (sex cell) that can be transmitted by a parent to his or her children. Genetic engineering is the manipulating or splicing of genes for scientific or medical purposes. The production of human insulin from modified bacteria is an example of one result of genetic engineering. Genetic disorders       Cystic fibrosis(CF), a genetic disorder that is present at birth and affects both the respiratory and digestive systems (see Chapter 7). Down syndrome(DS), a genetic variation that is associated with a characteristic facial appearance, learning disabilities, developmental delays, and physical abnormalities such as heart valve disease (Figure 2.9). Hemophilia(hee-moh-FILL-ee-ah), a group of hereditary bleeding disorders in which a bloodclotÝng factor is missing. This blood coagulation disorder is characterized by spontaneous hemorrhages or severe bleeding following an injury. Huntington’s disease(HD), a genetic disorder that is passed from parent to child. Each child of a parent with the gene for Huntington’s disease has a 50–50 chance of inheriting this defective gene. This condition causes nerve degeneration with symptoms that most often appear in midlife. ( Degenerationmeans worsening condition.) This damage eventually results in uncontrolled movements and the loss of some mental abilities. Muscular dystrophy(DIS-troh-fee), a group of genetic diseases that are characterized by progressive weakness and degeneration of the skeletal muscles that control movement (see Chapter 4). Phenylketonuria(fen-il-kee-toh-NEW-ree-ah)(PKU), a rare genetic disorder in which the essential digestive enzyme phenylalanine hydroxylaseis missing. PKU can be detected by a blood test performed on infants at birth. With careful dietary supervision to limit phenylalanine, found mostly in foods that contain protein, children born with PKU can lead normal lives. Without early detection and treatment, PKU causes severe intellectual disability (formerly referred to as mental retardation). Epithelial Tissue Epithelial tissue (ep-ih-THEE-lee-al) forms a protective covering for all of the internal and external surfaces of the body. These tissues also form glands.   Epithelium (ep-ih-THEE-lee-um) is the specialized epithelial tissue that forms the epidermis of the skin and the surface layer of mucous membranes (see Chapter 12). Endothelium (en-doh-THEE-lee-um) is the specialized epithelial tissue that lines the blood and lymph vessels, body cavities, glands, and organs. Connective Tissue Connective tissues support and connect organs and other body tissues. The four kinds of connective tissue are as follows:     Dense connective tissues, such as bone and cartilage, form the joints and framework of the body. Adipose tissue, also known as fat, provides protective padding, insulation, and support ( adip means fat, and -ose means pertaining to). Loose connective tissue surrounds various organs and supports both nerve cells and blood vessels. Liquid connective tissues, which are blood and lymph, transport nutrients and waste products throughout the body. Body System Major Structures Major Functions Skeletal System (Chapter 3) Bones, joints, and cartilage Supports and shapes the body. Protects the internal organs. Forms some blood cells and stores minerals. Muscular System (Chapter 4) Muscles, fascia, and tendons Holds the body erect. Makes movement possible. Moves body fluids and generates body heat. Cardiovascular System (Chapter 5) Heart, arteries, veins, capillaries, and blood Blood circulates throughout the body to transport oxygen and nutrients to cells, and to carry waste products to the kidneys where waste is removed by filtration. Lymphatic System (Chapter 6) Lymph, lymphatic vessels, and lymph nodes Removes and transports waste products from the fluid between the cells. Destroys harmful substances such as pathogens and cancer cells in the lymph nodes. Returns the filtered lymph to the bloodstream where it becomes plasma again. Immune System (Chapter 6) Tonsils, spleen, thymus, skin, and specialized blood cells Defends the body against invading pathogens and allergens. Respiratory System (Chapter 7) Nose, pharynx, trachea, larynx, and lungs Brings oxygen into the body for transportation to the cells. Removes carbon dioxide and some water waste from the body. Digestive System (Chapter 8) Mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas Digests ingested food so it can be absorbed into the bloodstream. Eliminates solid waste. Urinary System (Chapter 9) Kidneys, ureters, urinary bladder, and urethra Filters blood to remove waste. Maintains the electrolyte and fluid balance within the body. Nervous System (Chapter 10) Nerves, brain, and spinal cord Coordinates the reception of stimuli. Transmits messages throughout the body. Special Senses (Chapter 11) Eyes and ears Receive visual and auditory information and transmit it to the brain. Integumentary System (Chapter 12) Skin, sebaceous glands, and sweat glands Protects the body against invasion by bacteria. Aids in regulating the body temperature and water content. Endocrine System (Chapter 13) Adrenal glands, gonads, pancreas, parathyroids, pineal, pituitary, thymus, and thyroid Integrates all body functions. Reproductive Systems (Chapter 14) Male:penis and testicles; Female:ovaries, uterus, and vagina Produces new life.