Chapter 2: The Human Body in Health and Disease

anatomic reference systems

used to describe the locations of the structural units of the body

anatomy

study of the structures of the body

physiology

study of the functions of the structures of the body

anatomic position

describes the body assuming that the individual is standing in the standard position

body planes

imaginary vertical and horizontal lines used to divide the body into sections for descriptive purposes

vertical plane

up-and-down plane that is a right angle to the horizon

midsagittal plane

sagittal plane that divides the body into equal right and left halves

sagittal plane

vertical plane tat divides the body into unequal left and right portions

frontal plane

vertical plane that divides the body into anterior and posterior portions

horizontal plane

flat crosswise plane, such as the horizon

transverse plane

horizontal plane that divides the body into superior and inferior portions

ventral

front, or belly side, of the organ or body

dorsal

back of the organ or body

anterior

situated in the front

posterior

situated in the back

superior

uppermost, above, or toward the head

inferior

lowermost, below, or toward the feet

cephalic

toward the head

caudal

toward the lower part of the body

proximal

situated nearest the midline or beginning of a body structure

distal

situated farthest from the midline or beginning of a body structure

medial

direction toward, or nearer, the midline

lateral

direction toward or nearer the side and away from the midline

cranial cavity

located within the skull, surrounds and protects the brain

body cavities

spaces within the body that contain and protect internal organs

dorsal cavity

contains organs of the nervous system that coordinate body functions

spinal cavity

located within the spinal column, surrounds and protects the spinal cord

ventral cavity

located along the front of the body, contains the body organs that maintain homeostasis

homeostasis

process through which the body maintains a constant internal environment

home/o

constant

thoracic cavity

surrounds and protects the heart and lungs

abdominal cavity

contains the major organs of digestion

pelvic cavity

space formed by the hips bones and primarily contains the organ os the reproductive and excretory systems

abdominopelvic cavity

refers to the abdominal and pelvic cavities

inguinal

relating to the groin

hypochondriac regions

located on the left and right sides of the body, covered by the lower ribs

epigastric region

located above the stomach

lumbar regions

located on the left and right sides near the inward curve of the spine

umbilical region

surrounds the umbilicus

umbilicus

belly button/navel

iliac region

located on the left and right sides over the hip bone

hypogastric region

located below the stomach

peritoneum

multilayered membrane that protects and holds the organs in place within the abdominal cavity

parietal peritoneum

outer layer of the peritoneum that lines the interior of the abdominal wall

visceral peritoneum

inner layer of the peritoneum that surrounds the organs of the abdominal cavity

mesentery

fused double layer of the parietal peritoneum that attaches parts of the intestine to the interior abdominal wall

retroperitoneal

located behind the peritoneum

retro-

behind

peritonitis

inflammation of the peritoneum

periton/o

peritoneum

cells

basic structural and functional units of the body

cytology

study of the anatomy, physiology, pathology, and chemistry of the cell

cyt/o

cell

cell membrane

tissue that surrounds and protects the contents of the cell by separating them from its external environment

cytoplasm

material within the cell membrane that is not pat of the nucleus

nucleus

surround by the nuclear membrane, controls cell activities, helps cell divide

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

adult stem cells

undifferentiated cells found among differentiated cells in a tissue or organ

embryonic stem cells

undifferentiated cells that are unlike any specific adult cell

gene

fundamental physical and functional unit of heredity

genetics

study of how genes are transferred from parents to their children and the role of genes in health and disease

geneticist

specialist in genetics

dominant gene

if inherited from either patient, offspring will inherit that condition

recessive gene

only will be inherited if both parents have that gene

genome

complete set of genetic information of an individual

chromosomes

genetic structures located within the nucleus of the cell

somatic cell

any cell in the body except gametes

sex cell

only type of cell that does not contain 46 chromosomes

DNA

contains genes that provide information essential for heredity, determining our physical appearance, disease risks, and other traits

genetic mutation

change of the sequence of a DNA molecule

genetic disorder

pathological condition caused by an absent or defective gene

cystic fibrosis

genetic disorder that is present at birth and affects both the respiratory and digestive system

down syndrome

genetic variation that is associated with characteristic facial appearance, learning disabilities, and physical abnormalities such as heart valve disease

hemophilia

group of hereditary bleeding disorders in which a blood-clotting factor is missing

huntington's disease

genetic disorder that is passed from parent to child, causes nerve degeneration with symptoms that most often appear in midlife

muscular dystrophy

group of genetic diseases and degeneration of the skeletal muscles that control movement

phenylketonuria

genetic disorder in which the essential digestive enzyme phenylalanine hydroxylase is missing

tay-sachs disease

fatal genetic disorder in which harmful quantities of a fatty substance build up in tissues and nerve cells in the brain

tissue

group or layer of similarly specialized cells that join together or perform certain functions

histology

study of the structure, composition, and function of tissues

histologist

specialist in the study of the organization of tissues at all levels

epithelial tissues

form a protective covering for all of the internal and external surfaces of the body

epithelium

specialized epithelial tissue that forms the epidermis of the skin and the surface layer of mucous membranes

endothelium

specialized epithelial tissue that lines the blood and lymph vessels, body cavities , glands, and organs

connective tissue

support and connect organs and other body tissues

dense connective tissue

bone and cartilage, form the joints and framework of the body

adipose tissue

fat, provides protective padding, insulation, and support

loose connective tissue

surrounds various organs and supports both nerve cells and blood vessels

liquid connective tissues

transport nutrients and waste products throughout the body

muscle tissue

contains cells with the specialized ability to contract and relax

aplasia

defective development, or the congenital absence, of an organ or tissue

hypoplasia

incomplete development of an organ or tissue usually due to a deficiency in the number of cells

anaplasia

change in the structure of cells and in their orientation to each other

dysplasia

abnormal development, or growth, of cells, tissues, or organs

hyperplasia

enlargement of an organ or tissue because of an abnormal increase in the number of cells in the tissues

hypertrophy

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

gland

group of specialized epithelial cells that are capable of producing secretions

exocrine glands

secrete chemical substances into ducts that lead either to other organs or out of the body

endocrine glands

produce hormones, do not have ducts

adenitis

inflammation of a gland