Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Weeks 1-5
Anatomy Week 1-5
| Term | Definition |
|---|---|
| Scientific Method | Using detailed observations and vigorous tests, or experiments, sci-entists winnow out each element of an idea or hypothesis until a reasonable conclusion about its validity can be made. |
| Controlled Experiments | Rigorous ex-periments that eliminate any influences or biases not being directly tested |
| Theory | If the results of observations and experiments are repeatable, they may verify a hypothesis and eventually lead to enough confidence in the concept to call it a theory |
| Laws | Theories in which scientists have an unusually high level of confidence |
| Anatomy | defined as study of the structure of an organism and the relationships of its parts. |
| Dissection | Students of anatomy still learn about the structure of the human body by literally cutting it apart. |
| Biology | defined as the scientific study of life. |
| Gross anatomy | used to describe the study of body parts visible to the naked eye |
| Microscopic anatomy, | With the use of modern microscopes, many anatomists now specialize |
| cytology | including the study of cells |
| histology | the study of tissues |
| developmental anatomy | the study of human growth and development |
| pathological anatomy | and the study of diseased body structures |
| systemic anatomy. | study the body by systems |
| PHYSIOLOGY | Physiology is the science that deals with the functions of the living organism and its parts. |
| Federation of Associations of Anatomists | formed a worldwide committee to publish a list of “universal” or standard anatomical terminology. |
| Terminologia Histologica | was published for microscopic anatomy—the study of body structure requiring sig-nificant magnification for the purpose of visualization |
| eponyms, | or terms that are based on a person’s name |
| autopoiesis | One could say that living organisms are self-organizing or self-maintaining and nonliving structures are not. |
| cell theory, | states that any independent structure made up of one or more microscopic units called cells is a living organism. |
| characteristics of life | scientists sometimes define life by listing what are often called |
| metabolism | Each characteristic of life is related to the sum total of all the physical and chemical reactions occurring in the body. The term metabolism is used to describe these various processes. |
| atoms | There are more than 100 different chemical building blocks of nature called |
| molecules. | Combinations of atoms form larger chemical groupings, called |
| macromolecules. | Molecules, in turn, often combine with other atoms and molecules to form larger and more complex chemicals, called |
| organelles, | Chemical structures may be organized within larger units called cells to form various structures called |
| Mitochondria | the “powerhouses” of cells that provide energy needed by the cell to carry on day-to-day function-ing, growth, and repair |
| Golgi apparatus | set of sacs that provides a “packaging” service to the cell by storing material for future internal use or for export from the cell |
| Endoplasmic reticulum | network of channels within the cell that act as “highways” for the movement of chemicals and as sites for chemical processing |
| the cellular level. | the most important function of the chemical and organelle levels of or-ganization is that of furnishing the basic building blocks required for the next higher level of body structure— |
| Cells | he smallest and most numerous structural units that possess and exhibit the basic characteristics of living matter. |
| differentiate | Fat cells, for ex-ample, are structurally modified to permit the storage of fats, whereas other cells, such as cardiac muscle cells, are able to contract with great force |
| tissue | is a group of a great many similar cells that all developed together from the same part of the embryo and all perform a certain function. |
| matrix. | Tissue cells are surrounded by varying amounts and kinds of nonliving, intercellular substances, |
| There are four major or principal tissue types | epithelial, connec-tive, muscle, and nervous. |
| organ | is defined as a structure made up of several different kinds of tissues arranged so that, together, they can perform a special function. |
| system level | of organization involves varying numbers and kinds of organs arranged so that, together, they can perform complex func-tions for the body. |
| skeletomuscular system | both the skeletal and muscular systems work together to produce athletic movements, an athletic trainer may study them together as the |
| neuroskeletomuscular system. | A physi-cal therapist may also include concepts of nervous control of move-ment and study the |
| organism | is a marvelously coor-dinated team of interactive struc-tures that is able to survive and flourish in an often hostile envi-ronment. |
| Bilateral symmetry | To say that humans are bilaterally symmetrical simply means that the right and left sides of the body are mirror images of each other and only one plane can divide the body into left and right halves. |
| Ipsilateral | simply means “same side,” |
| contralateral | “op-posite side.” |
| Supine and Prone | terms used to describe the position of the body when it is not in the anatomical position. |
| Superior | “toward the head |
| inferior | “toward the feet.” |
| Anterior | “front” or “in front of” |
| posterior | “back” or “in back of.” |
| ventral | In humans—who walk in an upright position |
| dorsal ( | (toward the back) can be used for posterior |
| Medial | “toward the midline of the body” |
| lateral | “toward the side of the body, |
| Proximal | “toward or nearest the trunk of the body, or nearest the point of origin of one of its parts |
| distal | “away from or farthest from the trunk or the point of origin of a body part.” |
| Superficial | “nearer the surface” |
| deep | “farther away from the body surface.” |
| lumen | Many organs of the body are hollow, such as the stomach, small in-testine, airways of the lungs, blood vessels, urinary organs, and so on. The hollow area of any of these organs is called the |
| Central | “near the center.” |
| Peripheral | “around the boundary.” |
| Medullary | refers to an inner region or core of an organ |
| Cortical | refers to an outer region or layer of an organ. |
| Basal | refers to the base or widest part of an organ. |
| Apical | refers to the narrow tip of an organ. |
| body plane. | the body or an organ along such an imagined flat surface—a |
| section | The resulting cut is called a section of the body or organ. |
| There are three major body planes that lie at right angles | the sagittal, coronal, and transverse planes. |
| sagittal plane | Any lengthwise plane running from front to back and top to bottom, dividing the body or any of its parts into right and left sides, is called a |
| sagittal section | If a sagittal section is made in the exact midline of the body, result-ing in equal and symmetrical right and left halves, the section is called a median sagittal section or midsagittal section |
| coronal plane. | Any lengthwise plane running from side to side and top to bottom, dividing the body or any of its parts into anterior and posterior por-tions, is called a |
| coronal section or a frontal section. | A cut made along a coronal plane |
| transverse plane | Any crosswise plane that divides the body or any of its parts into upper and lower parts is called a |
| transverse section or horizontal section. | A cut along any trans-verse plane of the body or an organ may be called a |
| cross-section. | a cut along a plane parallel with the short axis of an organ is called a |
| longitudinal section | A cut along the long axis of an organ is called a |
| oblique sections. | Sometimes it is helpful to make a cut along a plane that is not at right angles to the planes we have already mentioned. Such diagonal cuts are called |
| dorsal cavities | form along the dorsum or back of the body early in development as bones grow around the tube that eventually forms our central nervous system. The dorsal cavities include the cranial cavity and spinal cavity. |
| ventral cavities | During early development, a huge internal body cavity subdivides into two major ventral cavities—the thoracic cavity (chest cavity) and the abdominopelvic cavity. |
| thoracic cavity | has a midportion called the mediastinum, which contains the heart and other structures surrounded by fibrous tissue. |
| mediastinum | which contains the heart and other structures surrounded by fibrous tissue. |
| pleural cavities | On the left and right sides of the mediastinum are spaces called pleural cavities in which the lungs reside |
| parietal | Often, one layer of the membrane called the parietal layer lines the cavity and doubles back on itself to form a visceral layer covering the or-gans. |
| pleural cavity | refer to the entire space to the side of the mediastinum or to just the potential space left surrounding the lung between the parietal and visceral pleura. |
| visceral pleura | where a parietal pleura hugs the inside of the thoracic wall and doubles back to cover the lung—thus forming a |
| abdominopelvic cavity | has an upper portion, the abdominal cavity, and a lower portion, the pelvic cavity. contains the liver, gallbladder, stomach, pancreas, intestines, spleen, kidneys, and ureters. |
| parietal peritoneum. | The membrane lining the inside of the abdominal cavity is called the |
| visceral peritoneum | The membrane that covers the organs within the abdominal cavity is called the visceral peritoneum. |
| peritoneal cavity. | there is a space or opening between the two membranes in the abdomen. This is called the peritoneal cavity. |
| hypochondriac | “under cartilage,” referring to the rib cartilage. |
| Epigastric | “upon (around) the stomach.” |
| iliac | refers to ileum, which is the lowest part of the small intestine. |
| Hypogastric | means “below the stomach. |
| The body as a whole can be subdivided into two major portions or components: | axial and appendicular. |
| upper extremity, | or upper limb, is divided into shoulder, arm, forearm, wrist, and hand compo-nents. |
| The lower extremity, | or lower limb, is divided into hip, thigh, leg, ankle, and foot. |
| leg | To an anatomist, leg refers to the area of the lower extremity between the knee and ankle, not to the entire lower limb. |
| cubital | can refer to the elbow or to the forearm. |
| crural | can refer to just the leg, or to just the thigh, or to the thigh and leg to-gether. |
| ELEMENTS AND COMPOUNDS | Substances are either elements or compounds.in the sense that it cannot be broken down or decom-posed into two or more different substances. Com-pounds can be broken down or decomposed into the elements that are contained within them. |
| ATOMS | smaller or subatomic parti-cles, some of which exist in a “cloud” surround-ing a dense central core called a nucleus. |
| CLOUD MODEL | found in either a central nucleus or its surrounding “electron cloud” or “field.” • Protons (p) • Neutrons (n0) • Electrons (e) |
| ATOMIC NUMBER AND MASS NUMBER | The number of protons in an atom’s nucleus, called its atomic number an atomic number of 1; this means that all hydrogen atoms—and only hydrogen atoms—have one proton in their nucleus. The term mass number refers to the mass of a single atom |
| ENERGY LEVELS | Each ring rep-resents a different energy level, and each can hold only a certain maxi-mum number of electrons |
| ISOTOPES | Iso-topes of an element contain the same number of protons but differ-ent numbers of neutrons. |
| CHEMICAL BONDS | . The result, called a chemical reaction, most often in-volves unpaired electrons |
| ionic Bonds | A chemical bond formed by the transfer of elec-trons from one atom to another is called an ionic, or electrovalent, bond. |
| Covalent Bonds | A chemical bond formed by the sharing of one or more pairs of electrons between the outer energy levels of two atoms is called a covalent bond. |
| HYDROGEN BONDS | In addition to ionic and covalent bonds, another type of attractive force, called a hydrogen bond, can exist between biologically impor-tant molecules. |
| CHEMICAL REACTIONS | 1. Synthesis reactions 2. Decomposition reactions 3. Exchange reactions |
| CATABOLISM | Catabolism consists of chemical reactions that not only break down relatively complex compounds into simpler ones but also release energy from them. |
| ANABOLISM | Anabolism is the term used to describe chemical reactions that join simple molecules together to form more complex biomolecules—notably, carbohydrates, lipids, proteins, and nucleic acids. |
| ORGANIC AND INORGANIC COMPOUNDS | Organic compounds are generally defined as compounds composed of molecules that contain carbon–carbon (C—C) cova-lent bonds or carbon–hydrogen (C—H) . Few inorganic compounds have carbon atoms in them, and none have C—C or C—H bonds. |
| WATER | it has been called the “cradle of life” because all living organisms require water to survive. |
| OXYGEN AND CARBON DIOXIDE | Oxygen (O2) and carbon dioxide (CO2) are important inorganic substances that are closely related to cellular respiration. |
| ELECTROLYTES | Other inorganic substances include acids, bases, and salts. These substances belong to a large group of compounds called electrolytes. |
| Acids and Bases | Acids and bases are common and very important chemical sub-stances in the body. |
| The pH scale | The term pH is literally an abbreviation for a phrase meaning “the power of hydrogen” and is used to mean the relative H ion concen-tration of a solution. |
| Buffers | The incredible constancy of the pH homeostatic mechanism re-lies partly on the presence of substances, called buffers, that mini-mize changes in the concentrations of H and OH ions in our body fluids. |
| Salts | A salt is any compound that results from the chemical interaction of an acid and a base. |
| typical or composite cell | are often introduced to the anatomy of cells by studying a so-called typical or composite cell—one that exhibits the most important characteris-tics of many different human cell types. |
| cytoplasm | The inside of the cell is composed largely of a gel-like substance called |
| cytosol, or sometimes intracellular fluid. | The cytoplasm is made of various organ-elles and molecules suspended in a watery fluid called;Serves as the boundary of the cell, maintains its integrity; protein molecules embedded in plasma membrane perform various functions—for example, they serve as m |
| plasma membrane | shows that a typical cell contains a variety of membranes. The outer boundary of the cell |
| luid mosaic model | shows a simplified view of the evolving model of cell membrane structure. This concept of cell membranes is called the |
| hydrophilic | water loving” |
| hydrophobic | water fearing |
| rafts | which are stiff groupings of membrane molecules (often very rich in cholesterol) that travel together like a log raft on the surface of a lake |
| integral membrane proteins | As their name implies, they are inte-grated into the structure of the membrane itself. |
| receptors | that can react to the presence of hormones or other regulatory chemicals and thereby trigger metabolic changes in the cell. |
| signal transduction. | he process by which cells translate the signal received by a membrane receptor into a specific chemical change in the cell is called |
| organelles | We now know that the cyto-plasm of each cell is actually a watery solution called cytosol plus hundreds or even thousands of “little organs,” or |
| endoplasmic reticulum (ER) | means literally a small network located deep inside the cytoplasm. |
| RER sacs | are dotted with innumerable small granules called ribosomes. |
| SER | —hence its smooth appearance and its name. The SER part of the network is usually more tubular in structure than the flattened sacs of the RER, |
| ribosomes. | Every cell contains thousands of;Many of them are at-tached to the RER, and many of them lie free, scattered throughout the cytoplasm. |
| vesi-cles | proteins synthesized by ribosomes and transported to the end of an ER canal are packaged into tiny membrane bubbles, or |
| secretion. | At the plasma membrane, the vesicles release their contents out-side the cell in a process called |
| lysosomes | have membranous walls. Lysosomes form when small portions of the plasma membrane pinch inward and separate into a vesicle or sac |
| autophagy | This process of “self eat-ing” is called |
| proteasome | is another protein-destroying organelle in the cell. |
| ubiquitins. | Before a protein enters the hollow interior of the proteasome, it must be tagged with a chain of very small proteins called |
| Parkinson disease | the proteasome system fails, and conse-quently, the still intact improperly folded proteins kill nerve cells in the brain that are needed to regulate muscle tension. |
| peroxisome | is another type of vesicle containing enzymes that is present in the cytoplasm of some cells. |
| mitochondria | Find the cell’s little “power plants” called |
| cristae. | They form a sac within a sac. The inner membrane is contorted into folds called |
| nucleus, | one of the largest cell structures (see Figure 5-1), usu-ally occupies the central portion of the cell. |
| chromatin | In nondividing cells, the DNA molecules appear as tiny bunches of tangled threads sprinkled with granules. This material is named |
| chromosomes | When the process of cell division begins, DNA molecules be-come more tightly coiled. They become so compact that they look like short, rodlike structures and are then called |
| nucleolus | The most prominent structure visible in the nucleus is a small nonmembranous body that stains densely when studied in the labo-ratory setting and is called the |
| cytoskeleton | is the cell’s internal supporting framework. Like the bony skeleton of the body, the cytoskeleton is made up of rather rigid, rodlike pieces that not only provide support but also allow movement. |
| microfilaments | The smallest cell fibers are called microfilaments. Microfila-ments often serve as part of our “cellular muscles.” They are made of thin, twisted strands of protein molecules (Figure 5-15, A). In some microfilaments, the proteins can be pulled by little “ |
| intermediate filaments | are twisted protein strands that are slightly thicker than microfilaments ( |
| micro-tubules | The thickest of the cell fibers are tiny, hollow tubes called micro-tubules. As Figure 5-15, C, shows, microtubules are made of protein subunits arranged in a spiral fashion. Microtubules are sometimes called the “engines” of the cell because they often m |
| centrosome. | An example of an area of the cytoskeleton that is very active and re-quires coordination by functional proteins is the |
| centrioles. | However, the general location of the cen-trosome is easy to find because of a pair of cylindrical structures called |
| aster | As this spindle forms, the cen-trosome is anchored by an aster, which is a formation of microtu-bules radiating outward from the centrioles. |
| molecular motors | The cell’s internal “feet” are actually little protein structures called |
| Microvilli | are found in epithelial cells that line the intestines and other areas where absorption is important ( |
| Cilia and flagella | cell processes that have cylinders made of mi-crotubules at their core. |
| Flagella | are single, long structures in the only type of human cell that has this feature: the human sperm cell |
| integrins | A group of IMPs called integrins helps hold cells in their place in a tissue. |
| Desmosomes | have the appearance of small “spot welds” that hold adjacent cells together. |
| Gap junctions | form when membrane channels of adjacent plasma membranes connect to each other. |
| Tight junctions | occur in cells that are joined near their apical surfaces by “collars” of tightly fused membrane. |
| INTRODUCTION TO TISSUES | Each tissue specializes in performing at least one unique function that helps maintain homeostasis, ensuring the survival of the whole body. |
| PRINCIPAL TYPES OF TISSUE | Epithelial tissue 2. Connective tissue 3. Muscle tissue 4. Nervous tissue |
| DEVELOPMENT OF TISSUES | Within the first 2 weeks after conception, cells of the offspring move and regroup in an orderly way into three primary germ layers called endoderm, mesoderm, and ectoderm |
| FLUID ENVIRONMENT OF THE BODY | Tissues differ in the amount and kind of fluid material be-tween the cells—the extracellular matrix (ECM). |
| COMPONENTS OF THE EXTRACELLULAR MATRIX | Proteins in the ECM include various types of structural protein fibers such as collagen and elastin, both of which are discussed frequently throughout this book. |
| Collagen | Collagenous fibers are made of the protein collagen and often occur in twisted bundles—an arrangement that provides great tensile strength |
| Elastin | Elastic fibers are made of a protein called elastin, which returns to its original length after being stretched (Figure 8-5). Elastin is a rubbery substance that is held in a fibrous shape by long, thin microfilaments |
| Glycoproteins and Proteoglycans | The ECM also contains many glycoproteins, which are mainly pro-tein molecules with attached carbohydrate subunits. Proteoglycans are hybrid molecules made up mostly of carbohy-drates attached to a protein backbone, as you can see in Figure 8-2, B |
| HOLDING TISSUES TOGETHER | it is the ECM that holds the tissue in a single mass. For example, in skeletal muscles, it is mostly a network of structural protein fibers in the ECM that holds skeletal muscle tissue together. In such cases, com-ponents of the ECM bind to the integrins |
| TISSUE REPAIR | tissues have varying capacity to repair themselves. Damaged tissue re-generates or is replaced by tissue we know as scars. Tissues usually repair themselves by allowing phagocytic cells to remove dead or injured cells and then filling in the gaps that are |
| BODY MEMBRANES | 1. Epithelial membranes, composed of epithelial tissue glued by a basement membrane to an underlying layer of supportive connective tissue. 2. Connective tissue membranes, com-posed exclusively of various types of connective tissue; no epithelial cells ar |
| EPITHELIAL MEMBRANES | There are three types of epithelial tissue membranes in the body: (1) cutaneous membrane, (2) serous membranes, and (3) mucous membranes |
| Cutaneous Membrane | The cutaneous membrane covers body surfaces that are exposed to the external environment. The cutaneous membrane, or skin, is the primary organ of the integumentary system. |
| Serous Membranes | Serous membrane lines cavities that are not open to the external environment and covers many of the organs inside these cavities. Serous membranes are sometimes called by their Latin name, serosa. |
| Mucous Membranes | Mucous membranes are epithelial membranes that line body sur-faces opening directly to the exterior. Mucous membranes are some-times called by their Latin name, mucosa. |
| CONNECTIVE TISSUE MEMBRANES | The sy-novial membranes lining the spaces between bones and joints that move are classified as connective tissue membranes. |
| epithelium | is subdivided into two types: (1) membranous (covering or lining) epithelium and (2) glandular epithelium. |
| Membranous epithelium | covers the body and some of its parts and lines the serous cavities (pleural, pericardial, and perito-neal), the blood and lymphatic vessels, and the respiratory, digestive, and genitourinary tracts. |
| Glandular epithelium | is grouped in solid cords or hollow follicles and tubes that form the secretory units of endocrine and exocrine glands. |
| Protection | It is the relatively tough and impermeable epithelial covering of the skin that protects the body from mechanical and chemical injury and also from invading bacteria and other disease-causing microorganisms. |
| Sensory functions. | Epithelial structures adapted for sensory functions are found in the skin, nose, eye, and ear. |
| Secretion. | Glandular epithelium is adapted for secretory activ-ity. Secretory products include hormones, mucus, digestive juices, and sweat. |
| Absorption | The lining epithelium of the gut and respiratory tract allows for the absorption of nutrients from the gut and the exchange of respiratory gases between air in the lungs and the blood. |
| Excretion | The unique epithelial lining of kidney tubules makes the excretion and concentration of excretory prod-ucts in the urine possible. |
| interstitial fluid | microscope, however, narrow spaces—about 20 nanometers (one millionth of an inch) wide—can be seen around the cells. These spaces, like other intercellular spaces, contain interstitial fluid ( |
| polarity | Sheets of epithelial cells make up the surface layer of skin and mucous and serous membranes. Epithelial cells exhibit a character-istic called |
| avascular | Epithelial tissues contain no blood vessels. As a result, epithelium is said to be avascular (a, “without”; vascular, “vessels”) |
| desmosomes and tight junctions | At intervals between adjacent epithelial cells, their plasma mem-branes are modified to hold the cells together. These complex inter-cellular structures, such as |
| Four cell shapes | called squamous, cuboidal, colum-nar, and pseudostratified columnar, |
| simple epithelium | An arrangement of epithelial cells in a single layer is called |
| stratified epithelium. | If epithelial cells are lay-ered one on another, the tissue is called |
| Tran-sitional epithelium | is a unique arrangement of differing cell shapes in a stratified, or layered, epithelial sheet. |
| Simple squamous epithelium | consists of only one layer of flat, scalelike cells |
| endo-thelium, | Blood and lymphatic vessel linings are called |
| mesothelium. | and the surfaces of the pleura, pericardium, and perito-neum are called |
| Simple cuboidal epithelium | is composed of one layer of cuboi-dal cells resting on a basement membrane (Figure 9-4). This type of epithelium is seen in many types of glands and their ducts. |
| Simple columnar epithelium | composes the surface of the mucous membrane that lines the stomach, intestine, uterus, uterine tubes, and parts of the respiratory tract (Figure 9-5). |
| Goblet cells | have large, secretory vesicles that give them the ap-pearance of a goblet. |
| mucus | The vesicles contain mucus, which goblet cells produce in great quantity and secrete onto the surface of the epithelial membrane. |
| cilia | are microscopic cell extensions, each supported internally by a cylindrical arrangement of microtu-bules. |
| microvilli. | In the intestine, for example, the plasma membranes of many columnar cells extend out in hundreds and hundreds of microscopic fingerlike projections called |
| Pseudostratified columnar epithelium | is found lining the air passages of the respiratory system and certain segments of the male reproductive system, such as the urethra (Figure 9-6). Although ap-pearing to be stratified, only a single layer of irregularly shaped co-lumnar cells touches the |
| Stratified squamous epithelium | is char-acterized by multiple layers of cells with typically flattened squa-mous cells at the free, or outer, surface of the epithelial sheet |
| keratinized stratified squamous epithelium | the presence of tough keratin fibers in the squamous cells contributes to the protec-tive qualities of skin covering the body surface. |
| Nonkeratinized stratified squamous epithelium | is found lining the vagina, mouth, and esophagus (Figure 9-8). Its free surface is moist, and the outer epithelial cells, unlike those found in the skin, do not contain keratin. |
| Stratified cuboidal epithelium | also serves a protective function. Typically, two or more rows of low cuboidal cells are arranged ran-domly over a basement membrane. |
| Stratified columnar epithelium | has multiple layers of columnar cells, with only the most superficial cells being obviously columnar in appearance. It is a protective type of epithelium found in only a few places in the human body. |
| Transitional epithelium | is a stratified tissue typically found in body areas that are subjected to stress and tension changes, such as the wall of the urinary bladder |
| umbrella cells | Cells in the apical (surface) layer are often called umbrella cells because of their wide, curving apical surface. |
| unicellular glands | Unlike the single or layered cells of membranous epithelium typi-cally found in protective coverings or linings, glandular epithelial cells may function singly as |
| multicellular glands | or they may function in clusters, solid cords, or hollow follicles as |
| Exocrine glands, | by definition, discharge their secre-tion products into ducts. The salivary glands are typical exocrine glands. |
| Endo-crine glands | are often called ductless glands because they discharge their secretion products (hormones) directly into blood or IF. |
| tubular and alveolar | Multicellular exocrine glands are most often classified by structure, with the shape of their ducts and the complexity (branching) of their duct systems used as distinguishing characteristics. |
| compound | exocrine glands have two or more ducts. |
| Apocrine glands | collect their secretory products near the apical face of the cell and then release them into a duct by pinching a vesicle off the distended end. |
| Holocrine glands | such as the sebaceous glands that produce oil to lubricate the skin—collect their secretory product inside the cell and then rupture completely to release it. |
| Merocrine glands | discharge their secretion product directly through the cell or plasma membrane. |
| Connective tissue | is one of the most widespread and diverse tissues in the body and is found in or around nearly every organ of the body. |
| mesenchyme, | Connective tissue arises during embryonic development from stem cell tissue called |
| Loose fibrous connective tissue, | shown in Figure 9-12, is some-times called areolar tissue. It is loose because it is stretchable, and ordinary because it is one of the most widely distributed of all tissues. |
| areolar | like a small space” and refers to the bub-bles that appear as areolar tissue is pulled apart during dissection. |
| Fibroblasts | are usually present in the greatest numbers in loose fi-brous connective tissue, |
| macrophages | are second. |
| Mast cells | also found in loose fibrous connective tissue, are ca-pable of releasing a variety of molecules such as histamine, heparin sulfate, leukotrienes, and prostaglandins. |
| Adipose tissue | differs from loose fibrous connective tissue mainly in that it contains predominantly fat cells, also called adipocytes, |
| white fat | The predominant form of adipose tissue is white fat, which serves mainly as an energy-storage depot for the body. |
| Brown fat | is a far less abundant form of adipose tissue. The small polygon-shaped adipocytes in brown fat are able to use fat stored in many small vesicles to generate heat with their numerous mitochondria |
| reticular tissue | A three-dimensional web—that is, a reticular network—identifies reticular tissue (Figure 9-16). The word reticular means “like a net.” Slender, branching reticulin fibers with reticular cells overlying them compose the reticular meshwork. |
| Dense fibrous tissue | consists mainly of fibers packed densely in the matrix. It contains relatively few fibroblast cells. |
| col-lagenous dense regular fibrous tissue | One form of dense regular fibrous tissue is predominantly bundles of collagenous fibers and may be called |
| elastic dense regular fibrous tissue. | Another form of dense (regular) fibrous tissue contains mostly elastic fibers and may be called |
| osteocytes, | The mature cells of bone, osteocytes, are embedded in a unique matrix material containing both collagen fibers and mineral salt crystals. |
| red bone marrow, | A lattice made of bone also serves as the sup-port for red bone marrow, which produces new blood cells. |
| membrane bones | Certain bones called membrane bones (e.g., flat bones of the skull) are formed within membranous tissue |
| endochondral ossification | whereas others (e.g., long bones such as the humerus) are formed indirectly through re-placement of cartilage in a process called |
| compact bone tissue | The type of bone tissue that forms the hard shell of a bone is called |
| osteon, | The basic organizational or structural unit of compact bone is the microscopic osteon, or haver-sian system |
| lacunae | Osteocytes, or bone cells, are located in small spaces, or lacunae |
| lamellae. | Osteocytes, or bone cells, are located in small spaces, or lacunae, which are arranged in concentric layers of bone matrix called lamellae |
| osteoblasts. | Mature osteocytes are actually trapped in hard bone matrix. At one time they were active, bone-forming cells called |
| osteoclast, | Another type of bone cell, the osteoclast, or bone-destroying cell, may dissolve the bone away from the mature osteocyte and release it to again become an active osteoblast. |
| cancellous bone tis-sue | Inside many bones is a lattice of thin beams of cancellous bone tis-sue |
| trabeculae, | These thin beams, or trabeculae, form a frame-work that supports a softer tissue—red bone marrow |
| myeloid tissue | Red bone mar-row is also called myeloid tissue;Myeloid tissue is a type of reticular tissue that contains the stem cells responsible for producing the various types of blood cells. |
| trabecular bone | Because cancellous bone looks somewhat like a sponge at first glance, it is sometimes called spongy bone tissue. This type of bone is also called |
| chondrocyte | Cartilage differs from other connective tissues in that only one cell type, the chondrocyte, is present. |
| perichon-drium, | Movement is through the matrix from blood ves-sels located in a connective tissue membrane called |
| Hyaline cartilage | The name is appropriate because the low amount of collagen in the matrix gives hyaline cartilage a shiny and translucent appear-ance. |
| Fibrocartilage | is the strongest and most durable type of cartilage |
| Elastic cartilage | contains few collagen fibers but large numbers of very fine elastic fibers that give the matrix material a high degree of flexibility |
| plasma | Whole blood is often divided into a matrix, or liquid fraction, called |
| formed elements, | Whole blood is often divided into a matrix, or liquid fraction, called plasma and formed elements, or blood cells. |
| Blood cells | Blood cells may be divided into three classes: red blood cells, or erythrocytes; white blood cells, or leukocytes; and thrombocytes, or platelets. |
| hematopoietic tissue. | Circulating blood tissue is formed in the red marrow of bones and in other tissues by a process of differentiation called hematopoiesis. This blood-forming tissue is sometimes given the status of a separate connective tissue type: |
| muscle tissue | are present in the body—skeletal muscle, smooth muscle, and cardiac muscle |
| Skeletal muscle tissue | makes up most of the muscles attached to bones; these are the organs that we think of as our muscles. |
| Smooth muscle tissue | also some-times called visceral muscle tissue (Figure 9-30), is found in the walls of the viscera (hollow internal organs, e.g., the stomach, intestines, and blood vessels; |
| Cardiac muscle tissue | makes up the wall of the heart |
| striated voluntary | Another name for skeletal muscle is |
| nonstriated involuntary. | Another name for smooth muscle is |
| neuroglia | Numerous surrounding cells called |
| neurons | The “nerve cells,” or neurons, are the conducting units of the nervous system. |
| nervous tis-sue | |
| soma | All neurons are characterized by a cell body called the |
| axon, | which transmits nerve impulses away from the cell body, |
| dendrites | which carry nerve signals toward the axon. |
| Microglia | help de-stroy pathogens and damaged tissue cells in the brain. |
| Schwann cells | and oligodendrocytes electrically insulate axons to increase their speed of conduction. |
| astrocytes | help regulate neuron func-tion, including protection from harmful toxins. |
| STRUCTURE OF THE SKIN OVERVIEW OF SKIN STRUCTURE | The skin—the cutaneous membrane—is a sheetlike organ that cov-ers the body and acts as a barrier between the internal and external environment.1. Epidermis—the superficial, thinner layer 2. Dermis—the deep, thicker layer |
| THIN AND THICK SKIN | Most of the body surface is covered by skin that is classified as thin skin. The hairless skin covering the palms of the hands (and finger-tips), soles of the feet, and other body areas subject to friction is classified as thick skin. |
| EPIDERMIS Cell Types | The epidermis is composed of several types of epithelial cells Keratinocytes eventually become filled with a tough, fibrous pro-tein called keratin. Melanocytes contribute colored pigments to the skin and serve to decrease the amount of ultraviolet (UV) l |
| Cell Layers | The cells of the epidermis are found in up to five distinct layers, or strata. Stratum Basal, Stratum Spinosum, Stratum Granulosum |
| Epidermal Growth and Repair | The most important function of the integument—protection—largely depends on the special structural features of the epidermis and its ability to create and repair itself after injury or disease. |
| DERMOEPIDERMAL JUNCTION | Electron microscopy and histochemical studies have demonstrated the existence of a rather unique area between the epidermis and dermis called the dermoepidermal junction (DEJ). |
| DERMIS Overview of Dermis | The dermis, or corium, is sometimes called the “true skin.” It is composed of two layers—a thin papillary layer and a thicker reticular layer. The dermis is much thicker than the epidermis and may ex-ceed 4 mm on the soles and palms. It is thinnest on the |
| Papillary Layer Dermal Papillae | Note in Figure 10-2 that the thin superficial layer of the dermis forms bumps, called dermal papillae, that project into the epider-mis. |
| Reticular Layer | The thick reticular layer of the dermis consists of a much more dense reticulum, or network of fibers, than is seen in the papillary layer above it. |
| HYPODERMIS | The hypodermis is sometimes called the subcutaneous layer, or superficial fascia. It is not always considered to be part of the skin proper, but is still included as part of the integu-ment. This layer lies deep to the dermis and thus forms a connection b |
| SKIN COLOR MELANIN Types of Melanin | Human skin ranges widely in color. The main determinant of skin color is the quantity and type of melanin deposited in the cells of the epidermis by melanocytes |
| Melanin Production | Of all body cells, only melanocytes have the ability to routinely con-vert the amino acid tyrosine into melanin pigments (Figure 10-8, top right). The pigment granules are produced and then released in tiny exosomes (vesicles) called melanosomes. |
| OTHER PIGMENTS Beta-carotene | In addition to melanin, other pigments such as the yellow pigment beta-carotene (-carotene) found in many vegetables and roots (e.g., carrots) also contribute to skin color. |
| Lipofuscin | As epidermal cells age and stop undergoing mito-sis, they often accumulate a brown-yellow pig-ment called lipofuscin. |
| Hemoglobin | An individual’s basic skin color can also change temporarily when the volume of blood flowing through skin capillaries increases or decreases. The reason is that blood contains the reddish pigment hemoglobin |
| Cosmetics and Tattoos | Pigments from cosmetics or from tattoos can also change the color-ing of the skin. Most cosmetics simply add layers of pigment on top of the skin. Some temporary tattoos also add layers of pigment on top of the skin. Henna tattoos stain epidermal cells, w |
| FUNCTIONS OF THE SKIN DIVERSITY OF SKIN FUNCTIONS | Skin functions are crucial to maintenance of homeostasis and thus to survival itself. They are also diverse and include such diverse pro-cesses as protection, sensation, growth, synthesis of important chemi-cals and hormones (such as vitamin D), excretion |
| PROTECTION Types of Protection | The keratinized stratified squamous epithelial cells that cover the epidermis make the skin a formidable barrier. It protects underlying tissues against invasion by hordes of micro-organisms, bars entry of most harmful chemicals, and minimizes mechanical |
| Surface Film | The ability of the skin to act as a protective barrier against an array of potentially damaging assaults from the environment begins with the proper functioning of a thin film of emulsified material spread over its surface. |
| SENSATION | The widespread placement of the millions of different somatic sensory receptors found in the skin enables it to function as a sophisticated sense organ covering the entire body surface |
| FLEXIBILITY | Contraction of our muscles produces the purposeful movement that serves as one of the most easily observed “Characteristics of Life” discussed in Chapter 1 |
| EXCRETION | By regulating the volume and chemical content of sweat, the body, through a function of the skin, can influence both its total fluid volume and the amounts of certain waste products, |
| HORMONE (VITAMIN D) PRODUCTION | The first step in the production of vitamin D in the body occurs when the skin is exposed to UV light. When this occurs, molecules of a chemical called 7-dehydrocholesterol, |
| IMMUNITY | Important defensive cells that attach to and destroy pathogenic mi-croorganisms are found in the skin and play an important role in immunity. |
| HOMEOSTASIS OF BODY TEMPERATURE | Despite sizable variations in environmental temperature, humans maintain a remarkably constant core body temperature. The func-tioning of the skin in homeostasis of body temperature is critical to survival and is examined in some detail |
| Heat Production | Heat is produced by one means—metabolism of foods. Because the muscles, brown fat, and glands (especially the liver) are the most ac-tive tissues, they carry on more metabolism and therefore produce more heat than any of the other tissues. |
| Heat Loss | As already stated, one mechanism the body uses to maintain relative constancy of internal temperature is to regulate the amount of heat loss. Some 80% or more of this transfer of heat occurs through the skin; the remainder takes place in mucous membranes. |
| Homeostatic Regulation of Heat Loss | The operation of the skin’s blood vessels and sweat glands must be coordinated carefully and must take into account moment-by-moment fluctuations in body temperature. Like most homeostatic mecha-nisms, heat loss by the skin is con-trolled by a negative fe |
| APPENDAGES OF THE SKIN Appendages of the skin consist of hair, nails, and skin glands. HAIR | We have about 5 million hairs on the skin of our body. About 150,000 hairs are on our heads, with the rest scattered all over the skin. Only a few areas of the skin are hairless—notably the palms of the hands and the soles of the feet. Hair is also absent |
| Development of Hair | tiny tubular pockets called hair follicles begin to develop in most parts of the skin. By about the sixth month of pregnancy the developing fetus is all but covered by an extremely fine and soft hair coat, called lanugo. |
| Appearance of Hair | Deposited in the cells of the hair are varying amounts of melanins, the pigments responsible for hair color. Although reflections of light can affect hair color somewhat, it is largely the amount, type, and distribution of melanin that determine the color |
| NAILS | Heavily keratinized epidermal cells compose fingernails and toe-nails. The visible part of each nail is called the nail body. The rest of the nail, namely, the root, lies in a flat sinus hidden by a fold of skin bordered by the cuticle Under the nail lies |
| SKIN GLANDS | The skin glands include three kinds of microscopic exocrine glands: sweat, sebaceous, and ceruminous ( |
| Sweat Glands | Sweat or sudoriferous glands are the most numerous of the skin glands. They can be classified into two groups—eccrine and apocrine—based on the type of secretion, location, and nervous system connections. |
| Eccrine Glands | Eccrine sweat glands are by far the most numerous, important, and widespread sweat glands in the body. |
| Apocrine Glands | Apocrine sweat glands are located deep in the subcutaneous layer of the skin in the armpit (axilla), the areola of the breast, and the pigmented skin areas around the anus. |
| Sebaceous Glands |
Created by:
lenora reeves
Popular Anatomy sets