A&P Integumentary System

ULTIMATE A&P INTEGUMENTARY SYSTEM STUDY GUIDE

Tissues

groups of similar cells and extracellular material that perform a common function.

Histology

The study of tissues.

Extracellular matrix

composed of varying amounts of protein fibers, water, and dissolved molecules.

Consistency - fluid to semisolid

4 major types of tissues

1. Epithelial

2. Connective

3. Muscular

4. Nervous

Epithelial Tissue

Covers body and organ surfaces, lines body and organ cavities, forms glands.

Connective Tissue

Binds, supports, and protects other tissues and organs

Muscular Tissue

Moves the skeleton, organ walls, or body structures

Epithelial Tissue

composed of one or more layers of closely packed cells and contains little or no extracellular matrix between the cells.

Cellularity of epithelial

Epithelial tissue is composed of almost entirely tightly packed cells

Apical surface

Basal surface

Epithelia has an ___________ which is exposed either to the external environment or some internal body space.

Also has a ____________ where the epithelium is attached to a basement membrane with underlying connective tissue.

Molecular layers of basement membrane in epithelial tissue

Lamina lucida, lamina densa, and reticular lamina

Strengthens the attachment

Functions of epithelial basement membrane

Avascularity of Epithelial

lacks blood vessels, however nutrients can diffuse across the basal surface from blod vessels within the underlying connective tissue.

To detect changes in the environment.

Function of extensive innervation (lots of nerves) in epithelial tissue

Physical protection

Selective permeability

Secretions

Sensations

Functions of epithelial tissue

Simple dimple

Single layer of cells

Stratified

Two or more layers of cells for more structural support and better protection

Pseudostratified

Different distribution of cells’ nuclei, all cells are attached to basement membrane but do not reach apical surface

Squamous

Flat, wide, and somewhat irregular

cuboidal

Cube-shaped

Columnar

column-shaped

Transitional

Readily change shape depending on the degree at which the epithelium is stretched

Simple squamous epithelium

Simple layer of flattened cells

Simple squamous epithelium

Form the thinnest possible barrier to allow rapid movement of molecules and ions across the epithelium membrane

Simple Squamous epithelium

Form the lining of the alveoli of the lungs

Simple Squamous epithelium

Found lining the lumen of capillary walls for easy diffusion of O2 and CO2

Simple Squamous epithelium

Form serous membranes, which cover body organs and secrete serous fluid.

Endothelium

Blood vessel walls (Simple Squamous Epithelium)

Mesothelium

Serous membranes of body cavities

Simple cuboidal epithelium

Allows for both absorption and secretion

Their shape make them ideal for forming structural components of glands

Simple cuboidal epithelium

Composes the walls of small duct like the kidney tubules

Forms the follicles of the thyroid gland and covers each ovary.

Absorption and secretion

basic Functions of simple columnar epithelium

Non-ciliated columnar epithelium

Often contains microvilli and a scattering of unicellular glands called goblet cells.

Simple columnar epithelium

Lines most of the digestive tract from the stomach to the anal canal

Secretes mucin to form mucus

Simple columnar epithelium

Pseudostratified columnar epithelium

(2) Cilia from apical surface

mucus covers apical surface

helps with movement

Simple columnar epithelium

Lines the larger bronchioles in the lungs and the luminal surface of the uterine tubes

Pseudostratified columnar epithelium

Found mostly in the upper respiratory tract (trachea)

Pseudostratified non-ciliated columnar epithelium

Rare, lacks goblet cells, and found in part of the male urethra

Keratinized stratified squamous epithelium

Filled with a protein called keratin, which is a tough, protective protein that strengthens the tissue but also kills the cell.

Non-keratinized stratified squamous epithelium

Lack keratin

Forms the surface of the pharynx, part of the larynx, esophagus, vagina, and anus

Transitional epithelium

Epithelium limited to the urinary tract

Glands

individual cells or multi-cellular organs composed mainly of epithelial tissue

Glands

Secrete substances either for use elsewhere int eh body or for elimination from the body

Such as mucin, ions, hormones, enzymes, or urea.

Endocrine glands

Glands that lack ducts and secrete hormones that are transported by the blood to target organs or tissues

Unicellular exocrine glands

Do not contain a duct and are located close to the surface of the epithelium

Multi-cellular exocrine glands

Contain numerous cells that work together to produce a secretion

Typically surrounded by a fibrous capsule which is divided into lobes

merocrine glands

package their secretions into secretory vesicles and release the secretions by exocytosis

salivary glands

Apocrine glands

secretion occurs when the cell’s apical portion pinches off, releasing cytoplasmic content

Mammary glands

holocrine glands

formed from cells that accumulate a product; the entire cell then disintegrates

Connective tissue

the most diverse, abundant, and widely distributed of the tissues.

Functions to support, protect, and bind organs

areolar

well vascularized connective tissue

dense regular

poorly vascularized connective tissue

contains fibroblasts

mature cartilage

avascular connective tissue

cells, protein fibers, and ground substance

All connective tissues share three basic components:

adipose

connective tissue that contains adipocytes

cartilage

connective tissue that contains chondrocytes

Resident cells

stationary cells which help support, maintain and repair the extracellular matrix

fibroblasts

flat cells with tapered ends

adipocytes

fat cells

mesenchymal cells

embryonic stem cells and divide when tissue becomes damaged

Fixed macrophages

type of WBC derived from monocytes which phagocytize damaged cells of pathogens.

(out of blood)

Wandering cells

Continuously move through the tissue

Primarily leukocytes

mast cells

small, mobile cells found close to blood vessels

Plasma cells

Formed when B-lymphocytes are activated. Produce antibodies

Free macrophages

Mobile phagocytic cells

protein fibers

strengthen and support tissue

Collagen fibers

strong, flexible, and resistant to stretching

Comprises about 25% of the body’s protein content

Reticular fibers

Similar to collagen but much thinner. Tough but flexible. Abundant in the framework of organs, such as lymph nodes, spleen, and liver

Elastic fibers

Contain elastin. Stretch and recoil. Appear yellow

Abundant in the skin, arteries and lungs

ground substance

A non-cellular material produced by the connective tissue cells

ground substance

Contains GAGs, that attract H2O which provides the fluidity.

May be viscous, semi-solid, or solid

mesenchyme

mucous

Two types of embryonic connective tissue

mesenchyme embryonic connective tissue

First kind of tissue in developing embryo

Mucous connective tissue

Located in the umbilical cord

Atoms

Cells

Tissues

Organ

Organ system

Organism

Levels of organization

Loose

Dense

2 Types of connective tissue proper

Areolar

Adipose

Reticular

Three types of loose connective tissue

Regular

Irregular

Elastic

Three types of dense connective tissue

Loose Connective Tissue

Contains fewer cells and protein fibers

Used for supporting surrounding structures and organs

Well-vascularized

Loose Areolar connective tissue

Collagen and some elastic fibers and well-vascularized

Fibroblasts

Found in skin and surrounding organs for protection

Loose Adipose connective tissue

Composed of adipocytes and well-vascularized

Filled with lipid droplets

Loose Reticular connective tissue

Houses abundant leukocytes and some fibroblasts within a network of reticular fibers

Forms the stroma of lymphatic organs

Dense regular connective tissue

Abundant collagen fibers, few fibroblasts, limited ground substance

found in tendons and ligaments

very few blood vessels

Dense irregular connective tissue

clumps of collagen fibers extending in all directions so resistant to stress in multiple directions

found in dermis of skin

Elastic connective tissue

Composed of numerous fibroblasts and densely packed elastic fibers to stretch and recoil

walls of large arteries, trachea, and vocal chords

Cartilage

Bone

Two types of supporting connective tissue

Cartilage

Firm, semisolid extracellular matrix containing collagen and elastic protein fibers.

more flexible than bone

avascular

hyaline

fibrocartilage

elastic cartilage

3 types of cartilage

Hyaline cartilage

provides flexible support to structures

most common type of cartilage

Structures of the respiratory tract, epiphyseal plates, and ends of long bones

fibrocartilage

Weight-bearing cartilage

dense collagen fibers resists compression and tensile forces

Elastic cartilage

Flexible cartilage containing numerous elastic fibers in its extracellular matrix

External ears and epiglottis

Bone connective tissue

Osseous connective tissue

more solid than cartilage

extensively vascularized

Compact

Spongy

Two types of bone

compact bone

Perforated by many neurovascular canals

Organized histologic pattern

Bone cells called osteocytes housed in lacunae

spongy bone

Located in interior of bone, ends of long bone

strong and light-weight

Blood

lymph

Two types of fluid connective tissue

blood

fluid connective tissue composed of formed elements and liquid ground substance called plasma

Lymph

derived from blood plasma but does not contain cellular components or fragments

Muscle tissue

Well-vascularized

produces movement

skeletal, cardiac, smooth

3 types of muscle tissue