Portage Learning Anatomy and Physiology Module 2

Tissue

group of cells that work together to perform one or more specific functions

Intracellular

internal environment inside the cells

Extracellular

environment outside the cells

Extracellular matrix

substance to help regulate their extracellular material and fluids

Histology

the microscopic study of the structure of tissues and their surrounding extracellular matrix

Epithelial

covers exposed surfaces, lines, pathways/cavities and can produce glandular secretions

Connective tissue

supports and underlines other structures and fills the internal space of the body

Muscle tissue

contract to enable movement

Nervous Tissue

carries electrical impulses and translates information to control activities of the body

Polarity

unique surfaces with specialized features

Apical (free)

facing external environment or inside of a lumen (opening). Allows cells to secrete or absorb materials from lumen.

Microvilli

finger-like extensions on apical that add extra surface area to cells, allowing for extra secretion and absorption

Cilia

longer cytoplasmic extensions that have an internal structure that allows for their movement (found in trachea and bronchi)

Avascular

do not have a direct blood supply

Basal surface

connects the basement membrane (noncellular - protein rich, allowing for cells to anchor to it for support)

Regenerative

the ability of epithelial tissue cells to regenerate through constant division of stem cells.

Cell Junction

connected between adjoining cells with specialized intercellular connections with unique proteins

Hyaluronan

polysaccharide derivative that helps lock epithelial cells together called intercellular cement

Gap junctions

permit the free diffusion of ions and small molecules between cells.

Tight junctions (occluding junctions)

serve as an impermeable barrier that do not allow solutes and fluids to diffuse between the cells in these locations.

Adhesion belt

forms deep to the tight junction, forming a handlike structure between cells.

Spot desmoses

help tie adjacent cells together and provide strong attachment between cells using CAM's.

Hemidesmos

connect half of the cell to the basal membrane

Stem cells

constantly dividing to replace lost or damaged cells.

High regeneration

Because of constantly damaged due to location in high-traffic areas.

Simple Epithelial Tissue

Cells that are only one layer thick.

Stratified Epithelial Tissue

Cells that have two or more layers.

Squamous Cells

Cells are wider than the height; thin and flat.

Cuboidal Cells

Cells have the same height, width and depth; square and cube.

Columnar Cells

Height of the cell is greater than width; tall, thin, rectangular.

Simple Squamous Epithelium

One layer thick, allows for materials to be exchanged through diffusion through cells.

Endothelium

Lining of the blood and lymphatic vessels.

Endocardium

Lining of the ventricles and atria of the heart.

Mesothelium

Lining the walls and closed cavities of the body (abdominal, pericardial and pleural cavities).

Stratified Squamous Epithelium

Forms the epidermis; found in oral cavity, esophagus and vagina.

Simple Cuboidal Epithelium

Absorption and secretion of substances; found in small ducts of exocrine glands, kidney tubules and thyroid gland.

Stratified Cuboidal Epithelium

Acts as a physical barrier for protection and specializes in secretion and absorption; found in lining of ducts, sweat glands and larger ducts of exocrine glands.

Simple Columnar Epithelium

Absorption and secretion; found in the small intestine and colon.

Stratified Columnar Epithelium

Serves mostly for protection; found in largest ducts of exocrine glands, pharynx, and epiglottis.

Pseudostratified Epithelium

Cells appear to be stratified but are actually one layer of cells made up of different sizes; functions for protection and secretion.

Transitional Epithelium

Allows cells to expand and stretch repeatedly to absorb fluid without causing cellular damage; found in the urinary tract (bladder and ureters).

Exocrine Glands

Release their products directly onto epithelial surface through duct or tube.

Endocrine Glands

Secrete their products directly into connective tissue; ductless.

Hormones

Products of an endocrine gland that enter bloodstream to reach target cell.

Paracrine Glands

Secrete substances that do not reach bloodstream but only affect other cells nearby in the same epithelium.

Merocrine Secretion

Product is delivered via membrane-bound vesicles to apical surface; vesicle fuse with plasma membrane and release via exocytosis.

Apocrine Secretion

Product is released from the apical side of the cell.

Holocrine secretion

Product accumulates within the maturing cell and at the appropriate time undergoes apoptosis (programmed cell death).

Unicellular glands

Simplest structure because it is one single secretory cell among other non-secretory cells.

Goblet cells

Found in ciliated columnar epithelium in the lining of intestines and trachea; function to secrete mucus to provide a protective layer.

Multicellular glands

Structure of more than one cell, classified by the arrangement of the secretory cells and type of branching the gland exhibits.

Simple exocrine glands

Duct is unbranched.

Simple tubular gland

Shaped like a tube.

Simple coiled tubular gland

Shaped like a coil.

Simple branched tubular gland

Multiple secretory branches.

Simple alveolar (acinar) gland

Outpouching of secretory portion.

Simple branched alveolar gland

Branches of multiple acinar-shaped secretary portions.

Compound glands

Duct is branched.

Compound tubular gland

More than one branch with tube-like secretary portion.

Compound alveolar gland

More than one branch with outpouching of secretary portions.

Compound tubulo-alveolar gland

More than one branch with a combination of tubelike and alveolar-type secretory portions.

Basal lamina

Created by connective tissue to connect with all other structures of the body.

Connective tissue fibers

Include collagen fibers, reticular fibers, and elastic fibers.

Collagen fibers

Long and straight with no branches, high tensile strength, flexible and strong when pulled lengthwise.

Reticular fibers

Thinner and have branching to form a mesh-like network, important for holding organs in place.

Elastic fibers

Branched and wavy, composed of elastin, allows return to original shape after stretching.

Ground substance

Clear, thick syrup substance with a high amount of water content, fills spaces between cells and fibers.

Fibroblast

Secretes hyaluronan and proteins, helps lock epithelial cells together.

Macrophages

Phagocytize (ingest) pathogens, damaged cells, or debris to rid them of the body.

Adipocytes

Fat cells that push the nucleus and other organelles off to the side.

Mesenchymal cells

First connective tissue to develop in an embryo, can divide and turn into other types of connective tissue cells.

Mast cells

Move around and tend to reside near blood vessels, release chemicals histamine and heparin after an injury.

Neutrophils and eosinophils

Phagocytic cells that move through connective tissue, attracted to the area to help fight infection.

Lymphocytes

Travel through connective tissues and throughout the entire body, can develop plasma cells to produce antibodies.

Areolar tissue

High number of elastic fibers in a loose, open network, acts as a shock absorber.

Adipose tissue

Provides padding, absorbs shocks, helps insulate the body from heat loss, and stores energy.

Reticular tissue

Contains reticular fibers that form a complex network of tissues to support functional cells of organs.

Dense regular connective tissue

Arranged as tightly packaged, parallel collagen fibers to withstand forces.

Tendons

Connect muscle tissue to bone.

Ligaments

Connect bone tissue to other bones or stabilize internal organs.

Aponeuroses

Flat sheets of fibrous connective material like a tendon.

Dense irregular connective tissues

Support stress from many different angles, interwoven network of fibers.

Elastic connective tissue

Primarily composed of elastic fibers, supports vertebral column.

Blood

Contains plasma and formed elements, including erythrocytes and leukocytes.

Erythrocytes

Transport oxygen and carbon dioxide in the blood.

Leukocytes

White blood cells, including neutrophils, eosinophils, basophils, lymphocytes, and monocytes.

Platelets

Tiny membrane-bound cytoplasm with special proteins and enzymes that help in blood clotting.

Lymph

Formed from interstitial fluid entering lymphatic vessels.

Cartilage

Made up of chondrocytes, avascular, surrounded by perichondrium.

Hyaline cartilage

Most common type of cartilage, provides stiff but somewhat flexible support.

Elastic cartilage

 contains a high number of elastic fibers

Fibrocartilage

Prevents bone-to-bone contact and limits movement.

Neurons

Conduct electrical impulses, allowing for propagation of information.

Skeletal muscle tissue

Contains large cells, moves or stabilizes the position of the skeleton.

Cardiac muscle tissue

Only found in the heart, produces movement to pump blood.

Pacemaker cells

Regulate the contraction of cardiac tissue at regular intervals.

Common characteristics of Connective tissue

Provide support, structure, protection and insulation; basal lamina created by connective tissue to connect with all other structures of the body; transport materials and provide storage and energy reserves.

Antibodies

Specialized proteins that help defend the body against pathogens.

Smooth muscle tissue

involuntary. Small and spindle shaped with ends that become gradually smaller at each end; moves food, urine and reproductive tract secretion, controls diameter of respiratory passageways; regulates diameter of blood vessels.

Smooth muscle tissue characteristics

Found throughout the body; nonstriated involuntary muscle - nervous system does not provide control; contract on their own with gap junctions.