Medic 14 A&P Ch 4 v2

Without; avascular

From; apocrine

Heart;pericardium

Cartilage;perichondrium

Tree; dendrites

ligament;demosome

Glue; neuroglia

Tissue; histology

entire;holocrine

Glass; hyaline cartilage

between; interstitial

to secrete; exocrine

Pool;lacunae

part; merocrine

nerve; neuron

bone;osseous tissue

around;perichondrium

to eat; macrophage

ribs; pleural membrane

false; pseudostratified

to set; interstitial

body; desmosome

plate or scale; squamous

vessel; vascular

• Identify the bodys four major tissue types and describe their roles
• discuss the types of functions of epithelial cells
• describe the relationship between form and functions for each epithelial type
• compare the structures and functions of the various types of connective tissues
• explain how epithelial and connective tissues combine to from four types of membranes and specify the functions of each
• discribe the three types of muscle tissue and the special structural freatures of each
• discuss the basic structure and role of neural tissue
• explaing how tissues respond i a coordinatied mannor to maintain homeostasis
• describe how aging affects the tissues of the body

Study of tissues

• Epithelial tissue
• connective tissue
• muscle tissue
• neural tissue

collections of cells and extracellular material that preform a specific, but limited range of functions

• Covers exposed surfaces 
• line internal passageways and chambers
• produce glandular secretions

• Fill internal spaces
• provides structural support
• store energy

conracts to produce active movement

• conducts electrical impulses 
• carries information

• Epithelia: Layers of cells that conver internal or external surfaces 
• Glands: are composed of secreting cells derived from epithelia

• As opposed to other tissue types epithelia cells are bound closely together
• A free (apical surface exposed to the enviroment or to some internal chamber or passageway
• Attachment ot underlying connective tissue by a basement membrane
• Avascular
• Epithelial cells that are damaged are continually replaced or regenerated

• cover external and internal body surfaces 
• covers skin, epithelia line inernal passageways like the respiratory, digestive reproductive and urinary tracts.

• Physical protection
• Control permeability 
• provide sensation
• specialized secretions: Exocrine, Endocrine

Protects eposed internal and external surfaces from abrasion, dehydration, and destruction by chemical or biological agents

Any substance that enters or leaves the body must cross and epithelium

Specialized epithelia cells can detect changes in the enviroment and relat information about such changes to the nervous system

• Gland cells are scattered among other cell types in the epithelium 
• glandular epithelium most or all cells are actively produce secretions

secretions are discharged to the surface of the epithelium

• Secretions are released into the surrounding tissue fluid and blood.
• these secretions are called hormones

• Transmembrane proteins calle cell adhesion molecules (CAMs)
• and intracellular cement (a protein polysaccharide mixture)

• Tight junction
• gap junctions
• desmosomes

• the lipid layers of adjacent cell membranes  tightly bound together by interlocking membrane proteins
• basal to the tight junction is a continuous adhesion belt that encircles cells and binds them to their neighbors
• tight junctions prevent passage or water and solutes between cells. common between epithelial cells exposed to harsh chemicals or powerful enzymes. like the digestive tract

• Two cells held together by embedded membrane proteins
• they are channel proteins they form a narrow pasageway that lets small molecules and ions pass from cell to cell.
• GAp juntions interconnect cells in some ciliated epithelia
• most abundent in cardiac muscle and smooth muscle tissue, they are essential to the coordination or muscle contractions.

the cell membrane  of two cells are locked together by intercellular cement and by membrane proteins connected to a network of intermediate filaments

• desmosomes hat form a small disc are called button desmosomes
• hemidesmosomes resemble half of abutton desmosomes and attach a cell to the basement membrane
• Desmosomes are abundant between cells in the spierficial layers of the skin

• the apical surface of epithelial cells have specialized structures that distinguish them from other body cells
• Microvilli line / cilia etc

• No cells in the basement membrane, consists of a network of protein fibers.
• provides a barrier that restricts the moment of proteins and othjer large molecules from the inderlying connective tissue into the epitheliem

Germinative cells/ stem cells

• Layering: simple and stratified 
• Cell shapes: squamous,cuboidal, and columnar

• Consists of a single layer of cells that cover the basement membrane
• Only found in protected areas of body due to how fragile they are
• they are characteristic of regions where secretion or absorption occurs

• Provides greater protecion because ot has several layers of cells about the basement membrane
• found in areas subject to mechanical or chemical stresses

thec ells are thin and flat, and the nucleus occupies the thickets portion of each cell

Resmble little hexagonal boxes when seen in three dimensions , but in typical secional view they appear square.

cells are also hexagonal but taller and more slender. The nuclei are crowded into a narrow band to close to the basement membrane and the height of the epithelium is several times the distance between the two nuclei

• Found where absorption takes place or where a slippery surface reduces  friction
• lungs,lining of ventral body cavities, and the lining of the blood vessesl and inner surfaces of the heart.

• Provides limited protection where secretion or absorption takes place. These functions are enhanced by larger cells, which have room for the necessary organelles
• Secrete enzymes and buffers into the pancreas and salivary glands
• Kidney tubules involved in the production of urine

• provides some protection and may also occur in areas of absorption or secretion
• lines stomach, intestional tract, and excretory ducts

• Looks stratified but isnt
• All cells make contact with basement membrane

most of the nasal cavity, trachea, and bronchi, and portions of the male reproductive tract.

Withstands considerable stretching. its lines the ureters and urinary bladder.

Where mechanical stresses are severe.

• epithelia lining ventral body cavities;lining of the heart and blood vessels; portions of the kidney tubules(thin sections of loops of henie); inner lining of cornea;alveoli 
• Reduces frictionl; controls vessel permeability; preforms absorption and secretion

• glands;ducts; portions of the kidney tubules; thyroid gland
• limited protection,secretion, absorption

• Lining of the stomach,intestine,gallbladder,uterine tubes and collecting ducts of kidneys
• Protection,secretion, absorption

• lining of the nasal cavity,trachea, and bronchi:portions of the male reproductive tract
• protection, secretion

• Urinary bladder; renal pelvis of kidneys; ureters
• permits expansion, and recoil after stretching

• Surface of the skin, lining of the mouth, throat, esophagus,rectum, anus, and vagina
• provides physical protection against abrasion,pathogens, and chemical attack

Are discharge their products a duct or tube onto some external or internal surface

• are produced by ductless glands and released into blood or tissue fluids 
• Unicellular glands(goblet cells)
• multicellular glands

simplest multicellular exocrine gland that lines the stomach and protects it fromits own acids and enzymes

mode of secretion

• Merocrine
• Apocrine
• Holocrine

• Mucin mixes with water to from mucus
• Cell stays intact

Involves loss of both cytoplasm and the secretory product

Entire cells becomes packed with secretions and ten bursts and dies

• Secretion occurs through exocytosis
• saliva from salivary glands; mucus in digestive and respiratory tracts; perspiration on the skin; milk in the breasts

• Secretion occurs through the loss of cytoplasm that contains secretory product
• milk in breats; viscous underarm perspiration

• Secretion occurs through loss of entire cell that contains secretory product
• Skin oils and waxy coating of hair (produced by sebaceous glands of the skin)

• Watery, solution that contains enzymes 
• secretions of parotid salivary gland

• thick, silppery mucus
• Secretions of sublingual salivary gland

• Produces more than one type of secretion
• secretions of submandibular salivary gland(serous and mucous)

are the most diverse tissues of the body.

• Specialized cells
• Protein fibers
• Fluid known as ground substance

extracellular proteins and ground substance

Epithelial tissue is comprised almost entirely of cells, the majority of the volume of connective tissue is the extracellular matrix

Many connective tissues are highly vascular, and contain receptors that provide pain pressure temperature and other sensations

• Support and protection
• Transportation of materials 
• storage of energy reserves 
• defense of the body

• Connective tissue proper:loose and dense
• Fluid connective tissue:blood and lymph
• Suupporting connective tissues:cartilage and bone

• consists of many type of cells and fibers within a matrix that contains a syrupy ground substance.
• examples are the tissue that underlies the skin,fatty tissue, and tendons and ligaments

• have a distinctive population of cells suspended in a matrix of watery ground substance that contains dissolved proteins.
• Blood and lymph

• have a less diverse cell population thatn connective tissue proper and a matrix of dense ground substnace and closely packed fibers.
• Cartilage and bone

Most abundant cells in connective tissue proper. Perminant residents responsible for producing and maintaining the connective tissue and ground substance

• Scattered throughout the matrix. "big eater" engulf or phagocytise damaged cells or pathogens that enter the tissue.
• Release chemicals that mobolize the immune system, and attract other macrophages and other cells involved in tissue defense

• Perminant residents
• contain such a large droplet of lipid that the nucleus and other organelles are squeezed to one side of the cell

Small mobile connective tissue often found near blood vessels. Cytoplasm of a mast cell is packed with vesicles filled with chemicals that are released to begin the bodys defensive activites after and injury or infection

• Collagen fibers
• Elastic fibers
• Reticular

Are long straight and unbranded. these strong but flexable fibers are the most common fibers in the connective tissue proper

Contain the protein elastin. THey are branched and wavy and after stretching will return to their original length

The least common of the three, are thinner than collagen fibers and commonly form a branching interwoven framework in various organs

• loose connective tissue 
• dense connective tissue

• is the least specialized connective tissue in the adult body
• Contains all the cells and fibers found in any connective tissue proper, in addtion to an extensive blood supply.

• Or fat
• is a loose connective tissue that contains large number of fat cells 
• common under the skin of the sides,buttock, and breasts.

• consist of mostly collagen fibers 
• may also be fibrous or collagenous tissues
• Dense regular conective tissue
• Dense irregular connective tissue

are chords of dense regular connective tissue that attach skeletal muscles to bones

• Resemble tendons but connect one bone to another
• ligaments contain elastic fibers as well as collagen fibers

Beneath dermis of skin, digestive tract, respiratory and urinary tracts: between muscles; around blood vessels nerves and around joints

Deep to the skin, especially at sides, buttocks, breasts, padding around eyes and kidneys

Provides padding and cushions shocks: insulates; stores energy reserves

• Between skeletal muscles and skeleton(tendons); between bones (ligaments) covering skeletal muscles; capsules of internal organs
• provides firm attachment conducts pull of muscles; reduces friction between muscles; stablizes relative postions of bones; helps preven overexpansion of organs

• blood and lymph that contain distinctive collections of cells in the fluid matrix.
• in blood the matrix is caled plasma.
• Red blood cells-transport oxygen
• white blood cells- immune
• platelets, which are cell fragments that function in blood clotting.

Cartilage and bone

Strong framework for the body

a firm gel that contains embedded fibers

• only cells found within the matrix, live in small pockets known as lacunae
• Due to cartilage being avascular , chondrocytes must obtain and eliminate waste products by diffusion

• a perchondrium
• Which contains an inner cellular layer and an outer fibrous layer

• Hyaline cartilage 
• Elastic carto;age
• fibrocartilage

Most common type of cartulage. the matrix contains closely packed collagen fibers which make hyaline cartilage tough but flexable

contains  numerous elastic fibers that make it extremely resilant and flexable

has little ground substance and its matrix is dominated by collagen fibers. these fibers are densly interwoven which makes this tissue extremely durable and tough

• Between tips of ribs amd bones of sternum; covering bone surfaces at synovial joints; supporting larynx, trachea and bronchi; forming par of the nasal septum
• Provides stiff but somewhat flexible support, reduces friction between bony surfaces

• Auricle of external ear; epiglottis; acoustic canal; cuneiform cartilages of larynx
• Provides support but tolerates distortion withot damage and returns to origional shape

• Pads within knee joint; between pubic bones of pelvis; intervertebral discs separating vertebrae
• resitis compression; prevents bone to bone contact; limits relative movement

• Lacuanae within the matrix contains bones cells or osteocytes
• Lacunae surrpond the blood vessels that branch thrpigh the bony matrix.

cytoplasmic extensions that reach blood vessels and other osteocytes through a branching network within the  boney matrix called canaliculi

is a covering that contains

Epitheelia and connective tissue combine to form membraes that cover and protect other structures and tissues

• Mucous
• serous
• cutaneous
• synovial

• Lines cavities that communicate with the exterior including the digestive, respiratory, reproductive and urinary tract
• the connective tissue portion of the lamina propria
• lined with simple epithelia that preform absorptive or secretory functions

• line the sealed internal subdivisions of the ventral body cavity
• Pleura
• Peritoneum
• Pericardium
• fiction is reduced by serous fluid formed from underlying tissues

• Covers the surface of the body 
• membrane is thick and relatively waterproof

Bones contact one another at joints

• Consists primarily of loose connective tissue and an incomplete layer of epithelial tissue
• lines joints that allow free movement

• Specialized for contraction
• interactions between filaments of myosin and actin. which are proteins in the cytoskeleton of many cells.

• Skeletal
• cardiac
• smooth

• contains very large multinucleated cells
• Because they are relaively long and slender they are ususally called muscle fibers
• Will not contract unless stimulated by nerves
• Striated voluntary muscle

• Only found in the heart
• Is striated  
• cell only has a single nucleus
• Cardiac muscle cells are interconnected at incalated discs, attachment sites that contain gap junctions and demosomes 
• pacemaker cells are responsible for the automaticty of the heart.
• Striated involuntary muscle

• Is found in the walls of blood vessels, around hollow organs.
• Cells is small and slender
• cells have one nucleus
• is not striated 
• smooth muscle cells can divide and can regenerate after injurt
• Smooth muscle cells may contract on their own or contractions may be triggered by neural activity.
• Nonstriated involuntary muscle

• is specialized for conduction of electrical impulses from one region of the body to the other.
• most neural tissue 98% is concentrated in the brain and spinal cord.

• Neurons
• Neuroglia
• Our concious and unconcious thought processes reflect communication between neurons.
• Neuroglia provide physical support for neural tissue, maintain the chemical composition of tissue fluids, supply nutrients to neurons, and defend the tissue from infection.

• Cell  body that contains a large nucleus
• numerous branching projections called dendrites- recieve information
• one axon- carry information to other cells.
• axons are also called nerve fibers
• each axon ends at a synaptic terminal, where the neuron communicates with other cells.

• Inflamnation 
• regeneration

Area is isolated from neighboring healhty tissue while dmaaged cells, tissue components and any dangerous microorganisms are cleaned up.

They trigeer inflammatory response by stimulating mast cells(release histamine and heparin)

Fibroblasts produce a dense network of collagen fibers known as scar tissue or fibrous tissue.

Permanent replacement  damaged cells with fibrous connective tissue