The Tissue Level of The Tissue Level of OrganizationOrganization

A. Types of tissuesA. Types of tissues B. Epithelial tissuesB. Epithelial tissues 1. General features1. General features 2. Covering and lining epithelia2. Covering and lining epithelia a. Arrangement of layersa. Arrangement of layers b. Cell shapesb. Cell shapes c. Classificationc. Classification (1) Simple squamous(1) Simple squamous (2) Simple cuboidal(2) Simple cuboidal (3) Simple columnar(3) Simple columnar (4) Stratified squamous(4) Stratified squamous (5) Stratified cuboidal (5) Stratified cuboidal

(columnar)(columnar) (6) Pseudostratified(6) Pseudostratified (7) Transitional(7) Transitional 3. Glandular epithelia3. Glandular epithelia a. Structural classificationa. Structural classification b. Functional classificationb. Functional classification

C. Connective tissuesC. Connective tissues 1. General features1. General features 2. Classification2. Classification a. Loose connective tissuesa. Loose connective tissues (1) Areolar(1) Areolar (2) Adipose(2) Adipose (3) Reticular(3) Reticular b. Dense connective tissuesb. Dense connective tissues (1) Dense regular(1) Dense regular (2) Dense irregular(2) Dense irregular (3) Elastic(3) Elastic c. Cartilagec. Cartilage (1) Hyaline(1) Hyaline (2) Fibrocartilage(2) Fibrocartilage (3) Elastic(3) Elastic d. Specialized connective tissuesd. Specialized connective tissues (1) Osseous(1) Osseous (2) Vascular(2) Vascular D. MembranesD. Membranes 1. Mucous membranes1. Mucous membranes 2. Serous membranes2. Serous membranes 3. Cutaneous membranes3. Cutaneous membranes 4. Synovial membranes4. Synovial membranes

What is a tissue?What is a tissue?

A similar group of cells working A similar group of cells working together to serve a particular functiontogether to serve a particular function

Types of TissueTypes of Tissue

1. epithelial 1. epithelial

2. connective2. connective

3. muscle 3. muscle

4. nervous4. nervous

Epithelial TissuesEpithelial Tissues

1. covering and lining1. covering and lining

2. glandular2. glandular

General Features of EpitheliaGeneral Features of Epithelia

1. closely packed cells1. closely packed cells

2. continuous sheets2. continuous sheets

3. apical vs basal surface3. apical vs basal surface

4. basement membrane4. basement membrane

5. avascular5. avascular

6. nerve supply6. nerve supply

7. high mitotic rate7. high mitotic rate

Apical Surface

Basal LaminaVs. Reticular Lamina

Covering and lining epitheliaCovering and lining epithelia You are responsible for Handout #2 You are responsible for Handout #2

Epithelial TissuesEpithelial Tissues1. arrangement of layers1. arrangement of layers

a. simplea. simple

b. stratifiedb. stratified

c. pseudostratifiedc. pseudostratified

2. shape of apical cells2. shape of apical cells

a. squamousa. squamous

b. cuboidalb. cuboidal

c. columnarc. columnar

d. transitionald. transitional

Simple SquamousSimple SquamousExternal Surface (Serosa) of Small Intestine

Location:

lining heart (endocardium) and blood vessels (endothelium), lymphatic vessels, alveoli of lungs, glomerular capsule of kidneys,part of serous membranes

Function:

diffusion, osmosis, and filtration

Stratified SquamousStratified SquamousSkin: Sole of Foot

Mucosa of Vagina

Location: keratinized form forms epidermis

nonkeratinized forms line mouth and tongue, pharynx, esophagus, anal canal, and vagina Function:

protection against wear-and-tear

Simple CuboidalSimple CuboidalKidney Tubules

Location:

lines kidney tubules and small ducts of many glands, covers ovary, forms pigmented epithelium of retina

Function:

absorption and secretion

Stratified CuboidalStratified CuboidalDuct of a Sweat Gland

Location:

relatively rare; lines larger ducts of some glands and part of the male urethra

Function:

protection

Simple ColumnarSimple ColumnarInternal Surface (Mucosa) of Small Intestine

Location:

lines GI tract from stomach to anal canal, ducts of some glands, gallbladder; ciliated form lines oviducts, uterus, central canal of spinal cord

Function:

Secretion and absorption

Stratified ColumnarStratified Columnar

Location:

Limited regions of thePharynx, larynx,Anal canal, and Male urethra(very rare)

PseudostratifiedPseudostratifiedMucosa of the Trachea

Location:

lines much of lower respiratory system down to bronchiolar level; nonciliated form may be found in some gland ducts, epididymis, and part of male urethra

Function:

secretion from goblet cells, movement of mucous across surface by ciliary action

TransitionalTransitionalAllantoic Duct of Umbilical Cord

Location:

urinary bladder!!!, portions of ureters and urethra

Function:

allows distention of organ without causing an increase in tension in wall of organ

Glandular EpitheliumGlandular Epithelium

1. secretory portions of glands1. secretory portions of glands

2. endocrine vs exocrine2. endocrine vs exocrine

Structural classification of Structural classification of exocrine glandsexocrine glands

1. unicellular gland (the goblet cell)1. unicellular gland (the goblet cell)

2. multicellular gland2. multicellular gland

Functional Classification of Functional Classification of Exocrine GlandsExocrine Glands

1. merocrine (eccrine)1. merocrine (eccrine)

2. holocrine2. holocrine

3. apocrine3. apocrine

Connective TissuesConnective Tissues

Three basic elements:Three basic elements:1. cells1. cells2. ground substance2. ground substance3. fibers3. fibers a. collagena. collagen b. elastinb. elastin c. reticular fibersc. reticular fibers

Matrix = ground substance + fiber(s)Matrix = ground substance + fiber(s)

Classification of Connective TissuesClassification of Connective Tissues

1. Loose connective tissues1. Loose connective tissues

a. areolar (fibroblastic cell type)a. areolar (fibroblastic cell type)

b. adipose (adipocytic cell type)b. adipose (adipocytic cell type)

c. reticular (fibroblastic cell type)c. reticular (fibroblastic cell type)

2. Dense connective tissues2. Dense connective tissues a. dense regular (fibroblastic cell type) b. dense irregular (fibroblastic cell type) c. elastic (fibroblastic cell type)

Classification of Connective Classification of Connective Tissues Continued…Tissues Continued…

3. Cartilage (chondrocytic cell type)3. Cartilage (chondrocytic cell type)

a. hyalinea. hyaline

b. fibrocartilageb. fibrocartilage

c. elasticc. elastic

4. Bone4. Bone

5. Blood5. Blood

Know Handout #3 Know Handout #3 Connective Tissue TypesConnective Tissue Types

Three Basic ElementsThree Basic Elements

1. Cells2. Ground substance (ground substance is a

more or less homogeneous, amorphous, water-based background substance in which the specific differentiated elements of a connective tissue are suspended.

3. Fibers (E.g. collagen, elastin, reticular)

Matrix= Ground substance + fibers that separates cells

Areolar (Loose)Areolar (Loose)

Location(s):Location(s): papillary dermis of skin, papillary dermis of skin,

hypodermis, mucous hypodermis, mucous membranes, blood vessels, membranes, blood vessels, nerves, and around body nerves, and around body organs (i.e. everywhere)organs (i.e. everywhere)

Description:Description: loosely woven fibers embedded loosely woven fibers embedded in ground substance; many in ground substance; many different cell types wander different cell types wander through; fibroblasts form basic through; fibroblasts form basic tissuetissue

Function:Function: strength, elasticity, and supportstrength, elasticity, and support

Adipose (Loose)Adipose (Loose)

Location: hypodermis; around heart, kidneys, and eyes; yellow bone marrow; around joints

Description: adipocytes that store fats, forming a characteristic “signet ring” appearance

Function: provide insulation, energy storage, protection from mechanical injury

Reticular (Loose)Reticular (Loose)

Location:stroma of liver, spleen, lymph nodes; red bone marrow; basement membranes

Description:net work of very short interlacing collagen fibers and fibroblasts

Function:form framework of organs, binds together smooth muscle cells

Dense RegularDense Regular

Location:tendons, aponeuroses, and most ligaments

Description:collagen fibers arranged in parallel bundles, with fibroblasts scattered between

Function:provides strong attachments between parts

Dense IrregularDense Irregular

Location:dense fascia, reticular dermis, perichondrium, periosteum, joint capsules, dura mater, membrane capsules, heart valves

Description:collagen fibers randomly arranged and fibroblasts, forming a sheet

Function:strength, support, and protection

Elastic (Dense)Elastic (Dense)

Location:lung, elastic arteries, trachea and bronchial tree, true vocal cords, vertebral ligaments, suspensory ligament of penis

Description:elastic fibers that branch freely, forming sheets or ligaments

Function:provides extensibility and elasticity to various organs that must be stretched

Hyaline CartilageHyaline CartilageLocation:articular surfaces of bones; anterior ribs; nose, parts or larynx, trachea, and bronchial tree; embryonic skeleton

Description:Chondrocytes embedded in cartilage matrix rich in collagen fibers

Function:resists compressive forces, provides smooth surfaces for articulation at synovial joints

FibrocartilageFibrocartilageLocation:pubic symphysis, intervertebral discs, menisci of shoulders and knees

Description:consists of scattered Chondrocytes with hyaline cartilage matrix among bundles of collagen fibers

Function:support, fusion (between pubic bones and between vertebrae), deepening of shoulder and knee joints

Elastic CartilageElastic CartilageLocation:epiglottis, external ear, auditory tubes

Description:Chondrocytes embedded in cartilage matrix rich in network of elastic fibers

Function:allows structure to be semi-rigid and extensible; structure can return to resting shape

BoneBoneLocation:comprises the bones of the skeleton

Description:osteocytes embedded in a mineralized matrix of collagen fibers and ground substance

Function:support, protection, storage, provides levers for movement; provides for blood cell formation

BloodBlood

Location:within blood vessels and heart

Description:formed cellular elements suspended in a liquid matrix (plasma)

Function:transport of gases, immune function, blood clotting

MembranesMembranes

1. mucous membrane (mucosa)1. mucous membrane (mucosa)2. serous membrane (serosa)2. serous membrane (serosa)

a. parietal layer vs. visceral layer a. parietal layer vs. visceral layer (serous fluid)(serous fluid)

b. endothelium (endocardium)b. endothelium (endocardium) c. mesotheliumc. mesothelium3. cutaneous membrane (epidermis)3. cutaneous membrane (epidermis)

________________________________________________________________________________4. synovial membrane (not really a membrane4. synovial membrane (not really a membrane))