The Tissue Level of Organization A. Types of tissues B. Epithelial tissues B. Epithelial tissues 1. General features 1. General features 2. Covering and lining epithelia 2. Covering and lining epithelia a. Arrangement of layers a. Arrangement of layers b. Cell shapes b. Cell shapes c. Classification c. 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 (columnar) (5) Stratified cuboidal (columnar) (6) Pseudostratified (6) Pseudostratified (7) Transitional (7) Transitional 3. Glandular epithelia 3. Glandular epithelia a. Structural classification a. Structural classification b. Functional classification b. Functional classification C. Connective tissues 1. General features 1. General features 2. Classification 2. Classification a. Loose connective tissues a. Loose connective tissues (1) Areolar (1) Areolar (2) Adipose (2) Adipose (3) Reticular (3) Reticular b. Dense connective tissues b. Dense connective tissues (1) Dense regular (1) Dense regular (2) Dense irregular (2) Dense irregular (3) Elastic (3) Elastic c. Cartilage c. Cartilage (1) Hyaline (1) Hyaline (2) Fibrocartilage (2) Fibrocartilage (3) Elastic (3) Elastic d. Specialized connective tissues d. Specialized connective tissues (1) Osseous (1) Osseous (2) Vascular (2) Vascular D. Membranes D. Membranes 1. Mucous membranes 1. Mucous membranes 2. Serous membranes 2. Serous membranes 3. Cutaneous membranes 3. Cutaneous membranes 4. Synovial membranes 4. Synovial membranes

What is a tissue? A similar group of cells working together to serve a particular function

Types of Tissue 1. epithelial 2. connective 3. muscle 4. nervous

Epithelial Tissues 1. covering and lining 2. glandular

General Features of Epithelia 1. closely packed cells 2. continuous sheets 3. apical vs basal surface 4. basement membrane 5. avascular 6. nerve supply 7. high mitotic rate Apical Surface Basal Lamina Vs. Reticular Lamina

Covering and lining epithelia You are responsible for Handout #2 Epithelial Tissues 1. arrangement of layers a. simple a. simple b. stratified b. stratified c. pseudostratified c. pseudostratified 2. shape of apical cells a. squamous a. squamous b. cuboidal b. cuboidal c. columnar c. columnar d. transitional d. transitional

Simple Squamous External 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 Squamous Skin: Sole of FootMucosa 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 Cuboidal Kidney Tubules Location: lines kidney tubules and small ducts of many glands, covers ovary, forms pigmented epithelium of retina Function: absorption and secretion

Stratified Cuboidal Duct of a Sweat Gland Location: relatively rare; lines larger ducts of some glands and part of the male urethra Function: protection

Simple Columnar Internal 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 Columnar Location: Limited regions of the Pharynx, larynx, Anal canal, and Male urethra (very rare)

Pseudostratified Mucosa 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

Transitional Allantoic 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 Epithelium 1. secretory portions of glands 2. endocrine vs exocrine

Structural classification of exocrine glands 1. unicellular gland (the goblet cell) 2. multicellular gland

Functional Classification of Exocrine Glands 1. merocrine (eccrine) 2. holocrine 3. apocrine

Connective Tissues Three basic elements: 1. cells 2. ground substance 3. fibers a. collagen a. collagen b. elastin b. elastin c. reticular fibers c. reticular fibers Matrix = ground substance + fiber(s)

Classification of Connective Tissues 1. 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 tissues 2. Dense connective tissues a. dense regular (fibroblastic cell type) b. dense irregular (fibroblastic cell type) c. elastic (fibroblastic cell type)

Classification of Connective Tissues Continued… 3. Cartilage (chondrocytic cell type) a. hyaline a. hyaline b. fibrocartilage b. fibrocartilage c. elastic c. elastic 4. Bone 5. Blood

Know Handout #3 Connective Tissue Types Three Basic Elements 1. Cells 2. 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) Location(s): papillary dermis of skin, hypodermis, mucous membranes, blood vessels, nerves, and around body organs (i.e. everywhere) papillary dermis of skin, hypodermis, mucous membranes, blood vessels, nerves, and around body organs (i.e. everywhere)Description: loosely woven fibers embedded in ground substance; many different cell types wander through; fibroblasts form basic tissue Function: strength, elasticity, and support

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) 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 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 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) 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 Cartilage Location: 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

Fibrocartilage Location: 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 Cartilage Location: 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

Bone Location: 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

Blood Location: within blood vessels and heart Description: formed cellular elements suspended in a liquid matrix (plasma) Function: transport of gases, immune function, blood clotting

Membranes 1. mucous membrane (mucosa) 2. serous membrane (serosa) a. parietal layer vs. visceral layer a. parietal layer vs. visceral layer (serous fluid) b. endothelium (endocardium) b. endothelium (endocardium) c. mesothelium c. mesothelium 3. cutaneous membrane (epidermis) ________________________________________ 4. synovial membrane (not really a membrane)