Anatomy and Physiology Lab I Jenny Simmons Email: jsimmons@irsc.edu

Tissues Histology: The study of tissues Tissue: A collection of cells that perform related functions, and are similar in structure 4 Major types of tissues: Epithelial Connective Muscular Nervous

Epithelial Tissue Found: covers body surfaces lines hollow organs, body cavities and ducts also found in glands. Has an apical or free surface which is exposed to the body exterior or the cavity of an internal organ Has a basal or attached surface that adheres to connective tissue attachment between the basal surface and the connective tissue is a thin extracellular layer called the basement membrane. Avascular---without blood vessels nutrients diffuse in from blood vessels in underlying connective tissue Good nerve supply Rapid cell division; responsive to environmental stresses Named according to the shape and arrangement of cells

Classification of Epithelia Simple: one layer Stratified: multiple layers of cells Figure 4.1a

Classification of Epithelia Squamous, cuboidal, or columnar Figure 4.1b

Simple Squamous Epithelia Function: filtration (kidneys) and diffusion (air sacs of lungs) Location: Kidney glomeruli, alveoli of lungs, lining of heart, kidney corpuscles, and blood and lymphatic vessels.

Lung

Simple Squamous Microscope slide #1

Simple Squamous (surface view) Microscope slide #22

Stratified Squamous Epithelia Function: Protects underlying tissue in areas subject to abrasion Location: lines skin(keratinized), mouth, esophagus, vagina (all non-keratinized) Microscope slide # 2 **Note: For all stratified epithelia: Name is based off cells on apical surface. All cells connected to basal membrane will either be cuboidal or columnar!

Epithelia: Simple Cuboidal Single layer of cubelike cells with large, spherical central nuclei Function in secretion and absorption Present in kidney tubules, ducts and secretory portions of small glands, and ovary surface

Simple Cuboidal Epithelia Microscope slide # 3 (you can also see simple cuboidal in slide #1)

Simple Columnar Function: Protection, secretion of mucus, absorption Location: lining of stomach, intestine, gallbladder, uterine tube, collecting ducts of kidneys Microscope Slide # 4

Simple Columnar Epithelium Gall Bladder Simple columnar epithelium lines the gall bladder. Note the underlying connective tissue with blood vessels.

Pseudostratified Columnar Ciliated Epithelia Function: Secretion and propulsion of mucus Location: Lining of ducts, ciliated: lines trachea and most of upper respiratory tract Features: Has goblet cells that secret mucus & is ciliated. Looks layered, but only has a single layer of cells (all cells are attached to basement membrane

Epithelia: Transitional (Microscope Slide #6) Several cell layers, basal cells are cuboidal, surface cells are dome shaped Stretches to permit the distension of the urinary bladder Lines the urinary bladder, ureters, and part of the urethra

Transitional Epithelium (Ureter) 3 apical (free) surface

Transitional Epithelium Urinary Bladder The expandable stratified epithelium of the bladder is referred to as transitional epithelium. Note that its surface cells are large rather than flattened as in stratified squamous epithelium.

transitional epithelium of mucosa Ureter 100X transitional epithelium of mucosa lamina propria smooth muscle adventitia

* Ureter 400X lamina propria smooth muscle transitional epithelium

Bladder (Empty) White line- defines height of epithelium

Bladder (Full) Orange arrow - Flattened "plump" cells White line- defines height of epithelium