Anatomy and Physiology

1. Anatomy and Physiology November 4, 2013

2. November 4, 2013 Objective • SWBAT: Differentiate between ALL types of tissues by their functions and characteristics. • Resulting in: A better understanding of tissues in the human body. • As measured by: An exit slip with 80% mastery.

3. Classification of Epithelia • Ask two questions: • How many layers? 1 = simple epithelium >1 = stratified epithelium

4. Apical surface Basal surface Simple Apical surface Basal surface Stratified (a) Classification based on number of cell layers. Figure 4.2a

5. Classification of Epithelia • What type of cell? • Squamous • Cuboidal • Columnar • (If stratified, name according to apical layer of cells)

6. Squamous Cuboidal Columnar (b) Classification based on cell shape. Figure 4.2b

7. Overview of Epithelial Tissues 1. Simple Squamous Epithelium • Description: single layer of flattened cells w/disc-shaped central nuclei & sparse cytoplasm, simplest of epithelia • Function: :Allows passage ofmaterials by diffusion and filtrationin sites where protection is notimportant; secretes lubricatingsubstances in serosae.

8. Epithelia: Simple Squamous • Locations: A. Endothelium • The lining of lymphatic vessels, blood vessels, and heart, air sacks of lungs B. Mesothelium • The epithelium of serous membranes in the ventral body cavity

9. (a) Simple squamous epithelium Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia. Air sacs of lung tissue Function: Allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae. Nuclei of squamous epithelial cells Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity (serosae). Photomicrograph: Simple squamous epithelium forming part of the alveolar (air sac) walls (125x). Figure 4.3a

10. Overview of Epithelial Tissues 2. Simple Cuboidal Epithelium • Description: single layer of cube-like cells with large, spherical central nuclei. • Function: Secretion andabsorption. • Location: Kidney tubules;ducts and secretory portionsof small glands; ovary surface.

11. (b) Simple cuboidal epithelium Description: Single layer of cubelike cells with large, spherical central nuclei. Simple cuboidal epithelial cells Function: Secretion and absorption. Basement membrane Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface. Connective tissue Photomicrograph: Simple cuboidal epithelium in kidney tubules (430x). Figure 4.3b

12. Overview of Epithelial Tissues 3. Simple Columnar Epithelium • Description: Single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells) • Function: :Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action.

13. Overview of Epithelial Tissues 3. Simple Columnar Epithelium continued: • Location: Non-ciliated type lines most of the digestive tract (stomach to anal canal),gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regionsof the uterus.

14. (c) Simple columnar epithelium Description: Single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain mucus- secreting unicellular glands (goblet cells). Simple columnar epithelial cell Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action. Location: Nonciliated type lines most of the digestive tract (stomach to anal canal), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus. Basement membrane Photomicrograph: Simple columnar epithelium of the stomach mucosa (860X). Figure 4.3c

15. Overview of Epithelial Tissues 4. Pseudostratified Columnar Epithelium • Description: Single layer of cells ofdiffering heights, some not reachingthe free surface; nuclei seen atdifferent levels; may contain mucus-secreting cells and bear cilia. • Function: Secretion, particularly ofmucus; propulsion of mucus byciliary action.

16. Overview of Epithelial Tissues 4. Pseudostratified Columnar Epithelium • Location: :Non-ciliated type in male’ssperm-carrying ducts and ducts oflarge glands; ciliated variety linesthe trachea, most of the upperrespiratory tract.

17. (d) Pseudostratified columnar epithelium Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus- secreting cells and bear cilia. Cilia Mucus of mucous cell Pseudo- stratified epithelial layer Function: Secretion, particularly of mucus; propulsion of mucus by ciliary action. Location: Nonciliated type in male’s sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract. Basement membrane Photomicrograph: Pseudostratified ciliated columnar epithelium lining the human trachea (570x). Trachea Figure 4.3d

18. 11-4-13 Exit Slip: On the paper given: make a simple drawing to represent each of the simple epithelia tissues discussed today in class. Simple squamous epithelium Simple cuboidal epithelium Simple columnar epithelium Pseudostratified columnar epithelium