Chapter 4

1. Chapter 4 The Tissue Level of Organization Lecture slides prepared by Curtis DeFriez, Weber State University

2. Tissues • __________ are a group of cells with a common embryonic origin that function together to carry out __________ __________. • They include various types, ranging from __________ (bone) to __________ (fat) to __________ (blood).

3. Tissues • __________ is the study of the microscopic anatomy of cells and tissues – it is a branch of __________. • Of the 10 trillion cells in our body, no single cell type can said to be “typical”. A trained histologist can recognize over ______ distinct human cell types under the microscope and is able to distinguish a cell from pancreatic tissue as opposed to a cell from the skin. • Each cell type has features particular to its function.

4. Intracellular Junctions • Tissues are formed by grouping cells together using a variety of __________ __________ . • Intracellular Junctions connect adjacent cells mechanically at the cell membranes or through cytoskeletal elements within and between cells.

5. Intracellular Junctions • __________ are found where a __________ is needed between cells. • They keep materials from leaking out of organs like the stomach and bladder.

6. Intracellular Junctions • __________ make an adhesion belt (like the belt on your pants) that keeps tissues from separating as they stretch and contract. • Cadherin is a __________ that forms the belt-like “__________”.

7. Intracellular Junctions • __________ act as “__________”. They also use cadherin glycoprotein (plus intermediate filaments) to hook into the cytoplasm.

8. Intracellular Junctions • __________ are half-welds that join cells to the basement membrane.

9. Intracellular Junctions • __________ are pores (__________) that allow small substances like ions to pass between cells. If one of the cells gets sick or dies, these seal like a hatch to prevent damage to other cells.

10. The 4 Basic Tissues • Of all the cells in the body, they combine to make only 4 basic tissue types: • __________ tissues • __________ tissues • __________ tissues • __________ tissues

11. The 4 Basic Tissues • __________ tissues __________ body surfaces and _____ glands and ______ hollow organs, body cavities, and ducts.

12. The 4 Basic Tissues • __________ tissues (C.T.) ______, _______, and __________ organs. • Fat is a type of C.T. that stores energy. • Red blood cells, white blood cells, and platelets are all C.T.

13. The 4 Basic Tissues • __________ tissues generate the physical force needed to make body structures _____. They also __________ used by the body. • __________ tissues _____ changes in the body and __________ by generating nerve impulses.

14. The 4 Basic Tissues • Tissues of the body develop from three primary germ layers: __________, __________, and __________ Epithelial tissues from all three germ layers • C.T. and muscle are derived from mesoderm. • Nervous tissue develops from ectoderm.

15. Epithelium • __________ is used to line surfaces and form __________ __________. Epithelium is also good at __________ things like mucous, hormones, and other substances . • All epithelia have a ___________________ and an attached basal surface. • Most epithelial tissue is avascluar

16. Epithelium • The _______ layer of the epithelium secretes a _____ __________ lamina; the underlying C.T. secretes a __________ __________. • Together the basal lamina and the reticular lamina form a non- cellular __________ membrane on which the epithelium sits.

17. Epithelium • Epithelia are named according to the __________ of their cells, and the __________ or __________ of their layers (of cells).

18. Epithelium

19. Epithelium • Naming epithelia according to shape

20. Epithelium • Naming epithelia according to arrangement

21. Epithelium • Naming epithelia • Three different cell shapes x three different cell arrangements = nine possibilities. Two of these are not used. Add __________(cells that change shape), and we’re back up to eight possible combinations. • If different shapes are present in layers of cells, the epithelium is always named by the shape of cells in the __________ (outermost) layer.

22. Epithelium • __________ Epithelium is composed of a __________ layer of __________ cells found: • In the air sacs of ____ • In the lining of blood __________, the __________, and lymphatic __________ In all capillaries, including those of the kidney • As the major part of a __________ membrane

23. Epithelium • __________ Epithelium is composed of a __________ layer of __________ cells. • It is often found lining the tubules of the kidneys and many other glands.

24. Epithelium • __________ Epithelium forms a __________ layer of __________ cells, ± cilia, ± microvilli, ± mucous (goblet cells). • __________ cells are simple columnar cells that have differentiated to acquire the ability to secrete mucous.

25. Epithelium • __________ __________ Epithelium appears to have layers, due to nuclei which are at various depths. In reality, all cells are attached to the basement membrane in a single layer, but some do not __________ __________. • __________ tissue has goblet cells that secrete mucous.

26. Epithelium • __________ Epithelium has an __________ surface that is made up of squamous (flat) cells. • The other layers have different shapes, but the name is based on the apical layer. • The __________ are ideal for protection against strong friction forces.

27. Epithelium • __________ Epithelium has an apical surface made up of two or more layers of cube-shaped cells. • Locations include the sweat glands and part of the ♂ urethra • __________ Epithelium is very rare, and for our purposes, hardly worth mentioning.

28. Epithelium • The cells of Transitional Epithelium change shape depending on the state of stretch in the tissue. • The apical “dome cells” of the top layer (seen here in relaxation) are an identifiable feature and signify an empty bladder . • In a full bladder, the cells are flattened.

29. Epithelium • Although epithelia are found __________ the body, certain ones are associated with specific body locations. • __________ epithelium is a prominent feature of the __________ of the skin.

30. Epithelium • __________ squamous makes up epithelial membranes and lines the blood vessels. • __________ is common in the digestive tract. • __________ __________ columnar is characteristic of the upper respiratory tract. • __________ is found in the bladder. • __________ lines ducts and sweat glands.

31. Covering and Lining Epithelium • __________ is a specialized __________ epithelium that lines the entire circulatory system from the heart to the smallest capillary – it is extremely important in reducing turbulence of flow of blood. • __________ is found in __________ membranes such as the pericardium, pleura, and peritoneum. • Unlike other epithelial tissue, both are derived from embryonic mesoderm (the middle layer of the 3 primary germ layers of the embryo).