Overview of Human Tissue Types: Structure, Function, and Classification

1. Chapter Five Tissues

2. Terms • Tissue • Histology: the study of tissue structure • Pathology: the study of cells and tissues for diagnostic purposes

3. 4 tissue types • Epithelial • Connective • Muscle • Nervous

4. Epithelial • Avascular • Has nerve supply • Easily renewable • Functions: protection, secretion, absorption, excretion, sensory reception • Classified by cell shape and layer arrangement

5. Epithelial cell shape • Squamous-flat and thin • Cuboidal-cube-shaped • Columnar-tall and cylindrical • Transitional-cell shape changes

6. Epithelial layer arrangement • Simple-single layer • Stratified- two or more layers • Pseudostratified-one layer that appears to have several layers

7. Simple Squamous Epithelium • Structure: • Single layer of flat thin cells • Function: • diffusion • Location: • Alveoli of lungs; capillaries; heart lining

8. Simple Cuboidal Epithelium • Structure: • Single layer of cube-shaped cells • Function: • Secretion and absorption • Location: • Ducts of glands; ovarian surface

9. Simple Columnar Epithelium • Structure: • Nonciliated: single layer of tall & narrow cells without cilia • Ciliated: single layer of tall & narrow cells with cilia • Function: • Nonciliated: secretion (Goblet cells) and absorption • Ciliated: movement of mucus • Location: • Lines tracts with environmental openings

10. Pseudostratified Epithelium • Structure: • 1 layer of tall & narrow cells that appears to be more than 1--but it is not • Ciliated (w/ cilia) and nonciliated (no cilia) • Function: • Secretion & movement of mucus • Location: • Lines airways of upper respiratory tract

11. Pseudostratified - ???

12. Stratified Squamous Epithelium • Structure: • 2 or more flat, thin layers • Function: • protection • Location: • Esophagus, tongue, vaginal lining, epidermis of the skin

13. Stratified Cuboidal Epithelium • Structure: • 2 or more layers of cube-shaped cells • Function: • Protection; limited secretion and absorption • Location: • Sweat gland ducts

14. Stratified Columnar Epithelium • Structure: • 2 or more layers of tall & narrow cells • Function: • Protection & excretion • Location: • Conjunctiva of eye; excretory ducts

15. Transitional Epithelium • Structure: • Appearance of cells ranges from squamous to cuboidal & columnar • Function: • Allows for stretching without tearing (distensibility) • Location: • Urinary bladder

16. Glandular Epithelium a/k/a Glands • Glands: consists of a cell or group of cells that secrete substances into ducts, onto surfaces, or into blood • 2 types: • Exocrine: secretion goes through a duct • Ex. Sweat, oil, saliva, pancreas • Endocrine: secretion goes into blood stream without passing through a duct • Ex. Thyroid, pituitary, & pancreas

17. Connective Tissue • Most abundant and widely distributed tissue in the body • Consists of cells and a matrix (determines a tissues qualities; may be fluid, gel, fibers) • Has a nerve supply • Highly vascular (except cartilage) **You only need to know the MATURE connective tissues.**

18. Mature Connective Tissue • Areolar • Adipose • Dense Regular • Dense Irregular • Elastic • Cartilage • Compact Bone • Blood

19. Areolar Connective Tissue • Location • Subcutaneous layer of skin • Function • Strength • Support • elasticity

20. Adipose Connective Tissue • Location • Around heart, kidneys, eyes, and in yellow bone marrow • Function • Energy reserve and protection

21. Dense Regular Connective Tissue • Location • Tendons • Muscle to bone • Ligaments • Bone to bone • Function • attachment

22. Dense Irregular Connective Tissue • Location • Fascia: covers organs • Periosteum: covers bones • Perichondrium: covers cartilage • Pericardium: covers heart • Function • Provides strength

23. Elastic Connective Tissue • Location • Lung tissue, trachea, vocal cords, bronchial tubes • Function • stretching

24. Cartilage • Location • Nose, voice box, epiglottis, external ear, pubis symphysis • Function • Support, cushioning, rigidity, flexibility

25. Compact Bone • Location • Bones (osteocytes) • Function • Support, protection, storage

26. Blood • Location • Blood vessels, heart • Function • Transport gases, immunity, clotting

27. Nervous Tissue • Tissue of the nervous system • Basic functioning unit = neuron

28. The neuron • Cell body (soma) • Dendrites (many) • Axon (one)

29. Muscle Tissue • 3 types • Skeletal • Smooth • Cardiac

30. Skeletal Muscle • Attaches to bones of skeleton • Striated (striped) in appearance • voluntary

31. Smooth Muscle • Makes up walls of internal organs • Nonstriated • Involuntary

32. Cardiac Muscle • Found in heart • Striated with intercalated discs • involuntary

33. Membranes • Tissues that cover or line a part of the body • 3 types • Mucous • Synovial • Serous

34. Mucous Membranes • Line body cavities that open to the environment • Secrete mucus • Ex: digestive system, reproductive system, respiratory system

35. Synovial Membranes • Line the cavities of some joints • Secrete synovial fluid • Lubricates joints to prevent friction during movement • Bursae are often present here as well • bursitis

36. Serous Membranes • Line body cavities that do not open to the environment • Secrete serous fluid • 2 layers: • Parietal: lines cavity wall • Visceral: covers organ(s) • 3 locations: • Lungs = pleura • pleurisy • Heart = pericardium • pericarditis • Abdomen = peritoneum • peritonitis

37. So... • Visceral pleura=covers lungs • Parietal pleura=lines thoracic cavity • Visceral pericardium=covers heart • Parietal pericardium=lines pericardial cavity • Visceral peritoneum=covers abdominal organs • Parietal peritoneum=lines abdominal cavity

38. Pleural membranes

39. Interactive Review • Blood • Muscle Tissue