A brief overview of histology.
- 2. Histology is the study of tissues. • Tissues (tissu = woven) • Group of cells • One common function • 4 primary tissue types: https://prezi.com/nmdubq8dvhzh/tissues/
- 3. EPITHELIAL TISSUE http://web.clark.edu/rrausch/biolabs/histo/epithelia/PCCE_100.jpg
- 4. Characteristics • 2 types: • Covering and lining epithelium • Glandular epithelium • Forms boundaries • Roles: • Protection • Absorption • Filtration • Excretion • Secretion • Sensory reception • Polarity • Specialized contacts • Connective Tissue supported • Regeneration • Avascular • Innervated What are some examples of these roles in the body?
- 5. Polarity • Apical-basal polarity • Apical Features • Microvilli • Cilia • Basal lamina • Glycoproteins & collagen • Filter • scaffolding Basolateral Surface Basal Lamina Apical Surface Microvilli Cilia
- 7. E.T. have a two-part name. • First part describes the number of layers of cells. • Simple = one layer • Stratified = more than one layer • Second part describes the shape of the cells. • Squamous = flattened • Cuboidal = box shape, tall as they are wide • Columnar = column shape, taller than they are wide
- 8. Nuclei usually conforms to the shape of the cell!!! Flattened cell = flattened nucleus Cuboidal cell = spherical nucleus Column cell = elongated nucleus This will help you when identifying tissue types!!!
- 9. Simple Epithelia: • Simple Squamous Epithelium • Filtration membrane of kidneys • Alveoli of lungs • Endothelium: friction reducing lining in lymphatic and cardiovascular system • Mesothelium: serous membranes Thin, absorption, secretion, gas exchange http://web.clark.edu/rrausch/biolabs/histo/epithelia/alveoli.jpg http://www.gwc.maricopa.edu/class/bio201/Histology/0SimpleSquam_Surface1_400X_rev.jpg
- 10. Simple Epithelia: • Simple Cuboidal Epithelium • Secretion and absorption • Glandular ducts • Kidney tubules Thin, absorption, secretion, gas exchange http://antranik.org/wp-content/uploads/2011/09/simple-cuboidal-epithelium.png • Simple Columnar Epithelium • Lines digestive tract • Absorption and secretion • Goblet cells • Microvilli http://www.ouhsc.edu/histology/Glass%20slides/52_03.jpg
- 11. Simple Epithelia: • Pseudostratified Columnar Epithelium • False layers • Goblet cells • Cilia • Lines respiratory tract (trachea) Thin, absorption, secretion, gas exchange http://antranik.org/wp-content/uploads/2011/09/pseudostratified-ciliated-columnar-epithelium.png
- 12. Stratified Epithelia: • Stratified Squamous Epithelium: • Protection • Apical cells are squamous, basal are cuboidal or columnar • Epidermis (keratinized) and body openings (non- keratinized) http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/ Exam%202%20Review/Epidermis_40x.jpg
- 13. Stratified Epithelia: • Transitional Epithelium • Ability to stretch and return to normal shape and size. • Urinary system (urinary bladder) http://www.highlands.edu/academics/divisions/scipe/biology/faculty/harnden/2121/images/transitional.jpg
- 14. Stratified Epithelia: • Stratified Columnar: • Rare in body • Pharynx (fair-inks), male urethra • Stratified Cuboidal: • Rare in body • Sweat glands, mammary glands
- 15. Glandular Epithelia: • Gland – one or more cells that secrete something (secretion). • Endocrine glands: • Ductless • Produce hormones • Most are multicellular organs (pituitary gland) • Exocrine glands: • Secrete directly onto surface (unicellular) or into ducts (multicellular) • Goblet cells are unicellular exocrine glands. • Multicellular exocrine glands: • Merocrine: secrete by exocytosis • Pancreas, sweat glands, salivary glands • Holocrine: secrete within cells and then cell ruptures • Oil glands (sebaceous glands) • Apocrine: apex of cell pinches off and releases secretion (mammary glands)
- 18. Classes of Connective Tissue Connective Tissues CT Proper Loose CT Areolar Adipose Reticular Dense CT Dense Regular Dense Irregular Elastic Cartilage Hyaline Elastic Fibrous Bone Fluid Blood Lymph
- 19. CT Characteristics • Ground Substance • Fills space between cells • Interstitial fluid, Cell Adhesion Molecules, proteoglycans • Fibers • Provide support • Three types: • Collagen: strongest • Stronger than steel fibers of same size! • Elastic: gives tissue some elasticity • Reticular: basement membrane, around capillaries • Cells • Immature (undifferentiated) secretes ground substance and fibers. • -blasts • Mature cells are less active. • -cyte
- 21. Connective Tissue Proper: Loose CT• Areolar CT • Support tissues, storage, defense • Universal packing material • Soaks up excess fluid during inflammation = edema. http://www.highlands.edu/academics/divisions/scipe/biology/faculty/harnden/2121/images/areolar.jpg
- 22. Connective Tissue Proper: Loose CT • Adipose Tissue • Store nutrients, primarily fat • Adipocytes • Closely packed cells • Shock absorption, energy storage, insulation • Poor heat conductor = loose less body heat • Abdomen, eyes, kidneys, beneath skin, etc. http://www.deltagen.com/target/histologyatlas/atlas_files/musculoskeletal/adipose_tissue_white_40x.jpg
- 23. Connective Tissue Proper: Loose CT • Reticular CT • Only reticular fibers • Fibroblasts • Lymph nodes, spleen, bone marrow • Forms network to support blood cells, mainly WBC’s
- 24. Connective Tissue Proper: Dense CT (AKA fibrous CT) • Dense Regular CT • Closely packed collagen fibers • High tensile strength • Fibroblasts • Wavy = little stretch • Poorly vascularized • Tendons – muscle to bone • Ligaments – bone to bone • Aponeurosis – muscle to muscle • Fascia – wraps muscle fibers, nerves, and blood vessels together http://classes.midlandstech.edu/carterp/Courses/bio210/chap04/Slide17.JPG
- 25. Connective Tissue Proper: Dense CT (AKA fibrous CT) • Dense Irregular CT • Thicker collagen bundles arranged irregularly • Found in dermis • High tensile strength http://www.ouhsc.edu/histology/Glass%20slides/43_04.jpg
- 26. Connective Tissue Proper: Dense CT (AKA fibrous CT) • Elastic CT • Stretchability • Some ligaments (vertebrae) • Larger arteries http://classconnection.s3.amazonaws.com/507/flashcards/974507/png/elastic_dense_connective_tissue 1327459744783.png
- 27. Cartilage • Withstands tension and compression. • No nerve fibers and avascular. • Heals slowly • Nutrients come from diffusion through perichondrium. • Up to 80% water • Chondroblasts produce new matrix until skeleton stops growing. • Chondrocytes are found in groups in cavities called lacunae.
- 28. Carilage • Hyaline – most abundant in body • Articular cartilage (end of long bones) • Absorb compression in joints • Nose • Connects ribs to sternum • Respiratory system • Embryonic skeleton http://kentsimmons.uwinnipeg.ca/cm1504/15lab42006/lb4pg6_files/image017.jpg
- 29. Cartilage • Elastic – elastic fibers • External ear and epiglottis • Fibrocartilage – rows of chondrocytes alternating with rows of collagen • Withstand heavy pressure • Intervertebral discs http://classes.midlandstech.edu/carterp/Courses/bio210/chap04/Slide20.JPG http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/ Exam%201%20Review/04-08i_Fibrocartilage.JPG
- 30. Bone Tissue • Osseous tissue • Support, protection, storage, blood cell production • Collagen and inorganic calcium salts • Osteoblasts and osteocytes • Highly vascular http://classes.midlandstech.edu/carterp/Courses/bio210/chap04/Slide22.JPG
- 31. Fluid CT • Blood: • Cells: RBC’s, WBC’s • Matrix: Plasma • Fibers: function in blood clotting • Lymph: blood in lymphatic system http://classes.midlandstech.edu/carterp/Courses/bio210/chap04/Slide23.JPG
- 32. MUSCLE TISSUE http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19917.jpg
- 33. Muscle Tissue • Many cells • Highly vascular • Produce body movements • Three types: • Skeletal • Cardiac • Smooth
- 34. Skeletal Muscle • Attached to bones • Movement of skeleton • Muscle fibers (muscle cells) • Striated (actin and myosin) • Multinucleated • Many mitochondria • Long, cylindrical • Voluntary Control http://cellbiologyolm.stevegallik.org/sites/histologyolm.stevegallik.org/images/SkeletalMuscle_2.jpg
- 35. Cardiac Muscle • Walls of heart • Pushes blood to lungs and body through blood vessels • Striated • Intercalated discs (cell to cell communication) • Branching • Involuntary control http://biologyonline.us/Online%20Human%20Biology/HB%20Lab/HB%20Lab%205/images/cardiac_muscle.jpg
- 36. Smooth Muscle • No striations • Spindle shaped • Walls of hollow organs other than heart • Involuntary control https://classconnection.s3.amazonaws.com/212/flashcards/852412/jpg/smooth01muscle.jpg
- 38. Nervous Tissue • Brain, spinal cord, nerves • Neurons and neuroglia (later chapters) http://www.eastcentral.edu/programs/nervous_labels.JPG
- 39. Neuron structure • Neuron = single nerve cell • Nerve = group of neurons http://training.seer.cancer.gov/images/anatomy/nervous/neuron.jpg