1. Tissues Chapter 5 http://asweknowit.net/images_edu/dwa5%20tissues.jpg

2. 4 Types of Tissues All tissues can be classified into four major categories based on structure and function: 1.Epithelial: Covers and protect body surfaces, lines body cavities, moves substances in and out of blood (secretion, excretion & absorption), form glands 2.Connective: support, connection, transport, protection 3.Muscle: moves the body & its parts; specialized for contractility 4.Nervous: provides communication between body parts and coordinates body functions

3. Embryonic Development Zygote becomes a blastocyst through mitotic division Cells of the blastocyst regroup into primary germ layers –Endoderm, mesoderm, ectoderm –Gastrulation: process of blastocyst differentiating into 3 germ layers –Histogenesis: process of germ layers differentiating into diff tissues

5. Epithelial Tissue Subdivided into 2 types: 1.Membranous –Covers the body & some of its parts –Lines body cavities (pleural, pericardial, peritoneal), blood vessels, respiratory, digestive and genitourinary tracts 2.Glandular –Form the secretion units of the endocrine & exocrine glands

6. Epithelial Tissue Functions of epithelial tissues: 1.Protection –Ex: skin protects body from injury & disease-causing micro-organisms 2.Sensory –Epithelial structures that specialize in sensory functions found in skin, nose, eye, ear 3.Secretion –Glandular epithelium secrete hormones, digestive juices & sweat 4.Absorption –Ex: gut absorbs nutrients; exchange of respiratory gases 5.Excretion –Ex: kidney tubules concentrate & excrete urine and other waste products

7. Epithelial Tissue Basement membrane –Thin, noncellular layer of adhesive –Connects epithelial tissue and underlying connective tissue Avascular –“without” vascular –Epithelial cells do not have blood vessels –Oxygen & nutrients diffuse from capillaries through connective tissue & basement membrane to epithelial cells

8. Classification of Membranous Epithelial Tissue Cell Shape –Squamous: flat, plate-like –Cuboidal: cube-shaped; larger cytoplasm –Columnar: narrow and cylinder-shaped –Pseudostratified: single-layered; all cells touch the basement membrane but may not extend to the top of the membrane Layers of Cells –Simple: single layer –Stratified: cells are layered on top of one another –Transitional: cell shape & layers differ

10. Founds in areas where diffusion or filtration are necessary Examples of locations: Alveoli (air sacs) Linings of blood & lymphatic vessels Surfaces of pleura, pericardium & peritoneum

11. Examples of locations: Glands and their ducts

12. Examples of Locations: Mucous membranes such as stomach, intestine, uterus Goblet cells (produce mucous) & microvilli (increase surface area) are usually found on these cell types

13. Examples of locations: Respiratory tract, male urethra Goblet cells & cilia present

14. Examples of locations: Skin Keratin (tough protein) provides (fig 5-8 – not pictured)

15. Examples of locations: Areas subject to stress and tension changes (Urinary bladder)

16. Glandular Epithelium Specialized for secretory activity Unicellular glands –Single celled –Ex: goblet cells Multicellular glands –Function in clusters, solid cords or specialized follicles

17. Endocrine vs Exocrine All glands are classified as endocrine or exocrine Exocrine glands –Discharge/secrete into ducts –Ex: salivary glands Endocrine glands –“ductless glands” –Secrete hormones directly into blood or interstitial fluid –Ex: pituitary and thyroid glands

18. Structural Classification of Exocrine Glands (Table 5-2, p. 133) Shape of gland: –Tubular –Alveolar (sac-like) Complexity of gland: –Simple (one duct) –Compound – > 2 ducts (branched)

20. Functional Classification of Exocrine Glands 1.Apocrine –Collect secretory products at apex (tip) –Apex of cell pinches off –Cell repairs itself & repeats process –Ex: milk-producing mammary glands 2.Holocrine –Collect secretory product inside the cell –Rupture to release (self-destructs) –Ex: sebaceous glands (oil glands) 3.Merocrine –Discharge through plasma membrane –This type applies to most exocrine glands –Ex: salivary glands

21. Figure 5-12, p. 132

22. Connective Tissue Most widespread tissue in the body Functions: –Connection –Support –Transport –Protection –Insulation

23. Characteristics of Connective Tissue Common origin – mesoderm Matrix –Intercellular material –Few cells, fibers, fluid, ground substance (material between cells) –Fibers: 1.Collagenous fibers 2.Reticular fibers 3.Elastic fibers

24. Fibers 1.Collagenous fibers –“white fibers” –Made of collagen (fibrous protein) –Tough, strong 2.Reticular fibers –Delicate –Reticulin – protein –Support small structures (ex: capillaries) 3.Elastic fibers –Extensible & elastic –Elastin – protein –Found in “stretchy” tissue (ex: cartilage of the external ear)

25. Classification of Connective Tissue 1.Fibrous –Loose (areolar) –Adipose –Reticular –dense 2.Bone 3.Cartilage –Hyaline –Fibrocartilage –elastic 4.Blood **Reference Table 5-3, pp. 134- 135**

26. Fibrous Connective Tissue 1.Loose connective (areolar) tissue (fig 5-13) –Stretchable –most abundant connective tissue in the body –Connects adjacent structures Ex: btwn other tissues and organs Ex: superficial fascia

27. Fibrous Connective Tissue 2. Adipose tissue (fig 5-14) –Contains mainly fat cells –Supportive/protection pads around kidneys & other body structures –Storage deposit for excess food –Insulating material, conserves body heat

28. Fibrous Connective Tissue 3. Reticular Tissue (Fig 5-16) –3D web of reticular fibers –Forms the framework of the spleen, lymph nodes & bone marrow –Meshwork filters harmful substances out of the blood

29. Fibrous Connective Tissue 4. Dense Fibrous Tissue (fig 5-17, 5-18, 5-19) Densely packed fibers Regular Dense CT –Fibers arranged in regular, parallel rows –Collagen fibers –Flexible, strong –Tendons (muscle to bone) & ligaments (bone to bone) Irregular Dense CT –Fibers intertwine –Withstand stress from any direction –Ex: dermis (inner layer of skin); outer capsule of kidney & spleen

31. Bone Tissue We will cover this when we cover the skeletal system Just know that bone is a type of connective tissue

32. Cartilage Only 1 cell type – chondrocyte –Located in lacuna Avascular – receive nutrients via diffusion Injuries to cartilage heal slowly due to poor nutrient delivery

33. Cartilage - Types 1.Hyaline cartilage –Most common –Covers ends of long bones (where joints articulate) –Found in supporting rings of respiratory tubes 2.Fibrocartilage –Strongest, most durable –Intervertebral disks –Menisci in knee joint 3.Elastic cartilage –Fine elastic fibers –High degree of flexibility –External ear

35. Blood Unusual type of connective tissue No ground substance Matrix = plasma (55%) Formed elements = blood cells (45%) –Erythrocytes – RBCs –Leukocytes – WBCs –Thrombocytes – platelets Transport function –Respiratory gases, nutrients, waste products

36. Muscle Tissue 3 types: –Skeletal muscle tissue –Smooth muscle tissue –Cardiac muscle tissue

37. Skeletal Muscle Tissue Muscles (attached to bone) “striated voluntary” muscle Structure: striations, multi-nucleated, long, tread-like cells, bundles of microfilaments

38. Smooth Muscle Tissue Aka: visceral muscle tissue Lines walls of hollow internal organs (viscera) –Stomach, intestines, blood vessels “non-striated involuntary” muscle Structure: long, narrow cells, non-striated

39. Smooth Muscle Tissue

40. Cardiac Muscle Tissue Walls of the heart “striated involuntary” muscle Structure: striations, dark band (intercalated disks (where plasma membranes meet up)

41. Nervous Tissue Rapidly integrates activities of various parts of the body Rapid communication is made possible b/c of the excitability & conductivity characteristics of the nervous tissue http://www.mindcreators.com/Images/NB_Neuron.gif

42. Nervous System 3 Parts: Brain Spinal cord Nerves Nervous Tissue: Common origin: ectoderm Two cell types: 1.Neurons (nerve cell) 2.Neuroglia (supporting cells)

43. Anatomy of Neurons Cell body – soma Cell processes: –Axon  transmits nerve impulses away from cell body –Dendrites  carry signals towards axon http://www.nida.nih.gov/jsp/MOD3/images/NEURON2.gif

44. Tissue Repair After mechanical damage or tissue injury: Phagocytic cells remove dead or injured cells Regeneration: growth of functional new tissue (via mitotic division) Repair capacity based on tissue type

45. Epithelial & Connective Tissue Repair Greatest capacity to regenerate Epithelial Tissue: –Cut/injury  cell division  tissue regeneration Connective Tissue: –Cut/injury  activation of cells that make collagen fibers  injury site filled w/ dense fibrous CT Small injury – dense fibrous CT replaced by normal tissue Deep/large injury – dense fibrous CT forms scar

46. Muscle Tissue Repair Limited repair capacity Damaged muscle tissue replaced with fibrous CT Results in loss of some or all ability to function normally

47. Nervous Tissue Repair Limited ability to regenerate Some neurons outside the brain and spinal cord can regenerate (slow process) Majority of the time: brain & spinal injuries always result in permanent damage

48. Body Membranes Membrane – thin, sheet-like structure Two types: –Epithelial membranes Composed of epithelial tissue and underlying connective tissue –Connective Tissues membranes Composed entirely of connective tissue

49. Epithelial Membranes 1.Cutaneous membrane –Cover body surfaces exposed to external environment (skin) 2.Serous membrane –Single membrane covering two different surfaces Parietal membrane – lines walls of body cavities Visceral membrane – covers surface of organs –Secrete thin, watery substance to prevent rubbing 3.Mucous membrane –Line body surfaces open to exterior Ex: respiratory, digestive, urinary & reproductive tracts

50. Connective Tissue Membranes Synovial membranes Lines spaces between bones & joints Secrete thick, colorless, lubricating fluid (synovial fluid) Fluid helps reduce friction btwn bone surfaces

52. Mechanisms of Disease – Tumors & Cancer Neoplasm – “new matter” (tumor) –Abnormal growth of cells Benign Tumors –Do no spread to other tissues –Slow growth –Encapsulated –Usually not lethal unless interfere w/ organs

53. Mechanisms of Disease – Tumors & Cancer Malignant tumors (cancer) –Not encapsulated –Spreads (metastasizes) –Cancer cells spread via blood or lymphatic system –Rapid growth/spread to nearby tissue

54. (Known) Causes of Cancer Genetic Factors –Inherited cancer genes “oncogenes” –Tumor suppressor gene – fails to operate –Usually genetic predisposition coupled with cancer- causing mechanisms Ex: breast cancer Carcinogens (cancer markers) –Affect genetic activity  abnormal cell reproduction –Also called mutagens –Ex: chemicals, sun, viruses Age –Some cancers arise based on age Ex: leukemia (young) & colon cancer (older adults)

55. Detection of Cancer Self-examination –Breast and testicular exams Medical Imagining –X-ray Ex: mammogram – detection of breast cancer –CT, MRI, ultrasound Produce cross-section of body images for tumor detection Blood tests –Look for tumor markers (ex: PSA) Biopsy –Removal of tumor tissue

56. Cancer Treatment Options Stage and grade cancer –Helps determine outcomes Surgical removal (if possible) –Could leave behind malignant cells Chemotherapy – cytotoxic (cell-killing) drugs –Destroys remaining malignant cells Radiation therapy –Destructive x-ray or gamma radiation destroys cancer cells Immunotherapy –Boosting immune system again viruses

57. Anthony’s Textbook of Anatomy and Physiology 17 th Edition. Thibodeau, Gary A. PhD and Patton, Kevin T. PhD. Mosby, Inc.