1. Ch. 4 Tissues & Membranes

2. Introduction Tissue Membrane
Group of cells with similar structure & function
Membrane
Sheets of tissues

3. Epithelial Tissue On outer coverings or inner linings No capillaries
Many capable of secretion
Called glandular epithelium (glands)
Classified based on type of cell it is made of, its shape, number of cell layers

4. Epithelial Tissue (cont.)
Three shapes
Squamous – flat
Cuboidal – cube shaped
Columnar – tall and narrow; like columns
Number of cell layers
Simple – single
Stratified – many
Fig. 4-1

6. Simple Squamous Epithelium
Single layer of flat cells (Fig. 4-2)
Cells are very thin & smooth
Alveoli (air sacs)
Capillary walls

7. Stratified Squamous Epithelium
Many layers of mostly flat cells; lower layers are rounded (Fig. 4-2)
Makes up epidermis
Barrier to microorganisms

8. Transitional Epithelium
Type of stratified epithelium
Surface cells change shape from round to squamous
In lining of urinary bladder (Fig. 4-2)

10. Simple Cuboidal Epithelium
Single layer of cube-shaped cells (Fig. 4-3)
In thyroid & salivary glands, make up portions of kidney tubules
Cells have microvilli involved in reabsorption

11. Simple Columnar Epithelium
Taller than wide cells
Secretion, absorption
Stomach lining
Small intestine lining (Fig. 4-3)
Have microvilli

12. Simple Columnar Epithelium (cont.)
Goblet cell
Unicellular gland
Secretes mucus
Found in intestinal lining & trachea

13. Ciliated Epithelium
Columnar cells with cilia on free surfaces (Fig. 4-3)
Lines nasal cavities, larynx, trachea, bronchial tubes
Cilia sweep mucus (with dust & bacteria) toward pharynx to be swallowed
Also in lining of fallopian tubes
Cilia sweep ovum toward uterus
Table 4-1

15. Glands Produce a substance that functions at that site or another site
Secretion
Unicellular glands
Goblet cells in lining of respiratory & digestive tracts; secrete mucus
Multicellular glands – most glands
Made of cells with a collective secretion
2 major groups: exocrine & endocrine

16. Glands (cont.) Multicellular glands Exocrine
Have ducts (tubes) to carry secretion away from gland to functional site
Salivary glands
Sweat glands
Gastric glands

17. Glands (cont.) Multicellular glands Endocrine Ductless
Secrete hormones
Bring about specific effects in target organs
Examples: thyroid, adrenal, pituitary glands

18. Glands (cont.) Multicellular glands Pancreas Both exocrine & endocrine
Exocrine portion
Secretes digestive enzymes carried to small intestine
Endocrine portion
Called “pancreatic islets” or “islets of Langerhans”
Secrete insulin and glucagon into the blood

19. Connective Tissue Types (Table 4-2) Areolar Adipose Fibrous Elastic
Blood
Bone
Cartilage

20. Connective Tissue (cont.)
All have cells and a matrix
Matrix – non-living intercellular material
Each type of connective tissue has its own matrix

21. Blood Consists of living cells and non-living plasma
Plasma is the matrix
Water contains dissolved salts, nutrients, gases, waste
Blood cells produced from red bone marrow
include RBCs (erythrocytes), platelets, and WBCs (leukocytes)

22. Blood (cont.) Red blood cells White blood cells Platelets
Carry oxygen bonded iron in hemoglobin
White blood cells
Destroy pathogens
Provide us with immunity
Platelets
Prevent blood loss (blood clotting)

23. Areolar (Loose) Connective Tissue
Cells are fibroblasts
Produce protein fibers
Collagen fibers are very strong
Elastin fibers are elastic
Protein fibers, tissue fluid make the matrix (Fig. 4-4)
Found beneath skin’s dermis
Mast cells and WBCs intercept pathogens before they reach the blood

24. Adipose Tissue Cells are adipocytes
Store fat
Small amount of matrix consists of tissue fluid, few collagen fibers (Fig. 4-4)
Most fat stored in areolar tissue between dermis and muscle
Adipose tissue also cushions organs (eyes, kidneys)

25. Adipose Tissue (cont.) Considered an endocrine tissue Produces leptin
Appetite-suppressing hormone
Secrete chemicals that regulate insulin use in glucose and fat metabolism
Involved in inflammation response

27. Fibrous Connective Tissue
Regular collagen fibers with a few fibroblasts
(Fig. 4-5)
Parallel arrangement provides strength, flexibility
In outer walls of arteries, tendons, ligaments
Poor blood supply
Slow repair process
Irregular fibrous conn. tissue forms the dermis and fasciae (membranes) around muscles
Dermis has a good blood supply

28. Elastic Connective Tissue
Mostly elastin fibers
In walls of large arteries
Surround alveoli

29. Bone Cells are osteocytes Matrix of Ca salts and collagen
Strong, hard, inflexible
Good blood supply
Stores calcium
Repairs quickly after simple fractures
Breastbone, pelvic bone contain red bone marrow that produces blood cells
Skeleton supports body
Some bones protect internal organs

30. Cartilage Protein-CH2O matrix Firm, smooth, flexible Locations
No calcium salts
Contains more H2O, making it resilient
Firm, smooth, flexible
Locations
joint surfaces
tip of nose, external ear
wall of trachea
discs between vertebrae

31. Cartilage (cont.)
Chondrocytes (cells) within cartilage matrix (Fig. 4-5)
No capillaries
Cells nourished by diffusion through the matrix; slow process
Slow repair or none at all
Surgery to remove damaged cartilage in knee joint

33. Muscle Tissue Specialized for contraction 3 types (Table 4-3) Skeletal
Smooth
Cardiac

34. Skeletal Muscle Striated or voluntary muscle (Fig. 4-6)
Cylindrical cells; many nuclei; appear striated (striped)
Muscles attached to bones

35. Smooth Muscle Involuntary or visceral muscle
Cells have tapered ends, one nucleus, no striations (Fig. 4-6)
Stomach & intestines
Artery and vein walls
Iris of eye

36. Cardiac Muscle
Cells are branched, have one nucleus, have faint striations (Fig. 4-6)
Interlocking folds called intercalated discs
Myocardium (cardiac muscle as a whole)
Muscle cells have ability to contract by themselves

38. Nerve Tissue Nerve cells (neurons)
2 divisions – central (CNS) and peripheral (PNS)
CNS – brain, spinal cord
PNS
Nerves emerging from CNS

39. Nerve Tissue (cont.) Functions of nerve tissue
Feeling, interpreting sensation
Initiation of movement
Rapid regulation of body functions
Organization of info. for learning, memory