Histology

1. Histology • Epithelial tissues • Connective tissues • Muscle tissues • Nervous tissues

3. Cuboidal Epithelium • Equal in height and width • Secretory portions of glands or in tubules of kidney and tissue covering the ovary

4. Squamous Epithelium • Flat irregular outline • Scalelike • Thin • Lining blood vessels, pericardium, pleurae, skin

5. Columnar Epithelium • Packed closely together • Protective covering for the inner surface of an organ • Lining of the digestive tract • Secretions

6. Stratified Columnar Epithelium • This is pseudostratified • True stratified composed of many layers • Notice these columnar cells are ciliated • Line trachea

7. Connective Tissue • Bone • Cartilage • Dense fibrous connective tissue • Loose fibrous connective tissue • Liquid connective tissue

8. Bone • Characterized by osteocytes in compact bone, with Haversian canals, concentric lacunae • Found in skeleton • Framework for movement, support, and protection • Stores minerals; makes blood

9. Bone • Dark stained areas lacunae • Lumen are Haverian canals

10. Cartilage • Chondrocytes in lacunae • Mostly intracellular • Found in pinna, ends of long bones, larynx, nose, between vertebrae, between rib and breastbone, trachae • Function is to cushion, lend rigidity to boneless structures, slippery surface for some joints

11. Types of Cartilage

12. Dense Fibrous Connective Tissue • Regularly arranged • Collagen and fibroblasts • Found in tendons and ligaments • Joins muscles to bones or bone to bone; provides protection and carries blood supply

13. Tendon Irregular Dense CT Dense Fibrous Connective Tissue

14. Loose Fibrous Connective Tissue • Elastic: elastin, capsules of organs, holds organ together, lungs and vessels • Areolar: loose weave, facial area beneath skin, collagen, support, reservoir fluids and salts • Reticular: surrounds individual cells, acts as filler tissue and support; muscle fibers, liver, lymph nodes, and spleen • Adipose: around organs, beneath skin, breast, cushions, insulates, and stores fat

15. Loose Fibrous Connective Tissue

16. Liquid Connective Tissue • Blood: found in heart and vessels; functions in respiration, nutrition, excretion, body temperature, disease protection • Lymph: found in tissue spaces between cells, cerebrospinal fluid; functions in bathing cells, nutrition, and protection from disease

17. Liquid Connective Tissue

18. Muscle Tissues • Skeletal • Smooth • Cardiac

19. Skeletal Muscle • Attached to skeleton • Voluntary control • Fibers are elongate, cylindrical, with blunt ends • Striated • Multiple Nuclei per fiber • Nuclei are peripheral • Has most rapid contraction speed • Has least duration of contraction length

20. Smooth Muscle • Located in walls in stomach, arteries, and veins • Involuntary control • Fibers are elongate, spindle, with pointed ends • No striations • One nuclei per fiber • Nucleus is centrally located • Has slowest contraction speed • Has greatest duration of contraction

21. Cardiac Muscle • Located in walls of heart • Involuntary control • Fibers are elongate, cylindrical, fibers branch and fuse • Has striations • One-two nuclei per fiber • Nuclei are located centrally • Has intermediate speed of contraction • Has intermediate duration of contraction

22. Muscle Tissues

23. Nervous Tissue • Neurons • Glial cells • Schwann cells

24. Neurons • 3 parts: soma, dendrites, and axon • Dendrites receive inputs • Axons conducts impulses away from the cell body toward another neuron, muscle, or gland • 3 types of neurons: motor (muscles), sensory (sense organs), and associative (relay from sensory to motor neurons)

25. Glial Cells • Many different types, including astrocytes • Supporting cells for neurons • Smaller and more numerous than neurons • Give rise to most tumors in CNS

26. Schwann Cells • May be categorized with glial cells • Supporting cells found outside CNS form sheaths • Nearly all neurons 2 micrometers or greater in diameter are myelinated-covered with Schwann cells

27. Nervous Tissue