Exploring Human Anatomy: Tissues to Organ Systems

1. Chapter 4From Cells to Organ Systems • Tissues • Anatomical terms • Integumentary system- Skin

2. Tissues • Groups of cells with a common function • Four primary tissues • Epithelia • Connective tissues • Muscle • Nervous

3. Epithelial Tissues • Line body cavities and cover surfaces

4. Epithelial Tissues: Classification • Shape • Squamous: flattened cells; line vessels, part of lungs, body surface • Cuboidal: cube shaped; form lining of tubules, glandular tissue • Columnar: column shaped; line respiratory, digestive, reproductive tracts

5. Epithelial Tissues: Classification • Number of layers • Simple/single–layered: adapted for diffusion across cell barriers; line glands, and respiratory, digestive, reproductive systems • Stratified/multiple–layered: provide protection, as in the skin surface

6. Connective Tissue Supports and Connects Body Parts: Basement Membrane • Fibrous connective tissue • Loose: surrounds many organs, lines cavities around blood vessels • Dense: forms tendons, ligaments, deeper layers of skin

7. Connective Tissue Supports and Connects Body Parts (cont.) • Special connective tissue • Cartilage: produced by chondroblasts; found in lacunae; no blood vessels; high collagen content • Bone: inorganic matrix with calcium salts for hardness • Blood: fluid matrix of plasma, red blood cells, white blood cells, and platelets • Adipose tissue: fat cells; function in insulation, protection, and energy storage

8. Fibrous Connective Tissue (cont.) Figure 4.3

9. Muscle Tissue: Contracts for Movement • Skeletal muscle • Moves body parts • Voluntary, multinucleated • Cardiac muscle • Functions in the heart • Involuntary, single nucleus • Smooth muscle • Surrounds hollow structures • Involuntary, single nucleus

10. Nervous Tissue: Transmits Impulses • Neuron: specialized nervous system cell • Structural components: cell body, dendrites, axon • Glial cells support neurons

11. Organs and Organ Systems Perform Complex Functions • Organ systems • Groups of organs that perform a common function • Examples • Digestive system: mouth, throat, stomach, intestines, and liver • Lymphatic system: lymph nodes, tonsils, and spleen

12. Body Cavities Figure 4.8

13. Anatomical Position or Direction Superior (closer to the head or upper part of a structure) Frontal plane Distal (farther away from the trunk) Transverse plane Proximal (nearer to the trunk) Inferior (farther from the head or toward the lower part of a structure) Posterior (at or near the back) Anterior (at or near the front) Midsagittal plane Figure 4.9

14. Skin: Integumentary System Figure 4.10

15. Skin: Integumentary System • Functions: prevents dehydration, protects from injury, serves as defense against microorganisms, regulates body temperature, makes vitamin D, provides sensation • Structure • Epidermis: outer layer, stratified squamous epithelial cells, no blood vessels, specialized keratinocytes and melanocytes • Dermis: deeper layer, support tissues, fibers

16. Accessory Structures of Dermis • Hair: shaft, follicle • Smooth muscle: attached to hair follicle, raises hair to upright position • Oil glands/sebaceous glands: secretion moistens and softens skin

17. Accessory Structures of Dermis (cont.) • Sweat glands: secrete sweat, help in temperature regulation • Blood vessels: supply nutrients, remove waste, assist in temperature regulation • Sensory nerve endings: detect heat, cold, touch, deep pressure, vibration

18. Homeostasis • Maintenance of relative constancy of the conditions of the internal environment • Mechanisms • Negative feedback: deviations from normal detected and counteracted • Components: controlled variable, sensor, control center, effector • Positive feedback: amplifies original change: • Rarely found in organisms