Introduction to Human Anatomy & Physiology and Tissues & Glands

1. Introduction to Human Anatomy & Physiology and Tissues & Glands Chapters 1 & 5

2. What’s in a Name? • anatomy – study of structures of the body and their relationship to one another • physiology – study of the function(s) of the body’s structures

3. Levels of Organization • review from biology – see p. 4 of book • atoms/molecules • cells • tissues • organs • organ systems • organisms

4. Homeostasis • word = “unchanging” • is actually a dynamic state that fluctuates within a narrow range to maintain balance • a negative feedback mechanism can help by shutting off or reducing intensity of a stimulus • works like a thermostat • ex: body temp, heart rate, blood pressure, breathing rate, hormone levels, etc.

5. ex: blood glucose levels

6. Opposite of Neg Feedback = • positive feedback – when stimulus intensifies in the same direction • ex: blood clotting and labor contractions

7. Anatomical Position

8. Basic Organization of the Human Body • Axial – head, neck, trunk • Appendicular – everything else

9. Relative Positions • superior vs. inferior • anterior (ventral) vs. posterior (dorsal) • medial vs. lateral • proximal vs. distal • superficial vs. deep • Intermediate • See p.14

10. Body Planes

11. Body Cavities • Dorsal Body Cavities • Cranial cavity – holds brain • Vertebral cavity – contains spinal cord

12. Body Cavities • Ventral Body Cavities • Thoracic cavity –houses lungs & heart • Abdominopelvic cavity – abdominal cavity contains stomach, intestines, spleen & liver – pelvic cavity contains bladder, some repro. organs & rectum *not physically separated from one another

13. Chapter 5 Tissues, Glands and Membranes

14. histology– the study of tissues • tissue– group of cells that are similar in structure and perform a common function • four types: • epithelial(covering) • connective(support) • muscle(movement) • nervous(control) • most organs contain all 4 types

15. Epithelial Tissue (Epithelium) • sheets ofcells that cover a body surface or lines a body cavity • two forms: • covering and lining epithelium • - ex: skin, lining of stomach • glandular epithelium– glands; cells specialized to produce and secrete substances • - ex: sweat glands & pituitary gland

16. Special characteristics of covering and lining epithelia: • closely packed cells • polarity → have a free apicalsurface and an attached basalsurface • supported by connective tissue • contain nerves but not blood vessels • regenerate frequently

17. Naming – each epithelium is given 2 names • 1st name = # layers of cells • simple→ one layer • stratified→ 2 or more layers • pseudostratified → one layer that looks like many • transitional→ different shaped cells that change shape when stretched

18. 2nd name = shape of cells at apical surface • squamous– flattened and scale-like • cuboidal– boxlike • columnar– tall and column shaped

19. Glandular Epithelia • gland–one or more cells that secrete a product • secretion– the process of making a substance to be released; the physical release from the cell • ex: the skin secretes sweat • ex: sweat is a liquid secretion of sweat glands

20. 1. Endocrine glands • ductless (tubeless) • produce hormones that are released directly into extracellular space (blood or other fluid) • we will cover more later in year 2. Exocrine Glands (2 types) • more numerous than endocrine glands • secrete product through duct and/or onto an epithelial surface

21. Unicellular Exocrine Glands • Scattered among cells with other functions • Produce mucin– a complex glycoprotein that dissolves in water when secreted → mucus • Ex: goblet cells in respiratory, digestive and urinary tracts

22. Multicellular Exocrine Glands • composed of duct (tube) and secretory unit

23. Connective Tissue • found everywhere in the body, but distribution varies • main subclasses: • connective tissue proper • cartilage • bone • blood

24. composition = CT cells, fibers and fluids containing proteins • general functions: • binding and support • insulation • protection • transportation

25. connective tissue cells • “blast” cells • fibroblasts – star-shaped cells that produce CT liquid and fibers • most common cell • chondroblasts – produce cartilage • osteoblasts – produce bone • hemocytoblasts – produce blood cells

26. 2. macrophages – phagocytize foreign materials and dead tissue cells

27. 3. mast cells – detect foreign substances and release the following: • heparin – anticoagulant (prevents blood clots) • histamine – released during inflammatory reactions and makes capillaries leak

28. Cartilage • qualities between dense connective tissue and bone → tough, but flexible • avascular and not innervated

29. Types: • 1. Hyaline cartilage (gristle): • covers ends of long bones • supports tip of nose • forms most of larynx, supporting cartilage in trachea and bronchial tubes • makes up embryonic skeleton &growth plates in children

30. 2. Elastic cartilage: • found where strength and exceptional stretchability are needed • ears and epiglottis

31. 3. Fibrocartilage: • serve as shock absorbers, are compressible – resists tension well • found in intervertebral discs and spongy cartilage of knee

32. Bone (osseous tissue) • rock-like hardness that supports and protects • hard because matrix has more collagen fibers and inorganic calcium salts • very well vascularized

33. Blood • most atypical connective tissue • transport gases, nutrients, wastes & hormones around the body • help regulate body temp

34. Muscle Tissue (3 types) • Skeletal Muscle • multinucleated and striated • voluntary control • makes up 40% body • connect to bones via tendons

35. 2. Cardiac Muscle • uninucleate and striated • involuntary control • cells branched and fit together at intercalated discs

36. 3. Smooth Muscle • uninucleate and unstriated • found in walls of hollow organs that contract and blood vessels

37. Nervous Tissue • composed of neurons and supporting neuroglial cells • located in brain, spinal cord and peripheral nerves