Chapter 1 The Study of Body Function

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Physiology Study of how the human body functions. Pathophysiology: How physiological processes are altered in disease or injury.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis Maintaining constancy of internal environment. Dynamic consistency. Maintained by negative feedback loops.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Feedback Loops Sensor: Sensor Detects deviation from set point. Integrating center: Determines the response. Effector: Produces the response.

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Negative Feedback Defending the set point. Reverse the deviation. Produces change in opposite direction.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hormone insulin restores plasma [glucose].

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Positive Feedback Action of effectors amplifies the change. Is in same direction as change. Examples: Oxytocin (parturition) Voltage gated Na + channels (depolarization)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Primary Tissues 4 Different Primary Tissues: Muscle Nervous Epithelial Connective

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Muscle Tissue Specialized for contraction. 3 Types of Muscle Tissue: Skeletal Cardiac Smooth

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skeletal Muscle Voluntary muscle. Striated. Attach to bones at both ends (tendons). Arranged in parallel. Grade contraction. Note the location of the nuclei along the edges of the cells.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cardiac Muscle Striated. Found only in the heart. Interconnected. Intercalated discs.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Smooth Muscle Not striated. Gap junctions connect them so they often act as a unit. Not graded. Peristalsis. Found in digestive tract, blood vessels, Bronchioles, urinary and reproductive systems.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous Tissue Neurons (nerve cells): Specialized for conduction of action potentials. Supporting cells: Provide anatomical and functional support.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Neuron Dendrites: Receive input. Cell body: Nucleus. Metabolic center. Axon: Conducts nerve impulses.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue Types of Epithelial Tissue: Cells that form membranes for coverings and linings: Squamous Columnar Cuboidal Exocrine glands (have ducts) Endocrine glands (secrete into blood stream)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Exocrine Glands Derived from cells of epithelial membranes. Secretions are released through ducts. Simple tubes or modified as acini (clusters around branched ducts). Examples: Tear glands Sweat glands Prostate glands ges/exocrine.gif

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Endocrine Glands Lack ducts. Secrete hormones into capillaries within the body. May be discrete organs: Primary functions are the production and secretion of hormones. nes.html

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Squamous Cells Flattened in shape. Adapted for diffusion and filtration. Line all blood vessels and the alveoli of the lungs.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cuboidal Cells Cube-shaped cells. Excretion, secretion and absorption. Line kidney tubules, salivary ducts, and pancreatic ducts.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Columnar Cells Taller column shaped cells. Excretion, secretion and absorption. May contain cilia. Line digestive tract and respiratory passageways.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Simple columnar epithelium is found in: ducts of exocrine glands ducts larger tubules or collecting ducts of the kidneytubules stomach, small intestine, and large intestinesmall intestine smaller respiratory tubes or bronchioles fallopian tubes goblet cells (small single-celled mucus- producing glands scattered among columnar epithelium of stomach and intestine) goblet cells

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue Large amounts of extracellular material (matrix) in the spaces between connective tissue cells. Matrix formed by secretions of the cells. Its composition determines the physical properties of ea. tissue, s.a. hardness, toughness and flexibility. 4 Types of Connective Tissue: Connective tissue proper Cartilage Bone Blood

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue Proper Loose connective tissue: Scattered collagen and tissue fluid. Dermis of skin  Dense fibrous connective tissue: Regularly arranged. Collagen oriented in same direction. TendonsTendons This tissue is composed mostly of non-stretching or branching collagen fibers and very few spaces, making it very strong. The "wavy" pattern of the fibers is a useful diagnostic pattern for this tissue. dense.htm Irregularly arranged. Resists forces applied in many directions. Capsules and sheaths

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Loose Connective Tissue

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. fibrous tendon Note boxcar arrangement of nuclei.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cartilage Chondrocytes. Supportive and protective tissue. Elastic properties to tissues. Precursor to many bones. Articular surfaces on joints. View slide

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Bone Matrix is collagen embedded in minerals, esp. Ca and phosphate Osteoblasts: Bone-forming cells Osteocytes: Trapped osteoblasts: less active Osteoclasts: Bone resorbing cells

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Collagen makes bone tough and able to resist fracture. Minerals make bone hard. Need both. Without protein, bone brittle; without minerals, bone soft and flexible Properties

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Compact Bone (osteons) Central canal through which blood vessels and nerves pass. Layers of bone with osteocytes embedded Canaliculi

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Bone Functions (1) Support (skeleton) (2) Movement (3) Protection (4) Mineral reservoir (esp. Ca and P) (5) Hemopoiesis (blood-cell formation)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood Classified as connective tissue. Half its volume is plasma. The rest is formed elements (cells and platelets).

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Organs Organs: Composed of at least two primary tissues. Serve different functions of the organ.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Systems Organs that are located in different regions of the body and perform related functions. Examples: Skeletal system Cardiovascular system GI system

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Body-Fluid Compartments 65-75% of total body weight H 2 0. Intracellular compartment: Fluid inside the cell. 2/3 of H 2 0 Extracellular compartment: 1/3 H Subdivisions: Blood plasma Interstitial fluid

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hyaline cartilage Bluish white matrix. Note chondrocytes, lacunae in slide of tracheal cartilage Return