1	Chapter 8 General Principles of Pathophysiology
2	Chapter 8, Part 1 The Cell and the Cellular Environment
3	Part 1 Topics The Cell Types of Tissue Disease Causes Disease Pathophysiology
4	The Normal Cell The cell is the fundamental unit of the human body. Cells contain all the necessary components for life functions.
5	Cell Structure The cell membrane is the outer covering that encircles and protects the cell. Cytoplasm is the thick, viscous fluid that fills and gives shape to the cell. Organelles are structures that perform specific functions within the cell.
6	Organelles Nucleus Endoplasmic reticulum Golgi apparatus Mitochondria Lysosomes Peroxisomes
7	Cell Function All human cells have the same general structure and genetic material. Differentiation causes cells to become specialized. There are seven major functions of cells.
8	Major Functions of Cells Movement Conductivity Metabolic absorption Secretion Excretion Respiration Reproduction
9	Tissues Tissue refers to a group of cells that perform a similar function.
10	Tissue Types
11	Epithelial Tissue Lines internal and external body surfaces and protects the body. Some forms perform specialized functions: Secretion Absorption Diffusion Filtration Skin, mucous membranes, lining of intestinal tract.
12	Muscle Tissue Has the capability of contraction when stimulated. Cardiac tissue is found only within the heart. Has the unique capability of spontaneous contraction without external stimulation. Smooth muscle is found within the intestines and encircling blood vessels. Generally under control of the autonomic nervous system. Skeletal muscle allows movement and is generally under voluntary control. Most abundant type.
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14	Connective Tissue Most abundant tissue in the body. Provides support, connection, and insulation. Examples include bone, cartilage, and fat. Blood is classified as connective tissue.
15	Nerve Tissue Specialized tissue that transmits electrical impulses throughout the body. Examples include the brain, spinal cord, and peripheral nerves.
16	Organs, Organ Systems, and the Organism An organ is a group of tissues functioning together. A group of organs working together is an organ system. The sum of all cells, tissues, organs, and organ systems makes up an organism.
17	Organ Systems Cardiovascular Respiratory Gastrointestinal Genitourinary Reproductive Nervous Endocrine Lymphatic Muscular Skeletal
18	System Integration
19	Homeostasis Homeostasis is the term for the body’s natural tendency to keep the internal environment and metabolism steady and normal.
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21	Metabolism Metabolism is the term used to refer to the building up (anabolism) and breaking down (catabolism) of biochemical substances to produce energy.
22	"The body’s cells interact and..." The body’s cells interact and intercommunicate with substances secreted by various body glands.
23	Endocrine Glands Sometimes called ductless glands. Secrete hormones directly into the circulatory system. Some endocrine glands include: Pituitary Thyroid Parathyroid Adrenal glands Islets of Langerhans in the pancreas Testes and ovaries
24	Exocrine Glands Secrete substances such as sweat, saliva, tears, mucus, and digestive juices onto the epithelial surfaces via ducts
25	Signaling Endocrine signaling Hormones distributed throughout the body. Paracrine signaling Secretion of chemical mediators by certain cells that act only upon nearby cells. Autocrine signaling Cells secrete substances that act upon themselves. Synaptic signaling Cells secrete neurotransmitters that transmit signals across synapses.
26	Hormones and neurotransmitters are received by various receptors: Nerve endings Sensory organs Proteins that interact with and then respond to the chemical signals and other stimuli
27	Many medications act upon these receptors: Chemoreceptors respond to chemical stimuli. Baroreceptors respond to pressure changes. Alpha and beta receptors respond to neurotransmitters and medications.
28	Homeostasis When normal intercellular communication and normal metabolism are disturbed, the body will respond in various ways to compensate and attempt to restore normal metabolism.
29	Interaction of Systems Stressors on a body system are inputs. The portion of the system creating the input is an effector. A negative feedback loop exists when body mechanisms work to reverse an input. Decompensation occurs when the system cannot compensate and restore homeostasis.
30	Pathophysiology The study of how diseases alter the normal physiological processes of the human body From the root “patho” meaning disease
31	How Cells Respond to Change and Injury
32	Cellular Adaptation Cells, tissues, organs, and organ systems can adapt to both normal and injurious conditions. Adaptation to external stressors results in alteration of structure and function. Examples: growth of the uterus during pregnancy, dilation of the left ventricle after an MI.
33	Types of Cellular Adaptations (1 of 2) Atrophy Decreased size resulting from a decreased workload Hypertrophy An increase in cell size resulting from an increased workload
34	Types of Cellular Adaptations (2 of 2) Hyperplasia An increase in the number of cells resulting from an increased workload Metaplasia Replacement of one type of cell by another type of cell that is not normal for that tissue Dysplasia A change in cell size, shape, or appearance caused by an external stressor
35	Cellular Injury Hypoxic Chemical Infectious Immunologic/inflammatory Physical agents Nutritional balances Genetic factors
36	Manifestation of Cellular Injury When cells are injured metabolism is changed, causing substances to infiltrate or accumulate to an abnormal degree in cells.
37	Cellular Swelling Results from a permeable or damaged cellular membrane Caused by an inability to maintain stable intra- and extra-cellular fluid and electrolyte levels
38	Fatty Change Lipids invade the area of injury. Occurs most commonly in vascular organs, most frequently the liver. Causes a disruption of the cellular membrane and metabolism and interferes with the vital functions of the organ.
39	Signs and Symptoms of Cellular Change Fatigue and malaise Altered appetite Fever Increased heart rate associated with fever Pain
40	Cellular Death (1 of 3) Apoptosis Injured cell releases enzymes that engulf and destroy the cell. Cells shrink. Eliminating damaged and dead cells allows tissues to repair and possibly regenerate.
41	Cellular Death (2 of 3) Necrosis A pathological process Cells swell and rupture Coagulative Liquefactive Caseous Fatty
42	Cellular Death (3 of 3) Gangrenous necrosis Cell death over a wide area Dry Wet Gas
43	The Cellular Environment: Fluid and Electrolytes
44	"Water is the most abundant..." Water is the most abundant substance in the human body.
45	Where the Water Is Found Intracellular fluid—fluid inside the cells Extracellular fluid—all the fluid outside the body cells Intravascular fluid—fluid within the circulatory system Interstitial fluid—fluid outside of the cell membranes but not within the circulatory system
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47	Dehydration Abnormal decrease in total body water Gastrointestinal losses Increased insensible loss Increased sweating Internal losses Plasma losses
48	Overhydration Retention of abnormally high amount of body fluid. Major sign is edema. In severe cases, heart failure may occur.
49	Electrolytes
50	Electrolytes Substances that separate into electrically charged particles called ions. Cations have a positive charge. Anions have a negative charge.
51	Cations
52	Sodium (Na⁺) Most prevalent cation in extracellular fluid. “Water follows sodium.” Important in transmission of nervous impulses. Hypernatremia is an abnormal increase in sodium. Hyponatremia is an abnormal decrease in sodium.
53	Potassium (K⁺) Most prevalent cation in the intracellular fluid. Important in transmission of electrical impulses. Hyperkalemia is an abnormally high potassium level. Hypokalemia is an abnormally low potassium level.
54	Calcium (Ca⁺⁺) Plays a major role in muscle contraction as well as nervous impulse transmission. Hypercalcemia is an abnormally increased calcium level. Hypocalcemia is an abnormally low calcium level.
55	Magnesium (Mg⁺⁺) Necessary for several biochemical processes. Closely associated with phosphate. Hypermagnesemia is an abnormally increased level of magnesium. Hypomagnesemia is an abnormally decreased level of magnesium.
56	Anions
57	Chloride (Cl^-) Negative charge balances the positive charge of cations. Major role in fluid balance and renal function. Associated with sodium.
58	Bicarbonate (HCO₃^-) Principal buffer of the body Neutralizes the hydrogen ion and other organic acids
59	Phosphate (HPO₄^-) Important in body energy stores Closely associated with magnesium in renal function Acts as a buffer, primarily in the intracellular space
60	Osmosis and Diffusion
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62	Types of Solutions Isotonic Solutions on opposite sides of a membrane are equal in concentration. Hypertonic The concentration of a given solute is greater on one side of a membrane than the other. Hypotonic The concentration of a given solute is less on one side of a membrane than the other.
63	Osmosis vs. Solutes (1 of 2) Osmosis The movement of water from an area of higher WATER concentration to an area of lesser WATER concentration. Because water is a solvent, it moves from an area of lower SOLUTE concentration to an area of higher SOLUTE concentration.
64	Osmosis vs. Solutes (2 of 2)
65	Active Transport The movement of a substance across the cell membrane against the osmotic gradient (toward the side that already has more of the substance). Faster than diffusion. Requires energy.
66	Facilitated Diffusion Certain molecules can move across the cell membrane with the assistance of “helper proteins.” Glucose is one example. Depending on the substance, this movement may or may not require energy.
67	"Osmotic pressure" Osmotic pressure Pressure exerted by the concentration of solutes on one side of a semipermeable membrane Oncotic force (colloid osmotic pressure) Osmotic pressure exerted by large protein particles
68	Starling’s Hypothesis Net Filtration = (Forces favoring filtration) MINUS (–) (Forces opposing filtration)
69	Edema Accumulation of water in the interstitial space due to disruption in the forces and mechanisms that normally keep net filtration at zero
70	Mechanisms That Cause Edema A decrease in plasma oncotic force An increase in hydrostatic pressure Increased capillary permeability Lymphatic channel obstruction
71	Edema (1 of 2) Can be local or within a certain organ system Sprained ankle vs. pulmonary edema
72	Edema (2 of 2) Water in interstitial spaces is not available for metabolic processes. Edema, therefore, can cause a relative condition of dehydration.
73	Intravenous Therapy
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76	Fluid Replacement
77	"Transfusion reactions occur when there..." Transfusion reactions occur when there is a discrepancy between the blood type of the patient and the type of the blood being transfused.
78	Signs and Symptoms of Transfusion Reactions Fever Chills Hives Hypotension Palpitations Tachycardia Flushing of the skin Headache Loss of consciousness Nausea Vomiting Shortness of breath
79	Treatment of Transfusion Reactions (1 of 2) IMMEDIATELY stop the transfusion. Save the substance being transfused. Rapid IV infusion.
80	Treatment of Transfusion Reactions (2 of 2) Assess the patient’s mental status. Administer oxygen. Contact medical direction. Be prepared to administer mannitol, diphenhydramine, or furosemide.
81	Intravenous Fluids
82	Hemoglobin-Based Oxygen-Carrying Solutions (HBOCs) Commonly referred to as “blood substitutes” Compatible with all blood types Do not require blood typing, testing, or cross-matching PolyHeme Hemopure
83	Colloids Colloids remain in intravascular spaces for an extended period of time and have oncotic force. Plasma protein fraction (Plasmanate) Salt-poor albumin Dextran Hetastarch (Hespan)
84	Crystalloids Crystalloid solutions are the primary compounds used in prehospital care. Isotonic solutions Hypertonic solutions Hypotonic solutions
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86	Most Commonly Used Solutions in Prehospital Care
87	Acid-Base Balance
88	Acid-Base Balance Acid-base balance is a dynamic relationship that reflects the relative concentration of hydrogen ions in the body. Hydrogen ions are acidic, and the concentration of them in the body must be maintained within fairly strict limits.
89	Hydrogen Ion Concentration A variation of only 0.4 of a pH unit in either direction of normal can be fatal in humans.
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92	Regulation of Acid-Base Balance
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94	Buffer System (Bicarbonate Buffer System) The fastest mechanism. Two components of this system are bicarbonate ion (HCO₃^-) and carbonic acid (H₂CO₃) and are normally in equilibrium with hydrogen (H⁺).
95	H⁺ + HCO₃^- H₂CO₃ Hydrogen may combine with bicarbonate to produce carbonic acid. In other circumstances carbonic acid will dissociate into bicarbonate and hydrogen.
96	Respiratory Mechanisms Increased respirations cause increased elimination of CO₂ which causes a decrease in hydrogen ions and an increase in pH.
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98	Kidney Mechanisms The kidneys regulate the pH by altering the concentration of bicarbonate ions in the blood.
99	Acid-Base Derangements
100	Respiratory Acidosis Caused by abnormal retention of CO₂ from impaired ventilation due to problems occurring in the lungs or respiratory center of the brain.
101	Respiratory Alkalosis
102	Metabolic Acidosis
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104	Metabolic Alkalosis The pH is increased and the CO₂ level is normal. It is usually caused by administration of diuretics, loss of chloride ions associated with prolonged vomiting, and overzealous administration of sodium bicarbonate.
105	Part 1 Summary The Cell Types of Tissue Disease Causes Disease Pathophysiology