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define pharmacology and what are the 3 processes
- the study of the body's functions inits normal human condition
- 1. physical 2. mechanical 3. biochemical
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the human body is a complex association of _______ ____ which form _______.
independent cells which form tissues
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to survive, cells need an environment (i.e. ______) that has: _____ _____ _____
- water
- food stuff (glucose, amino acids, and fatty acids)
- oxygen
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for the life process to go on, all elements must be maintained in an internal environment where there is sufficient 1._____ and2. ______ for 3._______ ______ or 4.______
- 1. heat
- 2. acidity
- 3. biochemical reactions
- 4. metabolism
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Homeostasis
A. One of the primary functions of the human body is to maintain a relatively even state of temperature, acid load, oxygenation, blood glucose, and so on, for internal life processes
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1. Wellness:
state of physiologic equilibrium
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2. Homeostasis:
body's process to attain internal equilibrium
- A. Cell wall membrane
- 1. Outside of the cell
- 2. Porous semipermeable dual layer lipid-protein matrix
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B. Cytoplasm
- 1. Internal fluid
- 2. Primarily water and organelles
- 3. Subunits with a specific cellular function(s)
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C. Nucleus
- 1. Center of cell
- 2. First organelle
- 3. Contains chromosomes and DNA
- a. Blueprints for cellular production and reproduction
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D. Lysosomes
- 1. Outside the nucleus
- 2. Inside the cytoplasm
- 3. Tiny sacs that contain enzymes which can break down proteins
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4. Break down foreign proteins in bacteria (i.e., antigens), or the cell'
chromosomes
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1. Largest organelle in the cell
- 2. Inside the mitochondria, glucose is transformed into the energy source adenosine triphosphate (ATP)
- a. Used to power the rest of the cell's functions
- i. Nicknamed the cell's "powerhouse
- b. Body must maintain complex set of conditions to work properly
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Sodium potassium pump
- 1. To make adaptations to the constantly changing conditions that exist within
- the body, cells need energy
- a. Adenosine triphosphate (ATP)
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2. Anaerobic metabolism:
- cell changes glucose into pyruvate acid, which is in
- turn convened into lactic acid by an enzyme (i.e., lactate dehydrogenase)
- a. Relatively inefficient (only yields two ATP, or about 2% of the energy
- available from glucose if oxygen were to be used, 1 00 times faster than
- aerobic metabolism)
- b. Cells that need quick energy in a short amount of time (i.e., skeletal
- muscles) use anaerobic metabolism
- c. Blood cells (erythrocytes) that carry oxygen cannot use the oxygen they
- carry
- i. Depend on anaerobic metabolism and save the oxygen for the cells
- of the body instead
- d. Can release 619 kCal of heat
- i. Comparable to aerobic metabolism
- ii. Can keep the body warm while not requu-ing complex interactions
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3. Aerobic metabolism:
- body uses eight different enzymes to divide glucose, a
- process called glycolysis (glycol- -"sugar"; -lysis - "to divide"), to create
- pyruvate
- a. Pyruvate and oxygen enter into the citric acid or Krebs cycle
- i. Complex series of changes facilitated by enzymes
- ii. There they undergo a process that creates ATP
- b. End result of this chemical reaction creates carbon dioxide (C02), water
- (H20), energy (in the form ofATP), and heat from the carbohydrate
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Glucose storage
- 1. When abundant, glucose not needed immediately is stored in the liver and muscles as a dual molecule called glycogen (glycol- - "sugar ; "gen — "create")
- a. When glucose levels fall, the body liberates some glucose from these stores
- b. These two bonded glucose molecules (glycogen) are broken down by an enzyme called glucagon into individual glucose molecules
- c. In the absence of other readily available glucose stores, the body can use other food sources to create glucose (i.e., gluconeogenesis)
- 2.
- Process of aerobic metabolism is dependent upon many organ systems
- working together in synchrony in order to be effective
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Fluid Balance
- A. Body is primarily made up of water
- 1. 50% to 55% of total body weight (TBW) in women
- 2. 55% to 60% of TBW in men
- B. Water is intracellular and extracellular
- 1. Majority of body water is intracellular (35% to 40%
- 2. Extracellular fluids include:
- a. Interstitial fluid: fluid between cells (16% TBW)
- b. Intravascular fluid: fluid found in blood
- i. Primarily plasma (4% TBW)
- C. Anatomists referred to spaces
- 1. First: fluid inside the cells
- 2. Second: fluid in the bloodstream
- 3. Third: volume of blood in between cells
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D. Nutritional flow:
- constant movement of fluids between compartments
- 1. Fluids can move from outside to inside the cells and from compartment to compartment by diffusion or osmosis
- a. Amount is controlled by pressure behind fluids or salts/proteins in the
- fluid of the other compartment
- 1. Hydrostatic pressure:
- pressure created by the force behind the volume of water
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2. Edema:
dramatic fluid buildup in the tissues
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3. Isotonic solution:
a balanced solution
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4. Hypotonic fluid/solution:
- fluid has more water and less salt (electrolytes)
- than the solution on the other side of a semipermeable membrane or has less
- water and more salt then the solution
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5. Oncotic pressure:
force similar to osmotic pressure created by proteins
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6. Albumin:
- most common intravascular protein
- Principally made in the liver
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7. Third spacing:
Whenever colloidal osmotic pressure (COP) is low fluid leaks from the intravascular space and into the interstitial space
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Temperature Regulation
- A. Enzymes within the cells operate best in a narrow temperature range of 98.6°F
- +/- 1°F
- 1. All endothermic (i.e., warm-blooded) animals create heat during cellular
- metabolism
- a. Used to maintain a relatively constant core temperature
- 2. At least 90% of all cellular metabolism is used to maintain that heat production
- a. Leaves little for other life processes
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B. Hyperthermia:
too much heat builds up in the body's core
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C. Hypothermia:
too little heat
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D. Anterior hypothalamus:
regulates body temperature
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E. Vasodilatation:
- one of the most effective heat-dissipating mechanisms that the body has
- I. Controlled by the parasympathetic nervous system
- 2. Surface capillaries under the skin react to dissipate the heat
- a. Causes skin to act as a massive radiator to allow heat to dissipate by conduction, convection, and radiation
- 3. If the body should start to cool, then the hypothalamus can either increase
- heat production by causing shivering, an involuntary contraction of muscles, and/or by vasoconstriction
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Temperature and oxyhemoglobin curve
- I. Fever is actually beneficial to the healing process at many levels
- 2. Hypothalamus controls mean body temperature
- a. During an infection, poisons from the bacteria (i.e., endotoxins), stimulate chemical mediators to affect the hypothalamus
- i. Reset hypothalamus thermostat and cause body temperature to raise
- ii. These pyrogens (fever producers) therefore create a pyrexia (Greek—fever) which makes the environment hostile to bacteria
- iii. Also moves the oxyhemoglobin dissociation curve to the right, improving oxygen off loading to the cells
- iv. Metabolism at the site also increasesStress
- 1. Stress: constantly changing conditions cause the body to respond in effort to
- regain homeostasis
- 2. Stressors: Hans Selye
- a. Rats physiologic response was not limited to injections only but to cold and injury as well
- 3. General adaptation syndrome stages
- a. Alarm stage: body responds to stressor
- b. Resistance: body attempts to regain homeostasis
- c. Exhaustion or recovery: exhaustion occurs when the body's response is insufficient to meet the challenge of the stressor
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i. Distress:
stress that overcomes the body's innate defenses, and leads to exhaustion
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ii. Eustress:
daily stress that essentially keeps body defenses on guard for larger stress threats
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B. Stress and the autonomic nervous system
- 1. Autonomic nervous system controls the moment-to-moment functions of most of the organs within the body
- a. Two divisions: sympathetic (the accelerator) and parasympathetic (the brake) nervous systems
- b. Effects of the parasympathetic system can be grossly characterized as the "feed and breed" regulation of the organs
- c. The sympathetic nervous system is reactive, stimulated by stressors, and promotes protection of the body
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2. Neurotransmitters:
- chemical messengers
- a. Neurons do not physically contact the organs that they innervate
- b. Neurons are separated by a gap (i.e., synapse)
- c. Nervous signal is transmitted across this synapse by a neurotransmitter to awaiting chemical receptors across the synapse called neuroreceptors
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i. Adrenergic transmission:
transmission of a nervous signal using adrenalined.
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Typical sympathetic nervous system transmission:
- i.'" An electrical stimulus releases norepinephrine from storage in
- pockets, or vesicles, within the neuron that travel to the synapse
- ii. Norepinephrine travels across the synapse to occupy neuroreceptors on the next neuron
- ill. Cause increased permeability of the affected neuron
- iv. Creates an electrical transference across the cell wall membrane that propagates the nervous signal or stimulates the affected organ
- e. Parasympathetic nerve uses acetylcholine
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i. Cholinergic transmission:
- transmission of a nervous signal using acetylcholine as the neurotransmitter at the motor endplate
- f There are different neurotransmitters in the different portions of the
- nervous system throughout the body
- 3. Neuroreceptors
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a. Parasympathetic nervous system:
nicotinic and muscarinic receptors
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b. Sympathetic neuroreceptors:
- alpha receptors and beta receptors
- i. Type one and type two
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Stress and the endocrine system
- 1. Two effects of stress:
- a. Initially, the sympathetic nervous system stimulates the medulla of the
- adrenal glands, an endocrine organ, to secrete the hormone, adrenaline
- i. Circulating adrenaline then goes to the liver and muscles where it
- stimulates glycolysis ofglucogen stores and liberates glucose into
- the bloodstream
- b. Simultaneously, sympathetic nervous system stimulates the release of
- corticotrophin-releasing factor (CRF) from the hypothalamus
- i. CRF stimulates the pituitary gjand to release several important
- stress hormones
- a) Vasopressin is a powerful vasopressor, a chemical that
- causes vasoconstriction particularly on the arterioles
- b) Cortisol is a glucocorticoid hormone that stimulates the
- production ofglucogen from amino acids and fatty acids
- contained in lipids, a process called glyconeogenesis
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Stress and the immune system
- 1.
- Major organs are directly innervated by the nerve fibers of the autonomic
- nervous system
- a. Hypothalamus acts through the pituitary gland and then the adrenal
- gland to modulate the immune response
- 2. Important function of the immune system may b to alert other organs of an impending systemic threat
- a. Done through the release of inflammatory mediatore (e.g., interferon)
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VIII. Cellular Adaptation
- A. Atrophy
- I. Reduction of cells
- a. Physiologic: loss of cells as a result of normal changes.
- b. Pathologic: loss of cells as a result of a disease
- i. Neuromuscular disease or diseases affecting muscles directlyIX.
- Hypertrophy
- 1. An increase in either the weight or functional capacity of a tissue or organ beyond what is nonnal
- a. Example: bodybuilder who undergoes resistance training to create
- enlarged, or hypertrophied, biceps muscles
- C. Cell replacement
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1. Metaplasia:
replacement of one adult cell type with another type of adult cell
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2. Hyperplasia:
- abnormal increase in the number of cells due to frequent cell
- division/reproduction which causes the tissue or organ to increase in size
- a. May be physiologic, compensatory, or pathologic
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D. Dysplasia
1. Too many new, or immature, cells that are not functional
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E. Apoptosis
- 1. Process of planned cell death
- a. To prevent intrinsic biochemical errors from accumulating within a cell, or to simply replace old worn out or senescent cells, all cells are
- programmed to commit suicide
- b. Maintains a relatively even number of cells among rapidly dividing
- cells
- c. Removes damaged cells
- 2. May also be a pathological condition when it is stimulated by DNA damage caused by oxygen-free radicals
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