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Pathophysiology Study Guide

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Pathophysiology Exam 1
Pathology: ​ The study and diagnosis of disease through examination of organs, tissues, cells,
and bodily fluids.
Physiology:​ ​The study of the mechanical, physical, and biochemical functions of living
organisms.
Together, ​Pathophysiology: The study of abnormalities in physiologic functioning of living
beings.
What is the framework of Pathophysiology consist of? ​ Etiology/Pathogenesis, Clinical
Manifestations, Implications/Treatments
Homeostasis: A state of equilibrium, of balance within the organism; maintaining internal
conditions in a stable state
Allostasis:​ ​The overall process of adaptive change necessary to maintain survival and
well-being; ​*​restores balance, ​*​is the activation of stress responses to return to homeostasis
General Adaptation System (GAS): 3 Physiologic Stages
1. Alarm Stage: ​Fight-or-Flight response. Begins in the hypothalamus>secretes
corticotropin-releasing hormone(CRH) to activate the Sympathetic Nervous System(SNS), which
in turn stimulates the Adrenal Medulla to release the Catacholamines: Epinephrine and
Norepinephrine.
Additionally, the hypothalamus secretes CRH to stimulate the Anterior Pituitary Gland to
release adrenocorticotropic hormone(ACTH). ACTH then causes the adrenal cortex to release
large amounts of glucocorticoids, specifically Cortisol.
This cascade of effects is termed the hypothalamic-pituitary-adrenal(HPA)axis. Once the
pituitary gland is activated, the alarm stage moves to the next stage in GAS: Resistance Stage
2. Resistance or Adaptation Stage:​ The Sympathetic Nervous System(SNS), the adrenal
medulla and cortex are working full force to mobilize resources to manage the stressor. These
resources are: glucose, free fatty acids, and amino acids. Concentrations of these resources
are increased through the effects of Cortisol and Catacholamines(Epi and Norepi).
These resources are used for energy, and also building blocks for growth and repair after stress
stops. The body returns to a steady state/homeostasis.
3. Exhaustion Stage:​ The body is no longer able to return to homeostasis. When energy
resources are completely depleted, death occurs because the body can no longer adapt.
Allostatic Load​: ‘Wear and Tear’ on the body and brain. The typical demands that are part of
daily life and unpredictable events. However, if chronic demands continue, the result is
Allostatic Overload.
Allostatic Overload:​ ​This is the ‘Cost’ to the body’s organs and tissues for an allostatic response
that is excessive or ineffectively regulated and unable to deactivate; body is now susceptible to
disease process.
Mediators of Stress and Adaptation Hormones:
The effects of Catacholamines are profound:​ ​they affect CV function, control of fluid volume
by activating the renin-angiotensin-aldosterone mechanism, play a role in inflammation and
immunity, affect metabolism, are associated with attentiveness, arousal, and memory
formation in the CNS.
Norepinephrine​: Primary constrictor of smooth muscle in blood vessels. It regulates blood flow
through tissues and its distribution through the organs, maintains blood pressure. It reduces
gastric secretion, inhibits insulin secretion, and dilates pupils.
Adrenocortical Steroids/Glucocorticoids:​ Have regulatory roles in maintaining fluid volume,
metabolism, immunity, inflammatory responses, and brain function.
Epinephrine: ​Increases heart rate, relaxes bronchial smooth muscle to dilate the airway for
better O2. Increases glycogenolysis, the release of glucose from the liver and inhibits insulin
secretion, further elevating blood glucose levels.
Aldosterone:​ Is secreted by the adrenal cortex. When the SNS activates the renin-angiotensin
system, the final chemical outcome is the release of Aldosterone.
*​ ​The primary effect of Aldosterone is reabsorption of sodium and water in the kidneys, and
increased excretion of potassium.
Because of osmotic force, water tends to follow sodium. Therefore, increases reabsorption of
sodium lead to increases ECF volume, and increased blood pressure.
Cortisol:​ Secreted by the Adrenal Cortex in response to ACTH from the anterior pituitary.
Cortisol binds to receptors on the hypothalamus and anterior pituitary gland to suppress CRH
and ACTH release in a negative feedback loop.
Cortisol affects protein metabolism: Anabolic effect of increase rates of protein synthesis in the
liver; Catabolic effect in muscle, lymphoid, and adipose tissue and on skin and bone.
Physical and Behavioral Indicators of High Stress:​ Increase in: blood pressure, respirations,
muscle tension, and pulse rate. Sweaty palms, cold extremities, fatigue, n/v, insomnia.
Anxiety, depression, loss of motivation, mental exhaustion, lack of good judgement and
concentration.
**Anti-diuretic Hormone(ADH) = Tap Water Hormone
**Aldosterone = Salt Water Hormone
Epidemiology:​ The study of the Patterns of Disease
Endemic:​ ​Disease that is native to a local region
Epidemic:​ Disease is disseminated to many individuals at the same time
Pandemic:​ These are Epidemics that affect large geographic regions, perhaps spreading
worldwide
Levels of Disease Prevention:
Primary Prevention: ​Immunizations, Health Education and Promotion, Adherence to Safety
Precautions (safety belts, driving the speed limit), taking precautions while using chemicals and
machinery
Secondary: ​Yearly physical exam, routine screenings, Amniocentesis
Tertiary: ​Once a disease becomes established, treatment generally falls into one of the
following categories:
MEDICAL: physical therapy, pharmacotherapy, psychotherapy, radiation therapy,
chemotherapy, immunotherapy, and experimental gene therapy
SURGICAL:
*Rehabilitative and Supportive Prevention: Supports optimal functioning; Prevents long-term
consequences of chronic illness; EXAMPLE: Prevent Pressure Ulcer, Promote Independence
after brain surgery.
General Adaptation Syndrome(GAS) – 3 Stages
Alarm Stage: ​“Fight-or-Flight”; The Hypothalamus senses a need to activate the GAS response
to stress, placing the balance of Homeostasis at risk.
1. Hypothalamus then secretes Coritcotropin Releasing Hormone (CRH) to activate the
Sympathetic Nervous System (SNS).
2. SNS then stimulates the Adrenal Medulla to secrete the Catacholamines: Norepinephrine
and Epinephrine.
3. The Hypothalamus also secretes CRH to stimulate the Anterior Pituitary Gland to release
Adrenocorticotropic Hormone (ACTH).
4. ACTH stimulates the Adrenal Cortex to release increases amounts of Glucocorticoids,
specifically Cortisol.
*This cascade of effects is known as the Hypothalamic-Pituitary-Adrenal (HPA) Axis. **Once
the Pituitary Gland is activated, the Alarm stage moves into the Resistance stage.
Resistance Stage:​ “Adaptation” stage/Allostatic Load
1. The SNS mobilizes resources to manage stress. *Resources: glucose, free fatty acids, omino
acids. These Resources are used for energy and as building blocks for the frowth and repair of
*the next stage of Exhaustion takes place.
Exhaustion Stage: ​The body is no longer able to return to homeostasis/no longer able to adapt.
*​Allostatic Load:​ “Wear-and-Tear”/Demands that are part of daily life
*​Allostatic Overload: ​“Cost” of the body’s organs and tissues for an allostatic response that is
excessive or ineffectively regulated and unable to deactivate.
*The Autonomic Nervous System: Regulates the activities of Internal Organs; it has 2 Main
Divisions:
Sympathetic Nervous System (SNS):​ **Fight-or-Flight”/In situations that require alertness and
energy such as facing danger or doing physical activities, the SNS mobilizes the body for action.
*Increases HR, Increases Respiratory Rate, Releases Stored Energy such as Glucose, Dilates
Pupils
*Decreases GI/Digestion and Renal/Urination
Parasympathetic Nervous System (PNS):​ “Rest-and-Digest”/Conserves and Restores
*Decreases HR, Decreases Respiratory Rate, Stimulates GI/Digestion, Removes Waste and
Stores Energy
Cellular Components:
Cytoskeleton​ is made up of actin, microtubules, and intermediate filaments. These proteins
regulate cell shape, movement, and the trafficking of intracellular molecules.
Nucleus​ contains DNA. These nuclear genes code for the synthesis of proteins.
Endoplasmic Reticulum and Golgi Aparatus​ function together to synthesize proteins and lipids
for transport to lysosomes or to the plasma membrane.
**Mitochondria ​is known as the “Powerhouse of the Cell”. Converts energy to forms that can
be used to drive cellular reactions. Contain enzymes necessary for Oxidative Phosphorylation
to produce Adenosine Triphosphate (ATP).
Glycolysis:​ Ten enzymatic steps are required in glycolysis to break glucose into two 3-carbon
pyruvate molecules. *A NET GAIN of 2 ATP molecules is achieved. **Anaerobic process!
*Gains 2 ATP for every P (Pyruvate).
Extracellular Fluid:​ Fluid outside the cell that contains higher concentrations of sodium,
chloride, calcium, and bicarbonate ions.
Intracellular Fluid:​ Contains high concentrations of potassium, magnesium, and phosphate
ions.
Passive Transport:​ NO ENERGY is used to transport K+ across the cell membrane; Diffusion and
Osmosis; HIGH concentration to LOW concentration
Active Transport: ​REQUIRES ENERGY *ATP to transport Na+ across the cell membrane.
Sodium/Potassium Pump:​ ​Maintains low sodium and high potassium concentrations in the
cell.
Fluid Distribution:​ Fluid distribution between the Vascular and Interstitial compartments is the
net result of ​*Filtration​ across permeable capillaries via ​Hydrostatic Pressure.
The distribution of fluid between the Interstitial and Intracellular compartments occurs
by​*Osmosis​ – Water moves in and out of the cells by Osmosis! ​Osmotic Pressure is the primary
force that causes Interstitial Fluid to move back into the Capillaries​.
Fluid Excretion:​ Urine, feces, sweat, respiration, vomiting, drainage
ECF Volume Deficit:​ “Saline Deficit”; CAUSES: ​GI Excretion or Loss​>Emesis, diarrhea, NG
Suction, Fistula drainage; ​Renal Excretion>​Adrenal insufficiency, Diuretic Use, Bed Rest; ​Other>
Hemorrhage, Diaphoresis, Paracentesis, Burns
ECF Volume Excess:​ “Saline Excess”; CAUSES: ​Excessive IV Infusion>​Normal Saline, Lactated
Ringers; ​Renal Retention of Sodium and Water>​Hyperaldosteronism, Chronic Heart Failure,
Cirrhosis, Acute Glomerulonephritis, Chronic End-Stage Renal Disease, Cushing Disease, and
Corticosteroid Therapy; SYMPTOMS>Bounding Pulse, Crackles, SOB
*2.2 lbs = 1 Liter of Fluid
Electrolyte Distribution:
*​Concentrations of Potassium, Magnesium, and Phosphate Ions are higher inside cells than in
the fluid outside the cells.
*​Calcium Ion concentration is higher in the Extracellular Fluid.
*The bones serve as an important reservoir of: Calcium, Magnesium, and Phosphate Ions!!
The cells and the bones are often called *Electrolyte Pools!!
Distribution of electrolytes between the Extracellular Fluid and the Electrolyte Pools is
influenced primarily by hormones such as ​Epinephrine, Insulin, and Parathyroid Hormone(PTH).
Kreb’s Cycle=Citric Acid Cyle:​ *ANAEROBIC PROCESS! This cycle ends with the production of
ATP. The purpose of the cycle is to break the C-C and C-H bonds. (C=Carbon, H=Hydrogen).
*Cellular Metabolism; This is the source of our energy!
Components of the Immune System:​ ​1.​ Skin and Mucous Membranes “First Line of Defense”
2.​ Lymphoid System: spleen, thymus gland, and lymph nodes; Secondary lymphoid organs
include: tonsils, spleen, lymph nodes and Pyer Patches; ​3.​ Bone Marrow (primary function is
formation of RBCs).
Macrophages and Dendritic Cells​ are often the first immune system cells to encounter a
pathogen or foreign antigen after it has entered the body.
Acute Infections and LEFT SHIFT: ​During an acute infection, an increase in the number of
Neutrophils occurs as the bone marrow releases stored Neutrophils. As Neutrophils are
consumed and Demand exceeds Production, an increase in the number of Immature
Neutrophils called BANDS occurs. ​*This increase in BAND cells is referred to as a “Shift To The
Left Of Normal”. A greater Shift To The Left indicates a more severe infection.
5 Cardinal Signs of Inflammation:
RED, SWOLLEN, HOT, PAIN, LOSS OF FUNCTION *Seen with both acute and chronic cases. The
systemic response​ to inflammation: Fever, Increase Neutrophil Count, Lethargy, Muscle
Catabolism ‘Wasting’
Humoral Immunity:​ B Cells are responsible for antibody-mediated immunity. B cells have two
major subpopulations: Memory Cells and Plasma Cells. Memory of exposure to an antigen is
stored in a clone of memory B Cells.
Antibody Structure:​ Antibody=Immunglobulin; Antibodies are differentiated into five classes:
IgG, IgM, IgA, IgD, and IgE
IgG:​ Most common type of immunoglobulin. Found in the intervascular and interstitial
compartments.
IgM:​ Predominantly found in intervascular pool.
IgA:​ Located in the tissue under the skin and mucous membranes. Primarily found in ​saliva,
tears, tracheobronchial secretions, colostrum, breast milk and GI/GU secretions.
IgD: ​Found in trace amounts in the serum. And is located primarily on the membranes of B cells
along with IgM.
IgE:​ Found by its Fc Tail to receptors on the surface of basophils and mast cells. *​It has a role in
immunity against Helminthic Parasites (Worms) and is responsible for initiating inflammatory
and allergic reactions (Hay Fever, Asthma). Functions as a signaling molecule and causes mast
cell degranulation when antigen is detected at the mast cell surface.
Passive Immunity:​ ​Involves the transfer of plasma containing preformed antibodies against a
specific antigen from a Protected/Immunized person to an Unprotected/Non-immunized
person. ​IgG ​antibodies can cross the placental barrier. ​IgA​ antibodies are received by
newborns in Breast Milk. ​Serotherapy​ involves direct injection of antibodies into an
unprotected person.
Active Immunity:​ A form of long-term acquired immunity that protects the body against a new
infection as the result of antibodies that develop naturally after an initial infection or artificially
after a vaccination.
Alterations in Immune Function: 4 Hypersensitivity Types
I​ – Allergic/Anaphylatic; Immediate Hypersensitivity; IgE is the principle mediating antibody;
Most important mediator is: ​Histimine! Also, Heparin decreases blood clot formation.
II​ – Tissue Specific; Transfusion reaction, Myasthenia Gravis, Grave’s Disease and Graft rejection
III​ – Immune Complex Reaction
IV​ – Delayed Hypersensitivity
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