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Advanced Pathophysiology Module 1
Basic Cellular Functions -
- Movement
- Conductivity
- Metabolic Absorption
- Secretion
- Excretion
- Respiration
- Reproduction
- Communication Functions of Plasma Membrane -
- Structure
- Protection
- Activation of Cell
- Transport
- Cell to Cell Interaction Nucleus Function - Membrane bound structure, controls cell division and contains genetic information/material Cytoplasm - Cytoplasmic matrix that surrounds organelles Mitochondria - Primary energy maker, responsible for cellular respiration & energy
production, makes ATP Smooth Endoplasmic Reticulum - An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down. Rough Endoplasmic Reticulum - An endomembrane system covered with ribosomes where many proteins for transport are assembled. Golgi apparatus - A system of membranes that modifies and packages proteins for export by the cell Lysosomes - originate in Golgi, 40 digestive/degradative enzymes that catalyze proteins, lipids, nucleic acids, carbs Peroxisomes - Contain oxidative enzymes that detoxify compounds and fatty acids and breakdown substances into harmless products Cytoskeleton - A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement Vesicles - small membrane sacs that specialize in moving products into, out of, and within a cell What are the 3 phases of catabolism for the production of ATP? -
- Can be striated (skeletal) or smooth (bowels, bronchi)
- Can generate forces that produce motion
- Can be smooth AND striated (diaphragm or intercostals) Cardiac & Neuro Cells Function -
- Stimulus causes excitation & electrical potential that passes along surface of cell to reach destination
- Cardiac muscle cells have automaticity GI & Kidney Cells -
- All cells take in nutrients but cells of intestines & kidneys specialize in absorption
- Kidney tubules reabsorb fluids and synthesize proteins
- Intestinal epithelial cells reabsorb fluid & synthesize protein enzymes Endocrine & Neuro Cells -
- Also have conductivity
- Release of hormone into blood stream by use in a distant site/target organ
- Ex: Pancreas releases insulin to signal muscle cells to absorb sugar from blood for energy Gonads & Mucus Cells - •Secretion
- Cells synthesize new substance from what they absorb
- Mucus gland cells can create mucus
- Ovaries secrete estrogen
- Testes secrete testosterone The plasma membrane is impermeable to water molecules, but what can diffuse through it readily? - Lipid-soluble molecules, urea, and uncharged particles, such as H2O & CO Hypertonic - hypertonic solution is one where the concentration of solutes is greater outside the cell than inside it. Glycolysis - A metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP Hypotonic - hypotonic solution is one in which the concentration of solutes is greater inside the cell than outside of it Isotonic - Isotonic environment, the relative concentrations of solute and water are equal on both sides of the membrane. Osmolality - osmoles of solute per kilogram of solvent (Osm/kg) Osmolarity - osmoles of solute per liter of solution (Osm/L) Osmosis -
- Filtration
- Osmosis Facilitated Diffusion - Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins. Moves with concentration gradient Active Transport - Active transport is the movement of a substance across a membrane against its concentration gradient. Requires ATP Exocytosis - a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane. equilibrium potential - When an ions concentration gradient is equal to its electrostatic gradient Endocytosis - The taking in of matter by a living cell by invagination of its membrane to form a vacuole. Action Potential - An action potential (AP) is the mode through which a neuron transports electrical signals. It is defined as a brief change in the voltage across the membrane due to the flow of certain ions into and out of the neuron. Depolarization -
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive. Depolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell. Repolarization - Period during which potassium ions diffuse out of the neuron. Repolarization refers to the change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential has changed the membrane potential to a positive value. Hyperpolarization - It inhibits action potentials by increasing the stimulus required to move the membrane potential to the action potential threshold. •Less Excitable Hypopolorization - Smaller than normal stimulus could reach threshold potential and depolarize the cell. •More Excitable What are the 4 main ions that effect resting potential? - K+, Na+, Ca++, Cl- Does Low Potassium Cause Cell to be MORE or LESS Excitable? Why? - Causes cell to be less Excitable, potassium (K+) is positivity charged. Having less potassium makes cell more negative or Hyperpolarized, requiring more stimulus to generate an action potential.
Neuro-hormonal Tight Junctions - Tight junctions, also known as occluding junctions or zonulae occludentes (singular, zonula occludens) are multiprotein junctional complexes whose general function is to prevent leakage of transported solutes and water and seals the paracellular pathway. Gap Junctions - Gap junctions are a specialized intercellular connection between a multitude of animal cell- types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells. What is transient direct link-up signaling? - When cell to cell receptors link together temporarily to communicate Desmosomes - Desmosomes are intercellular junctions that provide strong adhesion between cells. Because they also link intracellularly to the intermediate filament cytoskeleton they form the adhesive bonds in a network that gives mechanical strength to tissues. Paracrine Cell Communication - Paracrine signaling is a form of cell signaling or cell-to-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behavior of those cells. Autocrine Cell Communication - Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell, leading to changes in the cell. 4 Basic Types of Tissue -
- Epithelial
- Connective
- Muscle
- Neural 5 Types of Cellular Adaptation -
- Atrophy
- Hypertrophy
- Hyperplasia
- Dysplasia
- Metaplasia Atrophy -
- Shrinking in size such as skeletal muscle atrophy. Disuse atrophy, withdrawal of growth factors or hormones
- Physiologic atrophy—thymus gland atrophies in childhood Hypertrophy -
- Enlarging of cells and thus the organ usually due to increased workload
- Ex. Left ventricular hypertrophy, cells enlarge not multiply
- Physiologic hypertrophy turns into pathologic. Hyperplasia -
- Multiplication of cells (increased number of normal appearing cells in response to physiologic or excessive hormonal stimulation
- Increased rate of cell division
- After ovulation, estrogen stimulates endometrium to grow & thicken for implantation. anaplasia - lack of differentiation; cells are unorganized Dysplasia -
- Increased venous pressure and decreased reabsorption and thus increased hydrostatic pressure due to heart failure.
- Lymphatic obstruction decreasing absorption of fluid into lymphatic system. Oncotic Pressure (Colloid Osmotic Pressure) - Pressure exerted by plasma proteins that pull fluid back into blood vessel. Or into interstitial space. Remember RAAS System and Function - In the RAAS, circulating BP and renal blood flow, or serum Na+ concentrations are reduced, the kidneys (juxtaglomerular cells) produce renin. Renin stimulates the formation of Angiotensinogen I (an inactive polypeptide) from the Angiotensinogen produced by the liver. Angiotensin Converting Enzyme in pulmonary vessels converts ATI to ATII, which causes vasoconstriction and elevates systemic BP, consequently increasing renal perfusion. Aldosterone is a mineralocorticoid synthesized and secreted by the adrenal cortex as the end product of the RAAS. Once renal perfusion is restored, aldosterone promotes sodium and water reabsorption by the proximal tubules of the kidneys, conserving Na+, blood volume ("water follows salt") and blood pressure. Aldosterone also promotes the secretion (excretion) of potassium by the distal tubule of the kidney, reducing potassium concentrations in the ECF Natriuretics - ANP, BNP, Urodilatin - Does opposite of RAAS System. Responds to increase volume in vessels. Antidiuretic Hormone (ADH) - ADH is also called arginine vasopressin. It's a hormone made by the hypothalamus in the brain and stored in the posterior pituitary gland. It tells your kidneys how much water to reabsorb in distal renal tubules. ADH constantly regulates and balances the amount of water in your blood. Released in response to increased blood osmolality or decreased blood volume. Isotonic Fluid loss (Isotonic Dehydration) - Water and sodium are lost in equal proportions. Vomiting and diarrhea are most common especially in Gastroenteritis. Excessive sweating may also cause. Hemorrhage, wound draining and decreased fluid intake.
Isotonic Fluid Loss Exam Findings - Weight loss, Dry Mucus Membranes, Skin Turgor (Tenting), Hypovolemia, Oliguria, Increased Urine Specific Gravity, Elevated Liver Enzymes and Pancreatic Enzymes. Catabolism - Metabolic pathways that break down molecules, releasing energy. Why would you administer albumin to a patient with large volume ascites? - It pulls fluid into the capillaries from the interstitial space in attempt to increase capillary volume Hypertonic Dehydration (Hypernatremia) - Water excretion from body exceeds that of sodium excretion. Blood somolality increases causing water to shift from intracellular to extracellular space. Causes of Hypernatremia - Fever (Increases respiratory rate losing water, sweating, decreased fluid intake), Polyuria (Diabetes mellitus, Insipidus, and diuretic use), End-Stage Renal Disease (Tubal dysfunction and Free water clearance dysfunction. Hypernatremic Exam Findings - Intracellular dehydration, convulsions, pulmonary edema, hypotension, tachycardia, increased serum osmolality, increased serum sodium, decreased urine output (Unless caused by polyuria or diuretics), increased urine specific gravity. Clinical manifestations related to shrinking of the brain cells and alterations of membrane potentials Hypotonic Dehydration (Hyponatremia) - Sodium Loss is Greater than water loss. Decreases serum osmolality, shifts water from extracellular to intracellular.
Shallow respiration Irritability Confusion and drowsiness Weakness and fatigue Arrhythmias- irregular heart rate, tachycardia, prolonged qt, depressed P wave Lethargy Thready pulse decrease intestinal mobility, nausea and vomiting, decreased neuromuscular excitability deu to hyperpolarization. Hypokalemia Causes - B.A.D. L.O.A.D. B-arters/Conns syndrome (hyperaldosteronism) A-lkalosis D-iuretics L-axative abuse O-ther causes: insulin overdose A-cute glucose load D-iarrhea Alcohol use, chronic kidney disease, DKA, Folic acid deficiency. Hypercalcemia S/S - BACK ME B-one Pain A-rrhythmias C-ardiac Arrest,Constipation K-idney stones
M-uscle Weakness E-xcessive Urination Hypercalcemia Causes - 90% attributed to Hyperparathyroidism and Cancers. Other causes - Vitamin D and dietary calcium excess, hyperthyroidism, paget's disease, thiazide use. Hypophoshphatemia Causes - Intestinal malabsorption Increased renal excretion Hyperparathyroidism malnutrion, Vit D, deficiency, alcoholism, severe burns, DKA, Fanconi Syndrome, X-linked familial hypophosphatemia Hypophosphatemia S/S - Paresthesias, Muscle weakness, Muscle pain, Mental changes, Cardiomyopathy, Respiratory failure, increased serum calcium. Hyperphosphatemia Causes - Hypoparathyroidism, High Vit D, DKA, muscle damage, infections, acute and chronic renal failure, treatment with chemotherapy (releases large amounts of phosphate into serum), laxative and enema use containing phosphates. Hyperphosphatemia S/S - Neuromuscular irritability Muscle weakness Hyperactive reflexes Tetany Positive Chvostek's or Trousseau's sign
Causes for Acidosis - Lung Impairment - COPD, Pneumonia, lung diseases or traumas. Diarrhea, DKA, Renal failure, Drug Overdose. What are the different buffer systems? -
- lungs
- kidneys
- phosphate -bicarb
- plasma protein
- hemoglobin ( all 4 work together to provide the fastest correction of pH imbalance) lungs as a buffer - buffer by increasing or decreasing the respiratory rate and therefore the amount of CO available to make H2CO3 in the blood. More CO2 → lower pH, therefore increased respirations will exhale CO2 and increase the pH and vice versa. -work faster than kidneys Protein Buffer System - Hemoglobin serves as buffer. Hemoglobin = Amino Acid which has NH3+ _C_COO-, H+ can bind to COO- if blood is acidic, or release the H+ if blood is alkalinic. NH3+ can drop a H+ if blood is alkalinic or bind a H+ if blood is acidic. Approx 250 million Hemoglobin in every RBC. Causes of Alkolosis - Hyperventilation, vomiting, increased H+ loss from diuretics, high altitudes, hyper-metabolic states such as fever.
Bicarbonate Buffer System - a solution of carbonic acid and bicarbonate ions, regulated by lungs by blowing off CO2 and Kidneys by releasing Bicarbonate and/or excreting H+ -main plasma buffering system along with HgB -works fast Ammonia Buffer System - Ammonium is generated in tubular cells through glutamine metabolism. Ammonia binds to protons and helps kidneys when maximum proton absorption by tubules are reached. Phosphate Buffer System - Buffers ICF and Urine. Consists of Dihydrogen phosphate ions and Hydrogen Phosphate ions. Dihydrogen Phosphate can release an H+ increasing acidity and Hydrogen Phosphate ions can bind H+ to increase alkalinity. (works rapidly) DNA Structure - DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine What causes edema? -
- arterial dilation
- venous or lymphatic obstruction
- loss of plasma proteins
- increase capillary permeability
- increased vascular volume DNA Function -
