RNA-protein complexes synthesized in the nucleolus and secreted into cytoplasm. Provide sites for cellular protein synthesis
network of tubular channels that extend throughout outer nuclear membrane. Specializes in synthesis and transport of protein and lipid components of most organelles
network of smooth membranes and vesicles near nucleus. it processes and packages proteins onto secretory vesicles that break away from the complex and migrate to carious intracellular and extracellular destinations.
saclike structure that originate from golgi complex and contain enzymes for digesting most cellular substances to their basic form, such as amino acids, fatty acids, and sugar
contain metabolic machinery needed for cellular energy metabolism. enzymes found in the inner mem. of the mitochondria generate most of cells ATP
The primary functions of the nucleus are cell division and control of genetic information.
what is adaptation?
is a reversible, structural, or functional response both to normal or physiologic conditions and to adverse or pathologic conditions.
examples of adaptation
the uterus adapts to pregnancy—a normal physiologic state—by enlarging. Enlargement occurs because of an increase in the size and number of uterine cells. In an adverse condition such as high blood pressure, myocardial cells are stimulated to enlarge by the increased work of pumping.
what is atrophy?
a decrease or shrinkage in cell size
what is an atrophic muscle cell?
The atrophic muscle cell contains less endoplasmic reticulum and fewer mitochondria and myofilaments than found in the normal cell.
what is hypertrophy?
an increase in the size of cells and consequently in the size of the affected. The cells of the heart and kidneys are particularly prone to enlargement.
what is the reason for the increase in cell size?
The increased cellular size is associated with an increased accumulation of protein in the cellular components (plasma membrane, endoplasmic reticulum, myofilaments, mitochondria) and not with an increase in cellular fluid.
what are examples of hypertrophy?
-increased growth of the uterus and mammary glands in response to pregnancy
-kidneys can be
-skeletal muscle growth from weight lifting
what are the triggers of hypertrophy?
The triggers for hypertrophy include two types of signals: (1) mechanical signals, such as stretch, and (2) trophic signals, such as growth factors, hormones, and vasoactive agents.
how can the kidney be an example of hypertrophy?
When a diseased kidney is removed, the remaining kidney adapts to the increased workload with an increase in both the size and the number of cells. The major contributing factor to this renal enlargement is hypertrophy.
What is hyperplasia?
-an increase in the number of cells resulting from an increased rate of cellular division
-it is a response to injury, occurs when the injury has been severe and prolonged enough to have caused cell death
what are the two types of normal hyperplasia?
(1) compensatory and (2) hormonal
what is compensatory hyperplasia?
is an adaptive mechanism that enables certain organs to regenerate
what is an example of compensatory hyperplasia?
-removal of part of the liver leads to hyperplasia of the remaining liver cells to compensate for the loss.
-Significant compensatory hyperplasia occurs in epidermal and intestinal epithelia, hepatocytes, bone marrow cells, and fibroblasts, and some hyperplasia is noted in bone, cartilage, and smooth muscle cells.
-The callus, or thickening, of the skin as a result of hyperplasia of epidermal cells in response to a mechanical stimulus.
what is an example of hormonal hyperplasia?
-occurs chiefly in estrogen-dependent organs, such as the uterus and breast.
-After ovulation, for example, estrogen stimulates the endometrium to grow and thicken
-If pregnancy occurs, hormonal hyperplasia, as well as hypertrophy, enables the uterus to enlarge.
what is pathologic hyperplasia?
abnormal proliferation of normal cells, usually in response to excessive hormonal stimulation or growth factors on target cells
-most common example is of the endometrium from over secretion of estrogen
what is dysplasia?
abnormal changes in the size, shape, and organization of mature cells. Dysplasia is not considered a true adaptive process but is related to hyperplasia and is often called atypical hyperplasia
where does dysplasia normally take place?
changes often are encountered in epithelial tissue of the cervix and respiratory tract, where they are strongly associated with common neoplastic growths and often are found adjacent to cancerous cells
Does dysplasia mean the cells are cancerous?
dysplasia does not indicate cancer and may not progress to cancer. Dysplasia is often classified as mild, moderate, or severe. it is often reversible
what is metaplasia?
is the reversible replacement of one mature cell type by another, sometimes less differentiated, cell type
what is an example of metaplasia?
is replacement of normal columnar ciliated epithelial cells of the bronchial lining by stratified squamous epithelial cells. The newly formed cells do not secrete mucus or have cilia, causing loss of a vital protective mechanism
- it can be reversible if stop smoking
-prolong exposure can lead to cancer
what is cellular injury?
Most diseases begin with cell injury. Cellular injury occurs if the cell is unable to maintain homeostasis—a normal or adaptive steady state—in the face of injurious stimuli
what is reversible injury?
when injured cells recover
what is irreversible injury?
when injured cells die
what are examples of injurious stimuli?
chemical agents, lack of sufficient oxygen (hypoxia), free radicals, infectious agents, physical and mechanical factors, immunologic reactions, genetic factors, and nutritional imbalances
what is necrosis?
Cellular death eventually leads to cellular dissolution, or necrosis. Necrosis is the sum of cellular changes after local cell death and the process of cellular self-digestion, known as autodigestion or autolysis
what is apoptosis?
an active process of cellular self-destruction called programmed cell death and is implicated in both normal and pathologic tissue changes
Why is apoptosis necessary?
cells to die; otherwise, endless proliferation would lead to gigantic bodies. The average adult may create 10 billion new cells every day—and destroy the same number
What is the normal physiologic death by apoptosis?
• Involution of hormone-dependent tissue after hormone withdrawal
• Cell loss in proliferating cell populations (such as immature lymphocytes in the bone marrow or thymus that do not express appropriate receptors)
• Elimination of possibly harmful lymphocytes that may be self-reactive and cause cell death after performing useful functions (for example, neutrophils after an acute inflammatory reaction)
What is TBW?
The sum of fluids within all body compartments constitutes total body water (TBW)—about 60% of body weight in adults the rest of weight is from fat, fat-free solids, and bones
How is TBW expressed?
The volume of TBW is usually expressed as a percentage of body weight in kilograms. One liter of water weighs 2.2 lb
What is ICF?
Intracellular fluid (ICF) comprises all the fluid within cells, about two thirds of TBW
What is ECF?
Extracellular fluid (ECF) is all the fluid outside the cells (about one third of TBW) and is divided into smaller compartments
What are the smaller compartments of ECF?
-The two main ECF compartments are the interstitial fluid (the space between cells and outside the blood vessels) and the intravascular fluid (blood plasma)
-Other compartments include lymph and transcellular fluids, such as synovial, intestinal, and cerebrospinal fluid; sweat; urine; and pleural, peritoneal, pericardial, and intraocular fluids.
what is the distribution of TBW?
The distribution and the amount of TBW change with age
What is edema?
Edema is excessive accumulation of fluid within the interstitial spaces
What forces fluids into the tissues?
The forces favoring fluid movement from the capillaries or lymphatic channels into the tissues are increased capillary hydrostatic pressure, decreased plasma oncotic pressure, increased capillary membrane permeability, and lymphatic channel obstruction
What is pitting edema?
Dependent edema appears in the feet and legs when standing and in the sacral area and buttocks when supine. It can be identified by pressing on tissues overlying bony prominences
What percentage does sodium account for in the ECF?
Sodium (Na+) accounts for 90% of the ECF cations
What does chlorine do in the ECF?
Chloride (Cl−) is the major anion in the ECF and provides electroneutrality, particularly in relation to sodium
What is isotonic fluid loss?
The term isotonic refers to a solution that has the same concentration of solutes as the plasma. Isotonic alterations occur when TBW changes are accompanied by proportional changes in the concentrations of electrolytes
What does isotonic fluid loss cause?
hypovolemia. example, if an individual loses pure plasma or ECF, fluid volume is depleted but the concentration and type of electrolytes and the osmolality remain in the normal range (280 to 294 mOsm). Causes include hemorrhage
What is isotonic fluid excess cause?
What does hypervolemia cause?
Common causes include excessive administration of intravenous fluids, hypersecretion of aldosterone, or the effects of drugs such as cortisone (which causes renal reabsorption of sodium and water)
What is hypernatremia?
it occurs when serum sodium levels exceed 145 mEq/L.
What causes hypernatremia?
Increased levels of serum sodium may be caused by retention or infusion of sodium or by decreased intake or increased loss of water
What does hypervolemia cause?
Because sodium is largely in the ECF, increases in sodium concentration cause intracellular dehydration
The movement of water to the ECF may cause hypervolemia
What is dehydration?
Dehydration refers to water deficit but also is commonly used to indicate both sodium and water loss (isotonic or isoosmolar dehydration)
What are the clinical manifestations of water deficit?
symptoms of dehydration, such as headache, thirst, dry skin and mucous membranes, elevated temperature, weight loss, and decreased or concentrated urine
What are the clinical manefestations of hypernatremia?
weight gain, bounding pulse, and increased blood pressure.
CNS:symptoms are the most serious and are related to alterations in membrane potentials and shrinking of brain cells. Symptoms include muscle twitching and hyperreflexia, confusion, coma, convulsions, and cerebral hemorrhage from stretching of veins
How do you treat hypernatremia?
to give oral fluids or isotonic salt-free fluid (5% dextrose in water) until the serum sodium level returns to normal. it must be given slowly
how do you treat dehydration?
Fluid replacement must be administered slowly enough to prevent rapid movement of water into brain cells, which causes cerebral edema, seizures, brain injury, and death
what is hyponatremia?
Hyponatremia develops when the serum sodium concentration falls below 135 mEq/L
what is Dilutional hyponatremia
it occurs when there is replacement of fluid loss with intravenous 5% dextrose in water. The glucose is metabolized to carbon dioxide and water, leaving a hypotonic solution with a diluting effect
What is pure sodium depletion?
Pure sodium depletion is usually caused by vomiting, diarrhea, suctioning of gastrointestinal secretions, and burns or renal losses from use of diuretics
in what type of patient does hyponatremia occur most often?
Hospitalized elderly ppl
How do you get hyponatremia?
This occurs when there is loss of sodium, inadequate intake of sodium, or dilution of sodium by water excess.
What are symptoms of hyponatremia?
lethargy, confusion, apprehension, depressed reflexes, seizures, and coma. Muscle twitching and weakness are common
What are symptoms of pure sodium depletion?
may be accompanied by loss of ECF, causing hypovolemia with symptoms of hypotension, tachycardia, and decreased urine output
What are symptoms of dilutional hyponatremia?
is accompanied by weight gain, edema, ascites, and jugular vein distention
How do you treat Hyponatremia?
Hypertonic saline solutions are used cautiously with severe symptoms, such as seizures and must be given slowly to prevent osmotic demyelination syndrome in the brain. Restriction of water intake is required in most cases of dilutional hyponatremia
what is the pathophysiology of water excess?
When the body is functioning normally, it is almost impossible to produce an excess of TBW because water balance is regulated by the kidneys
what is water intoxication?
Some individuals with psychogenic disorders develop water intoxication from compulsive water drinking.
what are symptoms for water excess?
Acute excesses cause cerebral edema with confusion and convulsions. Weakness, nausea, muscle twitching, headache, and weight gain are common symptoms of chronic water accumulation.
What is Hypokalemia?
Potassium deficiency, or hypokalemia, develops when the serum potassium concentration falls below 3.5 mEq/L
What factors contribute to hypokalemia?
include reduced intake of potassium, increased entry of potassium into cells, and increased losses of body potassium
What are the ppl most likely to get hypokalemia?
elderly individuals with both low protein intake and inadequate intake of fruits and vegetables and in individuals with alcoholism or anorexia nervosa
what are symptoms of hypokalemia?
Severe loss results in neuromuscular and cardiac manifestations. Neuromuscular excitability decreases, causing skeletal muscle weakness, smooth muscle atony, cardiac dysrhythmias, glucose intolerance and impaired urinary concentrating ability
What is hyperkalemia?
Elevation of ECF potassium concentration above 5.5 mEq/L constitutes
what cases potassium excess? or hyperkalemia?
may be caused by increased intake, a shift of potassium from cells to the ECF, decreased renal excretion, or drugs that decrease renal potassium excretion
what are symptoms of hyperkalemia?
During mild attacks, increased neuromuscular irritability may be manifested as restlessness, intestinal cramping, and diarrhea. Severe hyperkalemia causes muscle weakness, loss of muscle tone, and paralysis.
Acid base balance?
Acid-base balance must be regulated within a narrow range for the body to function normally. Slight changes in amounts of hydrogen can significantly alter biologic processes in cells and tissues
what does the hydrogen ion do?
Hydrogen ion is needed to maintain membrane integrity and the speed of metabolic enzyme reactions.
what happens to the pH and acidity if a solution is high in hydrogen?
The greater the [H+], the more acidic the solution and the lower the pH
what happens to the pH and acidity of a solution that is low in hydrogen?
The lower the [H+], the more alkaline or basic the solution and the higher the pH.
What pH is defined as acidic?
if its <7.4
What oH is defined as basic or alkaline?
if its >7.4
what are the 2 forms body acids exist in?
volatile (can be eliminated as CO2 gas) and nonvolatile (can be eliminated by the kidney)
what is a volatile acid?
The volatile acid is carbonic acid (H2CO3), a weak acid (i.e., it does not release its hydrogen easily). In the presence of the enzyme carbonic anhydrase, it readily dissociates into carbon dioxide (CO2) and water (H2O). The carbon dioxide is then eliminated by pulmonary ventilation
what are nonvolatile acids?
Sulfuric, phosphoric, and other organic acids are nonvolatile strong acids (i.e., they readily release their hydrogens)
what is renal buffering?
The distal tubule of the kidney regulates acid-base balance by secreting hydrogen into the urine and reabsorbing bicarbonate.
What are acid based imbalances?
Pathophysiologic changes in the concentration of hydrogen ion in the blood lead to acid-base imbalances
what is Acidemia?
In acidemia the pH of arterial blood is less than 7.4
What is acidosis?
A systemic increase in hydrogen ion concentration or loss of base is termed acidosis
What is Alkalemia?
In alkalemia the pH of arterial blood is greater than 7.4
what is alkalosis
A systemic decrease in hydrogen ion concentration or excess of base is termed alkalosis
What is metabolic acidosis?
In metabolic acidosis the concentrations of non–carbonic acids increase or bicarbonate is lost from extracellular fluid or cannot be regenerated by the kidney. This can occur either quickly, as in lactic acidosis caused by poor perfusion or hypoxemia, or slowly
What is metabolic alkalosis?
When excessive loss of metabolic acids occurs, bicarbonate concentration increases, causing metabolic alkalosis.
What is hypochloremic metabolic alkalosis?
When acid loss is caused by vomiting, renal compensation is not very effective because loss of chloride (an anion) in hydrochloric (HCl) acid stimulates renal retention of bicarbonate (an anion),
What is respiratory alkalosis?
Respiratory alkalosis occurs when there is alveolar hyperventilation (deep, rapid respirations). or hypocapnia (decreased carbonic acid)
How do you get decreased carbonic acid concentrations?
Excessive reduction in plasma carbon dioxide levels (hypocapnia) decrease carbonic acid concentration.25,26 The Paco2 is <35 mm Hg and the pH is greater than normal