Home > Flashcards > Print Preview
The flashcards below were created by user
on FreezingBlue Flashcards. What would you like to do?
What is Biology?
- It is the study of living organisms with regard to their origin, growth, structure, behavior and reproduction.
What is Pathophysiology?
- The Study of the functioning of organism in the presence of suffering/disease.
What is Etiology?
- Cause of a disease process. Often helps the paramedic identify a reasonable approach to evaluation and initial treatment of a patient.
What three componets make up a cell?
- Cell membrane, The cytoplasm containing the internal components or organelles, and the nucleus.
What is the function of the cell membrane?
- It consists of fat and protein. It surrounds the cell and protects the internal components within the cytoplasm.
What is the function of organelles?
- They are found within the cells cytoplasm and operate in a cooperative and organized fashion to maintain the life of the cell.
What are Ribosomes?
- They are found in the organelles and contain RNA and protein. They interact with RNA from other parts of the cell, joining amino acid chains together to form proteins.
- When Ribosomes attach to endoplasmic reticulum, they create rough endoplasmic reticulum.
What is the endoplasmic reticulum?
- - It is a network of tubules, vesicles, and sacs.
- - Rough endoplasmic reticulum is involved in building proteins.
- - Smooth endoplasmic reticulum is involved in building lipids (fats), such as those found in the cell membranes and those found in carbohydrates.
What is the Golgi complex?
- - Located near the nucleus of the cell.
- - It is involved in the synthesis and packaging of various carbohydrates and complex protein molecules such as enzymes.
What are Lysosomes?
- - Membrane-bound vesicles that contain digestive enzymes.
- - These enzymes function as an intracellular digestive system, breaking down bacteria and organic debris that have been taken into the cell.
What are Peroxisomes?
- They are simular to lysosomes and are found in high concentrations in the liver and neutralize toxins such as alcohol.
What are Mitochondria?
- - It is a small, rod like organelles that function as the metobolic center of the cell.
- - They produce adenosine triphospahte (ATP), which is the major energy source for the body.
What is the nucleus?
- It contains the genetic material, called chromatin, and the nucleoli, which are rounded, dense structres That contain RNA.
What is RNA?
- It is reponsible for controlling the cellular activities.
What surrounds the nucleus?
- It is surrounded by the nuclear envelope, which is a membrane.
What are the four types of tissues?
- - Epithelial
- - Connective
- - Muscle
- - Nerve
What is the Epithelium?
- - It covers the external surfaces of the body.
- - It also lines hollow organs withing the body, such as the intestines, blood vessels, and bronchial tubes.
- - It provides protective barriers and plays a role in absorption of nutrients in the intestine and the secreation of various body substances.
What are endothelial cells?
- - They are epithelial cells that line the inside of blood vessels.
- - They regulate the flow of blood through the vessel as well as clotting of the blood.
What is connective tissue?
- - Binds the other types of tissues together.
- - Bones and and cartilage are sbutypes of connective tissue.
What is the Extrcellular matirx?
- - A nonliving substance consisting of protien fibers, nonfibrous protein, and fluid that separates connective tissues cells from one another.
- - Collagen is the major protein.
- - 12 types of collagen exist with types I, II, and III being the most abundant.
- - Alterations in collagen structure resulting from abnormal genes or abnormal processing of collagen proteins result in numerous diseases. (i.e. scurvy)
What is Adipose Tissue?
- Special type of connective tissue that contains large amounts of lipids (fats).
What are the two types of muscles tissue?
- - Striated muscles
- - Non-Striated (Smooth) muscles
What is fascia?
- A layer of fibrous connective tissue that separates individual muscles.
What are the two types of funtional muscle?
- - Voluntary (consciously controlled)
- - involuntary (not normally under conscious control)
What are the three types of muscles?
- - Skeletal muscle (Striated voluntary)
- - Cardiac muscle (striated involuntary)
- - Smooth muscle (nonstriated involuntary)
Where are smooth muscles found?
- - They are found in glands, digestive organs, lower airways, and vessels.
- - They are also responsible for constriction and dilation of the pupil of the eye.
What makes up the Central Nervous System (CNS)?
- Brain and the spinal cord.
Where are peripheral nerves found?
- They extend from the brain and spinal cord, exiting from between the vertebrea to various parts of the body.
What are Neurons?
- - They are the main conducting cells of nerve tissue.
- - The cell body of the neuron is the site of most cellular functions.
What is the role of the dendrites?
- They receive electrical impulses from axons of other nerve cells and conduct them towrd the cell body.
What is the role of axons?
- They typically conduct electrical impulses away from the cell body.
How does condution happen in a nerve?
- - Each neuron has only one axon, but it may have several dendrites.
- - Nerve cells are separated by a gap called the synapse.
- - Electrical impulses travel down the nerve and trigger the release of neuro-transmitters, which carry the impulse from axon to dendrite.
What is homeostasis?
- Adaptive response to various stimuli allw the cells and tissues to repond and function in stressful envitonments, in a constant effort to preserve a degree of stability or equilibrium.
What is cell signaling?
- - Type of cell communication through electrochemical process, in which they release molecules, such as hormones, that bind to proteins called receptors located on the surgace of the receiving cells.
- - This triggers chemical reactions in the receiving cells that lead to a biological action, when the action is completed, the opposing system turns off the action through a process called feedback inhibition or negative feedback.
What are three factors of homeostasis?
- - Size
- - Age
- - Underlysing medical conditions
What are Ligands?
- - Molecules that are either produced by the body (endogenous) or given as a drug (exogenous) that bind any receptor, anywhere, leading to any reaction.
- - They include medications, hormones, neurotransmitters and electrolytes.
What are Hormones?
- Substances that are formed in very small amounts in one specialized organ or group of cells and then carried to another organ or group of cells in the same organism to perform regulatory functions.
What are the four types of Hormones?
- - Endocrine Hormones: i.e. thyroid hormones, adrenal steroids, are carried to their target organ or cell group in the blood.
- - Exocrine hormones: Reach their target via a specific duct that opens into an organ, i.e. stomach acids and perspiration.
- - Paracrine hormones: i.e. histamine, Diffuse through intracellular spaces to reach their target.
- - Autocrine hormone: Hormone acts on the cell that secreted it.
What are Neurotransmitters?
- Proteins that affect signals between cells of the nervous system.
What is Atrophy?
- - Decrease in cell size due to loss of subcellular components, which in turn leads to a decrease in the size of the tissue and organ.
- - Decrease in size represents an attempt to cope with a new steady state with less than favorable conditions or a lack of use.
What is Hypertrophy?
- Increase in the size of the cells due to synthesis of more subcellular components.
What is Hyperplasia?
- An increase in the actual number of cells in the organ or tissue.
What is Dysplasia?
- - An alteration in the size, shape, and organization of cells.
- - Often found in dpithelial cells that have undergone irregular, atypical changes in response to shronic irritation or inflammation.
What is Metaplasia?
- Reversible cellulat adaptation in which one adult cell type is replaced by another adult cell type.
What % of the total body weight is fluid?
- - 50% to 70%
- - Average male is 60%
- - Average female is 50%
What are the two types of body fluid?
- - Intracellular fluid: 45% of body weight.
- - Extracellular fluid: 15% of body weight.
What is Passive transport diffusion?
- Movement of a substance from an area of higher concentration to an area of lower concentration.
What is Facilitated diffusion?
- A transport molecule (helper molecule) within the membrane helps the movement of a substance from areas of higher concentration to areas of lower concentration.
What is Osmosis?
- The movement of a solvent, such as water, from an area of low solute concentration to one of hight concentration through a selectively permeable membrane to equalize concentrations of a solute on both sides of the membrane.
What is Filtration?
- The movement of water and a dissolved substance from an area of high pressure to an area of low pressure.
What is Active transport?
-Movement via "pumps" or transport molecules that require energy and move substances from an area of low concentration to an area of high concentration.
What is a hypertonic solution?
- Solution with a higher solute concentration has a higher osmotic pressure.
What is a Hypotonic solution?
-Solution with a lower solute concentration has a lower osmotic pressure.
What is a Isotonic solution?
- Solutions with equal solute concentrations.
How does the Sodium Potassium pump work?
- It removes three Sodium ions from the cell for every two Potassium that are moved back into the cell.
What are the two ways intracellular fluid volume controlled?
- - By the proteins and organic compounds that cannot escape through the cell membrane.
- - The Sodium/Potassium pump.
- - Makes up 55% of the blood
- - Is composed of 91% water and 9% plasma proteins
- - Proteins include albumin, which maintains osmotic pressure; globulin; fibrinogen; and prothrombin, which assists with clottin.
What are the four forces that controls the equilibrium between the capillary and interstitial space?
- - Capillary hydrostatic pressure: Pushes water out of the capillary into the interstitial space.
- - Capillary colloidal osmotic pressure: Generated by dissolved proteins in the plasma that are too large to penetrate the capillary membrane.
- - Tissue colloidal osmotic pressure: Pulls fluid into the interstitial space.
- - Tissue Hydrostatic pressure: opposes the pushing of fluids from the capillary into the interstitial space.
What are the causes of Edema?
- - Increased capillary pressure: Arteriolar dilation, venous obstruction, increased vascular volume, increased levels of adrenocortical hormaones, premenstrual sodium retention, pregnancy, environmental hear stress, or the effects of gravity from prolonged standing.
- - Decreased colloidal osmotic pressure in the capillaries: Decreased production of plasma proteins or increased loss of plasma proteins.
- - Lymphatic vessel obstruction due to infection: Disease of the lymphatic structures or their removal.
What are the three types of hydration receptors?
- - Osmoreceptors: Monitor extracellular fluid osmolarity. located primarily in the hypothalamus. Production of ADH.
- - Volume-sensitive receptors: Located in the atria, when the intravascular fluid volume increases, the atria is streached leading to the release of natriuretic proteins.
- - Baroreceptors: Found primarily in the carotid artery, aorta, and kidneys. They are sensitive to changes in blood pressure.
What role does ADH have?
- - Also known as vasopressin, Stimulates the kidneys to resorb water, decreasing the blood's osmolarity.
- - It is released by the pituitary gland.
How much sodium does the average adult have?
- - 60 mEq of sodium for each kilogram of body weight.
- - The average adult ingests between 6 to 15g of sodium a day.
How is sodium regulated?
- - Primarily by the Renin-angiotensin aldoserone system (RAAS)
- - Also by natriuretic proteins.
What is RAAS?
- - A complex feedback mechanism reponsible for the kidneys regulation of sodium in the body.
- - If sodium is in excess it is excreted into the urine.
- - If sodium levels are low it resorbs sodium.
What is Renin?
- - A protein that is released by the kidneys into the bloodstram in response to changes in blood pressure, blood flow, the amount of sodium in the tubular fluid, and the glomerular filtration rate.
- - When renin is released it converts the plasma protein angiotensionogen to angiotensin I.
- - In the lungs anfiotensin I is converted repidly to angiotensin II, by angiotensin-converting enzyme (ACE), and in turn stimulates sodium resorption by the renal tubules.
- - It also constricts the renal blood vessels, slowing kidney blood flow and decreasing the glomerular filtration rate. As a result less sodium is filtered into the urine and placed back into the blood.
What is Tonicity?
- The tension exerted on a cell due to water movement across the cell membrane.
What is Oliguria?
- Decreased urine output.
What are signs and symptoms of high sodium levels?
- - Hyperthermia
- - Delirium
- - And Coma
What is Hepernatremia?
- A serum sodium lever greater than 148 mEq/L and a serum osmolarity greater than 295 mOsm/kg.
What is Hyponatremia?
- A serum sodium level less than 135 mEq/L and a serum osmolarity less that 280 mOsm/kg.
What is Hypokalemia? and what are signs and symptoms? What is the showing on a ECG?
- - Decreased serum potassium level.
- - Muscular weakness, fatigue , muscle cramps, glaccid paralysis, hyporeflexia and tetany.
- - Decreased amplitude and broadening of T waves, prominent U waves, premature Ventricular contractions and other arrhythmias, and depressed ST segments.
What is the normal potassium level?
- Between 3.5 to 5.0 mEq/L
What is Hyperkalemia? Signs and symptoms? and ECG findings?
- - Elevated serum potassium level
- - Muscle weakness, rarely flaccid paralysis.
- - Peaked T waves, widening of the QRS complex and arrhythmias (Vtach).
What is the normal level of Calcium?
- - 8.5 to 10.5 mg/100ml
- - 98% of calcium is found in bones and teeth.
What is hypocalcemia? Signs and Symptoms? ECG findings?
- - Decreased serum calcium level.
- - Neuromuscular and cardiovascular excitation, spasm of skeletal muscle causes cramps and tetany. Convulsions can occur as well as abnormal sensations of the lips and extremities.
- - Prolongation of the QT interval.
What is Hypercalcemia? Signs and symptoms?
- - Increased serum calcium level.
- - Constipation and frequent urination (Polyuria)
What is phospahte used for?
- It is a primarily intracellular anion and is essential to many body functions.
What is Hypophosphatemia? Signs and Symptoms?
- - Decrese in serum phosphate levels.
- - Muscle weakness, decreased deep tendon reflexes, mental obtundation, and confusion. Can lead to hemolytic anemia and increased susceptibility to infection.
What is Hyperphosphatemia? signs and symptoms?
- - Increase serum phosphate level.
- - Tremor, paresthesia, hyporeflexia, confusion, seizures, muscle weakness, stupor, coma, hypotension, heart failure, and prolonged QT interval.
What are normal magnesium levels?
- - 1.5 to 2.0 mEq/L
- - 50% of magnisium is stored in the bones, 49% in the body cells, and the remaining 1% in the extracellular fluid.
What is Hypomagnesemia? signs and symptoms?
- - Decrease of magnesium serum level
- - Weakness, muscle cramps and tremors. Patients can develop neuromuscular and CNS hyperirritability with tremors and jerking.
What is Hepermagnesemia? signs and symptoms?
- - Increased serum magnesium level.
- - muscle weakness, decreased deep tendon refleces, mental obtundation, and confusion. Weakness is common and respiratory muscle paralysis or cardiac arrest is possible.
What is the normal pH balance of the body?
- 7.35 to 7.45
What are Buffers?
- Molecules that modulate changes in pH.
What is alkalosis?
- pH balance greater than 7.45. Basic
What is acidosis?
- pH balance less than 7.35, acidic.
What is Metabolic acidosis?
- Abnormal acids in the blood for any of several reasons (sepsis, diabetic ketoacidosis, salicylate poisoning.
What is Metobolic alkalosis?
- rarely seen in an acute condition but is very common in chronically ill patients. Build up of metabolic base (chronic antacid ingestion or loss of normal acid through vomiting or nasogastric suctioning.)
What is Respiratory acidosis?
- - Occurs when CO2 retention leads to increased Paco2 levels.
- - Occurs in situations of hypoventilation i.e. heroin overdose or intrinsic lund diseases such as asthma or COPD.
What is Respiratory alkalosis?
- - Often called hyperventilation, many potentially serious diseases i.e. pulmonary embolism, acute MI, severe infection, diabetic ketoacidosis.
- - May be responsible for increased ventilatory levels.
What are Free Radicals?
- - Molecules that are missing one electron in their outer shell and results in chemical instability.
- - They randomly attack cells and membranes in an attempt to steal back the missing electron.
- - Can lead to tissue damage.
What is Virulence?
- A measure of the disease causing ability of a microorganism.
What is a phagocytes?
- White blood cells that engulf and consume foreign material such as microorganisms and cellular debris.
What causes a fever?
- Pyrogens: Chemicals or proteins that travel to the brain and affect the hypothalamus and stimulate a rise in the body's core temperature.
What is Apoptosis?
- - Normal cell death.
- - It is unique in that it is genectically programmed into the cell as a part of normal development, organogenesis, immune function, and tissue growth.
What should disease studies consider?
- - Icidence: Frequency of disease occurrence.
- - Prevalence: Number of cases in a particular population over time.
- - Mortality: Number of deaths from a disease in a given population.
What is Autosomal recessive?
- - A pattern of inheritance that involves genes located on autosomes (any chromosome other than sex chromosomes.
- - A person needs to inherit two copies of a particular form of such a gene to show that trait.
What is Autosomal dominant?
- Inheritance, a person needs to inherit only one copy of a particular form of a gene to show that trait.
What is Hemolytic anemia?
- - Increased destruction of red blood cells.
- - Has a number of causes.
- - Follows aspirin overdose or penicillin treatment is rare, more common in sulfa drugs used to treat UTI's.
What is Hemophilia?
- - Inherited disorder characterized by excessive bleeding.
- - Occurs only in males and is passed from asymptomatic mothers to sons.
What is Hemochromatosis?
- - Inherited disease in which the body absorbs more iron than it needs.
- - excess iron is stored in various organs including the liver, kidney and pancreas.
- - Can lead to diabetes, heart disease, liver disease, arthritis, impotence, and vronzed skin color.
When should you consider Syncope to be life-threatening?
- - Exrcise induced syncope
- - syncope associated with chest pain.
- - A history of syncope in a close family member.
- - Syncope associated with startle.
Whar percentage of people are affected by Mitral valve prolapse?
- - 7.6% of females
- - 2.5% of males
What is Hypercholesterolemia?
- An elevation of the blood cholesterol level.
What are the two type of Cholesterol?
- - High Ednsity Lipoproteins (HDL): good cholesterol.
- - Low density lipoproteins (LDL): Bad cholesterol.
What is Crohns Disease?
- - A chronic inflammatory condition affecting the colon and or terminal part of the small intestine.
- - Symptoms include frequent episodes of non bloddy diarrhea, abdominal pain, nausea, fever, weakness, and weight loss.
What is perfusion?
- Delivery of oxygen and nutrients and removal of wastes from the cells, organs, and tissues by the circulatory system.
What is Hypoperfusion?
- - Also known as shock
- - Occurs when the level of tissue perfusion decreases below normal.
What are the signs and symptoms of compensated shock?
- - Agitation, anxiety, restlessness
- - Sense of impending doom
- - Weak rapid pulse
- - Clammy skin
- - Pallor with cyanotic lips
- - Shortness of breath
- - Nausea, vomiting
- - Delayed capillary refill in infants and children
- - Thirst
- - Normal Blood Pressure
What are the signs and symptoms of Decompensated shock?
- - Altered Mental status
- - Hypotension
- - Labored or irregular breathing
- - Thready or absent peripheral pulses
- - Ashen, Mottled or cyanotic skin
- - Dilated pupils
- - Diminished urine output
- - Impending cardiac arrest.
What are the types of shock?
- - Central shock: consist of cardiogenic shock and obstructive shock
- - Peripheral shock: consist of hypovolemic shock and distributive shock
What is Cardiogenic shock?
- Occurs when the heart cannot circulate enough blood to maintain adequate peripheral oxygen delivery.
What is Obstructive shock?
- - Occurs when blood flow becomes blocked in the heart or great vessels.
- - pericardial tamponadeL Diastolic filling of the right ventricle is impaired due to significat amounts of fluid in the pericardial sac surrounding the heart.
What is Hypovolemic shock?
-Circulating blood volume is unable to deliver adequate oxygen and nutrients to the body.
What is Distributive shock?
- Occurs when there is widespread dilaion of the resistance vessls, capacitance vessels, or both.
What are the three most common types of distributive shock?
- - Anaphylactic shock
- - Septic shock
- - neurogenic shock
What is MODS?
- - Multiple Organ dysfunction syndrom
- - Progessive condition usually characterized by concurrent failure of several organs such as the lungs, liver, and kidneys, along with some clotting mechanisms.
- - Occurs after sever illness or injury.
- - First descibed in 1975 and is associated with a mortality rate of 60% to 90% and is the major cause of death in sepsis, trauma and burn injuries.
What is the inflammatory response?
- Response of the tissues of the body to irritation or injury characterized by pain, swelling, redness, and heat.
What is the immune response?
- The body's defens reaction to any substance that is recognized as foreing.
What is the lymphatic system?
- Network of capillaries, vessels, ducts nodes, and organs that helps maintain the fluid environment of the body by producing lymph and conveying it through the body.
What is a Lymph?
- A thin watey fluid that bathes the tissues of the body.
What is Mucosal associated lymphoid tissue (MALT)?
- - Contain immune cells that are in a position to intercept pathogens before they reach the general circulation.
- - Tonsils are perhaps the nest known type of MALT.
What are Gut associated lymphoid tissue (GALT)?
- Tissue lies just under the inner lining of the esophagus and intestines.
What are the primary cells of the immune system?
- Leukocytes or white blood cells.
What are the five types of leukocytes?
- - Basophils: Contain histamine granules and other substances that are released during inflammatory and allergic responses. They account for less than 1%. Release histamine and other chemicals that dilate blood vessels.
- - Eosinophils: Release substances that damage or kill parasitic invaders. They also play a major role in mediating the allergic respnse. They account for 1-3%. Release chemoactive substanxes that can result in severe bronchospasm.
- - Neutrophils: The most abundant white blood cells, accounting for 55-70%. They have a segmented nucleus and are often call polymorphonuclear leukocytes. Are largely responsible for protecting the body against infection and are key components of the first response to foreign body invasion. They are readily attracted by foreign antigens, which they destroy by engulfing and digesting the antigens.
- - Monocytes: Mature in the blood during their first 24 hours and then travel to the tissues, wher they differntiate into macrophages, which function primarily as scavengers for the tissues. Monocytes and macrophages represent one of the first lines of defense in the inflammatory process.
- - Lymphocytes: mediate the acquired immune response. Although most are found in th lymphoid tissues, many are found in circulaing lymph and blood as well. Two basic types B lymphocytes and T lymphocytes.
What are Mast Cells?
- They resemble basophils but do not circulate in the blood. They are found in the connective tissues, beneath the skin in the gastrointestinal mucosa, and in the mucosal membranes of the respiratory system. They play a role in allergic reactions, immunity, and wound healing.
What is Native Immunity?
- a nonspecific cellular and humoral response that operates as the first line of defense against pathogens. Most notive immunity is associated with the initial inflammatory resonse.
What is Acquire immunity?
- a highly specific, inducible, discriminatory, and unforgetting method by which armies of cells respond to an immune stimulant. Arises when the body is exposed to a foreing substance or disease and produces antibodies to that invader.
How do antibodies work?
- - A macrophage engulfs the antigen via phogocytosis and digests the antigen, pushing the discarded particles to the cell surgace. The remnants interact with Bcell and a helper T cell.
- - The antigen binds to both the b cell and the helper T cell, activatin both.
- - The activated helper T cell secretes a lymphokine, a substance that stimulates the B Cells to produce a clone. The clone is a group of identical cells formed from the same parent cell. Clone comprises two types of identical cells that have different functions: plasma cells, which make the antibodies, and memory cells, which remember the initial encounter with the antigen.
What are the three ways antibodies make antigens more visible to the immune system?
- - Antibodies act as opsonins, in where the antibody coats an antigen to facilitate its recognition by immune cells. Antibodies are not toxic by themselve, but they labe antigens so that other immune cells will attack them.
- - Antibidies cause antigens to clump for easier phagocytosis.
- - Antibodies bind to and inactivate some toxins produced by bacteria. Macrophages can then ingest and destroy the inactivated toxins.
What are the two major ways T cells lymphocytes recognize antigens and contribute to the immune system?
- - Secreting cytokines that attract other cells.
- - Becoming cytotoxic and killing infected or abnormal cells.
What are the four subgroups of T cells?
- - Killer T cells: Destroy the antigen.
- - Helper T cells: activate many immune cells including B cells and other T cells.
- - Suppressor T cells: Suppress the activity of other lymphocytes so they do not destroy normal tissue.
- - Memory T cells: Remember the reaction for the next time it is needed.
What is Membrane Attack Complex (MAC)?
Proteins that insert themselves into the bacterial membrane, weakening those areas in the membrane.
What are Slow reacting substances of anaphylaxis (SRS-A)?
Family of Bilogically active compounds derived from arachidonic acid.
What is the complement system?
- A group of plasma proteins that attract white blood cells to sites of inflammation, activate white blood cells, and directly destroy cells.
What is the coagulation system?
- Plays a vital role in the formation of blood clots in the body and facilitates repairs to the vascular tree.
What is Fibrin?
- Protein that polymerizes to form the fivrous complonent of a blood clot.
What is the kinin system?
- A general term for a grooup of polypeptides that mediate inflammatory responses by stimulating viceral smooth muscle and relaxing vascular smooth muscle to produce vasodilation.
What is the sequence of events of the cellular inflammation?
- - Margination
- - Activation
- - Adhesion
- - Transmigration (diapedesis)
- - Chemotaxis
What is general adaptation syndrome and what are its stages?
- - Term introduced by Hans Selye in the 1920's characterizes a three stage reaction to stressors, both physical and emotional.
- - Alarm
- - Resistance
- - Exhaustion
What is hypotholamic-pituitary-adrenal axis (HPA axis)?
- - Major part of the neuroendocrine system that controls reactions to stress.
- - It triggers a set of interactions among the glands, hormones, and parts of the midbrain that mediate the general adaptation syndrome.