SECTION 1 Basic Sciences Flashcards
Describe the murmurs heard for Mitral stenosis ?
Opening snap that occurs early in diastole and a RUMBLING diastolic murmur
What is the stethoscope location for mitral stenosis murmur where they are best heard?
Best heard with the chest piece placed over the APEX
Describe the murmurs heard for Mitral Regurgitation?
The cardinal feature of mitral regurgitation is a blowing holosystolic murmur HEARD THROUGHOUT SYSTOLE
Where does mitral regurgitation murmur radiates to?
AXILLA
Murmur heard throughout systole
Mitral regurgitation murmur
2 murmur heard over the CARDIAC APEX
Mitral stenosis and mitra regurgitation
Describe the murmurs f the patient has aortic
Stenosis
Systolic murmur,
Best stethoscope location for AORTIC Stenosis
second right intercostal space (over the aortic arch)
Murmur that radiates to the neck?
AORTIC Stenosis
Murmur description for aortic regurgitation
Diastolic murmur
Best murmur heard over the Left sternal border?
Aortic Regurgitation
When the ventricle fills more during diastole, more blood is ejected during systole. Whose law is this?
Starling’s (or Frank-Starling’s) law of the heart.
Starling’s law of the heart relates ventricular filling during diastole to the
amount of blood ejected during systole.
Starling Law, the greater the ventricular filling during diastole , meaning the greater the _______, the
Preload; The greater the quantity of blood pumped into the aorta during systole.
What causes a change in blood pressure when changing the patient’s position?
Altered preload (altered venous return) is most responsible for a change in blood pressure when the patient is re-positioned.
What nerves carry the afferent and efferent signals of the Bainbridge reflex?
stretch receptors send Afferent signals to the medulla via the vagus nerve. The medulla then transmits Efferent signals via the sympathetic nerves to increase heart rate (by as much as 75%) and myocardial contractility.
What does the Bainbridge reflex help prevent?
The Bainbridge reflex helps prevent damming up of blood in veins, the atria, and the pulmonary circulation.
When does the Bainbridge reflex get activated?
When the great veins and right atrium are stretched by increased vascular volume
Describe the venous drainage of the lung. BAHIB
The venous drainage of the bronchi occurs through the bronchial, azygous, hemiazygos, and intercostal veins, which then drain into brachiocephalic veins of the neck and ultimately the superior vena cava.
The pulmonary circulation returns to the heart via
the pulmonary veins, which empty into the left atrium.
Describe the Valsalva maneuver.
Forced expiration with the glottis closed.
Valsava maneuver increase what kind of pressure?
All intrathoracic pressures including intrapleural and intrapulmonary pressures.
With valsava maneuver, intrapleural pressures changes from _______. What happens to CO and BP?
Negative to positive, so venous return to the RV decreases and CO and BP decrease
With valsava maneuver what causes an increase in HR?
The decrease in BP results in a reflex increase in HR.
The healthy adult lung receives each minute an alveolar ventilation (V) of about how many L?
4 L/min is the alveolar ventilation rate.
Normal pulmonary blood flow (Q) per min?
5L/min
What is the average resting ventilation:perfusion (V/Q) ratio?
0.8 (4/5 = 0.8)
A V/Q ration between zero and 1 indicates (0
Relative shunt
A V/Q ration greather than 1 indicates what?
Dead-spacing
Compared with the apex of the lung, the base exhibits GREATER or LESSER PERFUSION?
GREATER
Perfusion (blood flow) is best in which part of the lung?
Dependent
The base on the lung is dependent in what position?
In the upright (sitting or standing)
What is the total quantity of CO2 delivered to, and used by, the tissues each minute?
250 ml/min of 02 is normally delivered to, and used by, the tissues.
VO2 (oxygen consumption) is how much per min?
3-4 mlO2/kg/min
What are the three ways C02 is transported in the blood? What percent for each route of transport?
(l) physically dissolved in solution, 5% to 10%;
(2) as bicarbonate ion (HCO~ · ), 80% to 90%;
{3) protein bound (plasma proteins and hemoglobin)-these are called carbamino compounds, 5% to 10%.
The majority of CO2 is transported in blood in the form of
Bicarbonate 80-90%
A large number of diverse insults can trigger acute respiratory distress syndrome. List factors that can lead to
ARDS.
SHAFT BRUDDS CPM Shock Head injury Aspiration Fat or air embolus Trauma Burns Radiation of thorax UREMIA Drug Ingestion Drowning Sepsis Cardiopulmonary bypass Pancreatitis Massive Blood transfusion
What are the pulmonary consequences of prolonged 100% oxygen administration?
Loss of surfactant (due to prolonged exposure to oxygen radicals), leading to ARDS (adult respiratory distress syndrome).
What is responsible for creating the resting membrane potential?
The resting membrane potential of nerve and muscle is due primarily to the diffusion of potassium ions (K+) out of cells through potassium leak channels.
Give two reasons for up-regulation of adrenergic receptors.
(1) Sympathetic denervation, and (2) treatment with a sympathetic competitive antagonist (e.g., beta blockade) causes adrenergic receptors to up regulate)
Identify two forms of the enzyme, monoamine oxidase (MAO).
The two known forms of monoamine oxidase (MAO) are type A (MAO-A) and type B (MAO-B).
What substances are metabolized by MAO-A (SEND)
Serotonin
Epinephrine
Norepinephrine
Dopamine
What substances are metabolized by MAO-AB
Tyramine (cheese, red wine beer)
Phenylethylmaine
Dopamine
What substance is metabolized by both MAO-A and MAO-B?
Dopamine
Where is monoamine oxidase type A (MAO-A) found?
Monoamine oxidase type A (MAO-A) is an enzyme present in the central nervous system, adrenergic nerve endings, liver and gastrointestinal tract.
MAO-A was involved in metabolic degradation of SEND (Serotonin, epi, nore, dopamine) by
Oxidative deamination
What two tracts transmit impulses from the motor cortex to the spinal cord?
Pyramidal and extrapyramidal tracts.
Impulses from the motor cortex are carried directly to the spinal cord via the
pyramidal tract (aka CORTICOSPINAL TRACT)
Impulses are also carried through the basal
ganglia, cerebellum and brainstem nuclei to the spinal cord by
Extrapyramidal system
What are components of the extrapyramidal system?
basal ganglia, cerebellum and brainstem nuclei
Are the effects of sympathetic stimulation of a motor or sensory nature?
Motor (efferent)
Where do preganglionic PARAsympathetic nerves originate?
Preganglionic parasympathetic nerves arise from nuclei of cranial nerves Ill, VII, IX and X in the brainstem and also from sacral segments (S2-S4) of the spinal cord
Owing to these origins, the parasympathetic system
is also known as the
craniosacral division.
Which autonomic nerves are cholinergic in nature?
Those fibers that release acetylcholine are cholinergic.
The cholinergic autonomic nerves are the the
- sympathetic and parasympathetic preganglionic neurons
- parasympathetic postganglionic neurons and the 3. sympathetic postganglionic neurons that
innervate sweat glands and piloerector muscles.
Sympathetic neurons release NE and EPI except two that release what?
Sympathetic postganglionic neurons that release SWEAT GLANDS and PILOERECTOR MUSCLES
Which three cranial nerves supply SENSORY innervation to the oropharynx? VGF
vagus (CN X), facial (CN VII), and glossopharyngeal (CN IX) nerves
Describe the anatomy and functions of the glossopharyngeal nerve (CN IX).
The glossopharyngeal nerve (GPN) supplies general and special (taste} sensory innervation to the posterior third of the tongue via the lingual branch (caution: not the lingual nerve, which is a terminal branch of the
mandibular division of CN V), the vallecula, the anterior surface of the
epiglottis, the posterior and lateral walls of the pharynx, and the tonsillar
pillars. Motor innervation from the glossopharyngeal nerve is to one of the
muscles of deglutition (swallowing).
Supply the posterior THIRD of the tongue
Glossopharyngeal nerve.
One of the muscles of deglutition (swallowing). [
Motor innervation from the glossopharyngeal nerve
The glossopharyngeal nerve (GPN) supplies general and special (taste} sensory innervation to the posterior third of the tongue via the
lingual branch
Innervates the vallecula
Glossopharyngeal nerve
Innervates the anterior surface of the epiglottis
Glossopharyngeal nerve
Innervates the posterior and lateral walls of the pharynx,
Glossopharyngeal nerve
Innervates the tonsillar pillars.
Glossopharyngeal nerve
What are the 3 division of Trigeminal nerve? OMaxMan
the ophthalmic, maxillary, and mandibula
Which nerve provides motor innervation to the muscles of mastication (chewing, “moves the mandible”)
masseter nerve
Which nerve give rise to the masseter nerve?
The anterior branch of the mandibular nerve (V3) gives rise to the masseter nerve
Provides sensory innervation to the lower teeth and gums (“feels the mouth inside and out”}.
The posterior branch of the mandibular nerve
The lingual nerve is a terminal branch of the
mandibular nerve:
General sensory innervation to the lingual mucous membranes,
The lingual nerve
Sensory innervation to the anterior two-thirds of the tongue
Lingual nerve (Mandibular nerve branch)
Sensory to the floor of the mouth
Lingual nerve (Mandibular nerve branch)
What is the chorda tympani nerve ?
A branch of the facial nerve, CN VII
What is the relationship between the chorda tympani nerve (branch ofCN VII) and the lingual nerve (Terminal branch of CN V3)
Chorda tympani joins lingual nerve, and courses with the lingual nerve to the anterior 2/3 of the tongue.
The chorda tympani supplies special sensory fibers to the
taste buds on the anterior two-thirds of the tongue.
What is the function of the Circle of Willis?
The Circle of Willis provides collateral blood flow to the brain if a major vessel carrying blood to the brain becomes obliterated.
What percent of the intracranial volume is occupied by brain?
80% brain matter and intracellular water
What percent of the intracranial volume is occupied by Blood?
12%
What percent of the intracranial volume is occupied by CSF?
8%
The composition of cerebrospinal fluid (CSF) differs from the composition of plasma LYTES?
7% more sodium
Higher magnesium
Higher Chloride
40% less Potassium
The composition of cerebrospinal fluid (CSF) differs from the composition of plasma GLUCOSE
30% less glucose
The composition of cerebrospinal fluid (CSF) differs from the composition of plasma HYDROGEN IONS
Higher H+ (lower pH);
How much cerebrospinal fluid is produced per day?
CSF production is about 500-750 mL/day
Cerebrospinal fluid production ranges from
15 mL/24 hours to 30 mL/24 hours,
What four factors determine how much of a substance will diffuse across the blood-brain barrier?
The movement of a given substance across the blood-brain barrier is governed simultaneously by its
size, charge, lipid solubility, and degree of protein binding in blood.
A substance generally must be_____and/or______ in order to cross the blood-brain barrier in substantial amounts.
very small or lipid soluble
What are the results of electrical stimulation to the reticular activating system (RAS)?
Stimulation of the reticular activating system (RAS) increases alertness..
Diffuse electrical stimulation of the RAS causes immediate and______cause a ________
marked activation of the cerebral cortex and will even cause a sleeping individual to awaken instantaneously
What is the typical time-frame for onset of autonomic hyperreflexia following spinal cord injury?
Autonomic hyperreflexia usually follows a period of spinal shock that typically lasts 1- 3 weeks. SO ONSET Is about after 3 weeks
How long does spinal shock last?
1-3 weeks
Onset of Hyperreflexia following SCI can be?
Few months to many years
What are four components for treatment for the syndrome of inappropriate antidiuretic hormone secretion?
RARA
- Remove the underlying cause(
3) Antagonize the effects of ADH on the renal tubule by giving demecolcine
(2) restrict water intake,
(4) administer hyperosmotic saline with or without diuretics.
Identify the gland that is both endocrine and exocrine.
Pancreas
What hormone does the pancreatic islet delta cells produce?
Somatostatin
What is the role of the hormone somatostatin?
Inhibits GI motilitiy and secretion including the production of HCL
The main physiologic function of glucagon .
increase serum glucose concentration by causing hepatic gluconeogenesis and glycogenolysis (breakdown of glycogen).
Plays a key role in glucose homeostasis
Glucagon
How does glucagon maintain homeostasis, 2 processes
Hepatic gluconeogeneis
Glycogenolysis
Antagonize effects of insulin
Glucagon
Effects of glucagon on gastric motility?
Inhibit gastric motility
Glucagon: Effects of gastric acid secretion?
Inhibit gastric secretion
Glucagon on bile secretion
Enhanced
Glucagon effects on tissue
Increased blood flow to tissues, especially kidneys
Glucagon effects on insulin
Increases insulin secretion
Glucagon and cardiac effects
inotropic and chronotropic
Glucagon and biliary effects?
relaxation of smooth muscle (biliary sphincter)
Identify the biochemical triad that defines diabetic ketoacidosis.
ketonemia, hyperglycemia, and acidemia.
What are the diagnostic criteria for diabetic ketoacidosis?
ketonemia or significant ketonuria
blood glucose above 250 mg/dL or known diabetes mellitus; and
serum bicarbonate below 18 mmol/L or arterial pH< 7.3.
It is generally recommended to cancel nonurgent or elective surgery in the patient with diabetes mellitus if the serum glucose rises above what value?
Above 400 mg/dL
The clinical syndrome of diabetic ketoacidosis (DKA) includes
dehydration and hypovolemic shock from hyperglycemic osmotic diuresis
compensatory hyperventilation {Kussmaul pattern)
life· threatening electrolyte depletion (especially hypokalemia and hypophosphatemia)
AG gap with DKA
Greater than 10
Anion GAP formula is
Na+ - (Cl+HCO3)
The increase in hepatic arterial flow in response to a decrease in portal blood flow occurs for two reasons:
(l) to maintain hepatic oxygen supply, and (2) to maintain
total hepatic blood flow, which is essential for clearance of many compounds.
What is the “arterial buffer respons”?
Adjusting hepatic arterial flow in response to changes in portal blood flow
What are seven functions of the liver?
storage and filtration of blood,
(2) metabolic functions such as carbohydrate, fat, and protein metabolism
(3) secretion of bile
4) storage of vitamins
(5) blood coagulation
(6) storage of iron
(7) detoxification and excretion of drugs.
How does glomerular filtration rate (GFR) change if the efferent arteriole dilates relatively more than the afferent
arteriole?
Glomerular filtration rate will decrease if the efferent arteriole dilates more than the afferent.
How does GFR change If the efferent arteriole constricts relatively more than the afferent arteriole?
GFR will increase if the efferent arteriole constricts more
than the afferent.
How does GFR change if the afferent arteriole dilates relatively more than the efferent arteriole?
Glomerular filtration rate will increase if the afferent arteriole dilates more than the efferent
How does GFR change if the afferent arteriole Constricts relatively more than the efferent?
GFR will decrease if the afferent arteriole constricts more
than the efferent.
List and define three causes of perioperative
acute renal failure
Prerenal failure
Renal failure
Post renal failure
Cause of prerenal failure
Decreased renal blood flow
Cause of IntraRenal failure
Renal tubular damage secondary to decreased renal
blood flow, nephrotoxic drugs, or release of hemoglobin or myoglobin
Causes of Postrenal failure?
Obstruction of urine flow due to for example obstruction of the ureters or urethra
What is the best indicator of renal reserve?
The best indicator of renal reserve is the trend in serum creatinine values.
An important early step in hemostasis is
vasoconstriction of the damaged vessel.
An important early step in hemostasis is vasoconstriction? _______play a key role in this initial vasoconstriction by release of what substances?
Platelets; The vascular contraction is a result of autonomic nervous system reflexes and the release of thromboxane A2
The endothelium releases many procoagulant
factors following vascular injury: name two key procoagulants released by the endothelium.
Endothelial damage following vascular injury initiates release of many procoagulant factors including tissue factor (flII, TF) and factor VIII:vWF(von willebrand’s factor)
In addition to its role in early vasoconstriction, thromboxane A2 plays a key role in
activation and aggregation of platelets.
Once platelets adhere, they are activated by a complex series of steps including
release of ADP and thromboxane A2
Describe the actions ofTxA2 in activation and adhesion of platelets.
Adenosine diphosphate (ADP) and TxA2 are ligands for G protein coupled receptors (P2Yu and • TPa, respectively} that trigger signal transduction pathways, ultimately leading to expression ofGPIIb/IIIA receptors (fibrinogen receptors) on the platelet surface. TxA2 appears to amplify the signal and action of more potent platelet agonists, such as thrombin (Ila) and ADP
What may be given to treat the patient with a fibrinogen {factor I) deficiency?
Cryoprecipitate
Which two veins combine to form the hepatic portal vein?
The (hepatic) portal vein is formed by the union of the splenic vein and superior mesenteric vein posterior to the neck of the pancreas at the level of L2.
Usually drains into the splenic vein but occasionally
(10%) the Tip:
inferior mesenteric vein
inferior mesenteric vein joins the splenic and superior
mesenteric veins at their confluence at
portal vein.
Portal system: if a question asks for two vessels, the “best” answer, in our opinion, is
splenic and superior mesenteric veins.
If the immune system overreacts to an allergen, what occurs?
a hypersensitivity (allergic) reaction occurs.
Immune-mediated hypersensitivity reactions are classified
into
Four groups
Type I immune mediated reactions are
anaphylactic or immediate-type hypersensivity reactions.
Type II immune mediated reactions are
Cytotoxic reaction (antibody-dependent cell-mediated cytotoxicity)
Type III reactions are
immune complex reactions that produce tissue damage by deposition of the immune complexes.
Type IV reactions are
Delayed type hypersensitivity reactions from interactions of sensitized lymphocytes with specific antigens.