Physiology Flashcards
(78 cards)
1
Q
Dopamine causes is shock
A
dopamine receptor mediated renal and mesenteric vascular dilatation and beta 1 receptor agonism at higher doses. This results in increased cardiac output. Since both heart rate and blood pressure are raised, there is less overall myocardial ischaemia.
2
Q
Noradrenaline is
A
Noradrenaline is a catecholamine type agent and predominantly acts as an alpha receptor agonist and serves as a peripheral vasoconstrictor.
3
Q
milrinone
A
Phosphodiesterase inhibitors such as milrinone act specifically on the cardiac phosphodiesterase and increase cardiac output.
4
Q
Effects of receptor binding
A
α-1, α-2 vasoconstriction
β-1 increased cardiac contractility and HR
β-2 vasodilatation
D-1 renal and spleen vasodilatation
D-2 inhibits release of noradrenaline
5
Q
majority of iron found in the body
A
70% of body iron is found bound to haemoglobin.
6
Q
Iron Absorption
A
Duodenum and upper jejunum
7
Q
Convergence of iron
A
Fe2+ (ferrous iron) much better absorbed than Fe3+ (ferric iron)
Ferrous iron is oxidized to form ferric iron, which is combined with apoferritin to form ferritin
8
Q
tannin found in
A
tea
9
Q
Decreased iron absorbtion by drugs
A
proton pump inhibitors, tetracycline
10
Q
Iron Transport
A
In plasma as Fe3+ bound to transferrin
11
Q
Second highest location of iron
A
Ferritin and haemosiderin 25%
12
Q
From substrate (angiotensinogen)
A
Into product (angiotensin)
13
Q
Surface of angiotensin
A
Liver
14
Q
Effect of renin on angiotensinogen
A
Hydrolysis
15
Q
posture stimulating renin
A
Erect
16
Q
Drugs reducing renin secretion
A
beta-blockers, NSAIDs
17
Q
Effect of Catecholamines on renin
A
Stimulates secretion
18
Q
The cerebral perfusion pressure calculated by
A
CPP= Mean arterial pressure - Intra cranial pressure
19
Q
What is Motilin
A
Motilin is released by the small bowel in response to alkaline contents in the duodenum/ jejunum and increases the migrating motor complexes in the small bowel
20
Q
Which hormone induced satiety
A
CCK
21
Q
Stimulating effect of Somatostatin
A
stimulates gastric mucous production
22
Q
Somatostatin secreting cell
A
D
23
Q
Mechanical effect of CCK
A
contraction of gallbladder and relaxation of sphincter of Oddi
24
Q
Function of arachnoid granulation
A
filter, reabsorb, and drain CSF from the subarachnoid space into the venous system.
25
Ventricular function of first and second heart sounds
1st- isovolumic contraction
(No blood going out)
2nd- isovolumic relaxation
(No blood coming in)
26
Stages of ventricular filling
Rapid inflow
Diastasis
Atrial systole
27
The fourth heart sound
(S4) is an abnormal heart sound that can be heard immediately before S1 and indicates increased resistance to ventricular filling due to high atrial pressure or increased ventricular thickness. The presence of an S4 may indicate myocardial infarction—an almost universal finding during the early stages of acute myocardial infarction (if the patient has sinus rhythm). or shock.including high atrial pressure, increased ventricular thickness
28
mechanism fourth heart sound
caused by the vibrations created when the atria contract and fill the ventricle in late diastole.
(During stage of ventricular filling called ATRIAL SYSTOLE)
29
Relation of atrial waves with heart sounds
Just after 1st- c wave
Just after 2nd- v wave
30
what is incisura in aortic pressure curve
The incisura, also known as the dicrotic notch, is a downward notch in the aortic pressure curve that occurs between systole and diastole. It's caused by a brief period of blood backflow before the aortic valve closes.
31
Monroe-Kelly Doctrine
considers skull as closed box, changes in pressure are offset by loss of CSF. When this is no longer possible ICP rises
32
Factors affecting the cerebral pressure include; systemic carbon dioxide levels
The reduction in arterial carbon dioxide tension (Pco2) causes cerebral vasoconstriction which, in turn, produces a diminution in total intracranial blood volume.
33
CSF produced by
ependymal ependymal cells in the choroid plexus (70%), or blood vessels (30%).
34
covering of ventricles in brain
The ventricles of the brain are lined with a single layer of ependymal cells, which form a structure called the ependyma. Ependymal cells are a type of cuboidal or columnar epithelium that are derived from the neuroepithelium. They have several characteristics, including:
Cilia
Ependymal cells are usually ciliated, and the motion of the cilia helps circulate cerebrospinal fluid (CSF) through the brain.
Desmosomes
Ependymal cells are joined by desmosomes, which form a brain–CSF barrier.
Choroid plexus
Ependymal cells form the epithelial layer that surrounds the choroid plexus, a network of blood vessels in the walls of the lateral ventricles. CSF is produced within the choroid plexus.
35
In Hypokalaemia
U have no Pot and no T, but a long PR and a long QT
36
Intrinsic Factor
In addition to hydrochloric acid, the parietal cells in the gastric mucosa secrete intrinsic factor, a 49-kDa glycoprotein that binds to vitamin B12 (cyanocobalamin) and is necessary for its absorption from the small intestine
37
trophic effect on the pancreas
A trophic effect on the pancreas is an increase in the weight of the gland, which is usually due to the proliferation of young acinar cells. Other effects of a trophic effect on the pancreas include: Increased flow rate of basal pancreatic secretion, Reduced protein concentration, and Fall in lipase concentration and output.
The trophic effect on the pancreas can be evaluated by measuring the pancreas' weight and the contents of DNA, RNA, and protein.
38
Permeability of jejunum vs ileum withpractical implication
jejunum is more permeable than the ileum.
The practical implication of this is that if an individual has an extensive intestinal resection and a high output, proximally sited stoma then administration of hypotonic rather than isotonic solutions will result in worsening of electrolyte disturbances as electrolyte rich secretions will enter the jejunum.
39
Effect of Cholecystokinin on glucagon
Stimulating
40
Which hormone increases gastric motility
Gastrin
41
Somatostatin secreting site
D cells in the pancreas and stomach
42
extrarenal synthesis of calcitriol
Calcitriol, the active form of vitamin D, can be synthesized in many tissues outside of the kidneys, including the skin, liver, and immune cells. These extrarenal sources of calcitriol are regulated independently of the kidneys.
43
Drugs causing hyperbaric
Thiazide
Lithium
44
Cause of milk alkali syndrome
Milk-alkali syndrome can be caused by the excessive intake of calcium and absorbable alkali. Sources of calcium and alkali include dietary supplements taken for the prevention of osteoporosis or hyperparathyroidism and antacids taken for peptic ulcer disease
45
What is Monroe-Kellie doctrine
hypothesis, states that the total volume of the brain, cerebrospinal fluid (CSF), and blood within the cranium is constant.
46
Meaning of Monroe-Kellie doctrine
This means that if one of these components (brain/CSF/blood) increases in volume, the volume of one or both of the other components must decrease.
47
Role of CSF in raised intracranial pressure
It shifts itself
Upto 100-120ml
48
What would happen when ICP equals to MAP
Neuronal death will occur
49
How CNS can autoregulate during raised systemic blood pressure
Vaso constriction and dilatation of the cerebral blood vessels is the primary method by which this occurs. Extremes of blood pressure can exceed this capacity resulting in risk of stroke.
50
The age at which a baby's fontanelles close
The age at which a baby's fontanelles close depends on the location of the fontanelle:
Posterior fontanelle
This fontanelle is usually closed by the time the baby is 1–2 months old, but it may be closed at birth.
Anterior fontanelle
This fontanelle usually closes between 7–19 months, with a median age of 13.8 months.
51
Fontanelles
Fontanelles, also known as soft spots, are important for a baby's brain growth and development. They are covered by a thick fibrous layer and are safe to gently touch. A baby's fontanelles can provide information about their hydration and brain status. For example, a sunken anterior fontanelle can indicate dehydration, while a bulging anterior fontanelle can indicate increased intracranial pressure or meningitis
52
oxygen-hemoglobin dissociation curve, also called the oxyhemoglobin dissociation curve or oxygen dissociation curve
a graph that shows the relationship between the amount of oxygen bound to hemoglobin and the partial pressure of oxygen in the blood
53
What does PO2 mean?
PO2 (partial pressure of oxygen) reflects the amount of oxygen gas dissolved in the blood. It primarily measures the effectiveness of the lungs in pulling oxygen into the blood stream from the atmosphere. Elevated pO2 levels are associated with: Increased oxygen levels in the inhaled air. Polycythemia.
54
What is Partial Pressure?
Partial Pressure is defined as if a container filled with more than one gas, each gas exerts pressure. The pressure of anyone gas within the container is called its partial pressure
55
What is this following equation?
Vx/Vtot=Px/Ptot=nx/ntot
Vx denotes the volume of the particular gas.
Px indicates the partial pressure of the gas x.
Vtot denotes the total volume of the mixture.
Nx indicates the amount of gaseous substance.
Ptot denotes the total pressure of the mixture.
Ntot is the total amount of substance in a mixture.
56
Feature of oxygen-hemoglobin dissociation curve
The curve is sigmoidal, meaning it has a steep slope at low oxygen partial pressures and a more gradual slope at higher partial pressures. This allows hemoglobin to bind oxygen efficiently at a wide range of partial pressures.
57
Bohr effect
An increase in carbon dioxide concentration shifts the curve to the right, which decreases oxygen affinity. This is mainly due to changes in pH, but carbon dioxide also has a direct effect.
58
What is the Haldane effect?
The Haldane effect is the ability of deoxygenated hemoglobin to carry more carbon dioxide (CO2) than in the oxygenated state. So deoxygenated blood contains more CO2 than oxygenated blood.
Deoxygenated hemoglobin has a higher affinity for CO2, which increases the pH of the RBC cytosol. This is because deoxygenated hemoglobin has an increased buffering capacity and becomes more basic.
59
Shifting of oxygen hemoglobin dissociation curve
A rightward shift of the curve indicates that hemoglobin has a decreased affinity for oxygen, thus, oxygen actively unloads.(RIGHT thing to do)
A shift to the left indicates increased hemoglobin affinity for oxygen and an increased reluctance to release oxygen.
(O2 is LEFT with hemoglobin)
60
What is D-2,3-BPG
D-2,3-BPG is present in human red blood cells (RBC; erythrocyte) at approximately 5 mmol/L. It binds with GREATER affinity to DEOXYGENATED hemoglobin (e.g., when the red blood cell is near respiring tissue) than it does to oxygenated hemoglobin (e.g., in the lungs) due to conformational differences: 2,3-BPG (with an estimated size of about 9 Å) fits in the deoxygenated hemoglobin conformation (with an 11-Angstrom pocket), but not as well in the oxygenated conformation (5 Angstroms). It interacts with deoxygenated hemoglobin beta subunits and decreases the affinity for oxygen and allosterically promotes the release of the remaining oxygen molecules bound to the hemoglobin. Therefore, it enhances the ability of RBCs to release oxygen near tissues that need it most. 2,3-BPG is thus an allosteric effector.
61
oxygen hemoglobin dissociation curve with altitude
The oxygen-hemoglobin dissociation curve shifts left at high altitudes due to respiratory alkalosis, which causes oxygen to load in the pulmonary capillaries. However, the body adjusts to this shift through a process called acclimatization, which shifts the curve back to the right. This shift is caused by an increase in 2,3-diphosphoglycerate (2,3-DPG) in red blood cells. The rightward shift improves oxygen delivery to tissues by reducing hemoglobin's affinity for oxygen.
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People also ask
How does hyperventilation cause paresthesia
The mechanism for hyperventilation causing Paresthesia, lightheadedness, and fainting is: hyperventilation causes increased blood pH (see Respiratory alkalosis for this mechanism), which causes a decrease in free ionized calcium (Hypocalcaemia), which causes paresthesia and symptoms related to hypocalcaemia.
Metabolic alkalosis
Metabolic alkalosis can lower ionized calcium levels, which can cause signs of hypocalcemia, such as tetany, Chvostek sign, or Trousseau sign.
Serum pH
The binding of calcium to albumin depends on the serum pH. Severe alkalosis can cause a decrease in ionized calcium levels, while severe acidosis can cause an increase.
63
Paneth cells
Paneth cells are a type of epithelial cell found in the small intestine that play a key role in maintaining intestinal health:
Function
Paneth cells are responsible for secreting antimicrobial peptides and other substances that help maintain intestinal homeostasis. They also support intestinal stem cells, which help renew the intestinal lining.
Location
Paneth cells are located at the base of the crypts of Lieberkühn, which are tiny invaginations in the mucosal surface of the small intestine.
Appearance
Paneth cells are pyramidal-shaped with large apical granules that fill most of their cytoplasm.
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Respiratory centres
Medullary respiratory centre
Apneustic centre
Pneumotaxic centre
65
Restoration of Voluntary
Medullary
66
Peripheral chemoreceptors respond to
reduced pO2,
increased H+ and increased pCO2
in
ARTERIAL BLOOD
67
Central chemoreceptors Respond to
INCREASED H+ in BRAIN INTERSTITIAL FLUID
68
J-receptors
Juxtacapillary receptors, also known as J-receptors or pulmonary C-fiber receptors, are sensory nerve endings in the lungs that respond to conditions that cause pulmonary interstitial congestion.
69
What is Octreotide
Octreotide is a synthetic analog of the natural hormone somatostatin.
Octreotide is used to treat acromegaly, while somatostatin is used to treat bleeding from ulcers and varices, and to prevent pancreatic complications after surgery.
70
Somatostatinomas
Somatostatinomas are rare pancreatic endocrine tumours and will result in the clinical manifestations of diabetes mellitus, gallstones and steatorrhoea
71
Basis of refeeding syndrome
Refeeding increases the basal metabolic rate. The process requires phosphates, magnesium and potassium which are already depleted, and the stores rapidly become used up.
Formation of phosphorylated carbohydrate compounds in the liver and skeletal muscle depletes intracellular ATP and 2,3-diphosphoglycerate in red blood cells, leading to cellular dysfunction and inadequate oxygen delivery to the body's organs.
72
Drugs increasing risk of refeeding syndrome
insulin, chemotherapy, diuretics and antacids
73
What does vitamin B Co strong contain?
Vitamin B compound and vitamin B compound strong are licensed for the treatment of vitamin B deficiency. They contain thiamine, riboflavin and nicotinamide. Vitamin B compound strong also contains pyridoxine.
1236
74
What is the mnemonic for normal anion gap acidosis?
The common causes of normal gap acidosis can be remembered with the acronym HARD-ASS: hyperalimentation, Addison's disease, renal tubular acidosis, diarrhea, acetazolamide, spironolactone, or saline infusion. HARD-ASS is the acronym describing causes of normal gap metabolic acidosis.
75
OFFLINE
. refeeding syndrome
. Shift of oxygen hemoglobin dissociation curve
. Cory cycle
. Anion gap disorders
.Which reduces the secretion of renin?
.A 48 year old man undergoes a right hemicolectomy for a large caecal polyp. In the immediate post operative period which of the physiological processes described below is least likely to occur?
Glycogenolysis
Increased production of acute phase proteins
Increased cortisol production
Bronchoconstriction
Release of nitric oxide by vessels
. Functions of components of RAAS
. oesophageal peristalsis
.lepton Vs ghrelin
. Parotid
.How long will it take for the serum PTH levels to fall if the functioning adenoma has been successfully removed?
.started on an adrenaline infusion. Which of the following is least likely to occur?
Peripheral vasoconstriction
Coronary artery vasospasm
Gluconeogenesis
Lipolysis
Tachycardia
.Which is the least likely to cause hyperuricaemia?
Severe psoriasis
Lesch-Nyhan syndrome
Amiodarone
Diabetic ketoacidosis
Alcohol
.hypokalaemia
.Which stimulate the adrenal medulla?
.Adult lung volumes
.Formation of IgG/A/M antibodies to the TSH receptors on the thyroid gland
*Which of the conditions listed below is most likely to account for the following arterial blood gas result:
pH 7.49
pO2 8.5
Bicarbonate 22
pCO2 2.4
Chloride 12meq
Respiratory alkalosis
Metabolic alkalosis
Metabolic acidosis
Type II respiratory failure
Metabolic acidosis with increased anion gap
*agents increases the rate of emptying of the vagotomised stomach?
*Amiloride is a weak diuretic which blocks the epithelial sodium channel in the distal convoluted tubule.
*Spironolactone is an aldosterone antagonist which acts at in the distal convoluted tubule.
*mechanism of action of glucocorticoids?
*inotropic?
Dopamine
Glucagon
Theophylline
Sodium thiopentone
Dobutamine
*represents atrial repolarisation?
P wave
T wave
Q-T Interval
P-R interval
None of the above
"Which of the following inhibits the secretion of insulin?
Adrenaline
Lipids
Gastrin
Arginine
Vagal cholinergic activity
*A 34 year old male donates a unit of blood. It is stored at 4 oC. After 72 hours which of the following clotting factors will be most affected?
Factor IV
Factor II
Factor VIII
Factor IX
Factor XI
*ECG of abnormal electrolytes
*Which of the following blood gas results would fit with metabolic acidosis with a compensatory respiratory alkalosis?
pH 7.36, PaCO2 7.3, PO2 8.9 (FiO2 40%), Bicarbonate 30.2, Base excess +5.3
pH 7.14, PaCO2 7.4, PaO2 8.9 (FiO2 40%), Bicarbonate 14 mmol, Base excess -10.6
pH 7.57, PaCO2 3.5, Pa O2 24.5 (FiO2 85%), Bicarbonate 23.5, Base excess +1.8 mmol
pH 7.32, PCO2 3.8, PaO2 22.2 (FiO2 40%), Bicarbonate 19.1, Base excess -7.9
pH 7.19, pCO2 10.2, pO2 16 (FiO2 85%), Bicarbonate 23.8, Base excess -2.2 mmol
*coagulation cascade
*A 63 year old man undergoes a laparotomy and small bowel resection. Twelve hours post operatively he is noted to have a decreased urine output. Which of the hormones listed below is most likely to be responsible?
Cortisol
Atrial natriuretic hormone
Vasopressin
Insulin
Glucagon
*cause a rise in the carbon monoxide transfer factor (TLCO)?
*High risk for re-feeding problems
If one or more of the following:
BMI < 16 kg/m2
Unintentional weight loss >15% over 3-6 months
Little nutritional intake > 10 days
Hypokalaemia, Hypophosphataemia or hypomagnesaemia prior to feeding (unless high)
If two or more of the following:
BMI < 18.5 kg/m2
Unintentional weight loss > 10% over 3-6 months
Little nutritional intake > 5 days
History of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids
*Which of the following treatments is not utilized in the treatment of overactive bladder syndrome?
Sacral neuromodulation
Botulinum toxin injections
Bladder drill
Oxybutinin
Colposuspension
*
76
Vomiting after a laparoscopic appendicectomy can be a symptom of what?
Vomiting after a laparoscopic appendicectomy can be a symptom of postoperative ileus,
Postoperative ileus (POI) is a condition that occurs after surgery and causes a disruption to the normal functioning of the gastrointestinal tract. It's characterized by:
Symptoms: Abdominal distention, vomiting, pain, nausea, and difficulty eating or passing gas
Duration: POI can last from a few hours to several weeks
Risk factors: Increasing age, longer surgery, bowel handling, and more
77
Treatment of postoperative ileus
Treatments for POI include: Nasogastric tube to decompress the digestive tract, Follow-up radiographs, Correction of water-electrolyte balance, and Urinary catheter.
78
Alveolar pressure during valsalva maneuver
not negative
