questions Flashcards
explain how liver cirrhosis can lead to portal hypertension? 6
1.) Liver cirrhosis causes liver tissue to become fibrous and rigid/hardened
2.) This disrupts the blood flow through the liver
Blood begins to backflow to the Portal Vein
3.)Blood accumulates and causes an increase in pressure — portal =hypertension
4. Blood continues backflowing to the collateral blood vessels in the upper GI tract and rectum/anus
5. Weak blood vessels — dilate and twist , become varicose veins
6. Eventually rupture due to the increased pressure — leading to bleeding
Explain how gallstones can lead to pancreatitis? 6
- Gallstone is squeezed out of the gallbladder with the bile after patient eats
- Blocks the sphincter of Oddi — bile is blocked
- Bile backflows into the pancreatic duct
- Presence of bile activates proteases — such as Trypsinogen — that are present in the pancreas
- These start to auto digest the pancreatic tissue
- Inflammatory response — Pancreatitis
• Explain how gallstones can lead to fatty stools?
• How can they also lead to pain in the upper right quadrant of the
abdomen?
5
- Block the sphincter of Oddi
- Bile cannot enter intestines — bile normally helps to break down fats - therefore absence of bile means fats go undigested through the intestines ; Lipase enzyme
- Undigested fats excreted with the stool
- Gallstones are sharp — scratch the common bile duct wall as they pass through — causing local injury
- Localized stimulation of nociceptors due to injury — pain response
- Explain first pass effect/metabolism of a drug?
* Which route of administration avoids the first pass effect? 2
- Part of the drug is metabolized by the liver before it reaches the systemic circulation, therefore reducing the bioavailability of the drug.
- Intravenous route as it enters the systemic circulation immediately
Define asthma 2
- A chronic inflammatory disease of the bronchioles
* Hypersensitivity of the bronchioles which results in bronchospasm
• Chloe is asthmatic, she has been prescribed a salbutamol inhaler.
Explain the mechanism of salbutamol, and how this will help her
symptoms of asthma?
4
- Salbutamol is an agonist of Adrenaline
- Binds to B2 receptors on the smooth muscle cells of the bronchioles
- Causes sympathetic stimulation — results in bronchodilation
- Therefore, dilated airways will reduce the symptoms of asthma
• Another drug that can be used is Ipratropium Bromide, explain the mechanism of this drug. 3
- Ipratropium Bromide is an antagonist of Acetylcholine
- It blocks the muscarinic receptors on the smooth muscle cells of the bronchioles
- Therefore, it inhibits Acetylcholine from binding and therefore stops bronchoconstriction from occurring
• Why do asthma sufferers have worse symptoms on exhalation? 3
- On exhalation, pressure in the airways naturally decreases
- This causes passive narrowing of the airways
- In asthma, the airway is already narrow, further narrowing of the airway on exhalation will cause worse symptoms
• Greg suffers from MS and neuropathic pain as a consequence. Explain
what Neuropathic pain is and how MS causes this? 4
- Neuropathic pain is pain that is felt from a normally non — painful stimuli
- MS causes demyelination of axons/damage and destruction to the myelin sheath
- This causes the neuron to become irritated
- A spontaneous action potential is created, if this occurs on a sensory neuron, the action potential is perceived as a pain message.
explain the pain pathway 6
• Localised injury stimulates local nociceptors = Transduction
• ISt order neuron — spinal cord
• 2nd order neuron — thalamus in the brain
• 3rd order neuron — somatosensory cortex of the brain
=Transmission
• PAG layer = perception of pain
• Finally, modulation of pain occurs — different in everybody, how the
body deals with the pain.
• Explain how opiates, such as Morphine, work to reduce pain? 8
- Bind to opiate receptors on the pre-synaptic membrane
- Stop calcium influx by closing the calcium ion channels
- Therefore no/very little neurotransmitter is released into the synaptic cleft
- Action potential (pain message) will be unable to be transmitted across.
- Also bind to opiate receptors on the post-synaptic membrane
- Cause the membrane to become hyperpolarized
- Hyperpolarized membrane is unable to generate an action potential
- Therefore pain messages will not be received, pain will be reduced.
• When a localized injury occurs, the symptoms of inflammation are
seen. Explain what these symptoms are and how they are caused?
5
•Localised injury activates Mast cells
•These release Histamine and Prostaglandins
Localized vasodilation occurs — increases blood flow to the area= Causing redness and heat
•Increased vascular permeability
• Fluid leaks into the localized area and accumulates—Causing swelling/oedema
•Presence of fluid stimulates local pain receptors—Causing pain
• NSAID’s such as ibuprofen can be used to reduce inflammation,
explain their mechanism of action. 4
- NSAID’s inhibit COX enzymes
- These enzymes increase prostaglandin productions, therefore when they are inhibited, prostaglandin production decreases
- Less prostaglandins reduces the strength of the inflammatoryresponse
- Therefore, causing a reduction:in the symptoms.
• Grace has been in a car accident and has lost a lot of blood.
• Her observations are
• HR 130
• RR 28
• BP 105/65
• Explain the physiological mechanisms behind the observations seen.
13
- As Grace has lost a lot of blood volume, her compensatory mechanisms are causing her observations.
- When her BP was falling, the baroreceptors — located in the aortic arch and carotid sinus — would have detected this.
- An afferent message would have been sent to the CCC in the medulla oblongata of the brain
- Then an efferent message would have been sent to the SA node to increase the firing rate
- Increased firing rate from the SA node = increased HR
- This is to try and maintain the blood pressure, and adequate circulatory flow around the body
- The loss of blood volume would also mean that there would be inadequate oxygen delivery to tissues.
- Cells would begin to respire anaerobically, causing Lactic Acid to be produced.
- This would lower the pH of the blood — detected by chemoreceptors.
- An afferent message would be sent to the RCC in the medulla oblongata of the brain
- An efferent would then be sent to the diaphragm and external intercostal muscles.
- Increased sympathetic stimulation — increase frequency and strength of contractions
- Causing an increased respiratory rate
• What type of shock is Grace suffering from?
• If her shock progresses, what would the hallmark symptom be to
diagnose this?
2
• Hypovolemic / hemorrhagic
• Hypotension with tachycardiac — as this would show failure of those
compensatory mechanisms
• Grace’s blood type is AB-, she needs a blood transfusion.
• What blood types can she be given?
3
• AB can receive all 4 —A, B, AB, and O • However Rhesus negative can only be given negative blood • Therefore she can be given -A- B- AB- O-
• What is hypoxia?
• What are the 4 types of hypoxia?
5
- A state in which the body is deprived of adequate oxygen supply at tissue level
- Hypoxic
- Anaemic
- Stagnant
- Histotoxic
• Define dementia
• What are the 3 types?
4
- A term to describe conditions that include a decline in memory and reduction in ability to do daily activities
- Alzheimer’s
- Frontotemporal
- Vascular
• What are the two types of hormones and what are their differences?
6
Peptide - Water soluble - Bind to receptor on the surface of the cell Steroid - Lipid soluble - Bind to receptor inside the cell
• Explain the fight or flight system, including the hormones involved? 8
- Acute stress stimulus
- Adrenaline and noradrenaline released from adrenal glands
- Sympathetic stimulation
- Increased HR and RR
- Dilated pupils
- Muscle tremors
- Eventually, noradrenaline causes parasympathetic stimulation
- Reverse of symptoms
• Explain how calcium levels are increased if they are too low?
4
- Parathyroid hormone released from parathyroid gland
- Increases activity of osteoclasts — more calcium released into body
- More calcium absorbed from intestines
- Stop calcium being excreted by kidneys
• Explain how blood glucose levels are reduced? 2
• Insulin released from Beta cells of the pancreas
Encourages uptake of glucose into target cells
• Promotes blood glucose to be converted into glycogen stores
• Explain how blood pressure is increased by the RAAS? renin aldosterone angiotensin system
11
- LOW BP detected by kidneys — Renin released
- Liver releases Angiotensinogen
- Renin + Angiotensinogen = Angiotensin 1
- Lungs release ACE (Angiotensin converting enzyme)
- Catalyzes the production of Angiotensin 2
- Angiotensin 2 directly causes vasoconstriction = increased SVR
- Stimulates release of Aldosterone from Adrenal Gland
- Increases sodium reabsorption at the distal convoluted tubule of the nephron
- Water follows sodium into the blood due to osmotic changes
- Increased blood volume increased CO
- Increase CO and SVR will increase blood pressure
• Explain the mechanism of ADH 6
- Released by pituitary gland in response to low
- Works on collecting duct of nephron
- Increases amount of aquaporin channels
- Water moves passively into blood
- Increase blood volume = Increase CO
- Increase BP
- Which of the following statement is correct about the mechanism of action of
antibiotics:
(1 mark)
- Penicillin inhibits peptidoglycan synthesis
- Streptomycin inhibits protein synthesis
- Metronidazole inhibits DNA synthesis
TRUE OR FALSE
Asthma is a chronic disorder Of the alveoli
Pneumonia is an acute infection Of the bronchi
Bronchitis is an inflammation Of bronchioles
ALL FALSE
First pass metabolism may reduce drugs bioavailability, Which organ is involved in
‘First pass metabolism’ of a drug:
LIVER
What substances normally found in the blood are not normally found in urine?
PROTEINS
