Exam questions LSS Flashcards
What are two exercise dependent events, that lead to increased venous return?
Activation of Muscle pump
Increased BP
Decreased venous compliance –> higher venous return and higher pressure leading to a higher CO (Frank-Starling-relationship)
What are two exercise dependent events that lead to decreased venous return?
More blood is going to muscle capillaries –> less blood is available circulation
Also higher perfusion of skin to cool down
Vasodilation of skin and pulmonary vessels –> decreased TPR
What are the three cells involved in atherosclerosis?
- Macrophages (Foam cells)
- Endothelial cells
- Vascular smooth muscle (–> stability + fibrous cap)
In which three ways can changes in arterial wall in atherosclerosis lead to clinical problems?
- Narrowing of blood vessels (stenosis) –> Angina Pectoris
- Aortic aneurism because of stiffening of arteries
- Thrombus may rupture and cause embolism
Hexagonal reference system: Which angle for which leads?
What is a normal interval for a RR interval?
0.6-1.2 s
What is a normal duration for a P wave?
80ms (<100ms)
What is a normal PQ/PR time?
120-200ms
What is a normal QT interval?
420ms (0.35-0.44, depending on heart rate)
What is the normal duration of a T-wave?
160ms
Name two properties of the myofilaments which are responsible for the Frank-Starling relationship
- Length of sarcomer –> number of crossbridges between actin and myosin
- The sensitivity of Troponin C to Calcium
When is renin being released?
- decreased filtrate osmolarity in macula densa (low Cl-, Na+)
- Sympathetic activity (via low BP)
- Low perfusion pressure of afferent arteriole
What is the blue line showing?
What would be the equivalent name of the line at the bottom (from A to B and further)
It is the end-systolic Pressure volume Line
–> rises because the higher the volume, the more pressure is required to pump it out
At bottom: End-diastolic pressure volume-line
Name 2 inflammatory mediators of Asthma
Histamine
Prostaglandin D2
Name 2 T-cell cytokines that cause B-cell proliferation
IL-21 and IL-4
IL-4, IFN-gamma, TGF-beta, IL-10
Which cell type would be increased in bacterial Lung infection?
Phagocytes: neutrophils (and macrophages)?
What is the main histological feature of emphysema?
Airspace enlargement
And also: fragmented alveolar walls
http://www.pathologyoutlines.com/topic/lungnontumoremphysema.html
What are the treatments for emphysema and explain their mechanism
-
Bronchodilator B2 agonist
* relaxes smooth muscle in the bronchioles –> dilating them, reducing resistance to airflow and making the pt breathe more easily.
2. Inhaled corticosteroids:
- they work by blocking the late-phase immune reaction, decreasing inflammation and reducing inflammatory cells (neutrophils, macrophages).
3. Dual protease inhibitor:
- inhibit the proteases produced by phagocytes in lung tissue (NE+MMP) which are destroying lung tissue.
What is the effect of parasympathetic innervation of the pulmonary vessels?
Probabaly vasodilation on pulmonary vessels (but no clue)
Name the changes and associated receptors when there is sympathetic stimulation to i) airways (1), ii) heart (2), iii) arterioles (1)
Airways – bronchodilation, relax SM –> beta2
Heart – increase heart rate + force –> beta1
Arterioles – vasoconstriction –> alpha1
State 2 physiological processes that cause vasodilation of the airways
Exercise
Childbirth???
How are the different zones in a hepatic acinus called?
1) Periportal
2) Transition zone
3) Pericentral
What are the structural characteristics of a resting parietal cell?
How does it change when activated?
Parietal Cell: Resting
- Many mitochondria (requires lots of ATP)
- Cytoplasmic tubulovesicles (contain H+/K+ATPase)
Parietal Cell: Secreting
- Tubulovesicles fuse with membrane and microvilli project into canaliculi
How are the fat strikes associated with the colon called?
Appendices epiploicae/omental appendices
What is the most common cause of acute liver failure in the UK and worldwide?
UK= paracetamol overdose
Worldwide= Viral hepatitis
Through which mechanisms is Calcium concentration decreased in a cardio-myocyte?
Na+/Ca2+ exchanger (membrane)
Sarcoplasmic riticulum (Ca2+ ATPase)
What effect does sympathetic activity have on Glomerular filtration rate?
Sympathetic activity decreased GFR
–> increasing BP –> less excretion
What is the difference between a carrier protein and a channel?
Channel proteins
- formation of aqueous pore to allow diffusion os specific molecules
Carrier protein
- Binding to protein induces conformational change in protein –> allows ion to pass through
What is the difference between primary and secondary active transport?
Primary
- something is actively pumped against its concentration gradient (normally ATP dependant)
Secondary
- something is transported against its concentration gradient but uses other molecules concentration gradient to do so
What is facilitated transport?
Down its concentration gradient but molecule needs facilitation (ion channels, carrier proteins)
What happens to Fe2+ iron once it is in the blood?
It gets into the blood via Ferroportin molecule
- Converted to Fe3+ by Hephastein
- Binds to Apotransferin
–> Travels in blood as transferrin
How is iron absorption regulated? (which molecule?)
Hepcidin suppresses ferroportin function –> supression of iron absobtion
What are the two primary and two secondary bile salts?
How do they relate to one another?
When do you sense thirst?
1) Body fluid osmolality is increased.
2) Blood volume is reduced.
3) Blood pressure is reduced.
Which hormone evokes the sensation of thirst?
Where does its control mechanism sit?
Angiotensin II
Decreased blood volume and pressure detected at subfornical organ neurons
What happens when plasma-osmolarity is increased?
Osmoreceptors gound in the hypothalamus, OVLT, (Organum vasculosum laminae terminalis) and SFO (subfornical organ)
- increase the sensation of thirst (main regulation)
- and increase ADH secretion
