Circulatory, Respiratory Flashcards
Primary rhythmic output that drives respiration originates at
Medulla oblongata
Functional unit of gas exchange in the lungs
Alveolus
Diaphragm is innervated by the
Phrenic nerves originating at C3-C5 of spinal cord
CO2 travels to the lung in all EXCEPT:
dissolved CO2, carbamate bound to proteins, histidine residues, bicarbonate ion
Carbamate bound to proteins
During respiration, [CO2] is lowest
In the alveoli-free airways at the end of inspiration
Haldane effect
For any partial pressure of CO2, the total amount of CO2 increases as the partial pressure of O2 decreases
Cheyne-Stokes breathing
Cyclic waxing and waning of tidal volume amplitudes, sleeping at high altitude
Chronic emphysema leads to all EXCEPT:
Hypoxia, hypercapnia, pulmonary hypotension, increased work load of the right heart
Pulmonary hypotension
In an ocean breath-holding dive to 10m, lung volume
decreases twofold
Systole:
Left ventricle contraction, propelling blood out the aorta into arties, BP 120 mmHg
Diastole:
ventricles relax, fill w blood, and arterial pressure reduces to around 80mmHg
Arteries
durable. Thick walls of smooth muscle and connective tissue with both collagenous and elastic fibers
Blood vessels
lined with epithelial cells, endothelial,
• Damage leads to atherosclerosis, cholesterol can build up and form plaque—arteriosclerosis
Arterioles
arteries branch to form these. Major area of resistance in cardio system
• Strong muscular walls, regulated by metabolites in blood
Capillaries
diffusion takes place here
• Greatest cross-sectional area
• Unicellular layer of endothelial cells, surrounded by basement membrane
Veins
Pressure reduces to 0-25 mmHg
• 50% of total blood volume resides here
• One-way valves
o Failure of these causes varicose veins
Sinoatrial node (SA):
- Near junction of superior VC and right atrium
* Point of origin for electrical impulse that propagates to the rest of the heart
Atrioventricular node (AV):
lower portion of right atrium near right ventricle
• Impuse from SA spreads to AV, then to bundle of His
• AV takes over if SA is damaged, slows heart rate
What NT released at SA increases heart rate?
Norepi/ epi released by adrenal medulla
Poiseuille’s Law
equation for blood flow.
• Flow rate proportional to R^4, extremely dependent on radius
• Flow rate inversely proportional to length
• High viscosity—low flow rate
• Difference in pressure drives blood
Fick’s Law:
governs diffusion, with net flux depending on concentration gradient, diffusion coeff, etc
Edema
results from blockage of lymph flow through the lymphatic system
• Increase in interstitial fluid, can’t be reabsorbed
Thrombin
serine protease involved in blood clotting.
• Works via cascade process
Vitamin K:
- Necessary enzyme has an absolute requirement for Vitamin K, so blood clotting issues arise without it
- Warfarin: Vitamin K antagonist, causes
