Circulatory systems (hearts) Flashcards
(20 cards)
What is open circulatory system and what species have it?
It where blood is pumped into cavity
insects have it
What is a single closed circulatory system and what species have it?
This is where blood passes through the heart 1 for each circulation and is transported in veins/vessel (not in contact w cells)
Bony fish have it
What is a double closed circulatory system and what species have it?
This is where blood passes through the heart twice for each circulation and is transported in veins/vessel (not in contact w cells)
E.g Humans
What do smooth muscle fibres do?
Constrict and dilate to control blood flow and pressure
What does collagen do?
Structural support, strength and shape
What does Elastin do?
Stretch and recoil to reduce pressure
What is the order of entry and exit of deoxygenated blood?
Ved Really Really Pulls Pum Like LA
Vena cava
Right Atrium
Right Ventricle
Pulmonary artery
Pulmonary vein
Left atrium
Left ventricle
Aorta
What is the sequence of valves in the heart from the enter of deoxygenated blood?
Atrioventricular then Semilunar x2
What are the 3 stages of the cardiac cycle?
Diastole
Atrial Systole
Ventricular Systole
What happens during Diastole?
Atria and ventricles are relaxed and blood flows in from the Venice and Pulmonary vein into the Atria of each side
What happens during Atrial Systole?
The Atria contract = ↓Vol but ↑pressure
This causes blood to flow through the atrioventricular valves into the ventricles
What happens during Ventricular systole?
Atrioventricular valves close
Then ventricles contract =↓Vol but ↑pressure
This causes blood to flow through the semilunar valves that have just opened and out the heart
What is the formula for cardiac output?
Heart rate X Stroke vol
What causes Atrial Systole?
The SAN sending a wave of depolarisation
What causes Ventricular Systole?
The same depolarising wave that caused Atrial systole reaches the AVN then after 1/10th a second sends an electrical impulse down a bundle of His which causes the ventricles to contract
What are the 4 types of irregular heartbeats?
Tachycardia - Too fast
Bradycardia - Too slow
Fibrillation - irregular contraction of atria or ventricles
Ectopic heartbeats - Extra out of sync heart beat
Explain the structure of Haemoglobin and how it forms oxyhaemoglobin
The quaternary structure has 4 haems (prosthetic group) each with an Fe²⁺ which is able to bind to O₂ so 1 haemoglobin can carry 4 O₂
Why does the concentration of CO2 in the blood determine its PH?
Cuz CO₂ + H₂O = H₂CO3 - Carbonic acid when then turns into H⁺ + HCO3- (hydrogen carbonate) which lowers PH
What is the chloride shift? (3/4)
CO₂+H₂O→H₂CO₃(carbonicacid)
carbonic acid dissociates: H₂CO₃→H⁺+HCO₃⁻
HCO₃⁻ moves out the RBC and Cl⁻ moves in to maintain charge neutrality
Why does fetal haemoglobin have a higher affinity to O₂ than adult? (3)
- The fetus get O₂ from its mother blood via placenta
-This blood has lower O₂ levels as its circulated around the mothers body
-So the fetus needs haemoglobin that can bind oxygen even when it’s at a low partial pressure hence the greater affinity
