Lecture 2 Flashcards
What are the three main components of circulatory systems?
- pump or propulsive structures
- fluid that circulates through the system
- system of tubes, channels or spaces
What are the three types of pumps?
Contractile chamber, skeletal muscle and pulsating blood vessels
What are contractile chambers?
The heart is composed of chambers which act as individual pumps
How does skeletal muscle act as a pump?
may contract to propel flow
What are pulsating blood vessels as pumps?
tube like hearts in invertebrates and early early vertebrate embryos
how are the chambers arranged in a bony fish heart?
they are arranged in series
how many chambers do amphibian hearts have?
3 chambers
How many chambers do noncrocodilian reptile hearts have?
5 chambers
What are some features of fish heart chambers?
They have serial contractile chambers, the valves are passive
How many atria and ventricles do amphibians have?
Two atria and one ventricle
why does the frog permit/withstand mixing of deoxygenated and oxygenating blood?
mixing is kept to a minimum from the way the heart is built, it also exchanges oxygen through the skin
What chambers make up turtle, snake and lizard hearts?
Two atria and the ventricle that has the cavum venosum, cavum pulmonae, and cavum arteriosum
What are the 4 systems that have evolved to supply oxygen to hearts of animals?
Coronary vessels, spongy myocardium, outer layer compact inner layer spongy, from lumen to coronary veins
What are the two phases of the mammalian cardiac cycle?
Systole, disastole
Vertebrate hearts are myogenic, what does this mean?
Autonomous contraction, no external input needed to contract
Cardiomyocytes are electricslly coupled via _____________
gap junctions
Cardiomyocytes connect at _________
intercalated disks
gap junctions mediate _________
facilitated diffusion
Where is the pacemaker in fish and in other vertebrates?
Sinus venosus in fish and SA node in right atrium
what does the P wave represent?
Atrial depolarization
What does the QRS complex represent?
ventricular depolarization and atrial repolarization
what does the T wave represent?
Ventricular repolarization
What is Tachycardia?
Higher than normal heart rate
What is Bradycardia?
Lower than normal heart rate
What waves would you not see if atrial fibrillation occurs?
P wave and T wave, the atrium is disturbed
What type of wave would you not see if ventricular fibrillation were to occur?
QRS complex, the ventricle is disturbed
What would you see in the ECG waves if an AV block was occuring? What can this lead to?
P and QRS complex dissociated, leads to V fib
What is a neurogenic heart?
Doesnt beat on its own, needs neural input to contract
What are the 3 ways that the myogenic heart is controlled?
Nervous control, hormonal control, intrinsic control
What is cardiac output formula?
Heart rate x stroke volume
What does the frank starling mechanism imply about heart size?
A larger heart fills with more blood than a small heart
