Evolution of circulation
10 important questions on Evolution of circulation
3 major steps in evolution coelom
2. Two compartments:
- Pericardial cavity
- pleuro- peritoneal cavity (salamanders)
- pericardial cavity (parietal + visceral pericardium)
- pleural cavity (parietal + pulmonal plaura)
- peritoneal cavity (somatic + visceral perionea)
Layers wall of the heart
- myocardium (middle layer, cardiac muscle)
- endothelium (inner layer, epithelial cells)
Generate action potentials
- You can find them in sinoartial node (SA node) and atrioventricular node (AV node)
- Together they are called the conduction system
- Action potentials are quickly transmitted via the conduction fibers because of their large diameter and gap junctions between the cells (in intercalated disk)
- The disks also have desmosomes to withstand the tension and stretching of the myocardium
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
The sequence of electrical events
2: AV node conducts less rapid -> AV nodal delay
3: Impulse travels to bundle of His in the interventricular septum
4: shortly thereafter, the bundle splits into bundle branches
5: Impulse travels further through branched Purkinje fibres
Factors that change stroke volume
- end-diastolic volume
- afterload
- Contractility and end-diastolic volume change stroke volume because they change the ventricular contraction
- A change in contractility means a change in contractile force at any given end-diastolic volume
- It is under complete influence of the sympathetic nervous system
Sympathetic nervous system heart
- It does so by releasing norepinephrinen -> activitates cAMP second messenger system -> activates protein kinases
- They open more calcium channels
- increase inflow of calcium during an action potential
- Just like with heart rate, epinephrine of the adrenal medulla does the same
Bulk flow (cardiovascular system)
- In the cardiovascular system it is the mean arterial pressure (MAP) and the central venous pressure (CVP) that drives the pressure gradient
- However, CVP is so small, it can be neglected; so DeltaP=MAP
- Flow = (pressure gradient)/(resistance) = DeltaP/R
Pulmonary circuit resistance
- resistance depends on radius and viscosity of the fluid
- When the radius decreases -> resistance increases
- When viscosity increases -> resistance increases
- The resistance of the total systemic circuit = total peripheral resistance (TPR)
- CO=MAP/TPR
Walls of blood vessels
- an endothelium
- a basement membrane (anchoring proteins)
- smooth muscle fibres
- fibrous and/or elastic connective tissue
Colloid osmotic pressure
- they exert a colloid osmotic pressure
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
