10.1 Flashcards
(46 cards)
What are the two parts of the pericardium?
- Fibrous pericardium
Anchors in place, prevents over stretching - Serous pericardium
Has 2 layers, Parietal and visceral
Has lubricating fluid
STRUCTURE OF THE HEART
What is the apex of the heart?
Pointed end of the heart. Formed by the tip of the left ventricle.
What are arterioles?
Thin vessels formed by arteries branching down in size.
What are venules?
Very thin vessels formed when capillaries REUNITE.
STRUCTURE OF THE HEART
Where does that heart lie?
Thoracic cavity, between the lungs.
2/3 of its mass lies to the left of the midline
What happens in systemic circulation?
Arteries and arterioles that carry OXYGEN and nutrient rich
blood throughout the body.
Veins and venules that carry CARBON DIOXIDE and waste to the right atrium.
What happens during relaxation phase?
Ventricles start to relax. All chambers of the heart enter diastole (dilation). The ventricles are filled to 75%.
What are arteries?
Thick, triple layered vessels that carry blood AWAY from the heart.
Electrical Cycle
- SA node
- Bachmann;s bundle
- AV node
- R and L bundle branches
- Purkinje fibers
What is vascular resistance?
What factors affect it?
The opposition to flow, affected by:
1. Lumen size
2. Length
3. Viscosity
What is Coronary Circulation?
Blood flow through the myocardium
What happens during ventricular systole?
Ventricles depolarize ejecting the blood into either the pulmonary
trunk (right ventricle) or the aorta (left ventricle).
What is the pericarduim?
Surrounds the heart, protects and holds the heart in place.
MAJOR BLOOD VESSELS
Coronary Sinus
Drains deoxygenated blood from the coronary veins into the right atrium.
What composes the electrical structure of the heart?
- Sinoatrial Node (SA)
- The atria (via Bachmann’s bundle)
- Atrioventricular (AV) node
- AV bundle branches (bundle of his)
- Right and left bundle branches
- Purkinje fibers
What is Blood Pressure?
Defined as pressure exerted on the walls of the vessels as the ventricles contract.
FUN FACT
Aorta has the highest BP
What is the excercise recommendation to improve cardiovascular health? and why?
At least 20 minutes 3-5 times weekly (run/brisk walk).
1. Increases our body’s ability to dissolve blood clots by increasing fibrinolytic activity.
2. Weight control
3. decrease anxiety and depression.
4. Control BP
5. Maintain low HR
What is blood flow regulated by?
Medulla oblongata and 3 types of receptors:
1. Proprioceptors- monitor movement of joints and muscles.
2. Baroreceptors- pressure in aorta and carotid arteries.
3. Chemoreceptors- stimulate
sympathetic and parasympathetic response to chemical changes.
What are the 3 phases of in a cardiac cycle?
- Relaxation
- Atrial Systole
- Ventricular Systole
WAVES ON AN ECG
What represents P?
Atrial depolarization (contraction)
What are the 3 layers of the heart?
- Epicardium- Outer- visceral layer of the serous pericardium.
- Myocardium - Muscle - 2 networks, atrial and ventricular, contract as a unit.
- Endocardium - Inner- Lines the myocardium and covers valves.
What are capillaries?
Hair-like microscopic vessels. Known as exchange vessels, which connect arterioles to venules.
Their small lumen allows blood to move slowly letting nutrients and other substances in and out.
What are the 4 principal branches of the aorta?
- Ascending Aorta
- Arch of the Aorta
- Thoracic Descending Aorta
- Abdominal Descending Aorta
What are the two types of circulation pathways?
- Systemic circulation
- Pulmonary circulation
