What is the pericardium?
Double serous membrane around the heart.
What is visceral pericardium?
Layer of pericardium directly next to the heart.
What is parietal pericardium?
Outside layer of paricardium.
What are the 3 layers of the heart wall?
Epicardium - Outside
Myocardium - Middle
Endocardium - Inner
What are the receiving chambers of the heart?
What are the discharging chambers of the heart?
What are the 4 heart valves?
Tricuspid / Atrioventricular
Pulmanary Semilunar \
Aortic Semilunar / Semilunar valves
What do the chordae tendinae (heart strings) do?
Hold valves in place.
What does the flow of blood from the Aorta do?
Leaves left ventricle.
What does the flow of blood from the pulmonary arteries do?
Leave right ventricle
What does the flow of blood from the Vena Cava do?
Enters right atrium.
What does the flow of blood from the pulmonary veins do?
Enter left atrium.
What makes up the hearts nourishing circulartory system?
How does blood enter the right atrium?
The coronary sinus.
What is the Intrinsic Conduction System? (how the heart beats)
Nodal System, heart muscles contract without nerve impulses in a regular continuous way.
What is the Sinoatrial Node?
The hearts natural pace maker.
What are purkinje fibers?
Fibers the cause the ventricles to contract.
How do the atria contract?
When do the ventricles contract?
After the atria relax.
What is systole?
What is diastole?
What is the cardiac cycle?
Events that complete one heart beat.
What happens during mid-late diastole?
blood flows into ventricles
What happens during Ventricular Systole?
Blood is pushed out of ventricle by increased blood pressure.
What happens during early diastole?
Atria finish refilling, low pressure in the ventricles.
What is cardiac output?
Amount of blood pumped by each side of heart in 1 minute.
What is stroke volume?
Amount of blood pumped by each ventricle in one contraction.
Heart Rate x Stroke Volume
What is starlings law of the heart?
The more the cardiac muscle is stretched, the stronger the contraction
What is the most common way to change Cardiac Output?
Change heart rate.
What causes increased heart rate?
Low blood pressure (Sympathetic nervous system)
Hormones (Epinephrine, Thyroxine)
Decreased blood volume.
What causes decreased heart rate?
Decreased Venous return
parasympathetic nervous system
High Blood pressure/volume
What are the 5 types of blood vessels?
What are the 3 layers or tunics of a blood vessel?
Tunic Intima - Endothelium
Tunic Media - Smooth muscle
Tunic Externa - Fibrous connective tissue
How is arterial blood moved?
By the pumping of the heart.
How is venous blood moved?
The "milking" action of muscles.
What is a vascular shunt?
directly connects an arteriole to a venule.
What is the pulse?
Pressure wave of blood.
What does systolic mean?
Pressure at the peak of ventricular contraction.
What does Diastolic mean?
Pressure when ventricles relax.
What effects blood pressure?
What effect does heat have on blood pressure?
What effect does cold have on blood pressure?
What is normal human blood pressure?
140 - 110mm Systolic
80 - 75mm Diastolic
What is hypotension?
Low systolic pressure
What is hypertension?
High systolic pressure.
What kind of heart develops in the embryo?
A tube heart that pumps by the 4th week.
When does the fetal "tube heart" become a 4 chambered organ?