2.5 Structure And The Function Of The Heart Flashcards
What do valves prevent?
The backflow of blood
What are the two types of valves?
AV Valves and SL Valves
What do AV Valves do?
Prevent blood flow from flowing back into the atria. These valves force blood into the ventricles
What do SL Valves do?
SL Valves prevent blood from flowing back into the ventricles. These valves force the blood to leave the heart
What does the pulmonary vein do?
Carries oxygenated blood from the lungs to the left atrium
What does the Aorta do?
Carries oxygenated blood from the left ventricle to the body
What does the vena cava do?
Carries deoxygenated blood from the body to the right atrium
What does the pulmonary artery do?
Carries deoxygenated blood from the right ventricle to the lungs
What is the Cardiac Output formula?
CO = HR X SV
Where is the SAN located?
The wall of the right atrium
Where do Sympathetic and Parasympathetic come from?
The Autonomic Nervous System
What are parasympathetic and sympathetic described as being?
Antagonistic
What is sympathetic?
Increases heart rate and release noradrenaline
What is parasympathetic?
Decreases heart rate and release acetylcholine
What can impulses in the heart be detected by?
Electrocardiogram (ECG)
What does the P wave detect?
The wave of electrical impulses spreading over the atria from the SAN
What does the Q-R-S complex detect?
The electrical impulses through the ventricles
What does the T wave detect?
The electrical recovery of the ventricles at the end of ventricular systole
How to work out ECG calculation?
60 divided by time of wave
What is blood pressure?
Blood pressure is the force exerted by blood against the walls of the blood vessels
How is blood pressure measured?
It is measured in millimetres of mercury (mm Hg)
How is blood pressure generated?
By the contraction of the ventricles and it is therefore highest in the large elastic arteries
When does blood pressure increase?
During ventricular systole
When does blood pressure decrease?
During diastole
What is a typical blood pressure reading for a young adult?
120/80 mm Hg
How is the first blood pressure measured?
After an inflatable cuff stops blood flow and deflates gradually, causing the blood to start to flow at systolic pressure
How is the second blood pressure measured?
When the blood flows freely though the artery at diastolic pressure
What equipment is used to measure blood pressure?
Sphygmomanometer
What is hypertension?
The prolonged elevation of blood pressure
What diseases is hypertension a major risk factor of?
Coronary heart disease and strokes
What is the cause of hypertension?
Unhealthy lifestyle
What is used to treat hypertension?
Statins
What are the 3 main blood vessels?
- Arteries
- Capillaries
- Veins
What is the circuit that blood goes?
The heart to the arteries to the capillaries to the veins and then back to the heart
What are the sections in an artery?
- Central Lumen
- Endothelum Lining
- Smooth Muscle
- Connective Tissue
What are the locations in a vein?
- Central lumen
- Endothelium lining
- Smooth muscle
- Connective tissue
What are the locations in a capillary?
- Lumen
- Endothelium
- Body Cells
What is vasodilation?
The widening of blood vessels
What causes vasodilation?
Smooth muscle cells relaxing
What is vasoconstriction?
The narrowing of blood vessels
What causes vasoconstriction?
Smooth muscle cells contracting
What is blood plasma?
A watery yellow fluid that contains many dissolved substance
What are the dissolved substance in blood plasma?
- Glucose
- Amino Acids
- Respiratory gases
- Plasma proteins
- Ions
What is between the artery and capillary?
The arteriole
What is between the capillary and the veins?
The venule
What is the first step in exchange of blood materials?
Blood is transported from the arteries then through the arteriole and enters the narrow capillaries in the capillary bed
What is the second step in the exchange of blood materials?
Pressure filtration squeezes the blood plasma through the capillary wall and into the surrounding cells losing its proteins and becomes tissue fluid
What is the third step in the exchange of blood materials?
Glucose/Oxygen diffuse out of the tissue fluid and into the surrounding cells. Carbon dioxide diffuses out of the surrounding cells into the tissue fluid
What is the fourth step in the exchange of blood materials?
Most of the tissue fluid is absorbed back into the capillaries and leaves the capillary bed via the venule
What is the fifth step in the exchange of blood materials?
Some of the tissue fluid does not return to the capillaries. The excess fluid is absorbed by lymph vessels
What is the sixth step in the exchange of blood materials?
The tissue fluid at this point is called lymph and is taken away by the lymph vessels where it is transported around the body at the lymphatic system
