Flashcards in Normal structure & Function Deck (119)
Main function of Heart?
Pump blood to all organs and tissues in body
Oxygen and nutrients to tissues and removes waste products
Prime function of right heart?
Via the pulmonary trunk drives the low pressure pulmonary circulation
Prime function of left heart?
Via the aorta drives high pressure systemic circulation
How many pumps does heart have?
High pressure pump?
On the left side. Forces blood to flow to other tissues around body and then back to the heart
Low pressure pump?
On the right side. Forces blood to flow to the lungs and back to the heart.
Blood circulates body via?
Blood returns to the heart via?
Features of Arteries?
The walls of larger central arteries are elastic and recoil to help propel blood
The walls of smaller arteries and arterioles are much more muscular and are mainly responsible for peripheral resistance to blood flow.
Features of veins?
Thin walls and easily distensible- act as a major reservoir of blood
Larger veins have valves that support unidirectional blood flow- important during standing and exercise
Capillaries structure and function?
Tiny vessels forming a network linking arterial and venous blood flow. In this gases and nutrients or waste are exchanged at a cellular level
Thin single layer of endothelial cells
Permeable to small molecules facilitating exchange of hormones, fluid and nutrients, electrolytes etc between interstitial fluid and blood.
What does the lymphatic system do?
It comprises of a network of thin walled vessels which enable excess interstitial fluid to return to the circulation
Where does the heart lie?
Lies in the chest cavity, deep to the sternum within the rib cage, between the lungs, superior to the diaphragm in the mediastinum.
Where is the base of your heart?
Closer to the head than the apex
Describe the position of the apex of the heart?
Lowest most lateral point of heart
5th left intercostal space just medial to the mid-clavicular line
4 reasons it is clinically important to know the location of the heart?
-It directs you to where you could normally find the apex beat
-Indicates listening areas on chest wall for where you could best hear heart sounds and murmurs
-Helps you know were best to place electrodes when recording a trace of hearts electrical activity
-Helps you know where to put pressure in CPR
Murmurs & heart sounds
Groove on the external surface of the heart that separates atria from ventricles
What do superior and inferior vena cavae do?
Drain blood from upper and lower parts of the body into the right atrium
What does aorta do?
Carries oxygenated blood from left ventricle to body
What do pulmonary arteries do?
Carry systemic venous blood from the right ventricle to the lungs
Where do the left and right coronary arteries rise from?
Root of the aorta just above the aortic valve, and lie within the coronary sulcus
Why is the left ventricular wall thicker than the right?
Pumps blood against high pressure in the systemic circulation, whereas RV pumps blood into low pressure pulmonary circulation
What are valves in heart for?
To maintain unidirectional blood flow between chambers and between chambers and vessels
How many pair of valves does heart have?
2- atrioventricular and semilunar
Located between atria and ventricles
Right side AV valve has 3 cusps and is called tricuspid
Left side valve has 2 cusps and is called mitral valve
Located within aortic and pulmonary trunk
Valve cusps are half moon shaped
They are called the aortic and pulmonary valves
Consists of strong fibrous framework that prevents main components of heart pulling themselves apart during contraction. Heart valves are also anchored by this.