EAC Cardio-Vascular CV System Flashcards
functions of the CV system
To transport essential foodstuffs, oxygen, water, enzymes and hormones to the cells of the body
To remove waste products that are produced by cell metabolism to the excretory organs
components of the CV system
Heart
Blood vessels
Blood
CV circulation divisions
Systemic: passage of blood around the body
Pulmonary: passage of blood through the lungs
Coronary: supply of blood to/from the heart muscle
Hepatic Portal: supply of blood to/from the liver (is a branch of systemic)
describe:
structure of the heart
The heart is a hollow cone shaped muscular organ
In an average adult it is the size of the owners clenched fist
state the location of the heart
The heart is situated within the thoracic cavity.
It lies in the mediastinum behind the sternum, in front of the spine, between the lungs and above the diaphragm.
The base lies behind the sternum and extends to the 2nd rib
The apex is approx. 9cm to the left of the midline, in the mid-clavicular line at the 5th intercostal space
describe the structure of the heart
The walls of the heart are composed of three main layers:
Pericardium (outer)
Myocardium (mid)
Endocardium (inner)
Pericardium consists of
Fibrous pericardium
Parietal pericardium
Pericardial space fill with Pericardial fluid
Visceral pericardium
function of: Pericardium
The pericardium prevents over distension of the heart and the pericardial serous fluid allows for smooth frictionless movement when the heart beats.
function of: Myocardium
Muscle of the heart, thickest around the left ventricle. has automaticity which means it doesn’t require outside stimulus to produce muscle contraction.
function of: Endocardium
A thin smooth squamous epithelial membrane to ensure smooth flow of blood through the heart.
It lines the chambers of the heart and the valves.
Its continuous with the lining of blood vessels.
Helps to prevent local blood clotting.
flow of blood through the heart (right side)
Inferior and superior vena cava
Right atrium
Tricuspid valve
Chordae tendineae
Papillary muscle
Right ventricle
Pulmonary valve
Pulmonary trunk
Left and right pulmonary artery
Lungs
flow of blood through the heart (left side)
Lungs
left and right pulmonary vein
Left atrium
Bicuspid valve
Chordae tendineae
Papillary muscle
Left ventricle
Aortic valve
Arch of aorta
Aorta
Rest of body
Describe:
Coronary circulation
Coronary circulation is the circulation of blood in the blood vessels of the heart muscle.
Right coronary artery
Left coronary artery
-which the Circumflex artery branches off
Describe:
Cardiac Cycle
Atrial systole - contraction of atria - 0.1 sec
Ventricular systole - contraction of ventricles - 0.3 sec
Cardiac diastole - relaxation phase - 0.4 sec
Describe:
Electrical Conduction System of the heart
specialised cardiac cells that produce electrical impulses to cause the heart to contract
Sino-Atrial node SA
Atrio-Ventricular node AV
Left and Right bundle branches
Purkinje Fibres
Explain:
Nervous Control of the heart
Cardiovascular centre located within the medulla oblongata
sympathetic/Parasympathetic nervous control regulates heart rate
Average heart rates
60-100 = adult
100-120 = 6-12yrs
120-140 = 1-5yrs
140-160 = 1mnth-1yr
factors that increase heart rate
position
age/sex
exercise
emotion
cardiac/medical conditions
shock and blood loss
drugs/chemicals
factors that decrease heart rate
age
general health
vagal stimulation
cardiac conditions
medical conditions
drugs
define:
Bradycardia
Slow heart rate of less then 60bpm
define:
Tachycardia
Rapid heart rate of more then 100bpm
name the 5 types of blood vessel
Arteries Arterioles Capillaries Venules Veins
describe:
structure of blood vessels
Three layers:
outer fibrous sheath = Tunica Adventitia
middle layer of muscle and elastic fibre = Tunica Media
smooth inner lining of endothelium = Tunica Intima
describe the structure and function of:
Arteries
carry blood away from the heart
they have a strong outer (tunica adventitia) coat and thick muscle layer (tunica media)
