Cardiovascular system (Heart) Flashcards
What are the two components of the cardiovascular
Heart and blood vessels
Functions of the cardiovascular system
-Transports blood throughout the body
-Allows exchanges between capillary blood and body cells
What is perfusion
delivery of blood
per time per gram of tissue
◦ mL/min/g
What are arteries
Oxygenated
carries blood away from the heart
Veins
Deoxygenated
Carries blood to the heart
Capillaries
exchange with systemic cells
What does it mean that the heart is two sided?
Each side of the heart has two chambers. The atrium which receives blood and the ventricles which pump the blood.
Left side of the heart
Receives oxygenated blood from the lungs and pumps it to the body
Right side of the heart
Receives deoxygenated blood from the body and pumps it to the lungs
The Great Vessels
Large arteries and veins directly attached to the heart
Heart valves
Create valves to prevent back flow to ensure one way blood flow
Atrioventricular valve (AV)
Right and Left segments; between atria and ventricles
Semilunar Valve
Located between a ventricle and an arterial trunk
(i.e. pulmonary and semilunar)
2 Circulation routes:
Pulmonary circulation
Systemic circulation
Explain pulmonary circulation
◦ Carries deoxygenated blood from right side of heart to lungs
◦ At lungs, blood picks up oxygen and releases carbon dioxide
◦ Returns blood to left side of heart
Explain systemic circulation
◦ Moves oxygenated blood from left side of heart to systemic cells
◦ At systemic cells blood exchanges gases, nutrients, and wastes
◦ Returns blood to right side of heart
what is the basic pattern
right heart - lungs - left heart - systemic tissues - right heart
What is the heart enclosed in?
Pericardium
what cavity contains the heart?
Thoracic cavity
What is the base of the heart?
posterio-superior surface
What is the apex?
inferior, conical end
Characteristics of the pericardium
Three layered fibro-serous sac surrounding the heard
as well as the pericardial cavity
Fibrous pericardium
Outermost covering
anchors heart and prevents it from overflowing
Parietal layer of serous membrane
Middle layer
Attaches to fibrous membrane
Visceral layer of serous membrane
Innermost later
attached directly to the heart
pericardial cavity
space between serous membrane
Superficial features of the heart
-External grooves (called sulci) mark borders of the hearts chambers
-Grooves contain coronary vessels supplying blood to heart wall
Coronary sulcus
separate atria from ventricles
intraventricular sulci
separate left from right ventricles
-anterior and posterior sides
Anterior view of the heart
right atrium and ventricle appear prominent
Right auricle prominent
Posterior view of the heart
◦ Left atrium and left ventricle prominent
◦ Left atrium forms base on posterior-
superior surface
◦ Pulmonary veins attached to left atrium,
superior and inferior vena cava
◦ Pulmonary arteries
What are the layers of Heart wall
-Epicardium (outermost)
-myocardium (middle)
-pericardium (innermost)
Interatrial septum
Separates left and right atrium
like nose septum
Interventricular septum
separates left and right ventricle
Right atrium contains…
-Pectinate muscles
-Fossa ovalis
Pectinate muscles
ridges on anterior wall and within auricle
Fossa ovalis
oval depression on interatrial septum
Entrances to the right atrium
- Coronary sinus (carrying blood from heart wall)
- Superior vena cava
- Inferior vena cava
Also exits through AV valve
Right ventricle contains:
Trabeculae carneae
Papillary muscles
Chordae tendineae (tendinous cords)
Superior exit to pulmonary trunk through pulmonary semilunar valve
Trabeculae carneae
irregular muscular ridges inside ventricle wall
Papillary muscles
cone-shaped projections extending from internal ventricle wall
Chordae tendineae
heart strings; Thin strands of collagen fibers attaching to AV valve
Ligamentum arterosium
Dense CT anchoring pulmonary trunk to aortic arch
Atrioventricular valves prevent back flow to…
atria
Semilunar valves prevent backflow to…
ventricles
myocardium is composed of…
cardiac muscle tissue
Features of cardiac muscles
short strands
striated
1 or 2 nuclei
metabolism of cardiac muscle
◦ High demand for energy
◦ Extensive blood supply
◦ Numerous mitochondria
◦ Able to use different types of fuel molecules
◦ Relies mostly on aerobic metabolism
Fibrous skeleton of the heart
Dense irregular connective tissue between the boundaries of atria and ventricles
◦ Framework for muscle attachment
◦ Electrical insulator
◦ Prevents ventricles from contracting at same time as atria
what is Coronary circulation
delivers blood to heart wall
what is the location of coronary arteries?
sit in coronary sulcus
Veins that drain cardiac muscle:
◦ Great cardiac vein
◦ Middle cardiac vein
◦ Small cardiac vein
ultimately drained to coronary sulcus and returned to right atria
Sinoatrial node (SA)
initiates heartbeat (pacemaker)
Innervation of the heart
Cardiac center of the medulla
◦ Contains cardioacceleratory and cardioinhibitory centers
◦ Receives signals from baroreceptors (stretch) and chemoreceptors (chemical) in cardiovascular system
◦ Modifies heart activity – does not initiate it
Parasympathetic innervation
Starts at medulla’s cardioinhibitory center (CN X)
◦ Decreases heart rate
Sympathetic innervation
Starts at medulla’s cardioacceleratory center (cardiac plexus)
◦ Increases heart rate
◦ Increases force of contraction
Heart contraction involves two elements
cardiac cells and conduction system
conduction system
initiates and propagates an action potential from nodal
cell
Cardiac muscle cells
fire action potentials and contract
◦ Signal moves from atria to ventricles
How is heartbeat initiated?
Nodal cells within the SA node
◦ Spontaneously depolarize and generate action potential
◦ These cells do not contract themselves
