Cardiovascular system anatomy Flashcards
The circulatory system functions as
The circulatory system functions as the transport system
Delivers oxygen, nutrients, hormones and regulatory chemicals to all cells
Transports carbon dioxide and other products of metabolism from the cells to the lungs, liver and kidneys
Distributes heat from inside the body to the extremities and vice versa
Circulatory system consists of
Heart, vessels, blood
Arteries
Carry blood away from heart
Vein
Carry blood towards the heart
Lymphatic vessels
Vessels that carry tissue fluid (or lymph) to large veins are called lymphatic vessels or lymphatics
Location of the heart in a canine
Extends from 3rd to 6th intercostal space
Long axis of heart forms a 45o angle with the sternum but varies between breeds
Deep chested breeds have a larger angle; barrel chested have a lower angle
Location of the heart of a cat
Extends from 3rd/4th to 6th/7th intercostal space
Forms a more acute angle so has increased sternal contact compared to dogs
Location of the heart of a equine or ruminnets
The heart is placed asymmetrically mostly on the left side
Located from the 2nd to the 5th intercostal space
Apex is at the level of the point of the elbow
Bovine has os cordis (small bone) within the heart to support the valves
Layers of the heart
Pericardium, myocardium, endocardium
The fibrous pericardium is the
is the thin fibrous-serous covering of the heart
The fibrous pericardium is outermost, extends to the diaphragm and covers major vessels at the heart base
Pericardium is the
Thin fibrous serous covering of the heart
Serous pericardium of the heart
lines the fibrous pericardium
This is the parietal layer
The visceral layer covers the heart itself
The fluid filled space between these layers is called the pericardial space or cavity
Myocardium is the
Is the muscle layer of the heart and is sandwiched between the visceral pericardium and the endocardium
Endocardium is the
thin membrane covering of the internal surface of the heart
Atrium is
which receives blood from large veins
A ventricle pumps blood from…
the heart via large arteries
R AV
Right tricuspid valve
L AV
Bicuspid or mitral valve
Atrioventricular valve connects
Connecting each atrium and ventricle is a large valve called the atrioventricular valve or AV valve
Leaflets do what
Heart valves have leaflets (cusps) which prevent the backflow of blood
Right atrium is and does
Thin walled
Receives systemic (means all part of body except lungs) veins
Blind ended portion known as the right auricle
Right ventricle is and does
More muscular than the atrium but a thinner wall than the left ventricle.
Does not reach apex of heart
Receives outflow from right atrium by way of the right AV (tricuspid) valve
Has papillary muscles (protrusions of cardiac muscle) which anchor the AV valve through chordae tendinea
Pulmonary trunk and semilunar valve is and does
The pulmonary trunk drains the right ventricle
Connects right ventricle to the pulmonary arteries
The pulmonary semilunar (three crescent moon shaped cusps) valve sits at the base (beginning) of the pulmonary trunk
Left atrium is and does
Thin walled chamber
Receives pulmonary veins
Left auricle – similar to right atrium
Left ventricle is and does
Thick walled and forms the apex of the heart
Receives outflow from left atrium by way of left AV (mitral) valve
Left AV valve is supported by chordae tendinea and papillary muscle
Aortic semilunar valve is where
Separates left ventricle from aorta
Aorta disturbs what from where
Distributes blood from Left ventricle to the body
Interventricular septum is where
Partition b/w ventricles
Interatrial septum is where
Partition b/w atria
Valves are and do
All the heart valves occur at approximately the same level in the heart.
Anchored in the connective tissue that separates the atria from the ventricles.
Function as one way valves
Av valves do what
- One border of the cusp (valve leaflet) is attached to the inner wall of the ventricle at the junction of atrium and ventricle
- The free borders are loosely attached to the wall of the ventricle by chordae tendinae which are fibrous cords resembling the strings of a parachute
- The chordae tendinae prevent the valves from flipping into the atria when the ventricles contract
- Instead, the AV valve closes as the blood in the ventricle pushes the valve leaflets together
- Blood must leave by the aorta or pulmonary trunk
The two semilunar valves are and do
Aortic and pulmonary
Prevent blood from returning into the ventricles when the ventricles relax
Arteries come from and turn into
Arteries have thicker, more muscular, walls than veins
Arteries start as large vessels which carry blood away from the heart and divide into smaller and smaller branches
Smaller arteries are called arterioles , which feed the capillaries
Capillaries are
thin walled tubes which are only wide enough for one red blood cell