Cardiology anatomy Flashcards
Function of chordae tendineae
During ventricular contraction the pressure in both ventricles increase and close the valves, the chordae tendinae tense to keep valves closed and prevent prolapse into atria
Why is myocardium on left ventricle thicker than right ventricle
left ventricle is responsible for pumping blood to all areas of body so need more muscular power and right is only to lungs
Why are coronary arteries openings at base of aorta
When valve opens openings are covered so high pressure blood doesn’t go into them.
Once pressure of blood leaving decreases aortic valve close and lower pressure backflow trickles into the coronary arteries
Act of valves in heart closing gives beating sound name sounds and what valve
Lub-dub
lub-tricuspid and mitral valve
dub- aortic and pulmonary valves
Function of fluid within pericardial cavity
lubrication for the unimpaired movement of the heart
If too much fluid in pericardial cavity what could occur
compression of heart(acute)- compress atria first as less muscular walls
pericardial effusion(fluid build up)- lead to cardiac tamponade(impairment of heart)
if builds up slow than pericardium can stretch to accommodate sum of it
2 subdivides of arteries
elastic and muscular
Benefit of elastic arteries
accommodate high pulsatile forces
Benefit of muscular arteries
allows vasocontriction and vasodilation
Name 2 arteries receptors
alpha and beta
Function of alpha receptors(arteries)
Contraction
Function of Beta receptors(arteries)
relaxation
Where can arterial pulses be felt-structures
Wherever a artery is close to surface or over bone and/or firm structures
Function of valves in veins
Prevent backflow of bloodP
Potential benefit of veins lacking a strong muscular wall
Allow greater capacitance-hold more blood without increase blood pressure
What is it called where areas in the body are supplied or drained by multiple vessels
Collateral circulation
Why is collateral circulation important
If a blood vessel is damaged or blocked it allows blood supply to be maintained to the particular area
3 vascular shunts exits in fetal circulation
Foramen ovale
Ductus arterious
ductus venosus
What are the 3 vascular shunts exists in fetal circulation allow
Allow blood to mostly bypass the liver and non-functioning lungs.
Where and what does foramen ovale do
Between the atria
blood bypasses the pulmonary circulation
closes shortly after birth
Where and what does ductus arteriosus do
Links the distal arch of aorta with pulmonary trunk
blood bypasses pulmonary circulation
becomes ligamentum arteriosum after birth
Where and what does ductus venous do
Shunts umbilical blood from the primitive liver to the IVC to ensure enough oxygen reaches the developing brain
Involutes by or just after birth
What is fibrous pericardium
tough fibrous sac surrounding serous pericardium, heart and pericardial cavity
What is serous pericardium
serous membrane forming a closed cavity (pericardial cavity)and it covers the heart (viceral)and lines the inner surface of firbous pericardial sac(parietal)
What is pericardial cavity
Potential space between visceral and parietal layers of serous pericardium
approx 1ml of yellow fluid
acts as lubricant to allow heart freedom of movemnt during contraction
Role of chordae Tendineae
Connect valve leaflets to papillary muscles
Function of chorda tendineae
Prevent valves from inverting into atria during ventricular contraction
Role of papillary muscles
Anchor chordae tendineae to ventricular walls
Function of papillary muscles
Contract to pull the chordae tendineae tight during ventricular contraction preventing valve prolapse
Role of interventricular septum
Divides right and left ventricles
Function of Interventricular septum
Prevents mixing of oxygenated and deoxygenated blood between two ventricles and provides structural support of heart
Role of Trabeculae carneae
Irregular muscular ridges found inside the ventricles
Function of Trabeculae carneae
Help with contraction of ventricles by reducing suction and increasing efficiency of blood flow
Role of pectinate muscles
Ridges of muscle found in atria especially right atrium
Function of pectinate muscles
increase surface area of atrial walls and assist in contraction of atria enhancing blood flow
Role of Moderator band(trabeculae septomarginalis)
A band of muscle found in the right ventricle
Function of moderator band(trabeculae septomarginalis)
Provides a pathway for electrical conduction, ensuring coordinated contraction of the right ventricle and helping to stabilize the structure of the heart
Role of Mitral valve
located between left atrium and left ventricle
Function of mitral valve
regulated blood flow from left atrium to left ventricle and prevents backflow during ventricular contraction
Role of tricuspid valve
positioned between the right atrium and right ventricle
function of tricuspid valve
control blood flow from right atrium to right ventricle and prevents backflow during ventricular contraction
Role of aortic valve
Located between left ventricle and aorta
Function of aortic valve
Allows oxygenated blood to flow from left ventricle into the aorta and prevents backflow
Role of pulmonary valve
positioned between right ventricle and pulmonary artery
Function of pulmonary valve
Ensures blood flow from right ventricle into pulmonary artery and prevents backflow
Role of myocardium
thick middle layer of heart muscle
Function of myocardium
responsible for contraction of the heart and generate force necessary to pump blood throughout body
Role of endocardium
Thin inner lining of heart chambers
Function of endocardium
Provides smooth surface for blood flow within heart and plays role in regulation for heart contraction
Role of epicardium
Outer layer of heart wall and also known as visceral pericadium
Function of epicardium
provides a protection layer and contains blood vessels, nerves and lymphatics to supply heart, and acts as lubricative surface between heart and surrounding surfaces
Role of Fossa ovalis
Remnant of foetal foramen ovale
Function of Fossa ovalis
Visible as depression in right atrium and in foetal development allowed blood to bypass lungs then sealed after birth
Describe ascending aorta
Inital part of aorta orginated from left ventricle at base of heart
Describe aortic sinuses
pockets between aortic valve cusps and vessel wall
rigth and left coronary arteries arise from cranial and left sinuses respectively
Describe aortic arch
continuation of ascending aorta and sends branches to head neck and thoracic limb
Describe brachiocephalic trunk
first branch of the aortic arch and gives rise to carotid artery and right subclavian artery
Describe left subclavian artery
Supply neck, thoracic limb and cranial portion of thoracic wall and branches as axillary artery in thoracic limb
Describe decendign aorta
part of aorta caudal to arotic arch and divided into thoracic aorta and abdominal aorta by diaphragm
Describe thoracic aorta
division of the decending aorta in the thoracic cavity and supply toracic wall via intercostal arteries
Branches of abdominal aorta
insert image(dissect notes)
What connects pericardium to the diaphragm
Phrenic pericardiac ligament
What connects pericardium to floor of the thorax
Sternopericardiac ligament
Structures located at base of heart
Great vessels-Aorta, Vena cava
Apex of heart formed by wall of what chamber
left ventricle
What structure lies within coronary and interventricular sulci
Coronary vessels fat
Heart is located in thorax at what number level of ribs
3-6
Purpose of intervenous tubercle/ridge
diverts the inflowing blood from cranial and caudal vena cava toward right orifice/valve
where are B1 receptors (heart)(sympathetic)
Primarily in SAN,AVN and cardiac myocytes
what do activation of B1 receptors(heart) (sympathetic)do
Increase heart rate
increase force of contraction
Increase conduction velocity
Where are a1 receptors(vessels)(sympathetic)
smooth muscle of arterioles in the skin,kidneys and GI tract
What do activation of a1 receptors(vessels)(sympathetic) do
Activation causes vasocontriction in these areas, to redirect blood flow from these non essential organs
Where are B2 receptors(vessels)(sympathetic)
Smooth muscle of arterioles in skeletal muscles and coronary arteries
What do activation of B2 receptors(vessels)(sympathetic)
Activation causes vasodilation increasing blood flow to these areas
What receptors relevant to CVS
beta receptors
What receptors are stimulatory
a1 and B1
What receptors are inhibitory
a2 and B2
Where is the heart Muscarinic M2 receptors(parasympathetic)
SAN, AVN, atrial myocardium
Effect of heart Muscarinic M2 recpetors(parasympathetic)
Vagus nerve releases acetylcholine
activates m2
which opens acetylcholine-activated potassium channel to slow firing of Sinus node so decrease heart rate
During fight or flight the sympathetic overpowers and vagus nerve uses acetylcholine to provide counterbalance from overstress
