Heart Flashcards
(24 cards)
The outer “sac” that protects and surrounds the heart. It has two main parts
Pericardium
Pericardium – The outer “sac” that protects and surrounds the heart. It has two main parts:
Fibrous pericardium
Serous pericardium
The tough outermost layer.
Like a strong bag that holds the heart in place and protects it.
Doesn’t stretch much – prevents the heart from overfilling.
Fibrous pericardium
A double-layered slippery membrane inside the fibrous pericardium.
It’s like a balloon wrapped around the heart
Serous pericardium
Serous pericardium has 2 layers
Parietal Layer: Lines the inside of the fibrous pericardium.
Visceral Layer (also called epicardium): Sticks directly onto the heart surface.
Between the parietal and visceral layers is the ___________ filled with a small amount of fluid to reduce friction as the heart beats.
Pericardial cavity
outer heart layer (same as visceral layer).
Epicardium
Between the parietal and visceral layers is the ___________, filled with a small amount of fluid to reduce friction as the heart beats.
Pericardial cavity
muscle layer that does the pumping.
Myocardium
Blood flow from heart to the body
Body
→ Superior & Inferior Vena Cava
→ Right Atrium
→ Tricuspid Valve
→ Right Ventricle
→ Pulmonary Valve
→ Pulmonary Arteries
→ Lungs
→ Pulmonary Veins
→ Left Atrium
→ Mitral (Bicuspid) Valve
→ Left Ventricle
→ Aortic Valve
→ Aorta
→ Body
smooth inner lining of heart
Endocardium
Before birth, babies have an opening between the right and left atria of the heart called the ________
It helps bypass the lungs since a fetus gets oxygen from the placenta, not the lungs. Normally, this opening closes shortly after birth when the baby starts breathing air.
Foramen ovale
Location: Between the right atrium and right ventricle
Function: Allows blood to flow from the right atrium to the right ventricle
Prevents backflow into the atrium when the ventricle contracts
Tricuspid valve
Location: Between the right ventricle and the pulmonary artery
Function: Opens to let deoxygenated blood flow from the right ventricle into the lungs
Closes to prevent blood from flowing back into the heart
Pulmonary valve
Location: Between the left atrium and left ventricle
Function: Lets oxygen-rich blood flow from the left atrium to the left ventricle
Closes to prevent backflow into the atrium
Mitral valve ( also called bicuspid valve)
Location: Between the left ventricle and the aorta
Function: Opens to let oxygen-rich blood flow from the heart into the body
Closes to keep blood from flowing back into the heart
Aortic valve
Deoxygenated blood ( body to lungs)
Blood from the body enters the:
Right atrium
→ passes through the tricuspid valve
→ into the right ventricle
→ pumps through the pulmonary valve
→ into the pulmonary artery
→ goes to the lungs to pick up oxygen
Oxygenated blood from the lungs
Oxygenated Blood (Lungs → Body)
Blood from the lungs returns to the:
Left atrium
→ passes through the mitral (bicuspid) valve
→ into the left ventricle
→ pumps through the aortic valve
→ into the aorta
→ then out to the body
Right atrium
The right atrium is the top right chamber of the heart.
It receives deoxygenated blood from three places:
Superior vena cava (from the upper body)
Inferior vena cava (from the lower body)
Coronary sinus (from the heart muscle itself)
Sinus venarum: The smooth part of the right atrium, where the veins empty into.
Atrium proper: The rough part of the right atrium, which contains the pectinate muscles that help with contraction.
Other internal features:
The fossa ovalis is a small dent, a leftover from fetal circulation.
The crista terminalis is a ridge that separates the sinus venarum from the atrium proper.
When the right atrium contracts, it sends blood through the tricuspid valve into the right ventricle.
The ________________is the wall of tissue that separates the right atrium and left atrium of the heart. Its main function is to prevent the mixing of oxygen-rich blood from the left atrium with oxygen-poor blood from the right atrium.
Interatrial septum
The ____________ is an important structure in fetal circulation. It’s a hole in the interatrial septum that allows blood to flow directly from the right atrium to the left atrium, bypassing the non-functioning fetal lungs.
Foreman ovale
Known as the pacemaker of the heart. It initiates electrical impulses that set the heart rate and cause the atria to contract.
SA Node (sinoatrial node)
A remnant of the foramen ovale from fetal life. It has no function after birth, but it’s a landmark that shows where the right and left atria were once connected.
Fossa ovalis
These are muscular ridges that help increase the force of contraction of the right atrium without increasing heart mass significantly.
Pectinate muscles
