Lecture 13 Heart Flashcards
What is the function of the heart?
Pump of the circulatory system
Pumps blood to carry nutrients to the cells
What is resting rate?
Resting rate: 72-75 beats/min
Cardiac Output
Cardiac out put is how much blood is coming out of the heart per min, which is 5 liters
We have about 5 liters of blood in our body
*Cardiac output: 5L of blood/min
Chambers of the heart
4 chambers 2 diff types
Atria: is thin walled because blood is only pumped next door
Atria are the upper chambers Left and Right
Ventricles have thick walls because they pump blood throughout the whole body or out to the lungs
Valves of the heart
Atrioventricular valves separate ventricles from atria
Two types :
1 Right AV valve: Tricuspid, blood starts here , then goes to bicuspid (Try before Buy)
2. Left AV valve : bicuspid
prevent back flow of blood
Semilunar valves: separate the ventricles from an artery
1. Pulmonary Valve
2. Aortic Semilunar valve
Always named after the artery they are coming off
Vessels of the Heart
Arteries: carry blood away from heart, high pressure (Aorta. Pulmonary trunk,
Veins: bring blood back to the heart
Veins: Pulmonary veins branch out from pulmonary trunk stick out from sides of heart. Superior Vena Cava, drains blood from head neck and arms superior portion of body, Inferior Vena Cava, drains blood from lower portion of of body to heart
What are great Vessels?
Arteries and veins directly entering or leaving the heart
SVC, IVC Pulomonary trunk, Aorta
Types of Circulation
- Pulmonary: goes to lungs
2. Systemic: body system
Pulmonary Ciruculation:
Generally right side
Sends blood to lungs then returns to left side of heart
Function: is to remove CO2 and collect oxygen to return to heart
Systemic Circulation
Left Side
Left atrium to left ventricle out the aorta,
Sends blood out of the body returns to right side of the heart
Function:Oxygen rich blood that is picking up CO2 on the way
Position of the heart
Slightly left of midline, deep to sternum, in mediastinum
sternum protects the heart in the mediastinum
Borders of the heart
Right border: right atrium and right ventricles
Left border: left atrium and left ventricle
Superior border: great vessels and ( Pulmonary trunk, aorta and SVC)
Inferior border: Right ventricle, because heart sits on the right side and the heart sits tilted
Apex of the heart
Inferior conical end
Base of the heart
left atrium
Pericardium
Pericardium is outer lining of the heart
It has 2 parts
1. Fibrous
2. Serous
Fibrous layer
Outer lining portion of the pericardium
Made of Dense CT
Attaches to great vessels and diaphragm
Serous Layer
Inner portion of pericardium
2 layers Parietal and visceral
Parietal Layer
Attaches to fibrous pericardium
Visceral Layer
- Attaches to outer surface of heart
Layers of the heart wall
- Epicardium
- Myocardium
- Endocardium
Epicardium
Visceral layer of serious pericardium (visceral layer is epicardium)
Tissue: simple squamous and areolar CT
Mycardium
Thickest middle layer
Tissue: cardiac muscle
muscle portion
Endocardium
Internal surface of heart
Tissue: endothelium and areolar CT
Made up of endothelium (specific type of simple squamos)
Auricles of the heart
part of the external anatomy of the heart
anterior part of atria, surface structure
Coronary Sulcus
Part of the external anatomy of the heart
separates atria and ventricles
indentation around the heart . Think crown around the heart
Anterior/Posterior Interventricular Sulcus
separates L and R ventricles
anterior and posterior indentation separates left and right ventricles
Fibrous Skeleton
Part of the Internal anatomy of the heart
Dense regular tissue between atria and ventricles
Function of Fibrous Skeleton
Supports and anchorage
Electrical insulation:
Electrically in atria will stay in the atria,
What happens in ventricles stays there, it keeps them separate
Right Atrium
Receives blood from:
IVC and SVC
Coronary sinus: drains heart , small vessel, when blood leaves aorta, small portion will go into the coronary sinus so that the heart gets oxygen rich blood
Features of Right atrium
Interatrial septum: wall dividing 2 atria
- Fossa ovalis: small depression on wall of the interatrial septum
- Pectinate muscles: found on anterior wall
Right AV Valve
Contain 3 flaps why called tricuspid valve
Valve prevents backflow, making it go out pulmonary trunk
Lubb: heart beat makes lubb dub sound, lubb is the closing of the AV valves. When the ventricles contract that is the lubb sound
Right Ventricle
Receives blood from right atria
Interventricular Septum
Part of ventricle features
wall dividing 2 ventricles
Trabeculae Carnae
part of ventricle features
irregular muscular ridges
Papillary Muscles
cone shaped muscles attaching to chordae tendineae
part of ventricle features
Chordae Tendineae
CT attaching to tricuspid valve, prevent prolapsing
chords that attach to valve they are what prevent prolapsing ( backflow, valves from flipping back)
Pulmonary Semilunar valve
3 thin pocket-like cusps
Not as strong and tricuspid and bicuspid valves
Prevent backflow during ventricular relaxation
“Dubb:When the pulmonary semilunar valve is where the dub sounds come in due to it shutting= the relaxation portion of the ventricles
Left Atrium
Receives blood from pulmonary veins (lungs)
has pectinate muscles
Left Av Valve
2 flaps (bicuspid valve)
- Prevents backflow during ventricular contraction
- “Lubb”
Lubb sound made due to ventricular contraction
Left Ventricle
Receives blood from left atrium
Thicker than right ventricle
**Thicker because it pushes blood to the entire body right side only to lungs
Aortic Semilunar Valve
- 3 thin pocket-like cusps
- Prevent backflow during ventricular relaxation
- “Dubb”
- Makes the Dubb sound during ventricular relaxation, prevents back flow as well
Conduction Pathway
Sinoatrial node SA node starts in right atrium send an impulse across both atria, cause to contract to the
AV node toward bottom of the right atrium takes the electrical stimulus to the ventricles av node only way to communicate to the ventricles
Then the stimulus is sent to the AV bundle that is in the interventricular septum
AV bundle splits into R and L bundle branches
Av bundles split into small fibers in the walls of ventricles that allow for electrical stimulation known as Purkinje fibers
Sinoatrial Node (SA Node)
location is the upper right Atrium
it is the start of the conduction system
it spreads the impulse from SA node ( R atrium) to the AV node across to the L atrium
Atrioventricular Node (AV Node )
Location: Lower right atrium
has a 0.1-0.2 delay
Delay is important: once AV node received stimulus it does not just send it off it hold it for .1-.2 seconds to give time for the heart to coordinate the contraction between the atrium and ventricles. The atria will contract first from SA node impulse once the Av node receives the impulse it will old to allow time for the ventricle to contract and the AV node to relax
AV bundle Location?
Interventricular Septum
Right and Left Bundle Branch
AV bundle branch splits into a Right and Left Bundle branch
Location : Interventricular septum
Purkinje Fibers
Location: myocardium of ventricles or ventricle walls
Spreads impulse to ventricles from apex
Atria and ventricle contractions
When atria contract, ventricles relax, when ventricles contract the atria should relax
