Cadiovascular Physio & Anatomy (struc. func) Flashcards
OVERVIEW
Pulmonary vs Systemic Circuit
1. Pulmonary- Right Side of Heart (wife always RIGHT, talk more, needs to be prioritized so always first thus to lungs)
Pumps blood thru the lungs -> blood picks up O2 -> drops off CO2
- Systemic- Left Side of Heart
Pumps blood thru the body’s tissues, supplies O2 and nutrients, and removes CO2
CARDIOVASCULAR SYSTEM
The cardiovascular system is formed by the ? & ?
- Primary function of cardiovascular system: ? *
The bloodstream is a ? system:
* Distributes ? & nutrients to tissues
* Removes ? & other wastes from metabolically active cells & delivers them to the lungs, kidneys, or liver, where they are excreted
Major role to maintain ?
CARDIOVASCULAR SYSTEM
The cardiovascular system is formed by the heart & blood vessels
Primary function of cardiovascular system: TRANSPORT!
The bloodstream is a transportation system:
* Distributes O2 & nutrients to tissues
* Removes CO2 & other wastes from metabolically active cells & delivers them to the lungs, kidneys, or liver, where they are excreted
Major role to maintain homeostasis
HEMODYNAMICS
Describes the principles that control ? flow in the cardiovascular system
Based on basic principles of ? applied to ? to and from the heart, and within the blood vessels:
* Flow
* ?
* Resistance
* ?
Depends greatly on the different ? (diameter, elasticity) of the different blood vessels
Blood vessels:
1. Closed ? system
2. Active participation in ? of blood flow to organs
HEMODYNAMICS
Describes the principles that control blood flow in the cardiovascular system
Based on basic principles of physics applied to blood flow to and from the heart, and within the blood vessels:
* Flow
* Pressure
* Resistance
* Capacitance
Depends greatly on the different characteristics (diameter, elasticity) of the different blood vessels
Blood vessels:
1. Closed passive system
2. Active participation in regulation of blood flow to organs
Resistance
is a force that ? the flow of a fluid. In blood vessels, most of the resistance is due to vessel ?.
? (or compliance)
ability to increase the volume of blood it holds without a large increase in BLOOD PRESSURE.
High capacitance → high blood ? and low ? (i.e., veins)
Resistance
is a force that opposes the flow of a fluid. In blood vessels, most of the resistance is due to vessel diameter.
CAPACITANCE (or compliance)
ability to increase the volume of blood it holds without a large increase in BLOOD PRESSURE.
High capacitance → high blood volume and low pressure (i.e., veins)
lower vesssel diameter -> higher resistance -> lower blood flow
(graph: higher pressure in artery and low volume; vein has higher volume even as the pressure increases - vein goes into heart)
Aorta (and artery)
Arteries: aorta is largest artery; deliver ** ? ** blood to the organs; thick or thin?-walled with lots of elastic tissue, smooth muscle and connective tissue; under ** ? **
Arterioles: ? branches of arteries; extensive ? muscle; highest or lowest? resistance to blood flow; highly innervated and can be contracted or relaxed in response to ? nerve stimulation or vasoactive substances
Capillaries: thin or thick?-walled with single layer of ? cells surrounded by basal lamina; sites of exchange of ?, gases, ? and ? between blood and tissues (lungs: blood and alveolar gas) can be selectively perfused with blood
Venules and veins: also thin-walled, contain endothelial cell layer and some elastic tissue, smooth muscle and connective tissue; ↓elastic tissue = higher or lower capacity? (explains why artery have thick diameter so lower the elastic tissue higher the capacity) ; veins contain largest percentage of blood in cardiovascular system; increased or decreased blood volume under low pressure?
Aorta (and artery)
Arteries: aorta is largest artery; deliver ** OXYGENATED ** blood to the organs; thick-walled with lots of elastic tissue (so small lumen), smooth muscle and connective tissue; under ** HIGHEST PRESSURE **
Arterioles: smallest branches of arteries; extensive smooth muscle; highest resistance to blood flow; highly innervated and can be contracted or relaxed in response to sympathetic nerve stimulation or vasoactive substances
Capillaries: thin-walled with a single layer of endothelial cells surrounded by basal lamina; sites of exchange of nutrients, gases, water and solutes between blood and tissues (lungs: blood and alveolar gas) can be selectively perfused with blood (single cell wall as see in pic)
Venules and veins: also thin-walled (so large lumen), contain endothelial cell layer and some elastic tissue, smooth muscle and connective tissue; ↓elastic tissue = higher capacity (ig elastic tissue are present more in the ones with v high BP such as in thick walled ones) ; veins contain largest percentage of blood in cardiovascular system; increased blood volume under low pressure
BLOOD VESSELS
Identify:
Area and blood volume
Arteries vs capillaries vs
veins
% of blood volume contained in each type of vessel
The graph shows the ones with lower pressure have high area such as capillaries and veins whereas the volume of blood in arteries, aorta and arterioles - have high pressure and so they have low area (lots of capillaries spread every where -> to bring gases and nutrients to tiny little cells)
CARDIAC CELLS - 3 Different Types
- WORKING MYOCARDIAL CELLS (CARDIOMYOCYTES/ MYOCARDIUM)
* Striated muscle specialized for ? & ? conduction
* Make up the ? & the ?
* Must be able to ?/lengthen, be ? & stretch - PACEMAKER CELLS (? CELLS)
* Cells that exhibit automatic rhythmical electrical discharge
(? action ?)
* Found in ? node, ? node, Purkinge Fibers
o Spontaneously generate electrical impulses (AP) and pass them along o Receive and respond to signals from the ? - CONDUCTING ?
* Carry the ? ? throughout the heart
* Found in the conducting system of the heart
- Receive and respond to signals from the brain
CARDIAC CELLS - 3 Different Types
- WORKING MYOCARDIAL CELLS (CARDIOMYOCYTES/ MYOCARDIUM)
* Striated muscle specialized for contraction & impulse conduction
* Make up the atira & the ventricles
* Must be able to strength/lengthen, be flexible & stretch - PACEMAKER CELLS (AUTORYTHMIC CELLS)
* Cells that exhibit automatic rhythmical electrical discharge
(* cardiac action potential *)
* Found in SA node, AV node, Purkinge Fibers
o Spontaneously generate electrical impulses (AP) and pass them along (contract muscle cells)
o Receive and respond to signals from the brain - CONDUCTING CARDIOMYOCYTES
* Carry the AP throughout the heart
* Found in the conducting system of the heart
- Receive and respond to signals from the brain
(note in the pic that the membrane potential of autorythmic and contractile cells look diff. - contractile one has peaks)
TYPES OF MUSCLE CELLS
Visceral:
- contract slowly or rapidly?
- found: viscera, blood vessels
- control: involuntary
Skeletal (Striated)
- contract slowly or rapidly?
- found: ?, ?, head and ?
- control: voluntary
Cardiac (striated)
- contract slowly or rapidly?
- found: ?
- control: involuntary
TYPES OF MUSCLE CELLS
Visceral:
- contract slowly
- found: viscera, blood vessels
- control: involuntary
Skeletal (Striated)
- contract rapidly?
- found: trunk, extremities, head and neck
- control: voluntary
Cardiac (striated)
- contract rapidly
- found: heart
- control: involuntary
CARDIAC MUSCLE
Similarities that cardiac muscle and skeletal muscle share
- Fibers are ?
- Myofibrils are made up from ?
& ? filaments - Similar ? arrangement
- Contains ? and ?
CARDIAC MUSCLE
Differences between cardiac and skeletal muscle cells
- Cardiac muscle tissue is ONLY found in the ?
- Contraction is involuntary
- cardiac Fibers are shorter or longer? & branched or unbranched?
- Usually uninucleated or multinucleated?
(possibly up to 4 nuclei) - High ? density
- Interconnected by ? disks
Allows the muscle cell to contract in a ? like pattern
(in pic: pink thing is mitochondria)
CARDIAC MUSCLE
Similarities that cardiac muscle and skeletal muscle share
- Fibers are striated
- Myofibrils are made up from actin
& myosin filaments - Similar sarcomere arrangement
- Contains sarcoplasmic reticulum and T-tubules
CARDIAC MUSCLE
Differences between cardiac and skeletal muscle cells
- Cardiac muscle tissue is ONLY found in the heart
- Contraction is involuntary
- cardiac Fibers are shorter & branched or unbranched?
- Usually uninucleated
(possibly up to 4 nuclei) - High mitochondria density
- Interconnected by intercalated disks
Allows the muscle cell to contract in a wave like pattern
CARDIAC MUSCLE is a functional syncytium
- Greek: Syn = together + Kytos = cell
- Do not ? into a single multinucleated fiber during embryonic development like ? muscle does (morphological syncytium)
- Cardiac myocytes branch during ? and ? to other myocytes
- Fibers remain ? as distinct cells with their sarcolemma but are also ? connected to each other through intercalated disks (desmosomes + GAP junctions)
CARDIAC MUSCLE is a functional syncytium
- Greek: Syn = together + Kytos = cell
- Do not fuse into a single multinucleated fiber during embryonic development like skeletal muscle does (morphological syncytium)
- Cardiac myocytes branch during development and bind to other myocytes
- Fibers remain separated as distinct cells with their sarcolemma but are also electrically connected to each other through intercalated disks (desmosomes + GAP junctions)
MYOCARDIUM
The INTERCALATED DISK is a dark, dense cross-band found at the end of each myocardial cell
- Part of the ? (plasma membrane)
- Contains 2 important ?
? JUNCTIONS
Forms ?
Allow ? ? of ions
Action potential travel ? from one cell to the next
?
Provide ? strength (web like thing in pic)
Anchors the end of the cardiac muscle fibers together
The INTERCALATED DISK is a dark, dense cross- band found at the end of each myocardial cell
- Part of the sarcolemma (plasma membrane)
- Contains 2 important cell-cell junctions
GAP JUNCTIONS Forms channels
Allow rapid diffusion of ions
Action potential travel easily from one cell to the next
DESMOSOMES
Provide mechanical strength
Anchors the end of the cardiac muscle fibers together
CARDIAC MUSCLE ACTION POTENTIALS
The normal/natural/primary ? of the heart is the sinoatrial (SA) node or sinus node
Located in the left or right? atrium
Starts the ? that is conducted
throughout the heart
Slower or faster? pacemakers are located in the AV node and Bundle of His-Purkinje system
o May capture/adjust the heart’s rhythm when:
SA node fires faster than normal
SA node fires slower than normal
Impulses generated in the SA node are ?
The normal/natural/primary PACEMAKER of the heart is the sinoatrial (SA) node or sinus node
Located in the right atrium
Starts the AP that is conducted
throughout the heart
Slower pacemakers are located in the AV node and Bundle of His-Purkinje system
o May capture/adjust the heart’s rhythm when:
SA node fires faster than normal
SA node fires slower than normal
Impulses generated in the SA node are blocked
AP goes to atrium part of the heart and then it contracts
eletrical impulse goes to the AV node and then goes to bundle of HIS AND GOES TO SPREADS INTO PURKINJE FIBERS (that’s how it reaches ventricular muscles fibers and contracts into ventricle)
CONDUCTION SYSTEM OF THE HEART
SINUS NODE (SA node) is a small strip of specialized ? muscle cells (pacemaker cells)
Located in the left or right? atrium
* Immediately below and slightly lateral to the opening of the cranial (superior) vena cava
The SA node fibers have almost no ? muscle filaments
Connect directly with ? muscle fibers, any action potential can spread ? into the atrial muscle wall
Action potential moves from SA node → atrial walls (Bachmann’s bundle, internodal pathways) then → to the ? node
CONDUCTION SYSTEM OF THE HEART
SINUS NODE (SA node) is a small strip of specialized cardiac muscle cells (pacemaker cells)
Located in the right atrium
* Immediately below and slightly lateral to the opening of the cranial (superior) vena cava
The SA node fibers have almost no contractile muscle filaments
Connect directly with atrial muscle fibers, any action potential can spread immediately into the atrial muscle wall
Action potential moves from SA node → atrial walls (Bachmann’s bundle, internodal pathways) then → to the AV node
CONDUCTION SYSTEM OF THE HEART
The AV-NODE ? impulse conduction from the atria to the ?
Located in the posterior wall of the right atrium immediately behind the ? valve which disallows opposing blood flow back into atrium
The delayed transmission allows time for the atria to empty their blood into the ? before ? contraction begins
AV node fibers have fewer ? junctions (faster or slower? ion movement between cells)
CONDUCTION SYSTEM OF THE HEART
The AV-NODE delays impulse conduction from the atria to the ventricles
Located in the posterior wall of the right atrium immediately behind the tricuspid valve which disallows opposing blood flow back into atrium
The delayed transmission allows time for the atria to empty their blood into the ventricles before ventricular contraction begins
AV node fibers have fewer GAP junctions (slower ion movement between cells thus conduction of electrical impulse is slower here )
AV-Bundle aka bundle of His passes downward in the ? septum and divides into left and right bundle branches
The branches lie beneath the * ? * (as seen in pic in ANS)
The AV-BUNDLE (Bundle of His) allows only forward or backward ? conduction from the atria to the ventricles
Atrial muscle is separated from ventricular muscle by a continuous ? skeleton:
which acts as an insulator to prevent ? of cardiac impulse between atrial and ? muscle through abnormal routes
AV-Bundle aka bundle of His passes downward in the ventricular septum and divides into left and right bundle branches
The branches lie beneath the * ENDOCARDIUM * (as seen in pic in ANS)
The AV-BUNDLE (Bundle of His) allows only forward conduction from the atria to the ventricles
Atrial muscle is separated from ventricular muscle by a continuous fibrous skeleton:
which acts as an insulator to prevent passage of cardiac impulses between atrial and ventricular muscles through abnormal routes
CONDUCTION SYSTEM OF THE HEART
Special PURKINJE FIBERS lead the AV-node impulse through the ? (Bundle of His) into the ?
The transmission velocity in the VENTRICULAR ? SYSTEM is fast or slow?
Cause ? transmission of the cardiac impulse throughout the entire remainder of the ? muscle
Each branch spreads downward toward the apex (highest point) of the ventricle, progressively dividing into smaller ?
- These branches in turn course ? around each ventricular chamber and back toward the ? of the heart
- The ends of the Purkinje fibers penetrate the ? and become continuous with the ?
CONDUCTION SYSTEM OF THE HEART
Special PURKINJE FIBERS lead the AV-node impulse through the AV bundle (Bundle of His) into the ventricles
The transmission velocity in the VENTRICULAR PURKINJE SYSTEM is fast
Cause instantaneous transmission of the cardiac impulse throughout the entire remainder of the ventricular muscle
Each branch spreads downward toward the apex (highest point) of the ventricle, progressively dividing into smaller branches
- These branches in turn course sideways around each ventricular chamber and back toward the base of the heart
- The ends of the Purkinje fibers penetrate the muscle and become continuous with the cardiac fibers
Base: oriented dorsocranially
Apex: points ventrocaudally and to the left
Left view of the heart AKA Auricular surface (both auricles are prominently observed from this view)
1, Left auricle; 2, pulmonary trunk; 3, right ventricle; 4, left ventricle; 5, Right auricle (PIC in ANS)
HOWEVER, in right somethings can’t be seen, the main one among them is the LEFT AURICLE!
Right view of the heart AKA Atrial surface (the right atrium is the prominent structure observed from this view)
1, Right atrium; 2, caudal vena cava; 3, aorta; 4, cranial vena cava
TWO completely separate circuits!
Pulmonary circulation
Systemic circulation
- Gas exchange in the lungs occurs via the * ? circuit *
- Gas exchange to all other body cells occurs via the * ? circuit *
*The right side of the heart (blue) receives ? blood from ? circulation and sends blood into ? circulation (which takes it into lungs to get oxygen)
- The left side of the heart receives ? blood from ? circulation and sends blood into systemic circulation (to allow gas exchange to all other body cells)
Pulmonary circulation
Systemic circulation
- Gas exchange in the lungs occurs via the * pulmonary circuit *
- Gas exchange to all other body cells occurs via the * systemic circuit *
*The right side of the heart (blue) receives deoxygenated blood from systemic circulation and sends blood into pulmonary circulation (which takes it into lungs to get oxygen)
- The left side of the heart receives oxygenated blood from pulmonary circulation and sends blood into systemic circulation (to allow gas exchange to all other body cells)
- The right atrium receives blood from the ? and ? vena cava (and from venous return from heart muscle itself)
- Right Atrium pumps blood into the Right Ventricle through the Right ? (Atrioventricular) Valve
- (“Tricuspid” .. Sometimes this name is a misnomer)
(The RIGHT AV valve stops backflow of blood from the Right ventricle into the Right atrium during ?) - Right Ventricle contracts to send blood to the lungs through the ? trunk & ** ? ? **
The ? ? valve prevents backflow of blood from pulmonary trunk into the right ventricle during ? - OXYGENATION IN THE LUNGS
- Oxygenated blood travels back to the heart through the pulmonary ? into the Left ?
- Left Atrium pumps blood into the Left Ventricle through the Left ? or (“ ? ”)
(The LEFT AV valve stops backflow of blood from the Left ventricle to the Left atrium during ?) - Left Ventricle contracts to send blood through the ? ? valve and into the ** ? ** out to the rest of the body (and to supply the heart muscle itself)
The ? ? valve prevents backflow of blood from aorta into the Left ventricle during ?
Pulmonary semilunar valve
- located between ? and the pulmonary ? (trunk)
Aortic semilunar valve
- located between the ? and the ?
Left AV Valve
- located between left atria and Left ventricle
Right AV Valve
- located between right atria and right ventricle
Systole = heart contraction
Diastole = heart rest (D = die -> rest)
- The right atrium receives blood from the cranial and caudal vena cava (and from venous return from heart muscle itself)
- Right Atrium pumps blood into the Right Ventricle through the Right AV (Atrioventricular) Valve
- (“Tricuspid” .. Sometimes this name is a misnomer)
(The RIGHT AV valve stops backflow of blood from the Right ventricle into the Right atrium during systole) - Right Ventricle contracts to send blood to the lungs through the pulmonary trunk & ** pulmonary arteries **
The pulmonary semilunar valve prevents backflow of blood from pulmonary trunk into the right ventricle during diastole - OXYGENATION IN THE LUNGS
- Oxygenated blood travels back to the heart through the * pulmonary veins * into the Left atrium
- Left Atrium pumps blood into the Left Ventricle through the Left AV or (“ mitral ”)
(The LEFT AV valve stops backflow of blood from the Left ventricle to the Left atrium during ?) - Left Ventricle contracts to send blood through the Aortic semilunar valve and into the ** AORTA ** out to the REST of the body (and to supply the heart muscle itself)
The Aortic semilunar valve prevents the backflow of blood from the aorta into the Left ventricle during diastole
Pulmonary semilunar valve
- located between right ventricle and the pulmonary arteries (trunk)
Aortic semilunar valve
- located between the left ventricle and the aorta
Left AV Valve
- located between left atria and Left ventricle
Right AV Valve
- located between right atria and right ventricle
The first tissue supplied by the heart is the heart itself!
pic demonstrates that during systole blood comes from left ventricle
Heart Auscultation
Listening for the Points of Maximum Intensity (PMI): Associated with each valve
Left Side:
“P” = pulmonary valve sound (3rd IC space)
“A” = aortic valve sound (4th IC space)
“M” = “mitral”/left AV sound (5th IC space)
Right Side:
“T” = “Tricuspid”/Right AV sound (4th IC space)
note: IC = intercoastal space: they are present between the ribs
2 NORMAL sounds of the heart are caused by blood stopping at ?
S1 = closure of ? and ?
S2 = closure of ? and ?
Blood Flow from one structure to another (through valves) is normally SILENT or loud? in normal dogs and cats.
2 NORMAL sounds of the heart are caused by blood stopping at ?
S1 = closure of left and right atrioventricular valves (LUB sound - sound is beginning of systole i.e. contraction)
S2 = closure of aortic and pulmonary semilunar valves (DUB sound)
Blood Flow from one structure to another (through valves) is normally SILENT in normal dogs and cats.
