Valves, Fibrous Skeleton, Conducting System Flashcards
Types of Heart Valves?
Atrioventricular(AV) valves (x2)
Semilunar(arterial) valves (x2)
Atrioventricular Valves separate the atria and ventricles
_________ (right side) and _______ (left side) containing _____ and ______ cusps respectively, each slung from a fibrous band or ________
Atrioventricular Valves separate the atria and ventricles
Tricuspid** (right side) and **bicuspid/mitral** (left side) containing **three** and **two** cusps respectively, each slung from a fibrous band or **annulus
The AV Valves free edge are attached to ________ which in turn are attached to __________ (outpouchings of ventricular muscle that help to close valves under high pressure)
The AV Valves free edge are attached to chordae tendineae which in turn are attached to papillary muscles (outpouchings of ventricular muscle that help to close valves under high pressure)
The Mitral (BIcuspid) Valve has _________ of different shapes secured to a fibrous ring at the AV junction (______)
The Mitral (bicuspid) Valve has 2 leaflets (cusps; anterior(A), posterior (P)) of different shapes secured to a fibrous ring at the AV junction (annulus)
posterior leaflet is shallow, aids in its closure
Adequate __________ is critical to valve competency and its depth/length is viewed as an important assessment of valve function
Adequate coaptation zone (seal between the two valves) is critical to valve competency and depth/length of coaptation is viewed as an important assessment of valve function
__________: failure of valve resulting in backflow of blood
Prolapse: failure of valve resulting in backflow of blood
Function of AV Valves when Arterial pressure > Ventricular
Function of AV Valves when Atrial pressure < Ventricular
_________ Valve
- 3 semilunar cusps (left, right, anterior), with free edges that ______ during valve closure
- Thickened __________ on middle free superior edge (thin lateral portion -______)
- Pocket-like _________ wall of pulmonary trunk behind each cusp
Pulmonary Valve
- 3 semilunar cusps (left, right, anterior), with free edges that coapt during valve closure
- Thickened nodule** on middle free superior edge (thin lateral portion -**lunula)
- Pocket-like sinus wall of pulmonary trunk behind each cusp
→ Aids valve closure by filling as ventricle relaxes
_______ Valve
- 3 semilunar cusps (left, right, posterior (non-coronary)), with free edges that _____ during valve closure
- Pocket-like _______ in wall of ascending aorta behind each cusp
- Origin of the ________________ from the left & right aortic sinuses
Aortic Valve
- Similar structure to pulmonary valve
- 3 semilunar cusps (left, right, posterior(non-coronary)), with free edges that coapt during valve closure
- Pocket-like sinus in wall of ascending aorta behind each cusp
- The right & left coronary arteries originate from the left & right aortic sinuses
coronary arteries fill when ________
coronary arteries fill when ventricles relax
Function of Semilunar Valves?
Describe the process when open/closed
A Valve _____ is one that doesn’t open properly
A Valve STENOSIS is one that doesnt open properly => Narrowing
A Valve __________ is one that doesn’t close properly
A Valve INSUFFICIENCY is one that doesn’t close properly
Advantages/Disadvantages of Mechanical Heart Valves?
Advantages:
–Durable materials; can last 30+ yrs
Disadvantages:
–Need for life-long anticoagulation therapy (e.g. Warfarin); predisposes to hemorrhage
–Clicking sound
–Potential for mechanical failure, embolism
Advantages/Disadvantages of Replacmetn Biological Valves?
Advantages:
–Better hemodynamics; less susceptible to thrombus formation; no requirement for anticoagulation therapy
Disadvantages:
–Shorter life-span (~15-20 yrs) in comparison to mechanical valves
–Potential for rejection
–Potential for calcification, particularly in younger patients
What causes the LUB and DUB sounds heard during Auscultation?
Opening of AV valves (S1) → LUB
Opening of Arterial valves (S2) → DUB
Role of the Fibrous Skeleton in the Heart?
- Dense CT rings surround valves; fuse and merge with the interventricular septum
- Support structure for heart valves (annulus fibrosis) changes size during cardiac cycle
- Insertion point for cardiac muscle bundles
- Electrical insulator between atria & ventricles
_____________:
- Specialised cluster of cardiac muscle cells & associated connective tissue
- Pacemakerof heart –initiates & regulates impulses for cardiac contractions
SA Node
- Specialised cluster of cardiac muscle cells & associated connective tissue
- Pacemakerof heart –initiates & regulates impulses for cardiac contractions
_________ control of SA node will accelerate heart rate while __________ control will return/reduce towards basal rate
Sympatheticcontrol of SA node will accelerate heart rate
Parasympathetic control will return/reduce towards basal rate
_____________
- Smaller collection of nodal tissue
- Located in interatrial septum near the opening of the coronary sinus
- Signal generated by SA node reaches AV node by ________________
- AV node distributes signal to ventricles through ___________
AV Node
- Smaller collection of nodal tissue
- Located in interatrial septum near the opening of the coronary sinus
- Signal generated by SA node reaches AV node by myogenic conduction (rapid)
- AV node distributes the signal to ventricles through AV bundle
Autonomic Nerve Supplu to SA Node
Parasympathetic:vagus nerve
- _______ heart rate
- ______ force of contraction
Sympathetic: T1-4 spinal nerves
- _______ heart rate
- ______ force of contraction
Autonomic Nerve Supplu to SA Node
Parasympathetic: vagus nerve
- Decreases heart rate
- Reduces force of contraction
Sympathetic:T1-4 spinal nerves
- Increases heart rate
- Increases force of contraction
Right bundles takes a shortcut to ant. papillary muscle through ________; helps to coordinate timing)
Right bundles takes shortcut to ant. papillary muscle through moderator band (septomarginaltrabecula; helps to coordinate timing)
