Exam 2 Cardiovascular Flashcards
Location of heart
Mediastinum
Mid thorax, between lungs
Pericardium and it’s layers
•a serous membrane
The two layers are as following
•Visceral: lines the organs
•parietal: lines the cavity
Pericarditis
Inflammation in pericardium
Chronic pericarditis
Increases pericarditis over time
(Gets worse and worse)
Treatment is removing excess fluid
Layers of the heart
•Epicardium
•myocardium
(makes up muscle of heart walks)
•endocardium
•Myocarditis (inflammation of myocardium) •Endocarditis (Inflammation of endocardium)
Myocarditis and Endocarditis
Inflammation of myocardium
and inflammation of endocardium
Four major chambers of the heart
Upper •left atrium •Right atrium Lower •left ventricle • right ventricle
Arteries take blood…
Veins take blood….
Away from the heart
Back to the heart
Needed by body’s cells to make atp
Oxygen
Bifurcation
When one vessel splits into two vessels
Right atrium receives blood from…
- superior and inferior vena cava
* the coronary sinus
The right ventricle…
Receives blood from the right atrium
Sends blood to the lungs
Left atrium
Receives blood from the pulmonary veins
Left ventricle
- Receives blood from left atrium
- sends blood all over the body
- thicker than the right ventricle
Right and left Antrioventricular valves
- Tricuspid on right
- Bicuspid (Mitral) on left
* prevents back flow
Heart valves
Valves open and close in response to pressure changes as the heart contracts and relaxes
Right and left semilunar valves
- pulmonary valves
- aortic valves
* prevents back flow from the arteries into the ventricles
Base
Top of heart
Apex
Bottom of heart
Heart Disorders
Mitral valve prolapse
Heart murmurs
Valvular stenosis
Pulmonary capillaries
Blood loses CO2 and gains O2
Systematic capillaries
Blood loses O2 and gains CO2
Coronary arteries
Branches arise from the ascending aorta
Blood flow delivers oxygenated blood and nutrients to the myocardium
Coronary veins
Branches converge at the lm coronary sinus
Removes carbon dioxide and wastes from the myocardium
Left coronary artery
Artery on left and right of heart
- circumflex artery- left atrium, left ventricle
- anterior interventrucular artery- interventricular septum
Right coronary artery
Marginal artery - right lateral heart walls
Posterior interventricular artery-R&L posterior ventricular walls
Cardiac veins
•return deoxygenated blood from myocardium
- great cardiac vein
- middle cardiac vein
- small cardiac vein
•empty kitchen not the Coronary Sinus
(Bag on back of heart)
Angina pectoris
•Chest pain
I
•insufficient blood flow/
Blockage of coronary artery
Infarct
Myocardial infarction- Heart attack
Death of Ischemic Cells
Cardiac Muscle
•Intercalated discs
(Gap junctions- electrically coupled)
(Desmosomes- prevent separation)
- Striated,
- branched cell
- 1-3 nuclei, many mitochondria
Intercalated discs
(Gap junctions- electrically coupled)
Desmosomes- prevent separation
Autorhythmic fibers
- self excitable
* autorhythmic
Cardiac muscle cells
Repeatedly generate action potentials
…..
SA node
Sinoatrial
“Natural pacemaker of the heart”
- impulses in right atrium 75 times per minute
- initiate action potentials the most frequently
AV node
Atrioventricular
- receives impulses
- Contains autorhythmic fibers
- ab node comes pacemaker at slower rate (50 bpm)
Signals from nervous system and hormones
modifies the heart rate and forces contraction
do not set the fundamental rhythm
Arrhythmias
Irregular heart rhythms
Fibrillation
Rapid irregular contractions
Heart block
-av node defect
- beat slower than atria
- implant pacemaker
Membrane potential
Measured by mV
Roughly -90 millivolts
Electrocardiogram (EKG)
measured in mV
Deflection waves (P wave- depolarization of atria) (QRS wave- depolarization of ventricles) (AV node) (Atrial repolarization obscured) (T wave- repolarization of ventricles)
Measuring voltage over time
Depolarization
Sodium flows into cell
Potassium flows out
Facilitated by Sodium
Causes muscle contraction
Repolarization
Opening of potassium channels
Facilitated by Potassium
Plateau
Maintained depolarization
Due to calcium
Facilitated by Calcium
Systole
Contraction
Diastole
Relaxation
Cardiac cycle Events
•electrical events
(Depolarization and repolarization)
- pressure changes
- volume changes
- mechanical events
- heart sounds
Mechanical events
….
Atrial contraction / Atrial systole
Contraction
Forces blood into ventricles
Isovolumetric contraction
.
Ventricular ejection
.
Stethoscope
Device allowing us to listen to heartbeat
Murmurs
Unusual heart sounds good
When blood goes somewhere it isn’t supposed to
Lub (S1)
First sound, longer, ab valves closing
Dup (s2)
Second sound, shorter, semilunar valves closing
Cardiac output (CO)
Volume of blood ejected from the ventricles into the aorta / pulmonary trunk every single minute
(Ml or L)
Stroke volume (SV)
Amount of blood pumped out of the ventricle every beat
(70ml/beat)
- 60% of blood chamber
- preload, contractility, and afterload
End diastolic volume
Relaxed). (EDV
Amount of blood in ventricle during diastole
End systolic volume
ESV
Amount of blood remaining in ventricle after systole
Preload
Amount of stretch put on ventricles
Cardiac muscles stretch just before contraction
Stretching muscle fibers
Increases force of contraction
Venous return
Blood going to heart
Connects two sides of heart
Most important factor in stroke volume
Contractility
Increase in contractility
Results in ejection or more blood from heart
Increases SV
Positive inotropic agents
Increase contractility
Sympathetic nervous system
Ca2+ (calcium)
Epinephrine
Negative inotropic agents
Decrease contractility
Calcium channel blockers
Afterload
Pressure ventricles must
overcome to eject blood
Increases ESV
Increased pressure
Amount of blood pressure found in aorta / pulmonary trunk
Hypertension
High blood pressure
Reduces ability of ventricle to eject blood
Autonomic nervous system
Sympathetic and Parasympathetic nerves
Sympathetic nerves
stimulate increased heart rate during stress
Parasympathetic nerves
Slow and steady heart rate after demand is over
Hormones that increase heart rate
Epinephrine
Thyroxine
Tachycardia
High Heart Rate >100 bpm
Bradycardia
Low heart Rate
<60 bpm
Heart rate
Faster in females
Fastest in fetus
Heat increases
Exercise decreased HR
Decreases with age
End diastolic volume
Stretches the heart
Increased preload
Positive inotropic agents
Increased sympathetic, catecholamines, or thyroid hormones in the blood
Increased calcium
Increase force of contraction of all levels of stretch
Decreased steroid blood pressure during diastole
Semilunar valves open sooner when blood pressure in aorta
pulmonary artery is lower
Increased stroke volume
Hypocalcemia
Low calcium blood levels
Depress heart activity
Hypercalcemia
High calcium blood levels
Increase heart activity
Hypernatremia
High sodium blood levels
Blocks calcium and contraction
Hyperkalemia
High potassium levels (k+)
Depolarization
Regular aerobic exercise
increase cardiac output
•decrease triglycerides
•
•
•
Transplant
Need donor with similar antigens
Intra-aortic balloon pump
Helps failing hearts
Heart ventricular assist devices
AIDS in pumping of ventricles
Coronary artery disease
Obstructed lumen
Atherosclerotic plaque
Congestive heart failure
Inadequate for tissue needs
Progressive Disease
High blood pressure
Coronary atherosclerosis (clogged vessels)
Myocardial infarction
Can result in pulmonary or systemic edema
Heart defects in babies
Coarctation of the aorta
Increase workload
Septal defects
Patient ductus arteriosus
Systemic blood with oxygenated pulmonary blood
Tetralogy of fallout
Multiple defects in babies
Hypertrophied
Enlarged
Atherosclerosis
Changes in walls of great arteries
lipid deposits
An increase stoke volume would cause…
An increase of cardiac output (CO)
Co= SV • HR
This part of the conduction system causes ventricular myocardial cells to contract…
Purkinje Fibers
P wave
Atrial contraction
Tunica interna
Tunica intima
Innermost layer of blood vessels
Tunica media
Middle layer of blood vessel
Has smooth muscle and elastic fibers
Tunica externa
Outermost layer of blood vessels
Arteries
Take blood away from the heart to the tissues
Walls of arteries are elastic
Absorbs pressure created by ventricles of the heart
Smooth muscle in the tunica media
Regulates blood flow
Capillary beds
Smallest substance exchange
Vessels connect arterioles and venules
Single layer of endothelium
Basement membrane
Exchange of nutrients
10-100/ bed
Veins
Return blood to heart
Brings blood back in
Arterioles
Smallest arteries
feed blood into capillary beds
Thin
Construct and dilate to control flow of blood into tissues
Venules
Drain capillary beds, empty into vein
Muscular arteries
Distributing arteries
Smooth muscle
fewer elastic tissue
Most of the body arteries
Distributes blood
Elastic arteries
Conducting arteries
Aorta and major branches
More elastic fibers
Less smooth muscle
Withstands great pressure
Vascular shunt
Connects arterioles and venules
precapillary sphincter
Smooth muscle fibers
Surrounding capillary
Regulate blood flow
Metarteriole
Feeds capillary bed
Postcapillary Venule
drains capillary bed
Continuous Capillaries
Intercellular clefts (allows passage of fluids through vessels)
Small solutes
Skin and muscles
Fenestrated capillaries
Found in intestines, endocrine glands, kidneys
Has Oval pores with delicate membrane
Sinusoidal capillaries
Found in liver, bone barrow, lymphoid tissue
Usually fenestrated
Veins
Formed from venules
Thinner tunica interna and tunica media
Thicker tunica externa
Low pressure
Elastic tissue; less smooth muscle
Contain valves
Blood Reservior: 65%
Found in veins
Venous sinuses
Coronary sinus
Varicose veins
Overworked valves give way
Becomes twisted
Obesity and pregnancy exert pressure on lower vessels
———-
Arteries anastomoses
.joints- movement may hinder flow
Present in brain, heart, abdominal organs
Venous anastomoses
More abundant
Vascular anastomoses
Provides alternative route for blood flow
Arterial anastomoses
Venous anastomoses
Blood reservoirs
Largest portion of blood;
In Systemic veins and venules
Systemic veins and venules (blood reservoirs) 64%
Capillary exchange
Gas exchange
Diffusion- simple diffusion;
substances such as oxygen, carbon dioxide, glucose, amino acids
Transcytosis- large, lipid-insoluble molecules (Like insulin).
Bulk flow- passive process; higher pressure to lower pressure
Filtration in reabsorption
Filtration- from blood capillaries into interstitial fluid;
•blood hydrostatic pressure and interstitial fluid osmotic pressure promotes filtration
Reabsorption-
•interstitial fluid hydrostatic pressure and blood colloid osmotic pressure promotes reabsorption
Venous blood return
Steady pressure
- respiratory pump-
- muscular pump-
Maintaining blood pressure
- Short term
- long term
Systemic blood pressure
BP of vessels- force exerted on vessel wall by blood (mm Hg)
- resistance to flow - pressure gradient keeps blood moving from high to low
Blood pressure
Systolic and Diastolic blood pressure
Higher the BP the higher the blood flow
Aorta-highest pressure
Venacava- lowest pressure
Determined by CO, blood volume, resistance,
Arterial blood pressure
Systolic pressure- 120 mm Hg
Diastolic pressure- 70-80 mm Hg; ventricles relax
Capillary blood pressure- enters at 40 mm Hg; exits at 20 mm Hg
Monitoring arterial blood pressure
Pulse pressure= Systolic- diastolic
-indicates elasticity of arteries
Mean Arterial Pressure (MAP)= diastolic + (pulse pressure/3)
-average pressure; propels blood to tissues
Measuring blood pressure
Listen for Korotkoff sounds
Sphygmomanometer- BP cuff
First sound- indicates systolic pressure
Diastolic pressure 70-80 mm Hg
Pulse
Alternating expansion and recoiling of elastic arteries
Changes occur during activity, posture changes, and emotional pressure
Maintaining blood pressure
Regulated by cardiac output, peripheral resistance, and blood volume
Short term regulation: neural and hormonal
Long term: renal
Peripheral resistance- amount of friction the blood encounters in the blood vessels
Total Peripheral Resistance (TPR)
Factors of resistance
Opposition to blood flow is due to friction
Higher resistance leads to lower flow
- blood viscosity- thickness of fluid; plasma proteins
- vessel length- usually constant; obesity-409 miles/2.2lb of fat
- vessel diameter- vasoconstriction
Vessel diameter
Decrease diameter increase resistance
Vasoconstriction- can change frequently
Vessel length
.
Blood viscosity
.
Short term bp controls
•Neural control-
Vasomoter center- changes in diameter
Vasomotor tone- construction
Baroreceptors- mechanoreceptors- become stretched/ pressure sensitive
Etc.etc…
•Hormonal control-
Primary hypertension
Factors:
Diet
Obesity
Age
Stress
Smoked
Secondary hypertension
Excessive renin secretion
Pharmaceutical hypertension treatment
Ace inhibitors
Diuretics
Beta blockers (beta 1 receptor)
Vasodilators
Calcium channel blockers
(All decrease blood volume)
Shock
Hypovolemic
Responses to shock
Renin-angiotensin-aldosterone system
Secretion of antidiuretic hormone
Release of local Vasodilators
Responses to hypovolemic shock
(Low volume shock)
Baroreceptors in carotid sinus and arch of aorta
Symptoms of shock
Tachycardia
Weak, rapid pulse
Hypotension
Altered mental status
Thirst
Decreased urine output
Special circulatory routes
Coronary circulation
Hepatic portal circulation
Aging in the cv system
Loss of compliance of aorta
Increased systolic blood pressure
Decline in max heart rate
Loss of cardiac muscular strength
Filtration
Promoted by blood hydrostatic pressure and Interstitial fluid osmotic pressure
Reabsorption
Promoted by Interstitial fluid
hydrostatic pressure and blood colloid osmotic pressure
Cardiac output
Venous return (SV)
Neural and hormonal control (HR)
Enhanced CO increases MAP
Peripheral resistance
Amount of friction the blood encounters in the blood vessels
Blood volume
Regulated by the kidneys
Control mechanisms of BP
Short term: neural and hormonal
Long term: renal
Blood viscosity
Thickness of a fluid
Increased viscosity (more resistance)
Usually constant
Ratio of rbcs to plasma and plasma proteins
Vessel length
The longer the vessel the more resistance
Usually constant
Obesity- 400miles/2.2lb of fat
Vessel diameter
Decrease diameter increase resistance
Vasoconstriction (can change frequently)
BP controls
Vasomotor center
Baroreceptors
Chemoreceptors
Higher brain centers
Vasomotor center
Oversees changes in diameter
Vasomotor tone- construction of arterioles
Baroreceptors
Carotid sinus reflex- protects blood supply to brain
Aortic reflex- maintains BP or systemic circuit
Inhibits vasomotor center causing arterioles & veins to vasodilate
Heart Rate and contraction force reduced
Chemoreceptors
Respond to change in: oxygen, carbon dioxide
Located in aortic arch
Increase CO and Vasoconstriction
Return of blood to heart & lungs
Higher brain centers
Hypothalamus
-mediated fight or flight response
-mediates blood flow during exercise or body temp changes
Cerebral cortex can modify sympathetic system
Vasoconstrictors
Hormonal Controls
- Adrenal medulla hormones
- NE and epinephrine vasoconstriction - Angiotensin ||
- stimulates release of aldosterone and ADH
- vasoconstriction up - ADH
- vasoconstriction up
Vasodilators Hormonal Controls
- ) Ateual natriuretic peptide (ANP)
- hormone produced by atria
- vasoconstriction down
OTHER CHEMICALS
- ) Inflammatory chemicals
- histamine
- vasoconstriction down (redness) - )Alcohol
- ADH release
- Vasoconstriction down (flushed appearance)
Renal regulation
Direct renal mechanism
Kidneys alter BP through blood volume
If BP is high, or BV high fluid filters out of the blood faster, produce more urine
If BP is low, or BV is low, kidney has time to return water to blood, less urine produced.
Renin-angiotensin mechanism
Drop in blood pressure
Drop in fluid volume
Angiotensin ||
Activation is caused by Renin
Angiotensin || causes
- release of aldosterone
- release of ADH
- stimulates thirst center
- vasoconstrictor
Decreased bp and bv
Leads to either
1.) endocrine mechanism
A. ADH
2.)Neural mechanism
A.Baroreceptors, chemoreceptors stimulated
B.general sympathetic activation
C. Cardiovascular centers stimulated
Autoregulation
The ability of a tissue to automatically adjust its own blood flow
Orthodontic Hypotension
Temporary low BP
Seen in elderly due to aged SNS
Reduced blood flow to brain
Chronic hypotension
Low blood viscosity
Hypertension
High BP
Normal during fever, physical exertion, and emotional stress
Chronic hypertension
Progressive disease
Major cause of heart failure, renal failure, and stroke
Heart works harder against greater resistance, myocardium enlarges,
Causes small tears in blood vessel walls
Homeostatic imbalances
Normal:
- less than 120 systolic
- less than 80 diatomic
Prehypertension:
- 120-139 systolic
- 80-89 diastolic
Stage 1 hypertension:
- 140-159 systolic
- 90-99 diastolic
Stage 2 hypertension:
- 160+ systolic
- 100+ diastolic
Primary hypertension
90% of hypertensive population
No underlying cause
Factors:
- diet
- obesity
- age
- stress
- smoking
Secondary hypertension
10% of hypertension population
Causes:
- excessive renin secretion
- arteriosclerosis
Treating hypertension
Loose weight
Limit alcohol consumption
Exercise
Reduce intake of sodium
don’t smoke
Manage stress
Hypertension medication
Diuretics
ACE inhibitors
Beta blocks
Vasodilators
Calcium channel blockers
SV x HR =CO
Cardiac output