Post on 27-Dec-2015
Cardiovascular DiseaseChapter 42
Epidemiology
#1 killer in 2005 – 864,480 deaths due to CVD
CVD – CardioVascular Disease
Includes: CHD (CAD) – Coronary Artery Disease (652,000) Cerebrovascular Disease – Stroke (144,000) Congestive Heart Failure
Arterial Disease = #1 killerWhat do arteries do?
-- Carry blood away from heart (oxygenated blood)
Why is oxygenated blood important?
-- Oxygen allows respiration to take place
Arterial Disease = #1 killerPage 2
What do coronary arteries do?
-- Supply cardiac muscle with oxygenated blood
How does coronary arterial disease = organism death?
-- IF the heart cannot do respiration, muscle stops.
-- IF cardiac muscle stops, then no oxygenated blood for the rest of the body
The Heart gets its oxygenated blood supply from the coronary arteries
Vascular Anatomy
Explain how Cerebrovascular Disease (Stroke) would develop?
Closed Circulatory SystemBlood is contained within vessels and pumped
around the body
Annelids, cephalopods, and all vertebrates
Arteries – Blood AWAY from the heart Contain significant amount of smooth muscle
Arterioles – smaller branches of arteries
Capillaries – microscopic vessels 1 cell thickness
Veins – carry blood back TO the heart Valves prevent backflow
Closed Circulatory System
Notes on Circulatory Cycle
Capillaries are for gas exchange
Arteries Capillaries Veins
Cardiac Cycle Always Atrium Ventricle
Atria – receive blood from body or lungs Ventricles – receive blood from atria, pump to
body or lungs
Right Atrium right ventricle lungs Lungs Left Atrium Left Ventricle Body From Body Veins Right Atrium
Cardiac Anatomyhttp://www.pbs.org/wnet/heart/tour/index.html
Cardiac CycleConsists of a systole and diastole
Systole – contraction phase
Diastole – Relaxation phase
Heart Rate – rate of contractions per minute
Stroke volume – amount of blood pumped by the left ventricle during the systole
Cardiac ValvesAtrioventricular valves – valve between atria &
ventricles Prevent backflow of blood into atria
Semilunar valves – Exit valves for ventricles Prevent backflow of blood into ventricles
AV valves close during Ventricular systole Usually OPEN
Semilunar valves close during Ventricular diastole Usually CLOSED
Valve Pathologies
Stenosis – valves are too narrow Does not allow blood to pass Increased chamber pressure
Regurgitation – incompetent valve Allows blood to backwash back into previous chamber
End result is excess pressure
Excess pressure wears down cardiac muscle
If uncorrected, Congestive heart failure will occur
Aortic valve stenosis is most dangerous
Electrical Signal TransmissionSinoatrial (SA) node – Pacemaker of the heart
Located in the upper wall of the right atrium Sets the rate of cardiac muscle cell contraction
AV node – Delays signals from the SA node Located in the lower wall of right atrium Allows atria to completely empty before ventricles contract
Artificial Pacemaker
Cardiac (Heart) RateAffected by
Sympathetic nerves – accelerate heart rate Parasympathetic nerves – decelerate heart rate
Body Temperature Increase Body temp 1°C 10 beats per minute Fever increase in pulse rate Exercise Rate increase
Hormones Epinephrine Increases heart rate
Questions
1. Once blood leaves the heart, in what order does it go through capillaries, arteries, arterioles, venules, and veins?
2. What is the path of blood in the heart?
3. Explain how heart disease develops?
4. If a patient has a 90% coronary blockage, what treatment is indicated? (Name at least 2)
5. Briefly explain atherosclerosis
Questions (Page 2)
6. Describe the cardiac cycle?
7. Name one of the 2 cardiac valve types
8. Name one of the 2 cardiac valve diseases
9. What is the SA node? (its nickname)
10. Name 3 things that affect heart rate.
Systemic Vascular Pressure
Blood pressure Typically taken at upper arm cuff Wrist monitors are not used for diagnostic
purposes
2 Types of blood pressure are taken Systolic
Remember from cardiac cycle? Vascular pressure when heart has contracted
Diastolic Remember from cardiac cycle? Vascular pressure when heart is relaxed
In a typical reading,-- 1st number is systolic (always larger)-- 2nd number is diastolic (always smaller)-- Extremely subjective measurement
What regulates or determines
blood pressure?Short- term
Smooth muscle contractions in arterioles Response to hormonal signals or physical exertion
Skeletal muscles contractions help to propel Valves in veins prevent backflow
Stress
Long-term Rennin-angiotensin II-aldosterone system Vascular constriction - Hypertension
Lymphatic SystemReturns lost fluid & proteins to the blood
In the form of lymph
Along lymph vessels are lymph nodes Filter lymph Part of immune system
attack viruses and bacteria here Uses White Blood Cells (WBC)
Blood
Notes on BloodPlasma
Mostly Water Ions, electrolytes, & plasma proteins Transports nutrients, gases, wastes, & hormones Oh yeah, and it carries Blood Cells
Cellular Constituents Red Blood Cells (RBC or erythrocytes)
Transports oxygen by hemoglobin White Blood Cells (WBC)
Part of immune system Platelets
Cellular fragments responsible for blood clotting
Red Blood Cells
Biconcave discs Increased surface area enhances O2 transport 250 million molecules of hemoglobin in each RBC Each hemoglobin = up to 4 O2 molecules
Lack nuclei (more room for hemoglobin)
Lack Mitochondria (so oxygen carried is NOT consumed)
Where do blood cells come from?
Stem cells in the red marrow of flat bones
Clotting
Comparative Circulatory Anatomy