1. The Cardiovascular System
Chapter 11
The Cardiovascular System

2. Heart (Cardiac Muscle)
General
continuous, rhythmic beating
delivers: to cells thru blood
oxygen
nutrients
hormones
electrolytes
pump to lungs
exchange CO2 for O2

3. Heart Anatomy of the Heart lies in the mediastinum pericardium
medial cavity of the chest
big as fist 2nd rib and 5th rib
pericardium
sac around heart
film of serous fluid friction free
Pericarditis - inflammation
heart wall
epicardium - visceral pericardium
myocardium - thick cardiac muscle and connective tissue
endocardium
endothelial lining of heart chambers

8. Chambers of the Heart right atrium right ventricle left atrium
recieves blood “deoxygenated”
superior & inferior vena cava
tricuspid valve
right ventricle
pumps blood to lungs
pulmonary artery
semilunar valve “pulmonary”
left atrium
recieves blood “oxygenated”
pulmonary veins bicupsid(mitral) valve
left ventricle
pumps blood to body
aorta
semilunar valve “aortic”

9. Septum Auricles Valves divides chambers (wall)
wrinkled flap like appendages on atria
musculi pectinati
muscle bundles in atria
Valves
prevent backflow
atrioventricular valves
tricupsid valve
mitral valve “bicuspid”
chordae tendinae
white cords anchor flaps of valves attached to papillary muscles
semilunar valves
pulmonary
aortic

10. Cardiac Circulation
coronary arteries - O2 and nutrients
arise from aorta
coronary veins take CO2 & wastes
coronary sinus ---> right atrium

11. Cardiac Function General Conduction 70 beats/min
its own conduction system
contracts independently
Conduction
sinoatrial (SA) node “pacemaker”
in right atrium ---> depolarization
atrical contract
internodal fiber bundles
depolarization node to node
atrioventricular (AV) node
junction of atria & ventricle
ventricular contraction

12. Atrioventricular Bundle
purkinje fibers
rapid impulses
failed pacemakers
slow h.r. – bradycardia < 60 beats/min
rapid h.r. -tachycardia > 100 beats/min
fibrillation
rapid uncoordinated heart beat

13. Cardiac Cycle Heart Sounds initiated by the SA node Cycle
Systole -contraction ventricles
Diastole -relaxed atria fill
Heart Sounds
auscultation
‘lubb dubb’
Lubb AV valves close
Dubb semilunar valves close
murmurs
abnormal heart sound
incompetent valve swishing sound
Stenosed- narrow valves

15. Stroke Volume Regulation
Cardiac Output
stroke volume
volume of blood pumped w/ each beat
cardiac output
4900 ml/min ---> 4.9 l/min
SV x VR ml/ beat x 70 beats/ min
exercise
increase SV increase venous return
cardiac reserve
ability of heart to increase cardiac output
Stroke Volume Regulation
healthy heart increase SV
Starling’s Law of the Heart
more cardiac muscle stretches greater stroke volume

17. Regulation of Heart Rate
autonomic nervous system
parasympathetic innervation
vagus nerve ---> ACH
slows h.r.
sympathetic innervation
speeds h.r. stimulate SA node
norepinephrine
AV cardiac muscle
hormones and ions
epinephrine speeds up h.r.
Ca++ levels down - h.r. down
thyroxine levels up -h.r. up
K + levels drop causes abnormal heart rate

18. temperature, gender, exercise, & age
fetus
heat h.r. goes up
congestive heart failure
hypertension
worn out and weak
age & coronary atherosclerosis

19. Electrocardiogram
three basic features of ECG
atria
P wave- depolarization of atria- atria contract
ventricle
QRS complex depolarization of ventricles
T wave repolarization of ventricles
shapes of the waves and the time intervals

21. Disturbances in Heart Rate & Rhythm
myocardial infarction- heart attack
Ischemia- lack of oxygen
Fibrillation- irregular heart beat
Atherosclerosis- narrowing of arteries
Artherosclerosis- scar tissue Ca build up

22. Systemic & Pulmonary Circulation
Capillaries ----> cells ----> capillaries ---->venuoles ---> veins ---> superior or inferior vena cava ---> right atrium ---> tricuspid valve --> right ventricle ---> pulmonary valve ---> pulmonary artery ---> lungs ---> pulmonary veins ---> left atrium ---> bicuspid valve --> left ventricle ---> aortic valve ---> aorta --->arteries ---> arterioles ----

23. Blood Vessels General closed system principal types of blood vessels
blood in vessels
principal types of blood vessels
arteries
blood away from heart
arterioles
capillaries
exchange materials w/ cells
capillary beds
veins
venuoles
blood toward heart

24. Blood Vessel Wall Major Arteries tunica interna ~ simple squamos
tunica media ~ smooth muscle
tunica adventitia ( externa) ~ connective
Major Arteries
aorta ~ largest artery
head and neck
carotid, brachiocephalic, subclavian
upper limbs and thorax
brachial, radial, ulnar
abdomen
hepatic
pelvis and lower limbs
renal - kidneys

26. Major Veins Capillaries superior vena cava inferior vena cava
head and neck
jugular & subclavian
upper limbs and thorax
brachial & radial
inferior vena cava
abdomen
hepatic and mesentaric
pelvis and lower limbs
renal and femoral
saphenous (LONGEST VEIN)
Capillaries
wall only one layer thick
exchange between blood & tissues
nutrients, oxygen, CO2, & wastes

28. Special Circulation brain hepatic mesenteric Circle of Willis
brain blood barrier
hepatic
digestive organs
liver
mesenteric
intestine

29. Physiology of Circulation
Pulse
expansion and recoiling of artery
carotid, brachial, and radial
Blood Pressure
general
systolic / diastolic
pressure against walls of artery
Gradient auscultatory method
120 mm Hg / 80 mm Hg brachial artery
Measuring Ventricular pressure
Systolic- contraction
Diastolic- relaxation

30. Factors Effecting Blood Pressure
resistance
directly related to cardiac output
vasoconstriction ~ sympathetic
chemicals , temperature, diet
Kidneys- blood volume
autonomic nervous system
Blood viscosity- > resistance
variations in pressure
hypotension
systolic < 100 mm Hg
diet
hypertension
> 140 / 90 sustained
myocardium enlarged

32. Cardiovascular Disease
Developmental
con genital
heart defects
Aging
atherosclerosis ~ narrowing of veins
cholesterol “LDL’s” ~ form plaque
ischemic heart disease ~ lack of oxygen
angina pectoris ~ heart pains
myocardinal infarction ~ heart attack
varicose veins ~ venous valves weaken
thrombophlebitis