Download Q1-3 Circulatory System

Circulatory System Ch34 Q1-3
I.
Circulatory System
A. General Facts
1. Most cells closed off from environment
2. Circulatory system provides transport service
3. Moves blood and lymph
4. Cardiovascular system – blood, heart and blood vessels
5. Lymphatic system – lymph, nodes and lymph vessels
6. Circulatory system – cardiovascular and lymphatic systems
combined
B. Heart
1. Major pump/ fist-sized
2. Location – thoracic (chest) cavity
3. Pericardium – sac-like membrane/ surrounds heart and secretes
lubricating fluid
4. Septum – divides heart – 2 sides
a. Rt – pumps blood – lungs
b. Left – pumps blood to body
5. 4 chambers
a. 2 upper atrium
b. 2 lower ventricles
6. Valves
a. AV valves – atrioventricular/ separate atriums from ventricles
b. Tricuspid – separate rt. Atrium and rt. Ventricle
c. Mitral (bicuspid) – separate lft atrium and lft ventricle
d. Semilunar valves – separate ventricles and lg vessels
e. Pulmonary valve – B/T rt ventricle and lungs
f. Aortic valve – B/T lft ventricle and aorta
7. Heart Circulation (Must memorize)
a. superior vena cava (vein, decreased O2, increased CO2)
b. Rt atrium
c. Tricuspid valve
d. Rt. Ventricle – pulmonary valve
e. Pulmonary artery (decreased O2, increased CO2)
f. Lungs
g. Pulmonary veins
h. Lft atrium
i. Mitral (bicuspid) valve
j. Lft ventricle
k. Aortic valve
l. Aorta (artery, increased O2, decreased CO2)
8. Control heart beat
a. heart muscle cells contract in waves/ stimulate neighboring
cells
b. Sinoatrial node (SA node)
Group specialized heart muscle cells in rt. Atrium
Initiate own electrical impulse and contract (pacemaker)
c. Atrioventricular node (AV node)
Located septrum B/T atria
Relay impulse to ventricles
d. Ventricles beat fraction of a second after atria
e. 2 phases of heart beat
Systole – Ventricles contract/ close AV valves and open SL
valves
Diastole – ventricles relax/ back press. Blood closes SL valves/
Opens AV valves
**lubb dub sound – closing valves
***heart murmur – defective valve not closing completely
C. Blood Vessels
1. Circulatory system – closed system (blood stays in heart and
vessels)
2. Arteries – lead away from heart/ smooth muscles allow
stretching/ *pulse – stretching arteries
3. Blood Pressure – force of blood against artery walls
a. Systolic Pressure – upper number (120mmHg) Pressure when
ventricles contract
b. Diastolic Pressure – ventricles relaxed (70mmHg)
c. Hypertension – high blood pressure
Caused from too much salt, “stiff” arteries, often unknown
Can cause strokes, kidney failure and congestive heart failure
D. Capillaries and Veins
1. Capillaries –
a. One cell thick
b. Service virtually every cell in body
c. Allow gas exchange (diffusion)
2. Veins –
a. Return used blood to heart
b. Less muscular than arteries
c. Under low blood pressure
d. Valves – stop back flow of blood
e. Skeletal muscles – help pump blood back to heart
E. Pattern of Circulation
1. Pulmonary Circulation
a. Rt. Ventricle sends to lungs
b.
c.
d.
e.
Reaches capillaries
CO2 and O2 diffuse lung cells to capillaries
Oxygenated blood enters pulmonary veins
Pulmonary veins dump into lft atrium
2. Systemic Circulation
a. Lft ventricle pumps to aorta and other systems
3. Coronary circulation – feeds heart/ cut off = heart attack
*atherosclerosis – build up of plaque/ blocks vessels
4. Renal circulation – ¼ of blood/ routed to kidneys to remove
waste products from blood
5. Hepatic Circulation
a. picks up nutrients from sm. Intestine
b. delivers to liver for storage