Download NEW!! PRINT ME!! Cardiovascular and Respiratory Notes File

The
Cardiovascular
System
Page 343
Heart facts:
-
-
It pumps 7,000 liters of blood each day and
contracts 2.5 billion times in a lifetime.
Hollow, cone shape that rests under the
diaphragm
14 cm long/9 cm wide (2nd-5th rib)
Pericardium covers the heart
Pericardial cavity is the space with fluid that
allows the heart to move friction free
Walls of the heart: epicardium (reduces friction),
myocardium (muscle), and endocardium
(contains blood vessels)
Heart actions:
-
-
Cardiac cycle (heart beat): atrial walls
contract/ventricular walls relax…vice versa
Heart sounds (lub dup): produced by
opening/closing of valves
-
-
Lub (ventricle contracts): AV closes…tri/bi
Dup (ventricle relaxes): PA closes…pul/aort
Blood pressure: Atrial contraction (systole)
Atrial relaxation (diastole)
Murmur – blood leaks thru the valves
Audio for heart sounds
Cardiac conduction system: areas that
initiate and distribute impulses thru
myocardium
1. Sinoatrial node (SA) – mass of tissue in
right atrium that initiates impulses
1.
2.
70-80 times a minute
Also called pacemaker…controls heart’s
rhythmic contractions
2. Atrioventricular node (AV) – located in
septum which allows atria to empty and
ventricles to fill
Electrocardiogram
(ECG or EKG)
 Electrocardiogram
(ECG): recording of the
electrical changes that occur in the myocardium
during the cardiac cycle.
Factors that affect heart rate:
1.
2.
3.
acetylcholine: hr increases
Temperature: hr increases w/ hot
temps
Ions: hr increases w/ high levels of
K…decreases w/ high levels of Ca
Daphnia Experiment
Cardiac Output
Cardiac Output Video
CO = SV x HR What do each of these abbreviations
stand for?
What determines the SV?
*
*
*
How to take blood pressure?
BLOOD VESSELS
Artery
arteriole
(away from heart)
capillary
venule
*site of nutrient,
gas, and waste exchange
vein
(back to heart)
 Closed
system of blood circulation
 Pulmonary circuit: sends deoxygenated blood to
lungs
 Systemic circuit: sends oxygenated blood and
nutrients to all body cells and removes wastes

The heart pumps 7,000 liters of blood through the body each
day, contracting some 2.5 billion times in an average lifetime.
Paths of Circulation
Pulmonary circuit: carries blood from heart to lungs
and back again (pulmonary artery/vein)
Systemic circuit: carries
blood from heart to body
and back again
(superior/inferior vena
cava/aorta)
Cut an artery, blood squirts out;
cut a vein, blood flows out
Contraction of the human heart
creates enough pressure to
squirt blood 30 ft.
Vasoconstriction: smooth muscles
contract/reduces diameter – FASTER FLOW
Vasodilation: smooth muscles relax/increases
diameter – SLOWER FLOW
Exercise increases oxygen delivery!
In order to increase heart size by 40%, you
must exercise 3 times a week, 30 minutes at
70-85% heart rate.
Events of Respiration:
1.
2.
3.
Gas exchange between the blood
and the air in the lungs (diffusion)
Gas transport in blood ‘tween the
lungs and body cells
Gas exchange ‘tween the blood and
the cells (cellular respiration)
o Lungs
•
•
•
•
•
Soft, spongy, cone-shaped
Suspended in thoracic cavity by
bronchus and blood vessels
Visceral pleura; parietal pleura; pleural
cavity
Right lung – larger, 3 lobes
Left lung - 2 lobes
Trachea
Bronchioles
Bronchii
Bronchioles
Alveoli ducts
Alveoli sacs
Alveoli
How does cellular respiration
occur?
-
The trachea (windpipe) traps particles and filters
air as it travels to the bronchial tree
The bronchial tree divides into smaller branches
that lead to the alveoli within each lung
The tree distributes the air to the alveoli which
are lined with capillary networks
The alveoli tissue is so thin that oxygen diffuses
into the blood and the carbon dioxide diffuses
into the alveoli
o
•
•
•
Bronchial Tree
Branched airways leading from trachea to alveoli in
lungs
Bronchii
bronchioles
alveolar ducts
alveolar
sacs
alveoli
Alveoli: small sacs where gases diffuse in and out of
blood in capillaries
Alveoli are air sacs that are lined with simple
squamous epithelium tissue, which allow for the
pressure differences of gases (O2 and CO2) to
diffuse through the membranes