Download The Circulatory System

Cardiovascular & Respiratory Systems
A.
B.
C.
D.
5 ounces
11 ounces
About 1 pound
2.5 pounds
B. 11 Ounces on average.
(The average brain weighs 3 pounds or 48 ounces)
Beats per Minute = 60-80
Beats per Day = 100,000
Beats per Year = 35 Million
Beats per Lifetime = 2.5 Billion
*Blood Pumped per minute (Rest) = 5 Liters/ 5 Quarts
Blood Pumped to over 75 Trillion Cells in Body
Through over 60,000 miles of vessels
*Cardiovascular
System
Cardio – pertaining to
Heart
Vascular- = a little
vessel, consisting of cells
joined into tubes for
transporting/circulating
CV system – Body
system transports
nutrients, gases,
hormones, cellular waste
products.
*Major Cardiovascular Functions
w Delivery:. oxygen and nutrients
w Removal: carbon dioxide and waste products
w Transportation: hormones
w Maintenance: body temperature, pH
w Prevention: infection (Helps Immune System function)
Heart is Center of
All Emotions.
Heavy Heart
7th century B.C. city-state of Cyrene. Cyrene traded the rare, now extinct, plant
silphium. It was known as a means for birth control. The seedpod of the
silphium looks exactly like a valentine's heart. Moreover, its use in sex is an
obvious connection to love

Heart


Arteries and arterioles


Carry blood away from the heart
Capillaries


Pumps blood
Exchange of nutrients with tissues
Veins and venules

Carry blood toward the heart
Thump-thump?


Artery - a high-pressure vessel, possess a thick layer of
smooth muscle to help off set the high blood pressures it
must endure, can constrict or dilate (Major Arteries)
Arteriole - a resistance vessel, possess a circular smooth
muscle layer, is the primary site of blood flow regulation

Capillary – site of nutrient transfer (Diffusion)

Venule – a pre-vein, small amount of muscle

Vein – a capacitance vessel, very elastic, capable of
“holding” blood; posses valves to prevent backflow
BLOOD
DISTRIBUTION
AT REST


Rhythmic skeletal muscle
contractions force blood in the
extremities toward the heart
One-way valves in veins prevent
backflow of blood
Respiratory System
VR-RA-RV-Lungs-LA-LV-Aorta-Body
Coronary Arteries-Heart
The Main artery & Largest (elastic). When the left ventricle contracts to force
blood into the aorta, the aorta expands. This stretching gives the potential
energy that will help maintain blood pressure during diastole as during this
time the aorta contracts passively.



The left ventricle receives oxygenated blood
from the left atrium via the bicuspid valve. The
blood is then transported throughout the body.
The thick walls of the left ventricle pumps
blood to the aorta, the systemic arteries, the
capillaries, the veins, and back to the right
atrium.
The left ventricle is also the main function of
stroke volume and cardiac output.
Muscles receive most of the cardiac output during exercise
because the muscles are the ones doing most of the work!



Epicardium – a connective tissue covering of
the heart which contains blood vessels,
lymph vessels, and nerve endings; provides
a lubrication buffer for the heart
Myocardium – the cardiac muscle layer; the
myocardium will be discussed in greater
detail in the next slide
Endocardium – the inner layer of
endothelial cells and more collagen
(connective) tissues
Myocardium—The Cardiac Muscle
w Thickness varies directly with stress placed on chamber
walls.
w Left ventricle is the most powerful of chambers and thus,
the largest.
w With vigorous exercise, the left ventricle size increases.
w The heart has autoconduction, i.e., it beats on its own
without nerve or hormonal control. Due to intercalated
disks—impulses travel quickly in cardiac muscle and
allow it to act as one large muscle fiber; all fibers
contract together.
Fig 9.3


Myocardium is striated muscle tissue, so it
has some similar aspects to skeletal muscle
However, it also has several qualities which
are much different

Differences from skeletal muscle:
 *Only one fiber type, so there are no fiber-type

differences within the myocardium
Cardiac muscle fibers are relatively short. Most
are only a few hundred sarcomeres in length
 *Cardiac muscle is not voluntary muscle

Cardiac muscle fibers are connected by
intercalated disc; creates a functional syncytium

*Records the electrical activity of the heart

P-wave


QRS complex


Atrial depolarization
Ventricular depolarization
T-wave

Ventricular repolarization

Video
Normal Inspiration: Diaphragm contracts (shortens) creating a vacuum in
the chest cavity.
Normal Expiration: Diaphragm relaxes and the chest cavity collapses
forcing air out.
Exercising Inspiration: Diaphragm, intercostal, and abdominal muscles
contract to lift the rib cage and create a greater vacuum in the chest cavity.
Exercising Expiration: All muscle relax and the chest cavity collapses
forcing air out.