Chapter 37: Circulatory
& Respiratory Systems
Section 37.1
Circulation: Structure and Function
 TRANSPORTATION
 Cells need to get nutrients and oxygen and
get rid of wastes
 Consists of heart, blood vessels, and blood
What needs to be transported in the
body?
Transportation in living organisms:
•
•
•
•
Oxygen from the lungs to the cells of the
body
Nitrogenous wastes to the kidneys for
removal
Carbon dioxide waste from cells to the lungs
for removal
Food nutrients from the intestines to cells
for energy
1. _________
Blood is contained in ____________.
vessels
2. The parts of the circulatory system are:
a. __________________
heart
vessels
b. __________________
blood
c. __________________
Heart: parts
 Hollow muscular organ that pumps blood
 Enclosed by a protective layer called the
pericardium
 The thick layer of muscle is called the
myocardium, which contains epithelial and
connective tissue.
 The myocardium contracts to pump
blood!
4 heart chambers
Atria: 2 upper chambers
that receive blood into
the heart. Receiving
chambers (singular =
atrium)
Ventricle: 2 lower chambers
that pump blood out of
the heart. Pumping
chambers. Ventricles have
thick muscle to pump to
the lungs/body
septum
II. The Heart
muscle
A. The heart is made up of ______________.
pericardium which
1. It is enclosed by the __________________
protects it.
2. The walls of the heart are made of a thick layer muscle called the
_________________________,
which
myocardium
is surrounded by layers of epithelial and
connective
___________________
tissue.
Pericardium
 Protective sac of
connective tissue
 Surrounds the heart
 Filled with
fluid
Check…
 Which body system acts in a way similar to a
transportation system?
a. circulatory c. excretory
b. nervous
d. respiratory
 In the walls of the heart, the thick layer of
muscle is called the
a. myocardium. c. connective tissue layer.
b. pericardium. d. epithelial tissue layer.
Circulation
 Septum – layer that divides left and
Myocardium
(heart muscle)
shown in red
right sides of heart
Epicardium
(Outer surface
of myocardium)
 Right side in charge of pumping
blood from heart to lungs
(pulmonary circulation)
 Left side receives blood from lung,
sends it out to rest of body!
(systemic circulation)
 After blood comes back from body,
blood returns to right side and back
to lungs for more O2
Endocardium
(Inner surface of myocardium)
Circulation Video Clip
Heart terminology
 Veins go to the heart
 Arteries go away from the heart
 Capillaries join the two and
bring blood close to cells
 One-way valves in the heart keep
circulation efficient
 Valves = flaps of connective tissue
between atria and ventricles that
open and close to move blood in a
one-way flow
72 times per minute.
B. The heart contracts about ____
70 mL of blood.
1. Each contraction pumps _______
left
right
C. The septum
_______ divides the _______
and _______
heart
sides of the ________.
1. This prevents the mixing of the side that carries
oxygen
blood with _________ and the side without.
D. Chambers of the Heart
atrium
1. The Upper Chamber is the __________.
receive the _________.
blood
a. Atria ________
ventricle
2. The Lower Chamber is called the ___________.
out
a. Ventricles
__________ pump blood ______.
3. The human heart has ___ atria and ___
2
2
ventricles.
heart animations
heart parts
Check…
 Which is the correct direction of blood flow?
a. left ventricle  pulmonary artery  aorta
b. right atrium  right ventricle  pulmonary artery
c. left ventricle  left atrium  aorta
d. right atrium  left atrium  pulmonary artery
 In the heart, the mixing of oxygen-rich and oxygen-poor
blood is prevented by the
a. septum.
c. tricuspid valve.
b. pericardium.
d. mitral valve.
Heartbeat
 2 networks of muscle fibers in heart
 One in atria, one in ventricles
 Pacemaker – group of cardiac muscle cells, also called
“sinoatrial node,” which contract and send an impulse to
the network of muscle fibers
 Blood can be stored in atria until it’s ready to move
 When the network in the atria contracts, blood in atria
flows into ventricles
 When muscles in ventricles contract, blood flows out of
heart!
When blood leaves the _________________ side of the
heart, it is oxygen-poor. When blood leaves the
_________________ side of the heart, it is oxygen-rich.
Blood vessels
 When blood leaves left side, it is full of oxygen
 Aorta = large blood vessel that receives blood after it
leaves left ventricle
 3 types of blood vessels
 Arteries, capillaries, veins
 Arteries:
 Super highways,
large, and muscular
 Carry oxygenated blood
(except pulmonary artery.)
Blood vessels continued
 Capillaries:
 Smallest with walls only one-cell thick
 Bring oxygen and nutrients to tissues and absorb CO2
 “Side streets and alley ways”
 Veins:
 Large and muscular
 contain valves and return blood to heart
Blood Pressure
 Blood pressure = force
of blood on arteries’ walls
 Sphygmomanometer = device
to measure blood pressure
in your arm
 Systolic pressure = force
in arteries when ventricles
contract
 Diastolic pressure =
force felt in arteries when
ventricles relax
Blood
 Body contains about 4-6 liters
 45% consists of cells
 Red blood cells called erythrocytes
which transport oxygen (the protein hemoglobin binds iron
and oxygen)
 White blood cells called leukocytes fight infection
 Platelets are cell fragments that aid in clotting
 55% consists of straw colored fluid called plasma
 90% water
 Contains albumins, globulins, and fibrinogen
Plasma
Platelets
White blood
cells
Red blood cells
Whole Blood
Sample
Sample Placed in
Centrifuge
Blood Sample
That Has Been
Centrifuged
plasma
Red blood
cells
Lymphatic
system
White BC
and
Platelets
Diseases of the Circulatory System
 Heart disease, stroke are
leading causes of death in US
 Main causes: high blood
pressure & atherosclerosis
 Atherosclerosis = condition
in which fatty deposits called
plaque build up inside the
arteries
Consequences of atherosclerosis
 Blocked arteries can cause
part of heart to die from lack
of oxygen
 If enough heart muscle dies,
heart attack occurs
 Blood clots can form, get
stuck in blood vessel leading
to brain
 Stroke occurs
Keeping your Circulatory System
Healthy!
 Exercise to keep your heart
strong
 Eat a low fat/low cholesterol
diet
 Don’t smoke!
 Cardiovascular diseases are
much easier to prevent than
to cure.
Check…
Which of the following is true about blood pressure?
 a. Diastolic pressure is higher than systolic pressure.
 b. It is not affected by atherosclerosis.
 c. It drops a great deal when traveling through
arteries.
 d. It is lower in veins than in arteries.
Which of the following are the smallest of the blood
vessels?
 a. veins
c. capillaries
 b. lymphatic cells
d. arteries
Blood Type Review…
 Which of the following genotypes result in the same
phenotype?
a. IAIA and IAIB
b. IBIB and IBi
c.
d.
IBI and IAIB
IBi and ii
 If a man with blood type A and a woman with blood
type B produce an offspring, what might be the
offspring’s blood type?
a. AB or O
c.
A, B, AB, or O
b. A, B, or O d.
AB only
Respiratory System
 2 kinds of respiration
1. Cellular respiration = breaking down food
molecules in the mitochondria in presence of
oxygen to make ATP
2. Respiration for the organism = gas exchange
(O2 in, CO2 out)
 Function of respiratory system: to bring about
exchange of oxygen and carbon dioxide between the
blood, air and tissues
Respiratory System diagram
Parts of Respiratory System
 Air: flows from the mouth & nose
 pharynx  larynx  trachea
 bronchus tubes
 bronchioles  alveoli
 Pharynx = passage for air/food
 Trachea = windpipe
 Epiglottis = flap of tissue that
covers entrance to trachea when
you swallow
 alveoli = air sacs surrounded by
capillaries
Keep it Clean!
 Cilia and mucus act as
filters along the pathway
 to keep lung tissue healthy,
need to keep air warm,
moist, filtered!
 Nose hairs filter dust
 Mucus moistens air, traps dust/smoke
 Cilia sweep dust, mucus away from lungs
so they can be swallowed or spit out
 animation
Larynx and Gas Exchange
 Larynx, or voice box, has two elastic folds of
tissue (your vocal cords!)
 2 bronchi (singular: bronchus) = passageways
from trachea to lungs
 These tubes subdivide into smaller tubes
(bronchioles)
 They end at alveoli (air sacs), where oxygen
diffuses into capillaries to enter _________,
while _________is picked up to be
_______________________
Breathing
 Movement of air into (inspiration) and out of
(expiration) the lungs
 Mainly controlled by brain!
 Diaphragm = large flat muscle at base of chest
cavity
 Process of breathing is driven by air pressure
 When diaphragm contracts, air comes in
 When diaphragm relaxes, air is exhaled
 animation
Check…
 Air is forced into the lungs by the contraction of the
a. alveoli.
b. bronchioles.
c. diaphragm.
d. heart.
 Which of the following activities is the best analogy
for respiration?
a. exchanging gifts c. receiving a gift
b. giving a gift
d. sitting in a chair
Respiratory Diseases
• Bronchitis: inflammation of bronchi
• Emphysema: loss of elasticity of lung tissue
alveoli can’t expand for gas ex.
tobacco damages the tissue
Nicotine paralyzes cilia in upper respiratory system!
NIDA.gov
• Asthma: narrowing of the bronchi and bronchioles due to
the constriction of muscles
around the airways. Environmental, genetic?
• Cystic fibrosis: recessive, autosomal genetic disease in
which lungs collect mucous and cause multiple infections.
Cystic Fibrosis
Check…
 Chronic bronchitis, emphysema, and lung cancer can
be caused by
a.swollen bronchi.
b. enlarged alveoli.
c. groups of cancer cells.
d. smoking.
 Air is filtered, warmed, and moistened in the
a.nose and mouth.
b.throat.
c.
d.
lungs.
pharynx.