Transcript Ch.37 - Jamestown School District

Unit 10 The Human Body
Ch. 37 Circulatory & Respiratory
Systems
Functions of the Circulatory
System
• The human circulatory system consists of
the heart, a series of blood vessels, & the
blood that
flows through
them
The Heart
• The heart is made almost entirely of muscle,
& is a hollow organ about the size of your
clenched fist
• Atria - the upper chambers that receive the
blood
• Ventricles - the lower chambers that pumps
the blood out of the heart
The Heart
• The heart functions as 2 separate pumps
• Pulmonary circulation - pathway on the
right side that pumps oxygen-poor blood
from the heart to the lungs
The Heart
• Systemic circulation pathway on the left side
that carries oxygen-rich
blood from lungs to the
heart, & the rest of the
body
Circulation Through the Heart
• Blood enters the heart through the right &
left atria
• It then flows out from the ventricles to
either the body or the lungs
• Valves - flaps between the atria & the
ventricles, prevent blood from flowing
backwards
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Blood Vessels
• Aorta - large blood vessel, carries oxygenrich blood away from heart to the body
• As blood flows through the circulatory
system, it moves through 3 types of blood
vessels: arteries, capillaries, & veins
Blood Vessels
• Arteries - vessels that carry blood away
from the heart to the tissues of the body
– They carry oxygen-rich blood
Blood Vessels
• Capillaries - smallest of the blood vessels
• Veins - return oxygen-poor blood to the
heart
Diseases of the Circulatory
System
• Cardiovascular diseases, like heart disease
& stroke, are among the leading causes of
death in the U.S.
• High blood pressure & atherosclerosis are 2
of the main causes of cardiovascular disease
Diseases of the Circulatory
System
• Atherosclerosis - condition where fatty
deposits, called plaque, build up on the
inner walls of the arteries
– Can cause heart attacks & strokes
Diseases of the Circulatory
System
• High blood pressure, hypertension,
increases the rate of heart attack & stroke
• High blood pressure occurs when deposits
of fat build up on the artery walls
Blood & the Lymphatic System
• Blood is a type of connective tissue
• It collects oxygen from the lungs, nutrients
from the digestive tract, & waste products
from tissues
• Blood helps regulate body temperature
• The components that make up blood help
fight infection, & repair damaged blood
vessels
Blood Plasma
• The human body has 4-6 liters of blood, or
8% of the total body mass
• 45% of blood consists of cells, that are
suspended in the other 55%, plasma
• Plasma - 90% water, 10% dissolved gases,
salts, nutrients, enzymes, hormones, waste
products, & proteins
Blood Plasma
Blood Cells
• The cellular portion of blood consists of red
blood cells, white blood cells, & platelets
Blood Cells
• Red blood cells transport oxygen, are the
most numerous, & get their color from
hemoglobin
– Hemoglobin - iron-containing protein
that binds oxygen in the lungs &
transports it to tissues throughout the
body where oxygen is released
Blood Cells
• White blood cells are the “army” of the
circulatory system - they guard against
infection, fight parasites, & attack bacteria
– Lymphocytes - a special class of white blood
cells, produce antibodies that are proteins that
help destroy pathogens
Blood Cells
• Blood clotting is made
possible by plasma proteins
& cell fragments called
platelets
• Platelets - large bone
marrow cells that have
broken into small fragments
The Lymphatic System
• A network of vessels, nodes, & organs
called the lymphatic system, collects the
fluid that is lost by the blood & returns it
back to the circulatory system
• Lymph - fluid collected by the system
The Lymphatic System
• The spleen is an organ whose main function
is to destroy damaged red blood cells &
platelets
• T cells (white blood cells) mature in the
thymus gland, which produces hormones
that promote their development
The Lymphatic System
What Is Respiration?
• At the cellular level, respiration takes place
in the mitochondria
• It releases energy from the breakdown of
food molecules in the presence of oxygen
What Is Respiration?
• At the level of the organism, respiration
means the process of gas exchange - the
release of carbon dioxide & the uptake of
oxygen between the lungs & the
environment
The Human Respiratory System
• The basic function of the human respiratory
system is to bring about the exchange of
oxygen & carbon dioxide between the
blood, air, & tissues
• The respiratory system consists of the nose,
pharynx, larynx, trachea, bronchi, & lungs
The Human Respiratory System
• Pharynx - passageway for both air & food
• Larynx - top of trachea, vocal cords
• Trachea - windpipe, receives
air from pharynx
The Human Respiratory System
• Bronchi - 2 large passageways in the chest
cavity, each leads into 1 of the lungs
• Inside the lungs, the bronchi divide into
even smaller tubes, called bronchioles
• Alveoli - tiny air sacs at the ends of the
bronchioles, where gas exchange takes
place
The Respiratory System
Gas Exchange
• There are about 150 million alveoli in each
healthy lung
• Oxygen diffuses across the membrane of the
alveoli into the capillaries, wrapped around
the outside of the alveoli
• At the same time, carbon dioxide diffuses
from the blood in the capillaries, into the
alveoli, to be excreted
Gas Exchange
Breathing
• Breathing is the movement of air
into & out of the lungs
• Diaphragm - large, flat muscle at
the bottom of the cavity
Tobacco & the Respiratory
System
• The upper part of the respiratory system is
able to filter out dust & foreign particles
that could damage the lungs
• Smoking tobacco damages that protective
layer
Tobacco & the Respiratory
System
• Tobacco contains nicotine, carbon
monoxide, & tar
• Nicotine - a stimulant drug that increases
heart rate & blood pressure
Tobacco & the Respiratory
System
• Carbon monoxide is a poisonous gas that
blocks the transport of oxygen by
hemoglobin in the blood
• Tar contains a # of compounds that have
been shown to cause cancer
Tobacco & the Respiratory
System
• Smoking reduces life expectancy
• Only 30% of male smokers live to age 80,
but 55% of male nonsmokers live to that
age
• Smoking can cause respiratory diseases
like: chronic bronchitis, emphysema, &
lung cancer
Tobacco & the Respiratory
System
• Chronic bronchitis occurs when the bronchi
become swollen & clogged with mucus
• Emphysema - the loss of elasticity in the
tissues of the lungs, making breathing very
difficult
Tobacco & the Respiratory
System
• Lung cancer is deadly because its cells can
spread to other locations
• By the time lung cancer is detected, it has
spread to dozens of other places
Tobacco & the Respiratory
System
• Smoking is also a major cause of heart
disease, it constricts, or narrows, the blood
vessels
• There is a drastic change in body
temp. & in circulation
immediately after smoking a
cigarette