Download Chapter 33: The Circulatory and Respiratory Systems Every breath

Chapter 33:
The Circulatory and Respiratory Systems
Every breath we take brings air into the body. Oxygen in that air is
needed by every cell in the body. The circulatory system brings that
oxygen and other nutrients to your cells.
Protozoans – single celled organisms in water
absorb nutrients through the cell membrane and
circulate materials by diffusion and cyclosis:
streaming of the cytoplasm.
Hydra – Tiny freshwater animals that absorb and
circulate materials from cell to cell through cell
membranes.
Earthworm – some cells are NOT in direct contact with environment.
Nutrients, oxygen, and wastes are transported by the fluid blood inside
vessels or organs. This is called a closed circulatory system.
Grasshopper –The vessels that carry the blood
empty into large cavities called sinuses. The
blood bathes the body tissues and is then
reabsorbed into the circulatory system. This is
an open circulatory system.
Human Circulatory System
We have a closed circulatory system with a heart, blood, and blood
vessels that transport oxygen, CO2, hormones, and nutrients in the body.
Function:
1. Transport dissolved and suspended materials throughout the body
2. The system also plays a role in our immunity
Blood: fluid medium of transport of the circulatory system
The Heart
- A hollow organ near center of chest composed mostly of muscle.
- The human heart is like two separate pumps sitting side by side.
Each side has two chambers called atria and ventricles.
ATRIUM (plural atria): upper chamber of heart that RECEIVES blood
coming into the heart
VENTRICLE: lower chamber of heart that PUMPS blood out of heart
4 chambers – left atrium, right atrium, left ventricle, right ventricle.
Each side of the heart pumps blood to a different part of the circulatory
system. The right side of heart is separated from and never mixes with
the left side of the heart. They’re two separate pumps lying side by side.
ARTERIES – blood vessels that take blood AWAY from the heart
VEINS – blood vessels that take blood TO the heart
Capillaries - small blood vessels where nutrients & wastes exchanged
RIGHT SIDE OF HEART - Pulmonary Circulation – Blue blood:
Only pumps deoxygenated (blue) blood from heart to the lungs.
Pulmonary = lungs. Goes to lungs to pick up oxygen
LEFT SIDE OF HEART - Systemic Circulation – Red blood
Pumps OXYGENATED (red) blood to the rest of the body. Blood that has
returned from the lungs with oxygen go through this side of heart.
Valve: specialized flap of tissue that prevents backflow of blood.
Blood Flow Through the Heart – Refer to page 950 in your book
1. Deoxygenated blue blood (blood
lacking oxygen) enters heart
through the vena cava (the great
vein) dumps into Right Atrium.
2. Blood then goes from the Right
Atrium through the tricuspid
valve into the Right Ventricle.
3. From the Right Ventricle blood
passes through a Semilunar valve
into the Pulmonary Arteries
which take the deoxygenated blue
blood to lungs to pick up more O2 .
4. The oxygenated red blood goes
into pulmonary veins that bring it
to heart thru the Left Atrium.
From the Left Atrium the blood goes through the bicuspid valve to
the Left Ventricle. The Left Ventricle pumps this oxygenated
blood another semilunar valve into the Aorta, and the aorta
branches into arteries that carry the oxygen rich blood to all
the body cells. After cells use up the oxygen, the deoxygenated
blue blood goes back through veins to the heart to step #1 above.
The heart makes a “lub-dup” sound.
Lub: sound of the valves between atria & ventricles shutting
Dup: sound of the semilunar valves of pulmonary arteries & aorta
shutting
Great website showing how the heart pumps:
http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_pumping.html
Label the following: Superior vena cava, heart, lungs, inferior vena cava,
pulmonary artery, aorta, pulmonary vein, right ventricle, left ventricle,
right atrium, left atrium, right lung, left lung, head and arms, trunk/ legs
The Blood (4-6 Liters of blood in the body)
- 45% of the fluid consists of red blood cells, white blood cells, and
platelets. The remaining 55% of the fluid is called plasma.
Plasma: fluid part of blood; 90% water, 10% sugars, salts, & proteins
Red Blood Cells
- Also called erythrocytes
- Contain hemoglobin: an iron-containing protein that binds and
carries oxygen
White Blood Cells
- Also called leukocytes
- Fight infection, parasites, bacteria
Platelets and Blood Clotting
- Platelets are cell fragments in blood that aid in blood clotting
Diseases of the Circulatory System
1. High blood pressure (hypertension): when blood pressure in
arteries remains above normal. Causes – stress, excessive salt
consumption, cigarette smoking, heredity factors
2. Atherosclerosis: arteries become narrower and inelastic because of
deposits of cholesterol & other fatty materials on their inner walls.
Heart disease: blockage of coronary arteries
that supply the heart muscle, reduced oxygen supply to heart
Blood Conditions
1. Anemia: low iron containing hemoglobin in RBCs causes less
oxygen to be carried
2. Sickle-cell anemia: sickle shaped
(moon/cresent) RBCs; causes
blockage in capillaries causing
pain, weakness, deficient oxygen
carrying capacity. Also shorter life
span for RBC.
3. Leukemia: disease of bone marrow
where there is uncontrolled
production of nonfunctional white blood cells, weakens immune
system and ability to fight off disease. Type of cancer.
4. Hemophilia: sex-linked genetic disorder characterized by poor
clotting ability of blood due to absence of a certain protein that
clots blood.
Respiratory System
Respiration
Cellular respiration: breaking down food in the presence of oxygen
to produce energy for cells.
Respiration at the organism level: exchange of oxygen and CO2
between the organism and its environment. O2 in, CO2 out
Pathway of Respiratory System
Nose and Mouth – Pharynx (throat) – Larynx (voice box) – Trachea
(windpipe) – Bronchi – Bronchioles – alveoli (gas exchange in lung)
Gas exchange
Millions of alveoli in the lung provide enormous surface area for gas
exchange. Oxygen breathed into the lung diffuses across the alveoli into
thin capillary walls containing blood. The capillaries connect with larger
arteries and veins and transport the oxygenated blood. At the same
time CO2 diffuses in the opposite direction – from blood of capillaries
into alveoli of lungs then up through the respiratory system & out.
Role of hemoglobin
Hemoglobin – a protein containing iron that is found in RBCs.
Hemoglobin picks up oxygen from lung by binding to it and carries it to
other cells & tissues that need the oxygen for cellular respiration.
Anemia: deficient or lack of iron leads to less hemoglobin in RBC
and less ability to carry the oxygen.
Cilia: hair-like structures that line the respiratory track and sweep
materials away from the lungs. Respiratory system also lined with a
protective thin layer of mucus.
Breathing:
Movement of air into and out of the lungs.
No muscles connected to lungs, the force that drives air into lungs is air
pressure. Lungs are sealed in 2 sacs called pleural membranes, inside
chest cavity. At the bottom of the chest cavity is the diaphragm muscle.
Inhale: breathe in, diaphragm contracts expanding chest cavity
Exhale: breath out, diaphragm relaxes, putting pressure on lungs
forcing air out
(Muscles around chest provide extra force)
Breathing is part voluntary (controlled by you) and involuntary
(controlled by Medulla)
Smoking
Three most dangerous substances in tobacco:
Nicotine – addictive substance in tobacco
Carbon Monoxide – colorless, tasteless, poisonous, odorless gas
Tar – brown, sticky mixture of chemicals
Chronic Bronchitis –bronchi become swollen and clogged with mucus
Emphysema – loss of elasticity in the tissue of the lungs
Lung Cancer – disease caused by small groups of cancer in the lungs
Smoking affects other body systems:
- Circulatory: increases heart rate, hypertension, atherosclerosis
- Nervous System: dulls senses of smell and taste
- Digestive system: stomach cancer; stomach acid issues
- Reproductive system: decreases sperm, sperm motility, shape;
impotence; significant decrease in fertility for women
- Endocrine System: decrease levels of blood clotting hormone
Respiratory System Anatomy
Pharynx: throat (back of the mouth)
Larynx: voice box (below pharynx)
Trachea: windpipe, rings of cartilage
Bronchi: trachea leads into 2 branched tubes in chest called
bronchi. The bronchi further branch into smaller
bronchioles of lungs
Alveoli: bronchioles branch into millions of little air sacs
called alveoli where gas is exchanged – oxygen moves into
blood with inhaled air, CO2 moves out with exhaled air
Epiglottis: Covers trachea when eating food so food does not
get into respiratory tract
Diaphragm: flat muscle at bottom of chest assists breathing