Respiration and Excretion
Chapter 13: Respiration and Excretion
The Respiratory System (Pages 430-438)
Introduction (Page 430)
Functions of the Respiratory System:
Move oxygen from the outside environment into the body.
Remove carbon dioxide and water from the body.
Why the Body Needs Oxygen (Pages 430-431)
Chemical Reactions:
The chemical reactions to release energy that take place inside cells must have oxygen.
Definition of Respiration:
Respiration is the process in which oxygen and glucose undergo a series of chemical reactions inside cells to release energy.
Products of Respiration:
a. Energy
b. Carbon dioxide
c. Water
Breathing vs. Respiration:
To a scientist, breathing and respiration do not mean the same thing.
Dependence on Organ Systems:
The respiratory system depends on:
a. Circulatory system
b. Excretory system
It does not depend on:
b. Reproductive system
d. Digestive system
The Air You Breathe (Page 431)
About Oxygen:
a. The air you breathe is part of the atmosphere, the blanket of gases that surrounds Earth.
b. Oxygen makes up about 21 percent of the gases in the atmosphere (not 78%).
c. Your body does not use all of the air that you breathe into your lungs.
d. Most of the air you breathe in goes back into the atmosphere when you exhale.
The Path of Air (Pages 432-434)
Breathing Other Particles:
True statement: When you breathe in air, you also breathe in dust, pollen, and microorganisms.
Flowchart for the Path of Air:
Air enters the body through two nostrils.
Air moves through the pharynx, which is also part of the digestive system.
Air moves into the trachea (windpipe).
Air moves through the bronchi, passages that direct air into the lungs.
Function of a Sneeze:
A sneeze shoots particles and bacteria out of the nose and into the air.
Alternate Name for Pharynx:
Another name for the pharynx is the throat.
Matching Activity: Parts of the Nose with Functions
Nostrils - (b) Openings in the nose through which air enters.
Nasal Cavities - (d) Contain blood vessels that heat the air you breathe in.
Mucus - (a) Moistens the air and traps particles in the air.
Cilia - (c) Tiny hairlike extensions that sweep mucus into the throat.
Connected Body Parts to Pharynx
Body parts connected to the pharynx:
a. Stomach
b. Nose
c. Mouth
d. Ears
Structure of the Trachea:
The walls of the trachea are made up of rings of cartilage that strengthen the trachea and keep it open.
Cilia and Mucus in Trachea Movement:
True statement: The cilia and mucus in the trachea sweep upward, moving the mucus toward the nose where it is sneezed out.
Food in Trachea:
If food enters the trachea, a person can choke.
Main Organs of the Respiratory System:
Circle the main organs:
a. Trachea
b. Bronchi
c. Lungs
d. Alveoli
Bronchus Division in Lungs:
True statement: Inside the lungs, each bronchus divides into smaller and smaller tubes.
Alveoli Function
Gas Exchange Process:
The blood picks up oxygen from the air inside the alveoli.
Gas Exchange Definition:
During gas exchange, oxygen passes through the wall of the alveolus and through the capillary wall into the blood. Carbon dioxide and water pass from the blood into the alveoli.
Reason for Large Oxygen Absorption in Lungs:
The alveoli provide a large surface area in a relatively small space.
How You Breathe (Pages 436-437)
Breathing Rate and Oxygen Need:
False statement: The more oxygen you need, the more slowly you breathe.
Definition of Diaphragm:
The diaphragm is a large, dome-shaped muscle that plays an important role in breathing.
Breathing Cycle Diagram: Process of Breathing:
Rib muscles and diaphragm contract, making the chest cavity larger.
The pressure of the air inside the lungs decreases.
Air rushes into the lungs, and you inhale.
The rib muscles and diaphragm relax, and the chest cavity becomes smaller.
The air is squeezed out of the lungs, and you exhale.
How You Speak (Pages 437-438)
Voice Box Alternate Name:
Another name for the voice box is the larynx.
Definition of Vocal Cords:
Vocal cords are folds of connective tissue stretching across the opening of the larynx that produce the voice.
Mechanism of Voice Creation:
Muscles make the vocal cords contract. Air from the lungs rushes through the opening between them. The movement of the vocal cords makes the air molecules vibrate to create a sound.
Reading and Note Taking Recommendation
Note Taking Strategy:
To take notes effectively, write down the headings in the section. Under each heading, write the main idea and important details, including key terms and their definitions. Reread the section and take organized notes.
Smoking and Your Health (Pages 440-444)
Chemicals in Tobacco Smoke (Pages 440-441)
Harmful Chemicals in Tobacco Smoke:
Chemical | What It Is | How It Harms the Body
Tar | Dark, sticky substance that forms when tobacco burns | Clumps cilia together so they can’t keep harmful materials out of the lungs.
Carbon monoxide | Colorless, odorless gas produced when things are burned | Binds to hemoglobin in red blood cells in place of oxygen.
Nicotine | A drug that produces addiction, or physical dependence | Speeds up the nervous system, heart, and other organs.
Respiratory System Problems (Pages 441-442)
Effects of Tobacco Smoke:
a. Tobacco smoke does not harm the respiratory system. False
b. Smokers cough frequently because their cilia cannot sweep away mucus. True
c. Smokers do not get as much oxygen because mucus buildup blocks air flow into the lungs. True
d. Heavy smokers can easily take part in vigorous sports. False
Respiratory Problems from Long-term Smoking
Three respiratory problems that result from long-term smoking:
a. Chronic bronchitis
b. Emphysema
c. Lung cancer
Long-term Bronchitis Impact Statement:
False statement: Long-term bronchitis has no effect on the breathing passages.
Definition of Emphysema:
Emphysema is caused when chemicals in tobacco smoke damage lung tissue and breathing passages.
Cigarette Smoke and Cancer:
False statement: Cigarette smoke has over 40 different chemicals that cause cancer.
Circulatory System Problems (Page 443)
Effects of Tobacco Smoke on Blood Vessels:
Chemicals from tobacco smoke enter the blood and are absorbed by blood vessels, irritating them and causing a buildup of fatty material.
Heart Attack Probability:
True statement: Smokers are more likely to have heart attacks than nonsmokers.
Passive Smoking (Page 443)
Definition of Passive Smoking:
In passive smoking, people involuntarily inhale the smoke from other people’s cigarettes, cigars, or pipes.
Health Risks of Passive Smoking:
True statement: Passive smoking causes respiratory problems and increases the risk of heart disease and lung cancer in nonsmokers.
Choosing Not to Smoke (Page 444)
When Smokers Begin Smoking:
Most smokers began smoking when they were teenagers.
Reasons for Temptation to Start Smoking:
a. Friends may pressure them.
b. Advertisements about smoking may appeal to them.
Difficulty of Stopping Smoking Statement:
True statement: It is very easy to stop smoking once you have started.
The Excretory System (Pages 445-450)
Introduction (Page 445)
Function of the Excretory System:
The excretory system collects wastes produced by cells and removes the wastes from the body.
Process of Waste Removal:
The process of removing wastes from the body is excretion.
Organs of the Excretory System (Pages 445-446)
Three Wastes the Body Must Get Rid Of:
Carbon dioxide, excess water, and urea.
Matching Activity: Terms with Definitions
4. Urea - (c) A chemical that comes from the breakdown of proteins.
5. Kidneys - (a) The major organs of the excretory system.
6. Urine - (b) A watery fluid produced by the kidneys.
Flowchart for Waste Removal
Removing Wastes Flowchart Process:
Blood flows through the kidneys, which filter the blood, removing the wastes.
Urine flows from the kidneys through two narrow tubes called ureters to a sacklike muscular organ called the urinary bladder, which stores urine.
When the bladder is full, urine flows out of the body through a tube called the urethra.
The Filtering Process (Pages 446-448)
Definition of Nephrons:
Nephrons are tiny structures that remove wastes from blood and produce urine.
Stages of Urine Formation:
a. Wastes and needed materials are removed from the blood.
b. Much of the needed material is returned to the blood.
Filtering Results and Analysis
True/False Statement on Filtration:
False statement: Urea and glucose stay in the capillaries while blood cells and protein molecules move into the capsule of a nephron.
Substances Returned to Blood and Kept in Kidneys:
Returned to blood: Glucose and water
Stay in kidneys: Urea and other wastes
Importance of Urine Analysis
Use of Urinalysis by Doctors:
Analyzing the contents of urine can detect some medical problems, such as diabetes or kidney malfunction.
Water Balance in the Body (Pages 449-450)
Regulation by Kidneys:
The kidneys help maintain homeostasis by regulating the amount of water in the body.
True/False Statement on Body Water Regulation:
False statement: If you’ve been sweating a lot and haven’t had much to drink, your body will absorb less water and produce a larger volume of urine.
Other Organs of Excretion (Page 450)
Three Other Organs of Excretion (not including the kidneys):
a. Lungs
b. Skin
c. Liver
Function of the Liver:
The liver breaks down proteins into urea, and it produces bile.