Download Chapter 10: The Breath of Life-Respiration

Chapter 10: The Breath
of Life-Respiration
UNIT 3 (2)
Reminder:
•Homeostasis- Also called dynamic equilibrium, is the
tendency for living things to maintain a constant/ balanced
internal state of optimal conditions
•Can include: maintenance of body temperature, blood sugar
levels, water levels, Gaseous Wastes, blood PH, etc.
Respiration and Homeostasis
•How does our respiratory system help us to maintain homeostasis in
our bodies? (Diffusion of gasses)
•Remember: cell theory states that all living things are made up of one
or more cells (approximately 37.2 trillion- not including bacteria!)
•Complex multicellular organisms are made up of various organ
systems which are made up of tissues which are further made up of
cells
•All animal cells require oxygen (O2) to perform their vital metabolic
processes.
Respiration and Homeostasis (cont’d)
•Animal body cells undergo cellular respiration to create the energy
source ATP from glucose.
•Cells use ATP to perform their functions.
•As can be seen, this process requires oxygen.
•No oxygen- much less ATP
So What Does This Have To Do With
Homeostasis?
•Respiratory system acts as a surface for gas exchange that allows oxygen
to enter the blood stream and carbon dioxide to exit.
• Oxygen must be able to diffuse into blood stream and cells
• Carbon dioxide must be able to diffuse into the lungs and out of cells
• Achieved through both diffusion and facilitated diffusion throughout the body
•Oxygen is taken to all major organs and muscle tissues by circulatory
system.
•Without oxygen, the cells in these tissues would be unable to produce ATP
to perform necessary functions.
• (Ex: heart muscle contractions, food digestion, waste filtration in kidneys, cerebral functioning,
synthesis of insulin, immune system functioning, etc.) (317-1)
Respiratory Surfaces:
The Lung
•Respiratory surface of humans, connected to the air via internal
passageways.
•The lung systems of all animals (that have them) share 3 basic
principles:
1. One or two lungs with a moist surface (gas must be dissolved in water
to diffuse across cell membranes)
2. A means of forcibly bringing air in contact with the moist surface
3. A circulatory system to transport gasses to and from the lungs
◦ (Gas is exchanged between the blood and air in lungs)
Respiration Subdivided: Pg 335
•In mammals, respiration can be subdivided into 4 processes:
1. Breathing: Divided into inhalation an exhalation, the moving of air
into and out of the lungs.
2. External Respiration: Exchange of O2, and CO2 between air and
blood. (air sacs in lungs= alveolus/ alveoli)
3. Internal Respiration: Exchange of O2 and CO2 between the blood
stream and surrounding cells. (blood to tissue)
4. Cellular Respiration: see formula, complex chemical reaction in
mitochondria that uses oxygen and glucose to produce energy.
Respiration Subdivided
How Does The Air Reach The Lungs?
•The following is the pathway of a single breath of air:
1. Air is inhaled through either the nose or mouth
◦ Nostrils preferred as cilia filter dust from air
2. Air enters the nasal or oral cavity (depends on entry point)
• Here it is warmed(heat from blood stream), filtered(cilia), and moistened
(small bones called turbinates secrete mucus)
3. Air enters the pharynx (throat)
◦ Air inhaled nasally and orally both travel here
How Does The Air Reach The Lungs?
4. Air passes through the glottis (covering of windpipe)
◦ Glottis is protected by a flap (epiglottis) to keep liquids and food from
entering the lungs.
5. Air passes the larynx (voice box)
6. Air passes into the trachea (windpipe)
◦ Carries air down to the bronchi
◦ Cilia and secreted mucus help to push dust and particles back out
◦ Supported by cartilage rings to prevent collapsing of windpipe (pressure
changes)
How Does The Air Reach The Lungs?
7. Air enters the bronchi (singular-bronchus)
◦ Large tube that divides into two (one for each lung)
◦ Each bronchus divides further into a network of smaller tubes called
bronchioles
8. Bronchioles transport the air to air sacs within the lung called alveoli
(alveolus)
◦
◦
◦
◦
The sacs are moist and surrounded by a network of capillaries
This is the site of gas exchange between the lungs and blood stream
The sacs increase the surface area of the lung
Only a single cell thick wall (like capillary)
Pathway of air video Respiration Song (Mr. Freeborn will have second-hand embarrassment because it is cheesy)
Pathway
The Breathing Process: Inhalation
•Inhalation is the process by which air is
brought into the lungs. Three main
processes occur:
1. The intercostal muscles(attached to
ribs) contract
2. The contraction lifts the ribs up and
out, increasing area in chest cavity
3. The diaphragm pulls downward,
giving the lungs more room to
expand
As volume in thoracic cavity increases,
the pressure decreases. The negative
pressure allows air to fill the lungs and
causes expansion of lungs to occur
The Breathing Process: Exhalation
•Exhalation is the process by which air
is pushed out of the lungs. Three main
processes occur:
1. The intercostal muscles(attached to
ribs) relax
2. The relaxing allows the ribs to take
their former position, decreasing
area in the chest cavity
3. The diaphragm moves upward,
causing the lungs to contract
As volume in thoracic cavity decreases,
the pressure increases. The positive
pressure pushes air out of the lungs,
causing them to deflate
Composition of Inhaled vs. Exhaled Air
Introducing Respiratory Volumes
•There are various volumes of air that we refer to when speaking about respiratory volumes.
•Respiratory volumes can refer to the volume of air that the lungs can: hold, inhale, exhale, and
retain.
1. Tidal Volume (TV): The volume of air inhaled and exhaled during regular
breathing. (about 500 mL of air)
2. Inspiratory Reserve Volume (IRV): The additional amount of air that can be
taken in above tidal volume/ regular breathing.
◦ Ex: Deep Breathing, Yawning, etc
◦ About 2000 mL of air
Introducing Respiratory Volumes
3. Expiratory Reserve Volume (ERV): Additional volume of air which can be
forced out of the lungs above regular/tidal exhalation.
◦ About 1500 mL
4. Vital Capacity (VC): Refers to the total amount of air that can be moved into
and out of the lungs
◦ VC= TV+IRV+ERV
5. Residual Volume (RV): The volume of air which always remains in the lungs
after a full exhalation.
◦ About 1500 mL of air is always present in the lungs
◦ This amount of air must always remain in the lungs, otherwise the lungs would
collapse!
6. Respiratory Efficiency: The rate at which oxygen from the lungs diffuses into
the blood stream. Faster= more efficient
HW/SW: Pg. 342 # 1,2,3,5,6
Pg. 349 # 2,5,8
Lung Capacity Graphs
Should be able to
label a diagram like
this
Located on Pg. 341 of
Biology textbook
Respiratory Health: Lung Conditions
1)Lung Cancer: What is it? (DOE)
•Lung Cancer is caused by the abnormal growth of cells in the lung
•This growth is caused by unchecked rapid cell division (mitosis) in the lung
•These abnormal cells form a large mass called a carcinoma (tumor)
•The carcinoma will spread and kills healthy cells around it
• (can also block off blood or air flow in various areas of body if it grows too
large)
1) Lung Cancer: Two Types
•There are two types of cancer:
1. Primary Cancer- located at the site of original cell mutation (where it started)
2. Secondary Cancer- Cancer in other parts of the body, caused by the original
tumor
◦ Cancer cells shed off of carcinoma and can enter blood stream (metastasize)
◦ Blood stream carries them to other parts of the body where they can form new tumors
Carcinoma
1) Lung Cancer: Causes (DOE)
•Various causes of lung cancer
1. Carcinogens- cancer causing agents (like those found in cigarettes)
◦ These chemicals irritate cells, causing them to become anaplastic or less specialized
◦ This can induce rapid rate of mitosis causing growth of tumors
2. Radon Gas Exposure- radon gas is normally used in “radiation therapy” to
treat cancers and is also found in some rocks
3. Natural Mutation- Only happens about 1% of the time
4. Genetics- Predisposition to certain cancer (ex: breast cancer)
1) Lung Cancer: Symptoms (DOE)
•Lung cancer has various symptoms
•In regard to lung cancer, symptoms often don’t appear until the cancer has
spread too much and it is often too late
•Symptoms of lung cancer include:
•
•
•
•
•
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Chronic cough
Chest pains
Shortness of breath
Weight loss and loss of appetite
Fever with no apparent cause
Coughing up blood
1) Lung Cancer: Treatment and Effects
Effects of Lung Cancer: Lung cancer often results in death, usually death is not
caused by the primary cancer but by secondary cancers caused by the original
tumor (ex: cancer cells taken to brain-form brain tumor)
Treatments of Lung Cancer:
•Radiation and chemotherapy if cancer is not too advanced
• Radiation- targeted radiation used to kill cancer cells in a specific part of the body
• Chemotherapy- drugs used to inhibit cell division, impacts the entire body
•Surgery
2) Pneumonia: What is it?
•Pneumonia is a disease of the lung in which the alveoli (air sacs) become
inflamed (swell) and fill with liquids.
•Liquids usually include the body’s mucus.
•This results in the alveoli becoming much less effective at exchanging gasses
with the blood and as a result, cells around the body will starve for oxygen.
2) Pneumonia: Two Types
•There are also two types of pneumonia:
1. Lobar Pneumonia: This is pneumonia which affects a lobe of the lung.
Always caused by bacteria.
2. Bronchial Pneumonia: This type of pneumonia affects patches throughout
both lungs.
2) Pneumonia: Causes and Treatments
•Causes of pneumonia include infections by bacteria, viruses, mycoplasmas
and fungi:
• Bacterial Pneumonia (occurs only lobar pneumonia) is caused by the bacterium
Streptococcus pneumoniae. (Treated with antibiotics)
• Viral pneumonia is caused by viruses, but are less severe than bacterial pneumonias. (no
treatment – left to run its course)
• Mycoplasma Pneumonia is caused by mycoplasmas (organisms having both characteristics
of bacteria and viruses) and takes a long time to cure.
•Treatments: Antibiotics for bacterial cases, vaccines against the flu are used to
prevent pneumonia from occurring in the first place.
3)Asthma: What is it? Symptoms
• Asthma is a disease where the airways in the lungs constrict, obstructing air
flow.
• Bronchioles in the lungs constrict due to muscle spasms
• Can occur at any age and results in “Asthma Attacks”
• Symptoms include:
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•
•
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Shortness of breath
Coughing
Wheezing
Chest Tightness
• Symptoms usually worsen at night or early morning, and can also be caused
in response to exercise and cold air.
3) Asthma: Causes and Treatment
•The cause of asthma is currently unknown. Various stimuli are thought to
trigger the lungs and airways, causing them to narrow and secrete mucus,
reducing or blocking off air flow.
• Sometimes asthma may be present as a child and then disappear into adulthood.
•Treatments for asthma exist in the form of drugs called “Bronchodilators.”
Inhaling these drugs into the airways causes the bronchioles to dialate (open
up/expand) making it easier to breathe.
• Bronchodilators also referred to as “puffers”