Chapter 16 - Respiratory System Flashcards
Respiration
Respirationis the life-sustaining process in which gases are exchanged between the body and the outside atmosphere. Specifically, oxygen moves from the outside air into the body; and water vapor, carbon dioxide, and other waste gases move from inside the body into the outside air.
2 processes of respiratory system:
Respiration by the respiratory system actually involves two subsidiary processes. One process is ventilation, orbreathing. This is the physical process of conducting air to and from the lungs. The other process is gas exchange. This is the biochemical process in which oxygen diffuses out of the air and into thebloodwhile carbon dioxide and other waste gases diffuse out of the blood and into the air.
The respiratory tract has two major divisions: the ____respiratory tract and the ____ respiratory tract
upper, lower
Divisions of the upper respiratory system:
Nasal cavity, Pharynx, Larynx
Nasal Cavity
continuation of the nostrils, traps larger foreign particles, warms and humidifies air, involved in taste
Pharnyx
tube like structure connects nasal cavity to back of mouth, channels air and food.
Larynx
voice box, contains vocal cords, protect trachea from food
Divisions of the lower respiratory system:
Trachea, Bronchi and Bronchioles, Lungs,
Trachea
Windpipe—widest passageway in the respiratory tract.
Two main bronchial tubes
Right and left bronchi.
The bronchi carry air between the trachea and lungs. Each bronchus branches into smaller, secondary bronchi; and secondary bronchi branch into still smaller tertiary bronchi. The smallest bronchi branch into very small tubules called bronchioles. The tiniest bronchioles end in alveolar ducts, which terminate in clusters of miniscule air sacs, called alveoli (singular, alveolus), in the lungs.
Lungs
Thelungsare the largest organs of the respiratory tract
Surrounded by Pleura that secrete fuid and allow he lngs to move freely within pleural cavity.
Right lung is larger and contains three lobes. Left lung is smaller and contains only two lobes. Smaller lung leaves room for the heart.
Alveoli
Air-sac tisue that makes up most of the lungs. Both lungs combined may have 700 million alveoli.
Main way that respiratory system protects itself:
Mucociliary escalator
Cells can not survive for long without what?
Cells cannot survive for long without oxygen, and if there is too much carbon dioxide in the blood, the blood becomes dangerously acidic (pH is too low). Conversely, it there is too little carbon dioxide in the blood, the blood becomes too basic (pH is too high).
____breathing lowers the carbon dioxide level (and raises the oxygen level and pH); slower breathing has the _____ effects.
Faster, opposite
Another name for breathing
Breathing is also calledventilation,and it is one of two parts of the life-sustaining process of respiration, the other part being gas exchange.
2 processes of breathing:
Inhalation and Exhalation
Inhalation:
DIaphragm contracts, expanding thoracic cavity. Lower air pressure in lungs than outside of body.
ExhalationL
Daiphragm relaxes, air pressure in lungs increases to be higher than external environment. This is a passive process. Lungs contract to their pre-inflated size.
biological basis lfor unconscious control of breathing
Unconscious breathing is controlled byrespiratory centersin the medulla and pons of the brainstem (see diagram below).The respiratory centers automatically and continuously regulate the rate of breathing depending on the body’s needs
Gas Exchange
Gas exchangeis the biological process through which gases are transferred across cell membranes to either enter or leave the blood.
Alveoli
The basic functional units of the lungs where gas exchange between the air and the blood takes place are the alveoli.Alveoli (singular, alveolus)are tiny air sacs that consist of connective and epithelial tissues. The connective tissue includes elastic fibers that allow alveoli to stretch and expand as they fill with air during inhalation. During exhalation, the fibers allow the alveoli to spring back and expel the air. Special cells in the walls of the alveoli secrete a film of fatty substances called surfactant. This substance prevents the alveolar walls from collapsing and sticking together when air is expelled. Other cells in alveoli include macrophages, which are mobile scavengers that engulf and destroy foreign particles that manage to reach the lungs in inhaled air.
he pulmonary artery carries ____ blood from the heart to the ____
deoxygentated, lungs
Gas Exchange
Gas exchange occurs bydiffusionacross cell membranes. Gas molecules naturally move down a concentration gradient from an area of higher concentration to an area of lower concentration. This is a passive process that requires no energy. To diffuse across cell membranes, gases must first be dissolved in a liquid. Oxygen and carbon dioxide are transported around the body dissolved in blood. Both gases bind to the protein hemoglobin in red blood cells, although oxygen does so more effectively than carbon dioxide. Some carbon dioxide also dissolves in blood plasma.
Gas exchange by diffusion depends on what?
Gas exchange by diffusion depends on the large surface area provided by the hundreds of millions of alveoli in the lungs. It also depends on a steep concentration gradient for oxygen and carbon dioxide. This gradient is maintained by continuous blood flow and constant breathing.
Asthma
Asthmais a chronic inflammatory disease of the airways in the lungs, in which the airways periodically become inflamed. Symptoms of asthma include difficultybreathing, coughing, wheezing, shortness of breath, and chest tightness.
Pneumonia
Another common inflammatory disease of the respiratory tract ispneumonia.In pneumonia, inflammation affects primarily the alveoli, which are the tiny air sacs of the lungs. Inflammation causes some of the alveoli to become filled with fluid so that gas exchange cannot occur.
COPD, open up!
Chronic obstructive pulmonary disease (COPD)is a lung disease characterized by chronic poor airflow. The main symptoms include shortness of breath and a cough that produces phlegm. These symptoms are usually present for a long period of time and typically become worse over time. Eventually, walking up stairs and similar activities become difficult because of shortness of breath.
The physiological changes that occur with COPD include a breakdown of alveolar walls, reducing the surface area for gas exchange.
Lung cancer
Lungcanceris a malignant tumor characterized by uncontrolled cell growth in tissues of the lung. The tumor may arise directly from lung tissue (primary lung cancer) or as a result of metastasis from cancer in another part of the body (secondary lung cancer). Primary lung cancer may also metastasize and spread to other parts of the body. Lung cancer develops following genetic damage toDNAthat affects the normal functions of the cell. As more damage accumulates, the risk of cancer increases. The most common symptoms of lung cancer include coughing (especially coughing up blood), wheezing, shortness of breath, chest pain, and weight loss.
The danger of lung cancer
Most cases of lung cancer cannot be cured. In many people, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. About 10 percent of people with lung cancer do not have symptoms when they are diagnosed, and the cancers are found when they have a chest X ray for another problem. In part because of its typically late diagnosis, lung cancer is the most common cause of cancer-related death in men and the second most common cause in women (after breast cancer). Common treatments for lung cancer include surgical removal of the tumor, radiation therapy, chemotherapy, or some combination of these three types of treatment.
Sleep Apnea
Sleep apneais characterized by pauses in breathing that occur most often because of physical blockage to airflow during sleep. When breathing is paused, carbon dioxide builds up in the bloodstream. The higher-than-normal level of carbon dioxide in the blood causes the respiratory centers in the brain to wake the person enough to start breathing normally. This reduces the carbon dioxide level, and the person falls back asleep. This occurs repeatedly throughout the night, causing serious disruption in sleep. Most people with sleep apnea are unaware that they have the disorder because they don’t awake fully enough to remember the repeated awakenings throughout the night.
As many as ____ of all people who smoke tobacco die from it.
half
long-term smokers can expect their lifespan to be reduced by as much as ____ years, and they are three times as likely to die before the age of ___ as non-smokers.
18, 70
Nicotine FACTS BOYYY
Tobacco containsnicotine,which is a psychoactive drug. Although nicotine in tobacco smoke does not directly cause cancer or most of the other health risks of smoking, it is a highly addictive drug. In fact, nicotine is even more addictive than cocaine or heroin. The addictive nature of nicotine explains why it is so difficult for smokers to quit the habit even when they know the health risks and really want to stop smoking. The good news is that if someone does stop smoking, his or her risks of smoking-related diseases and death soon start to fall. For example, by one year after quitting, the risk of heart disease drops to only half of that of a continuing smoker.
Additional adverse health effects of smoking
A wide diversity of additional adverse health effects are attributable to smoking, such as erectile dysfunction, female infertility, and slow wound healing.
