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.