Chapter 39: The Respiratory System

air passage to lungs

enters through mouth or nasal cavity where it is warmed and moistened, passes through the larynx, through the trachea which divides into two bronchi that lead to the lungs

protection from particulate matter

nasal hairs trap dust and large particles, mucus lining in the nasal cavity and trachea trap dust and microbes, and cilia lining airways move mucus and large particles away from the lungs and toward the throat

pharynx

throat

larynx

voice box

trachea

carry inhaled air to lungs and exhaled air out of the body, made of incomplete rings of hyaline cartilage and smooth muscle

right lung

larger, three lobs

left lung

smaller, two lobes

bronchi division

small passages in the lungs that divide into terminal bronchioles which divide into respiratory bronchioles which divide into alveoli

alveoli

tiny air sacs in the lungs where gas exchange occurs, made up of simple squamous epithelium

tidal volume (TV)

the amount of air that is inspired and expired during a normal breath

expiratory reserve volume (ERV)

the additional amount of air that can be exhaled after a normal exhalation

inspiratory reserve volume (IRV)

the additional amount of air that can be inhaled after a normal inhalation

how gas pressure influences how gas is moved into and out of the body

the change in partial pressure from the alveoli to the capillaries drives oxygen to tissues and carbon dioxide to blood from the tissues

capillaries

smallest blood vessels in the body

thoracic cavity function

airtight allowing pressure changes and volume changes to occur, when volume changes air is moved in and out of the lungs

diaphragm during inhalation

contracts and flattens causing volume to increase and pressure to decrease and air to enter the lungs

diaphragm during exhalation

relaxes and domes upward causing volume to decrease and air to leave the lungs

compliance

how elastic the lung is

resistance

how much obstruction there is in the airways

recruitment

process of opening airways that normally remain closed when cardiac output increases

V/Q mismatch

mismatch of amount of air and amount of blood in the lungs. produces dead space and leads to decreased oxygen levels and increased carbon dioxide levels in the blood

dead space

broken down or blocked lung tissue. anatomical or physiological

hemoglobin

protein molecule found in red blood cells. four subunits: two alpha and two beta

how oxygen is transported to body tissues

it enters the blood and binds to a heme group on each subunit of hemoglobin and is pumped to the heart through arteries to body tissues

how carbon dioxide is transported from body tissues to the lungs

dissolution directly into the blood, binding to a hemoglobin, or carried as a bicarbonate ion