Respiration Lecture Vocabulary

alveoli

clusters of thin-walled sacs at the terminal branches of the conducting airways

surfactant

type of phospholipid, which facilitates lung expansion

alveolar macrophages

phagocytic cells which remove particles of dust and debris from alveolar spaces

respiration

exchange of gases between the atmosphere, blood, and cells

inspiration

inflow

expiration

outflow

diaphragm

dome-shaped, muscular and membranous structure that separates the thoracic (chest) and abdominal cavities in mammals

external intercostal muscles

small muscles located in between each rib, starting at the first rib and extending down to the 11th rib, raises the ribs

scalene muscles

elevate the first two ribs, the three muscles found on each side of the neck, spanning between the transverse processes of the cervical vertebrae and the upper two ribs

sternomastoid

raises the sternum, powerful neck muscle that allows you to bend your neck and turn or tilt your head.

tidal volume

the amount of air that moves in or out of the lungs with each respiratory cycle, 500 mL of air

compliance

how much effort is required to stretch or distend the lungs

newborn respiratory distress syndrome

a deficiency of pulmonary surfactant, occurs in babies born early (premature) whose lungs are not fully developed

spirometer

used to measure changes in lung volume that occur with different respiratory efforts

obstructive lung disease

disease that affects the airway, shortness of breath because it's hard for them to exhale all the air from their lungs

asthma

airway obstruction due to constriction of the smaller airways (bronchi and bronchioles) and caused by allergy-induced spasm of the smooth muscle in the walls of these airways

emphysema

breakdown of alveolar walls and loss of elasticity, occurs due to release of destructive enzymes from alveolar macrophages following chronic exposure to cigarette smoke or other irritants

barrel chest

lungs remaining inflated due to loss of elasticity and size of chest cage increases

saturation curve

a plot of the percent saturation of hemoglobin as a function of the partial pressure of oxygen (PO2

hemoglobin

red protein responsible for transporting oxygen in the blood of vertebrates. Its molecule comprises four subunits, each containing an iron atom bound to a heme group

oxyhemoglobin

oxygen and hemoglobin combine in a readily reversible reaction to form this

hypoxia

deficiency in the amount of oxygen reaching the tissues

phrenic nerve

innervates the diaphragm, causes diaphragm to contract and relax

intercostal nerve

innervates the external intercostal muscles, aids in the contraction of muscles and the return of sensory information from the skin and parietal pleura

hyperventilation

diaphragm and external intercostal muscles contract more forcefully and more frequently

chemoreceptors

on the ventral surface of the brain stem and in the carotid and aortic bodies on the large vessels leaving the heart, special nerve cells that detect changes in the chemical composition of the blood and send information to the brain to regulate cardiovascular and respiratory functions