Ch. 10 - Respiratory System Flashcards
What is the primary function of the respiratory system?
brings Oxygen into the body and carbon dioxide out of it
Respiratory system works with what other system?
Cardiovascular system
What are the secondary functions of the respiratory system?
phonation (voice production)
regulation of body temperature
regulation of acid-base balance
sense of smell
The normal pH of blood is?
7.4 7.35 to 7.45 is an acceptable range
The more carbon dioxide there is in the blood, the _______ the blood pH, and the more ______ the blood.
lower
acidic
The more oxygen there is in the blood, the _____ the blood pH, and the more ______ the blood.
higher
akaline
The definition of respiration is defined in two ways, which are?
external and internal respiration
What is external respiration?
means exchange of oxygen and carbon dioxide between inhaled air and the blood flowing through the pulmonary capillaries
What is internal respiration?
means exchange of oxygen and carbon dioxide between the blood in the systemic capillaries and all the cells and tissues of the body
What are the structures of upper respiratory system (outside the lungs)?
Nostrils, nasal passages, pharynx, larynx, trachea
What are the structures of the lower respiratory system?
bronchi, bronchioles, alevolar ducts, alveoli
nares (nostrils) are?
external openings of the respiratory tube
lead into the nasal passges
where are the nasal passages?
between the nostrils and the pharynx
nasal septum?
separates the left and right nasal passage
What are the structures of the nose?
nares (nostrils), nasal passages, nasal septum, hard and soft palates, turbinates
hard and soft palates?
separate the nasal passages from the mouth
turbinates (nasal conchae)?
divide each nasal passage into 3 main passages
- thin, scroll-like bones covered with nasal epithelium
- dorsal and ventral
Nasal passages are lined with?
pseudostratified columnar epithelium
In the nose _____ project from the cell surfaces up into a layer of mucus
cilia
In the nose _____ is secreted by mucous glands and goblet cells.
mucus
What are nasal passages function?
warm, humidify, and filter inhaled air
What does the nasal passages do to warm air?
air is warmed by blood flowing through blood vessels just beneath the nasal epithelium
What does the nasal passages do to humidify air?
Air is humidified by mucus and other fluids on the epithelial surface
What does the nasal passages do to filter inhaled air?
air is filtered as it passes through the winding passages produced by the turbinates - particles do not readily pass through but become trapped in the mucous layer; cilia move mucus and trapped foreign material upward to the pharynx and mouth
paranasal sinuses?
ciliated out pouchings of the nasal passages contained within spaces in certain skull bones
- most animals have two frontal sinuses and two maxillary sinuses within the frontal and maxillary bones
Larynx and ______ work together to prevent ______ from interfering with _____ and vice versa.
______ control actions of the muscles around the pharynx
pharynx , swallowing, breathing
reflexes
What is the common passageway for respiratory and digestive systems?
pharynx
_____ ______ divides pharynx into the dorsal ___________ (respiratory passageway and the ________ ________ (digestive passageway into the esophagus and ventrally into the larynx.
soft palate
nasopharynx
ventral oropharynx
What happens when swallowing?
breathing stops, opening into larynx is covered, material to be swallowed moves to rear of pharynx, esophagus opens
What happens after swallowing?
larynx is reopened and breathing resumes
What is the larynx?
short, irregular tube connecting pharynx with the trachea
Larynx is composed of segments of _____ that are connected to each other and the surrounding tissues by _____.
cartilage
muscles
In the larynx what are the cartilage components?
epiglottis, arytenoid cartilages, thyroid cartilage, cricoid cartilage
What are the most common cartilages in the larynx?
epiglottis and arytenoid cartilages
Epiglottis?
single, leaf-shaped; projects forward from the ventral portion of the larynx
During swallowing, the epiglottis is pulled back to cover the opening of the larynx
Arytenoid cartilage?
paired; attachment is the site of the vocal cords
muscles adjust the tension of the vocal cords by moving the cartilages
Arytenoid cartilages and the ____ _____ form the boundaries of the glottis
vocal cords
What are the larynx functions?
voice production and prevention of foreign material being inhaled, control airflow to and from the lungs
With voice production what is vocal cords?
two connective tissue bands attached to the arytenoid cartilages -stretched across lumen of larynx parallel to each other
Vocal cords vibrate as ____ passes over them.
air
muscles attached to the _________ ________ control the tension of the vocal cords
arytenoid cartilages
______ _______ opens the glottis wide; no sound
Complete relaxation
_________ the tension produces lower-pitched sounds
Lessening
________ the tension produces higher-pitched sounds
Tightening
One of larynx functions is to . prevent foreign material being inhaled in the larynx how does this happen?
during swallowing, muscle contractions pull the larynx forward and fold the epiglottis back over its opening
Another function of larynx is ________ _______ to and from the lungs.
Control airflow
Small adjustments in the size of the glottis aid movement of air
Describe the trachea?
- short, wide tube
- extends from the larynx into the thorax
- Divides into the two main bronchi that enter the lungs - one go to the right and the other to the left - called bifurcation
- Composed of fibrous tissue and smooth muscle held open by hyaline cartilage rings
- Lined with ciliated epithelium
- c-shaped rings of hyaline cartilage
- open part of trachea rings face dorsally
- gap between the ends of each ring bridged by smooth muscle
Describe the bronchial tree?
- Each bronchus divides into smaller bronchi, which divide into even smaller bronchi
- bronchioles subdivide into alveolar ducts
- alveolar ducts end in groups of alveoli - gas exchange
- arranged like bunches of grapes
- alveolar sacs: groups of alveoli
- autonomic nervous system controls smooth muscle fibers in wall of bronchial tree
In the bronchial tree the ________ ________ _______ controls smooth muscle fibers in wall of bronchial tree
Autonomic nervous system
Bronchodilation is?
Bronchial smooth muscle relaxes
aids respiratory effort during intense physical activity
Bronchoconstriction is ?
Bronchial smooth muscle partially contracts
Returns size of the air passage
Irritants in inhaled air can cause bronchoconstriction
Alveoli?
Site of external respiration
Tiny, thin-walled sacs of simple squamous epithelium
Surrounded by networks of capillaries
Lined with fluid that contains sulfactant
Describe lungs?
Each lung has a base, an apex, and a convex lateral surface
Base is in the caudal part of the thoracic cavity
Lies directly on cranial surface of diaphragm
Apex lies in cranial portion of thoracic cavity
Describe the lobes of the lungs?
Lungs are divided into lobes - most species
Lobes are distinguished by the major branches of the bronchi
Hilus- small, well-defined area on medial side of lung ( site where air, blood, lymph, and nerves enter and leave the lung
In pulmonary circulation, _______ _______ enters the lungs from the right ventricle of heart through the ________ _________.
Deoxygenated blood
Pulmonary artery
Pulmonary artery splits into ______and ______ pulmonary arteries that enter the two lungs.
Left and right
_______ ________ enter capillary networks around the alveoli.
Pulmonary arterioles
Oxygenated blood returns to the left side of the heart in the _________ ________.
Pulmonary veins
In the thoracic cavity, what is the area between the lungs?
Mediastinum
What does the mediastinum contain?
Heart, trachea, esophagus, blood vessels, nerves,lymphatic structures
What is the pleural?
- thin membrane that lines thoracic cavity and covers organs and structures in the thorax
- visceral layer - covers thoracic organs and structures
- parietal layer lines the cavity
- space between the two pleural layers is filled with a small amount of pleural fluid
- helps ensures that surfaces of organs slide smoothly along the lining of the thorax during breathing
What is the diaphragm?
Thin, dome-shaped skeletal muscle sheet
Forms caudal boundary of thorax
Important respiratory muscle - flattens when it contracts
Enlarges volume of the thorax and aids inspiration
what is the process of respiration?
pressure within the thorax is negative with respect to atmospheric pressure
- pulls lungs tight out against the thoracic wall
- lungs follow passively as movements of the thoracic wall and diaphragm alternately enlarge and reduce the volume of the thorax
- negative intrathoracic pressure helps draw blood through veins and into the atria
What is inspiration?
process of drawing air into lungs (inhalation)
results from enlargement of the volume of the thoracic cavity by the inspiratory muscles
Diaphragm relaxes
What are the inspiratory muscles?
diaphragm and external intercostal muscles
external intercostal muscles located in the external portion of the intercostal spaces (between ribs)
What is expiration?
process of pushing air out of lungs (exhalation)
results from decrease in size of thoracic cavity
What are the expiratory muscles?
internal intercostal muscles and abdominal muscles
Internal intercostal muscles located between the ribs, deep to the external intercostal muscles
Contraction of abdominal muscles pushes _____ ______ against the diaphragm and pushes _______ back into its full dome shape.
abdominal muscles
diaphragm
With respiratory volumes, what is tidal volume?
volume of air inspired and expired during one breath - varies according to body’s needs
With respiratory volumes, what is minute volume?
volume of air inspired and expired during 1 minute of breathing
With respiratory volumes, what is residual volume?
volume of air remaining in the lungs after maximum expiration
What is alveolar gas exchange?
simple diffusion of gas molecules according to concentration gradient
Oxygen diffuses from the alveolar air into the blood of the alveolar capillary
Carbon dioxide diffuses from the blood into the alveolus
What is partial pressure of gases?
pressure of each individual gas in a mixture of gases
partial pressures of oxygen and carbon dioxide in the blood of alveolar capillaries is determined by the partial pressures of oxygen and carbon dioxide in alveolar air
What is the respiratory center?
area in the medulla oblongata of the brain stem
controls respiratory muscle contractions - directs timing and strength of contraction
Individual control centers - inspiration, expiration, breath holding
Can be consciously controlled for brief periods
What is a mechanical control system?
stretch receptors in the lungs set limits on routine resting inspiration and expiration
Respiratory center sends out nerve impulses when lungs inflate to a certain point -stops muscles contractions that produce inspiration and starts contractions to produce expiration
Another set of nerve impulses sent when lungs deflate sufficiently - stops expiration and starts the process of inspriation again
What is a chemical control system?
- adjusts the normal rhythmic breathing pattern produced by the mechanical control system
- Chemical receptors in carotid artery and aorta monitor blood carbon dioxide, pH and oxygen
- Blood level of carbon dioxide and blood pH are usually linked
- Increased carbon dioxide in blood and decreased blood pH triggers respiratory center to increase rate and depth of respiration
- Decreased carbon dioxide in blood pH; increased blood pH level triggers respiratory center to decrease rate and dept of respiration
What is hypoxia?
decrease in blood oxygen level
What is slight hypoxia?
triggers respiratory center to increase the rate and depth of breathing
What is severe hypoxia?
Neurons of he respiratory center can become so depressed that adequate nerve impulses cannot be sent to the respiratory muscles - can cause breathing to decrease or stop completely
