A&P final: chapter 22- respiratory system

what are the four processes of respiration?

pulmonary ventilation

external respiration

transport of respiratory gases

internal respiration

what is pulmonary ventilation?

process of respiration which is breathing, consists of inspiration and expiration

what is inspiration?

moves air into lungs from the atmosphere

what is expiration?

moves air out of lungs into the atmosphere

what is external respiration?

process of respiration (2)

where does oxygen diffuse from during external respiration?

from the lungs to the blood

where does carbon dioxide diffuse from during external respiration?

from the blood to the lungs

what is transport of respiratory gases?

a process of respiration where the cardiovascular system transports gases using blood as the transporting fluid

where is oxygen transported from during the transport of respiratory gases?

from the lungs to the tissue cells of the body

where is carbon dioxide transported from during the transport of respiratory gases?

from the tissue cells to the lungs

what is internal respiration?

a process of respiration (4)

where does oxygen diffuse from during internal respiration?

from blood to tissue cells

where does carbon dioxide diffuse from during internal respiration?

from tissue cells to blood

what do tissue cells use during cellular respiration?

oxygen

what do tissue cells produce during cellular respiration?

carbon dioxide

what are the functions of the nose?

to provide an airway for respiration, to moisten and warm entering air, to filter and clean inspired air, to serve as a resonating chamber for speech, to house the olfactory receptors

what does the olfactory mucosa line?

the slitlike superior region of the nasal cavity

what does the olfactory epithelium contain?

smell receptors

what does the respiratory mucosa line?

most of the nasal cavity

what is the respiratory mucosa?

a pseudostratified ciliated columnar epithelium

what does the respiratory mucosa contain?

scattered goblet cells

what do goblet cells in the respiratory mucosa rest on?

lamina propia that are supplied with seromucous nasal glands

what do seromucous nasal glands contain?

mucus secreting mucous cells and serous cells

nasal glands secrete what each day (about a quart)?

mucus that contains lysozymes

what is the respiratory zone?

the actual site of gas exchange

what does the respiratory zone consist of?

respiratory bronchioles, alveolar ducts, alveoli, and all microscopic structures

what is the conducting zone?

provides air to reach the gas exchange sites

what does the conducting zones consist of?

nose, pharynx, larynx, trachea, bronchi, and terminal bronchioles

what is the larynx?

the voice box

how much does the larynx extend?

5 cm

where does the larynx extend from?

from the level of the third to the sixth cervical vertebra

what is the laryngeal prominence?

the “book spine” that lies in the anterior midline of the neck, adam’s apple

what are the three parts of small cartilage?

arytenoid, cuneiform, and corniculate cartilage

where are the vocal ligaments?

they lie under the laryngeal mucosa on each side

what do the vocal ligaments attach?

the arytenoid cartilages to the thyroid cartilage

what do vocal folds lack?

blood vessels

what is the glottis?

the vocal folds and medial opening between them where air passes through

as air rushes up from the lungs, what happens to the vocal folds?

they vibrate

what are the false vocal cords?

they help close the glottis when we swallow but play no direct part in sound production

what does speech involve?

the intermittent release of expired air as the glottis opens and closes

what happens when your vocal folds are tense?

they vibrate faster and produce a higher pitch

what causes a deep voice?

during puberty the larynx enlarges, causing the vocal folds to become longer and thicker

what does loudness of voice depend on?

the force in which the airstream rushes across the vocal folds

what does a greater force produce in terms of loudness of voice?

a stronger vibration and louder sound

what happens to vocal folds when we whisper?

they do not move

what happens to vocal folds when we yell?

they vibrate vigorously

what provides power for the airstream?

the muscles of the chest, abdomen, and back

why is the length of the pharynx a resonating chamber?

to amplify and enhance sound quality

what cavities contribute to vocal residence?

oral, nasal, & sinus

what does good enunciation depend on?

muscles in the pharynx, tongue, soft palate, & lips

what is the valsava maneuver?

when the glottis closes to prevent exhalation + the abdominal muscles contract —> help empty the rectum + stabilize the body trunk when lifting a heavy load

what is the thyroid cartilage in the larynx?

formed by fusion of two cartilage plates at the midline, resembles an upright open book

what do the small cartilages form?

part of the lateral and posterior walls of the larynx

what is the epiglottis?

the ninth cartilage, spoon shaped that is composed of elastic cartilage

what is the epiglottis covered by?

taste bud containing mucus

what is the trachea?

“windpipe” which descends from the larynx through the neck into the mediastinum

how long is the trachea?

10-12 cm

what is the tissue composition of the tracheal wall?

the cilia is yellow with grasslike projections, with mucus secreting goblet cells which contain short microvilli between the ciliated cells

what does the tracheal wall consist of?

the mucosa, submucosa, adventitia, and a layer of hyaline cartilage

what is the submucosa?

a connective tissue layer deep to the mucosa which contains seromucous glands that help produce mucus sheets within the trachea

what is the submucosa supported by?

16 to 20 c-shaped rings of hyaline cartilage encased by the adventitia

what is the function of the cartilage rings in the trachea?

it prevents collapsing and keeps the airway patent (open) despite pressure changes that occur during breathing

where does the trachea divide the left and right bronchi?

at level of T7

how does the right bronchus differ from the left?

it is wider, shorter, and more vertical

what is a common issue seen in the right bronchus?

inhaled foreign objects tend to get stuck more often

what does each main bronchus subdivide into?

lobar (secondary) bronchi

how many lobar bronchi are on each side?

three on the right and two on the left

what do the lobar bronchi divide into?

segmental (tertiary) bronchi

what are passages smaller than 1mm in diameter called?

bronchioles

what are the tiniest passages less than 0.5 in diameter called?

terminal bronchioles

what is a structural change that occurs when conducting tubes become smaller?

support structure changes: plates of cartilage replace cartilage rings

what is a structural change that occurs when conducting tubes become smaller?

epithelium type changes: changes from pseudostratified columnar to simple columnar to simple cuboidal

what is a structural change that occurs when conducting tubes become smaller?

amount of smooth muscles increases

what are alveoli?

thin walled air sacs

when/where does the respiratory zone begin?

when terminal bronchioles begin to feed into respiratory bronchioles within the lung

what protrudes from the small bronchioles?

scattered alveoli

what do respiratory bronchioles lead into?

alveolar ducts

what do alveolar duct walls consist of?

diffusely arranged rings of smooth muscle cells, connective tissue fibers, and outpocketing alveoli

what do alveolar ducts lead into?

terminal clusters called alveolar sacs

how many gas filled alveoli are in the lungs?

300 million

what are the walls of the alveoli composed of?

type I alveolar cells

what forms the respiratory membrane?

the capillary + alveolar walls and their fused basement membranes

what is the respiratory membrane?

a 0.5 μm thick blood air barrier which has blood flowing past on one side and gas on the other

what are the three types of cells found in the alveoli?

type I alveolar cells, type II alveolar cells, alveolar macrophages

what are type I alveolar cells?

squamous epithelial cells that form the major part of the alveolar walls

what are type II alveolar cells?

cuboidal epithelial cells that are scattered among type I cells

what do type II alveolar cells secrete?

surfactant and antimicrobial proteins

what is surfactant?

a detergent like substance that coats gas-exposed alveolar surfaces

what are alveolar macrophages

cells that crawl freely along internal alveolar surfaces consuming bacteria, dust, and other debris

what features does the alveoli have?

surrounded by fine elastic fibers and contains open alveolar pores which allow air pressure throughout the lung to be equalized

what is the left lung subdivided by?

the oblique fissure: into superior and inferior lobes

what is the right lung subdivided by?

the oblique and horizontal fissures: superior, middle, and inferior lobes

what does each lung lobe contain?

pyramid shaped bronchopulmonary segments

how do the right and left bronchopulmonary differ?

right lung has 10 segments, left lung has 8-10 segments

what are lobules?

the smallest subdivisions of the lung which are visible to the naked eye

what is stroma?

the balance of lung tissue made up of mostly elastic connective tissue

what is the intrapulmonary pressure?

the pressure in the alveoli: rises and falls with the phases of breathing

what is the intrapleural pressure?

the pressure in the pleural cavity

what causes negative intrapleural pressure?

the lungs natural tendency to recoil and the surface tension of the alveolar fluid

what is transpulmonary pressure?

the difference between the intrapulmonary and intrapleural pressures: keeps the lungs from collapsing