a&p 2: respiratory system

respiration

the ventilation of the lungs (breathing); part of cellular metabolism

What is the function of respiration related to gas exchange?

O₂ and CO₂ are exchanged between blood and air.

How does respiration contribute to communication?

It enables speech and other vocalizations.

What role does respiration play in olfaction?

It is involved in the sense of smell.

How does respiration influence acid-base balance?

It influences pH of body fluids by eliminating CO₂.

What is the role of respiration in blood pressure regulation?

It helps in the synthesis of angiotensin II.

How does breathing affect blood and lymph flow?

It creates pressure gradients between thorax and abdomen that promote flow.

What is the function of the lungs in blood filtration?

Lungs filter small clots from the blood.

How does breath-holding assist in expulsion of abdominal contents?

It aids in urination, defecation, and childbirth (valsalva maneuver).

principal organs in respiratory system

pharynx, larynx, trachea, bronchi, lungs

What are the microscopic air sacs in the respiratory system called?

Alveoli

What happens to incoming air in the alveoli?

It stops in the alveoli.

How do alveoli exchange gases with the bloodstream?

Through the alveolar wall.

What happens to air after it exchanges gases in the alveoli?

It flows back out.

What does the conducting zone of the respiratory system include?

Nostrils through major bronchioles

What is the primary function of the conducting zone?

Serves only for airflow

Does the conducting zone participate in gas exchange?

No, it does not

respiratory zone of the respiratory system

Consists of alveoli and other gas exchange regions

Upper respiratory tract—in head and neck

Nose through larynx

Lower respiratory tract—organs of the thorax

Trachea through lungs

What is one function of the nose related to air?

Warms, cleanses, and humidifies inhaled air

What is a sensory function of the nose?

Detects odors

How does the nose contribute to voice?

Serves as a resonating chamber that amplifies voice

Nose extends from nostrils (nares) to

the posterior nasal apertures (choanae)—posterior openings

What are the right and left halves of the nasal cavity called?

Nasal fossae

What divides the nasal cavity into right and left halves?

Nasal septum

Which bones form the roof of the nasal cavity?

Ethmoid and sphenoid bones

What forms the floor of the nasal cavity?

Hard palate

What separates the nasal cavity from the oral cavity?

Hard palate

What allows you to breathe while you chew food?

Hard palate

What drains into the nasal cavity?

Paranasal sinuses and nasolacrimal duct

What is the vestibule in the context of the nasal cavity?

The beginning of the nasal cavity; a small, dilated chamber just inside the nostrils.

What type of epithelium lines the vestibule?

Stratified squamous epithelium.

vibrissae

Stiff guard hairs that block insects and debris from entering the nose.

posteriorly the nasal cavity expands into a larger chamber with not much _______ _______

open space

nasal conchae

Chamber behind vestibule is occupied by three folds of tissue

What are the three types of nasal conchae?

Superior, middle, and inferior nasal conchae (turbinates)

Where do the nasal conchae project from?

Lateral walls toward the septum

What is a meatus in the context of nasal anatomy?

A narrow air passage beneath each concha

What is the function of the narrowness and turbulence created by the nasal conchae?

To ensure that most air contacts mucous membranes

What are the functions of the nasal conchae?

Cleans, warms, and moistens the air

What is the function of the olfactory epithelium?

Detects odors

Where is the olfactory epithelium located?

Covers a small area of the roof of the nasal fossa and adjacent parts of the septum and superior concha

What do the immobile cilia on sensory cells in the olfactory epithelium do?

Bind odorant molecules

What lines the rest of the nasal cavity except the vestibule?

Respiratory epithelium

What type of epithelium is the respiratory epithelium?

Ciliated pseudostratified columnar epithelium with goblet cells

Are the cilia in the respiratory epithelium motile?

Yes, cilia are motile

What do goblet cells in the respiratory epithelium secrete?

Mucus

What is the function of cilia in the respiratory epithelium?

Cilia propel mucus posteriorly toward the pharynx

Where does the mucus propelled by cilia go?

Swallowed into the digestive tract

What is erectile tissue also known as?

Swell body

Where is the extensive venous plexus located in relation to erectile tissue?

In the epithelium of the inferior concha

How often does the tissue on one side of erectile tissue swell with blood?

Every 30 to 60 minutes

What happens when the erectile tissue swells?

It restricts airflow through that fossa, directing most air through the other nostril

What is the purpose of allowing the engorged side time to recover?

To prevent drying

How often does the preponderant flow of air shift between the nostrils?

Once or twice an hour

Pharynx (throat)

muscular funnel extending about 5 in. from the choanae to the larynx

Three regions of pharynx

nasopharynx, oropharynx, laryngopharynx

Nasopharynx

Receives auditory tubes and contains pharyngeal tonsil

90° downward turn traps large particles (>10 μm)

Oropharynx

Space between soft palate and epiglottis, contains palatine tonsils

Laryngopharynx

Epiglottis to cricoid cartilage, esophagus begins at that point

What is the function of the nasopharynx?

The nasopharynx passes only air.

What type of epithelium lines the nasopharynx?

Pseudostratified columnar epithelium.

What do the oropharynx and laryngopharynx pass?

Air, food, and drink.

What type of epithelium lines the oropharynx and laryngopharynx?

Stratified squamous epithelium (non-keratinized).

What is the role of the muscles of the pharynx?

They assist in swallowing and speech.

What is the primary function of the larynx (voice box)?

To keep food and drink out of the airway

What is an additional role of the larynx?

Phonation — the production of sound

How long is the larynx?

About 4 cm (1.5 in.) long

What is the function of the epiglottis?

flap of tissue that guards the superior opening of the larynx.

How does the epiglottis position itself at rest?

It stands almost vertically.

What happens to the larynx during swallowing?

Extrinsic muscles of the larynx pull it upward.

What role does the tongue play during swallowing in relation to the epiglottis?

The tongue pushes the epiglottis down to meet the larynx.

What does the epiglottis do during swallowing?

It closes the airway and directs food to the esophagus behind it.

What is the role of the vestibular folds of the larynx?

They play a greater role in keeping food and drink out of the airway.

How many cartilages make up the framework of the larynx?

nine

What is the shape and position of the epiglottic cartilage?

Spoon-shaped and located in the epiglottis; it is the most superior cartilage.

What is the largest cartilage in the larynx?

Thyroid cartilage.

What is the laryngeal prominence commonly known as?

Adam's apple.

What shape is the thyroid cartilage?

Shield-shaped.

What hormone stimulates the growth of laryngeal cartilages, making them larger in males?

Testosterone.

What does the cricoid cartilage connect?

It connects the larynx to the trachea.

What is the shape of the cricoid cartilage?

Ring-like.

What are the paired cartilages located posterior to the thyroid cartilage?

Arytenoid cartilages (2)

What are the paired cartilages that are attached to the arytenoid cartilages like a pair of little horns?

Corniculate cartilages (2)

What are the paired cartilages that support soft tissue between the arytenoids and the epiglottis?

Cuneiform cartilages (2)

What ligaments suspend the larynx from the hyoid bone?

Thyrohyoid ligament

What ligament suspends the trachea from the larynx?

Cricotracheal ligament

What is the function of ligaments associated with the larynx?

They suspend the larynx from the hyoid and hold it together.

What are the superior vestibular folds also known as?

False vocal cords

Do the superior vestibular folds play a role in speech?

No, they play no role in speech.

What is the function of the superior vestibular folds during swallowing?

They close the larynx.

What do vocal cords produce when air passes between them?

Sound

What do vocal cords contain?

Vocal ligaments

What type of epithelium covers the vocal cords?

Stratified squamous epithelium

Why is the stratified squamous epithelium suited for the vocal cords?

It can endure vibration and contact.

What is the glottis?

The vocal cords and the opening between them.

Adult male vocal cords, when compared to female cords

- Usually longer and thicker

- Vibrate more slowly

- Produce lower-pitched sound

Loudness

determined by the force of air passing between the vocal cords

Vocal cords produce crude sounds that are formed into words by what?

actions of pharynx, oral cavity, tongue, and lips