lab 6 - excercise 35: structure of the respiratory system

what does the nasal septum do and what is it made of?

separates the nasal cavities and is composed of:

• perpendicular plate of the ethmoid bone

• comet

• septal cartilage

what’s the entrance of the external nares (naris, singular) protected by?

guard hairs

what’s the region of the nose just posterior to the external nares?

nasal vestibule; which is lined with stratified squamous epithelium

what’s behind the vestibule?

nasal cavity

what is the nasal cavity lined with?

mucous membrane that moistens air entering the respiratory system, trapping dust particles

• made of connective tissue and respiratory epithelium

what is respiratory epithelium composed of?

pseudostratified ciliated columnar epithelium with globlet cells

what are the three protrusions that push into the nasal cavity and line the lateral walls of the cavity?

nadal conchae

what is the purpose of nasal conchae?

causes the air to swirl in the nasal cavity and come into contact with the mucous membrane

where does the nasal cavity terminate?

where two openings, the internal nares (conchae), lead to the pharynx

what are the three regions of the pharynx?

• nasopharynx (directly posterior to nasal cavity)

• oropharynx (behind oral cavity; common passageway for food, liquid, and air)

• laryngopharynx (superior to the larynx)

what are the two openings on either side of the lateral nasopharynx?

auditory tubes

what is the uvula?

small, pendulous structure that partially separates the oral cavalry from the orapharynx

• flips upward during swallowing, helps prevent fluids from entering nasopharynx

what is the larynx also known as?

the voice box because it is an important organ for sound production in humans

what is the function of the larynx?

controls the pitch of voice

what is responsible for the sonority (sound quality) of the voice?

the shape of the oral cavity and the placement and size of the paranasal sinuses

where is the larynx located?

about the fourth through sixth cervical vertebrae and consist of a number of cartilages

what is the most prominent cartilage in the larynx?

the thyroid cartilage; a shield shaped structure made of hyaline cartilage

why is the thyroid cartilage more prominent in males?

influence of testosterone

what is inferior to the thyroid cartilage?

cricoid cartilage

cricoid cartilage

composed of hyaline cartilage; relatively narrow at the anterior but increases in size at its posterior surface

what is superior to the cricoid cartilage in the posterior wall of the larynx?

paired arytenoid cartilages

where do the arytenoid cartilages attach?

posterior end of the vocal folds (true vocal cords)

how is pitch controlled?

muscles pull the arytenoid cartilages, stretching the vocal cords, and increasing pitch

what muscles pull the arytenoid cartilages that control pitch?

intrinsic muscles attached to the arytenoid cartilages from the back, while the vocal folds are held stationary by the thyroid cartilages in the front

what is above the vocal folds?

vestibular folds (false vocal cords)

what are at the posterior, superior edge of the larynx?

corniculate and cuneiform cartilages

what are these made of?

hyaline cartilage

what is the most superior cartilage of the larynx?

epiglottis, composed of elastic cartilage

what is the glottis?

the opening of the larynx; covered by the epiglottis when swallowing

cough reflex

attempts to propel the liquid out of the respiratory system (frequently through the nose)

what is the trachea also known as?

the windpipe; because it conducts air from the larynx to the lungs

what is the trachea?

straight tube whose lumen is kept open by tracheal cartilages

what shape are tracheal cartilages?

c - shaped

what are the tracheal cartilages composed of?

hyaline cartilage

what is at the most inferior portion of the trachae?

center point known as the carina

what is the trachea lined with?

respiratory epithelium

what does the trachea split into?

main, or primary, bronchi

what does each lung receive air from?

primary bronchus; contain hyaline cartilage and lined with respiratory epithelium

what do the primary bronchi of the lung divide to form?**

lobar, or secondary, bronchi - which further divide to form segmental, or tertiary, bronchi

what does the extensive branching of the bronchi form?

tracheobronchial tree

what is the difference in lobes between the right and left lungs?

the right lung has three lobes and the left lung has two lobes

what lobes are in the right lung compared to the left lung?*

right lung: superior, middle, and inferior lobes

left lung: superior and inferior lobes; AS WELL AS an indication occupied by the heart; known as the cardiac notch

where are the lungs located?

pleural cavities; one of each side of the mediastinum

parietal pleura

outer membrane on the chest cavity wall

visceral pleura

membrane on the surface of the lungs

what’s the space in-between the membranes?

pleural cavity

what do the pleura secrete?

pleural fluid, which allows the visceral and parietal pleura to slide across one another - but the pleural fluid also causes the membranes to stick to one another

what happens when the chest cavity expands?

the parietal pleura moves with it and causes the visceral pleura to expand as well, thus causing the lungs to inflate