Respiratory System 2 (Lower)

Front 1

Lower Respiratory Tract

Back 1

– larynx
– trachea
– bronchi
– Bronchioles
• Includes structures involved in gas exchange:
– respiratory bronchioles – alveolar ducts – alveoli
•Lower respiratory tract infections affect some or all of these structures

Front 2

Larynx

Back 2

– Also called the voice box
– Cylindrical air way (円筒)
– Continuous with the laryngopharynx superiorly
– Continuous with the trachea inferiorly
– Has several major functions

Front 3

Functions of the larynx 1-3

Back 3

1) Air passage way – Normally the larynxis open
2) Prevents ingested materials from entering the respiratory tract
– During swallowing the superior opening covered
3) Produces sound for speech
– Ligaments vibrate when air passes over them during expiration
• termed vocal cords

Front 4

Functions of the larynx 4

Back 4

4) Assists in increasing pressure in the abdominal cavity – Epiglottis closes over the larynx
• air cannot escape
– Abdominal muscles simultaneously contract
– Action called the Valsalva maneuver
– Valsalva facilitates several physiological processes
• elimination of urine from the bladder
• elimination of feces from the gastrointestinal tract
• expulsion of a baby during childbirth

Front 5

Functions of the larynx 5

Back 5

•
Participates in both a sneeze and cough reflex – Irritantsinthenasalcavitycantriggerasneeze – Irritantsinthetracheaandbronchicantriggeracough – Abdominalmusclescontractforcefully
– Thoracic pressure increases
– Initially closed vocal cords are forcibly opened by pressure
– Explosive blast of exhaled air is a cough or sneeze
• helps remove irritants from the respiratory tract

Front 6

Larynx Anatomy

Back 6

• Laryngeal inlet (laryngeal aperture)
– Opening connecting the pharynx and the larynx
• Formed and supported by 9 pieces of cartilage
– Cartilage held in place by ligaments and muscles
– Single thyroid, cricoid, and epiglottis cartilages
– Paired arytenoid, corniculate, and cunei form cartilages

Front 7

Larynx Anatomy (continued)
• Thyroidcartilage

Back 7

– Largest laryngeal cartilage
– Shield shaped
– Forms lateral and anterior walls of the larynx
– Anterior protrusion is the laryngeal prominence,or Adam’sapple
• generally larger in males
• enlarges during puberty
– Attached to the lateral surface of the cricoid cartilage

Front 8

Larynx Anatomy (continued)
• Cricoidcartilage

Back 8

– Ring-shaped
– Inferiortothethyroidcartilage

Front 9

Larynx Anatomy (continued)
Epiglottis

Back 9

– Spoon-orleaf-shaped
– Anchored to thyroid cartilage
– Projects posterosuperiorly into the pharynx
– Closes over laryngeal inlet during swallowing
* Epiglottis composed of flexible elastic cartilage

Front 10

Larynx Anatomy (continued)
• Paired cartilages

Back 10

– Arytenoid
– Corniculate
– Cuneiform
– Smaller, located internally
• All cartilages composed of hyaline cartilage, except the epiglottis
– Epiglottis composed of flexible elastic cartilage

Front 11

Larynx Anatomy (continued)
• Laryngeal ligaments classified as extrinsic or intrinsic

Back 11

– Extrinsic ligaments
• attach to the external surface of the laryngeal cartilages
• extend to other structures (e.g., hyoid bone, trachea) – Intrinsic ligaments
• are located within the larynx
• include the vocal ligaments and the vestibular ligaments

Front 12

Larynx Anatomy (continued)
• Vocalligaments

Back 12

–Extend anterior to posterior between the thyroid and arytenoid cartilages
– Composed primarily of avascular elastic connective tissue
– Covered with mucosa to form the vocal folds (true vocal cords)
– Produce sound when air passes between them
– Opening between the ligaments = rima glottidis
– Rimaglottidis+vocalfolds=glottis

Front 13

Larynx Anatomy (continued)
• Vestibular ligaments

Back 13

– Extendbetweenthyroidcartilagetothearytenoidandcorniculate cartilages
– Coveredwithmucosatoformthevestibularfolds • locatedsuperiorlytothevocalfolds • vestibularfolds=falsevocalcords • playnoroleinsoundproduction
• protectthevocalcords – Openingbetweenvestibularfolds=rimavestibuli