Lecture 18- Respiratory System

Question 1

Major functions of respiratory system

Answer 1

Supply blood with O2 for cellular respiration and dispose CO2

Functions in olfaction and speech

Question 2

Four processes of respiration

Answer 2

Respiratory system:

Pulmonary ventilation (breathing)- movement of air into and out of the lungs

External respiration- exchange of O and CO2 between lungs and blood

Circulatory system:

Transport of O2 and CO2 in blood

Internal respiration- exchange of O2 and CO2 between blood and body tissues through blood vessels

Question 3

Major organs in upper respiratory tract

Answer 3

Nose and nasal cavity
Parasail sinuses
Pharynx
Larynx

Question 4

Major organs in lower respiratory tract

Answer 4

Trachea
Bronchi and branches
Lungs and alveoli

Question 5

External nares

Answer 5

Nostrils

Question 6

What is the nasal cavity lined with?

Answer 6

anterior nasal cavity is lined with skin containing sebaceous sweat glands, and hairs.

Remainder of nasal cavity is lined with two types of mucous membranes:

The olfactory mucosa contains receptors for smell.

The respiratory mucosa has scattered goblet cells, for mucus production.

Question 7

Nasal conchae

Answer 7

Protrude into the nasal cavity from each lateral wall, increasing mucosal surface exposure in order to filter, heat and moisten air

Question 8

What surrounds nasal cavity?

Answer 8

paranasal sinuses within the frontal, maxillary, sphenoid, and ethmoid
bones that serve to lighten the skull, warm and moisten air, and produce mucus.

Question 9

Nasopharynx

Answer 9

ONLY air passageway and contains the pharyngeal tonsil, which traps and destroys airborne pathogens

Question 10

Oropharynx

Answer 10

Air and food passageway that extends from the sot palate to the epiglottis and contains the palatine and lingual tonsils

Question 11

Larygopharynx

Answer 11

Air and food passageway that lies directly posterior to the epiglottis, extends to the larynx and is continuous inferiorly with the esophagus

Question 12

Larynx

Answer 12

attaches superiorly to the hyoid bone, opening into the laryngopharynx, and attaches inferiorly to the trachea.

Provides open airway, routes food and air into proper passageways and produces sound through vocal cords

Question 13

What does the larynx consist of?

Answer 13

hyaline cartilages: thyroid, cricoid, arytenoid, corniculate, and cuneiform cartilages; and the epiglottis, which is elastic cartilage.

Question 14

Epiglottis

Answer 14

designed to close off the larynx during swallowing to prevent food or liquids from entering the airways.

Question 15

Glottis

Answer 15

term for the vocal folds and the medial space between them.

Question 16

What does voice production involve?

Answer 16

intermittent release of expired air and the opening and closing of the glottis.

Question 17

How is pitch of voice determined?

Answer 17

length and tension of the vocal folds change, pitch of the voice varies.

as tension increases, pitch becomes higher. Longer, thicker vocal folds vibrate more slowly and produce a lower pitched sound.

Loudness of voice is determined by force of air forced over vocal folds

Question 18

Trachea (windpipe)

Answer 18

descends from the larynx through the neck into the mediastinum, where it terminates at the primary bronchi

Question 19

What is trachea lined with?

Answer 19

ciliated pseudostratified columnar epithelium, designed to propel mucus upward toward the pharynx.

Question 20

What supports the trachea?

Answer 20

C-shaped cartilaginous rings associated with the connective tissue submucosa, preventing collapse, while allowing the esophagus to expand normally during swallowing.

Question 21

Trchealis

Answer 21

smooth muscle that decreases the trachea’s diameter during contraction, increasing the force of air out of the lungs.

Question 22

Conducting zone

Answer 22

consists of right and left primary bronchi that enter each lung and diverge into secondary bronchi to each lobe of the lungs.

Secondary bronchi branch into several orders of tertiary bronchi, which branch into bronchioles.

Question 23

What are the structural changes that occur when airways become smaller?

Answer 23

The supportive cartilage changes until it is no longer present in the bronchioles

The mucosal epithelium transitions from pseudostratified columnar, to columnar, and finally, to cuboidal in the terminal bronchioles.

The relative amount of smooth muscle in the walls increases, allowing significant changes in resistance to airflow in the smaller airways.

Question 24

Respiratory zone

Answer 24

begins as the terminal bronchioles feed into respiratory bronchioles that terminate in alveolar ducts within clusters of alveolar sacs, which consist of alveoli.

Question 25

What forms the respiratory membrane?

Answer 25

the capillary endothelium and the alveolar epithelium

Question 26

What does the respiratory membrane consist of?

Answer 26

single layer of squamous epithelium type I alveolar cells, surrounded by a basal lamina.

Interspersed among the type I alveolar cells are cubodial type II alveolar cells that secrete surfactant to reduce surface tension in the lungs.

Question 27

Alveoli

Answer 27

surrounded by elastic fibres, contain alveolar pores to allow airflow between adjacent alveoli, and have alveolar macrophages to phagocytose any foreign particles that get in.