Chapter 23 Flashcards
Respiration
The process of supplying the body with O2 and removing CO2.
What are the three basic steps of respiration? Describe them:
- Pulmonary ventilation AKA breathing: the inhalation (inflow) and exhalation (outflow) of air and involves the exchange of air between the atmosphere and the alveoli of the lungs. Inhalation permits O2 to enter the lungs and exhalation permits CO2 to leave the lungs.
- External (pulmonary) respiration: the exchange of gases between the alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane. In this process, pulmonary capillary blood gains O2 and loses CO2.
- Internal (tissue) respiration: the exchange of gases between blood in systemic capillaries and tissue cells. In this step the blood loses O2 and gains CO2.
Cellular respiration
Metabolic reactions within cells that consume O2 and give off CO2 during the production of ATP.
Respiratory system
Consists of the nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, and lungs.
What two ways can the parts of the respiratory system be classified?
- Structure
- Function
Structurally, the respiratory system consists of two parts. What are they? Describe them:
- Upper respiratory system: includes the nose, nasal cavity, pharynx, and associated structures.
- Lower respiratory system: includes the larynx, trachea, bronchi, and lungs.
Functionally, the respiratory system consists of two parts. What are they? Describe them:
- Conducting zone: consists of a series of interconnecting cavities and tubes both outside and within the lungs. These include the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles; their function is to filter, warm, and moisten air and conduct it into the lungs.
- Respiratory zone: consists of tubes and tissues within the lungs where gas exchange occurs. These include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli and are the main sites of gas exchange between air and blood.
What are the three functions of the respiratory system?
- Provides for gas exchange: intake of O2 for delivery to body cells and removal of CO2 produced by body cells.
- Helps regulate blood pH.
- Contains receptors for sense of smell, filters inspired air, produces vocal sounds (phonation), and excretes small amounts of water and heat.
Nose
Is a specialized organ at the entrance of the respiratory system.
What two portions does the nose consist of?
- External nose
- Internal nose
Bony framework
Formed by the frontal bone, nasal bones, and maxillae.
Cartilaginous framework
Formed by the septal nasal cartilage, lateral nasal cartilages, and alar cartilages.
Septal nasal cartilage
Forms the anterior portion of the nasal septum.
Lateral nasal cartilages
Inferior to the nasal bones.
Alar cartilages
Form a portion of the walls of the nostrils.
External nares (nostrils)
Two openings on the undersurface of the external nose.
What are the three functions of the inferior structures of the external nose?
- Warming, moistening, and filtering incoming air.
- Detecting olfactory stimuli.
- Modifying speech vibrations as they pass through the large, hollow resonating chambers.
Resonance
Prolonging, amplifying, or modifying a sound by vibration.
Nasal cavity (internal nose)
A large space in the anterior aspect of the skull that lies inferior to the nasal bone and superior to the oral cavity; is lined with muscle and mucous membrane.
Nasal septum
Divides the nasal cavity into right and left sides. The anterior portion of the nasal septum consists primarily of hyaline cartilage; the remainder is formed by the vomer and the perpendicular plate of the ethmoid, maxillae, and palatine bones.
Internal nares (choanae)
Two openings which the nasal cavity communicates with the pharynx through.
Paranasal sinuses
Drain mucus. Also serve as resonating chambers for sound as we speak or sing.
Nasolacrimal ducts
Drain tears.
What two regions can the nasal cavity be divided into? Describe the epithelium, cilia, goblet cells, and special features for these regions:
- Respiratory region:
Epithelim: ciliated pseudostratified columnar
Cilia: yes.
Goblet cells: yes.
Special features: contains conchae and meatuses - Olfactory region:
Epithelim: olfactory epithelium (olfactory receptors).
Cilia: yes.
Goblet cells: no.
Special features: functions in olfaction.
Respiratory epithelium
Found within the respiratory region. Lined with ciliated pseudostratified columnar epithelium with numerous goblet cells.
Describe the epithelium, cilia, goblet cells, and special features for the nasal vestibules:
Epithelium: nonkeratinized stratified squamous.
Cilia: no.
Goblet cells: no.
Special features: contains numerous hairs.
The superior, middle, and inferior ______ subdivide each side of the nasal cavity into a series of groove-like air passageways called the superior, middle, and inferior ______.
Nasal conchae; meatuses
What does the arrangement of nasal conchae and meatuses do?
Increases surface area in the internal nose and prevents dehydration by trapping water droplets during exhalation.
Olfactory epithelium
Found within the olfactory region. Made up of the olfactory receptor cells, supporting cells, and basal cells. Contain cilia but no goblet cells.
Pharynx
AKA throat; functions as a passageway for air and food, provides a resonating chamber for speech sounds, and houses the tonsils, which participate in immunological reactions against foreign invaders.
What three anatomical regions can the pharynx be divided into?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Describe the epithelium, cilia, goblet cells, and special features for the nasopharynx:
Epithelium: ciliated pseudostratified columnar.
Cilia: yes.
Goblet cells: yes.
Special features: passageway for air; contains internal nares, openings for auditory (pharyngotympanic) tubes (eustachian tubes), and pharyngeal tonsil.
Soft palate
Forms the posterior portion of the roof of the mouth. Is an arch-shaped muscular partition between the nasopharynx and oropharynx that is lined by mucous membrane.
Describe the epithelium, cilia, goblet cells, and special features for the oropharynx:
Epithelium: nonkeratinized stratified squamous.
Cilia: no.
Goblet cells: no.
Special features: passageway for both air and food and drink; contains opening from mouth (fauces). Contain the palatine and lingual tonsils.
Describe the epithelium, cilia, goblet cells, and special features for the laryngopharynx (hypopharynx):
Epithelium: nonkeratinized stratified squamous.
Cilia: no.
Goblet cells: no.
Special features: passageway for both air and food and drink.
Describe the epithelium, cilia, goblet cells, and special features for the larynx (voice box):
Epithelium: nonkeratinized stratified squamous above the vocal folds; ciliated pseudostratified columnar below the vocal folds.
Cilia: no above folds; yes below folds.
Goblet cells: no above folds; yes below folds.
Special features: passageway for air; contains vocal folds for voice production.
How many pieces of cartilage is the wall of the larynx composed of? What are they?
9; thyroid cartilage (single), epiglottis (single), cricoid cartilage (single), arytenoid cartilages (pairs), cuneiform
cartilages (pairs), and corniculate cartilages (pairs).
Which of the paired cartilages is most important? Why?
The arytenoid cartilages because they influence changes in position and tension of the vocal folds (true vocal cords for speech).
Cavity of the larynx
The space that extends from the entrance into the larynx down to the inferior border of the cricoid cartilage.
Laryngeal vestibule
The portion of the cavity of the larynx above the vestibular folds (false vocal cords).
Infraglottic cavity
The portion of the cavity of the larynx below the vocal folds.
Thyroid cartilage (Adam’s apple)
Consists of two fused plates of hyaline cartilage that form the anterior wall of the larynx and give it a triangular shape. Is present in both males and females but is usually larger in males due to the influence of male sex hormones on its growth during puberty.
Epiglottis
A large, leaf-shaped piece of elastic cartilage that is covered with epithelium. The “stem” of the epiglottis is the tapered inferior portion that is attached to the anterior rim of the thyroid cartilage. The broad superior “leaf” portion of the epiglottis is unattached and is free to move up and down like a trap door.
Glottis
Consists of a pair of folds of mucous membrane, the vocal folds (true vocal cords) in the larynx, and the rima glottidis (space between them).
During swallowing, the ______ and ______ rise. Elevation of the ______ widens it to receive food or drink; elevation of the ______ causes the ______ to move down and form a lid over the ______, closing it off.
The closing of the ______ in this way during swallowing routes liquids and foods into the esophagus and keeps them out of the ______ and airways. When small particles of dust, smoke, food, or liquids pass into the ______, a cough reflex occurs, usually expelling the material.
Pharynx; larynx; pharynx; larynx; epiglottis; glottis
Larynx; larynx; larynx
Cricoid cartilage
A ring of hyaline cartilage that forms the inferior wall of the larynx.
Arytenoid cartilages
Triangular pieces of mostly hyaline cartilage that are located at the posterior, superior border of the cricoid cartilage.
Corniculate cartilages
Horn-shaped pieces of elastic cartilage that are located at the apex of each arytenoid cartilage.
What do the cilia in the upper respiratory tract do?
Move mucus and trapped particles down toward the pharynx (While the cilia in the lower respiratory tract move them up toward the pharynx).
The mucous membrane of the larynx forms two pairs of folds. What are they? What are there functions?
- Vestibular folds (false vocal cords): superior pair. Function in holding the breath against pressure in the thoracic cavity.
- Vocal folds (true vocal cords): inferior pair. Principal structures of voice production.
Rima vestibuli
The space between the vestibular folds.
Laryngeal ventricle
A lateral expansion of the middle portion of the laryngeal cavity inferior to the vestibular folds and superior to the vocal folds.
Pitch
Controlled by the tension on the vocal folds. If they are pulled taut by the muscles, they vibrate more rapidly, and a higher pitch results. If muscle tension is decreased, they vibrate more slowly, and a lower pitch results. Due to the influence of androgens, vocal folds are usually thicker and longer in males than in females, and therefore they vibrate more slowly. This is why a man’s voice generally has a lower range of pitch than that of a woman.
Sound
Originates from the vibration of the vocal folds, but other structures are necessary for converting the sound into recognizable speech. The pharynx, mouth, nasal cavity, and paranasal sinuses all act as resonating chambers that give the voice its human and individual quality. We produce the vowel sounds by constricting and relaxing the muscles in the wall of the pharynx. Muscles of the face, tongue, and lips help us enunciate words.
Describe the epithelium, cilia, goblet cells, and special features for the trachea (windpipe):
Epithelium: ciliated pseudostratified columnar.
Cilia: yes.
Goblet cells: yes.
Special features: passageway for air; contains C-shaped rings of cartilage to keep trachea open.
What are the four layers of the tracheal wall, from deep to superficial?
- Mucosa
- Submucosa
- Hyaline cartilage
- Adventitia
Fibromuscular membrane
Spans the open part of each C-shaped cartilage ring that faces posteriorly towards the esophagus. Contains trachealis muscle and elastic connective tissue.
Trachealis muscle
Transverse smooth muscle fibers that, with the help of elastic connective tissue, allow that diameter of the trachea to change subtly during inhalation and exhalation, which is important in maintaining efficient airflow.
At the superior border of the fifth thoracic vertebra, the trachea divides into two bronchus. What are they? Describe them:
- Right main (primary) bronchus: goes into the right lung; more vertical, shorter, and wider than the left, so an aspirated object is more likely to enter and lodge in the right main bronchus than the left.
- Left main (primary) bronchus: goes into the left lung.
Describe the epithelium, cilia, goblet cells, and special features for the main bronchi:
Epithelium: ciliated pseudostratified columnar.
Cilia: yes.
Goblet cells: yes.
Special features: passageway for air; contain C-shaped rings of cartilage to maintain patency.
Carina
Internal ridge where the trachea divides into right and left main bronchi.
Describe the epithelium, cilia, goblet cells, and special features for the lobar bronchi:
Epithelium: ciliated pseudostratified columnar.
Cilia: yes.
Goblet cells: yes.
Special features: passageway for air; contain plates of cartilage to maintain patency.
Describe the epithelium, cilia, goblet cells, and special features for the larger bronchioles:
Epithelium: ciliated simple columnar.
Cilia: yes.
Goblet cells: yes.
Special features: passageway for air; contain more smooth muscle than in the bronchi.
Describe the epithelium, cilia, goblet cells, and special features for the smaller bronchioles:
Epithelium: ciliated simple columnar.
Cilia: yes.
Goblet cells: no.
Special features: passageway for air; contain more smooth muscle than in the larger bronchioles.
Describe the epithelium, cilia, goblet cells, and special features for the terminal bronchioles:
Epithelium: nonciliated simple columnar.
Cilia: no.
Goblet cells: no.
Special features: passageway for air; contain more smooth muscle than in the smaller bronchioles. Contain club (Clara) cells
Club (Clara) cells
Found in terminal bronchioles. May protect against harmful effects of inhaled toxins and carcinogens, produce surfactant, and function as stem cells (reserve cells), which give rise to various cells of the epithelium.
Describe the branching of airways from the trachea (bronchial tree)
Trachea -> main bronchi -> lobar bronchi -> segmental bronchi -> bronchioles -> terminal bronchioles
As the branching becomes more extensive in the bronchial tree,
several structural changes may be noted. What are the main three?
- Mucous membrane in the bronchial tree
- Plates of cartilage
- Amount of smooth muscle
Lungs
Paired cone-shaped organs in the thoracic cavity. They are separated from each other by the heart and other structures of the mediastinum.
Pleural membrane (pleura)
Double-layered serous membrane that encloses and protects each lung.