(Lesson 19) Respiratory System Flashcards
Respiratory System
Supplies the body’s trillions of cells with oxygen and disposes of CO2.
Pumlonary Respiration
Air moved in and out of the lungs so gases in the air sacs (alveoli) of the lungs are continuously replaced.
AKA **Ventilation **or breathing
External Respiration
Gas exchange must occur between the blood and air at the lung alveoli. Oxygen in the air sacs diffuses into the blood; CO2 in blood diffuses into air sacs.
Transport of respiratory gases
Oxygen and CO2 must be transported between the lungs and the celld of the body. This is accomplished by the cardiovascular system with blood serving as the transporting fluid.
Internal respiration
At the systemic capillaries, gases must be exchanged between blood and tissue cells.
Cellular respiration
The process by which oxygen is used by the cells and CO2 is produced as a waste product during this chemical process that converts glucose to cellular energy (ATP)
Organs of the respiratory system
- nose
- nasal cavity
- paranasal sinuses
- pharynx
- larynx
- bronchi and smaller branches
- lungs
- Alveoli
Nose
the only externally visible part of the respiratory system.
- provides airway for respiration
- moisten and warms entering air
- filters inhaled air to cleanse it of foreign particles
- serves as a resonating chamber for speech
- houses olfactory receptors
External nose
Consists of:
- frontal and nasal bones superiorly
- maxillary bones laterally
- flexible plates of hyaline cartilage inferiorly (lateral, septal, and alar cartilages)
Nasal Cavity
lies in and posterior to the external nose.
- Nares
- posterior nasal apertures
- lined with ciliated pseudostratified columnar epithelium
- vestibule
- lined with 2 types of muscous membranes
- olfactory mucosa
- near the roof of the nasal cavity.
- Houses receptors for smell
- respiratory mucosa
- lines the majority of the nasal cavity
- olfactory mucosa
External Nares
nostrils
Posterior nasal apertures
AKA choanae/internal nares
connection between the nasal cavity and the nasopharynx
Boundaries of nasal cavity
- roof is formed by ethmoid/sphenoid bones
- floor is formed by palate
- anteriorly, hard palate (palatine bone and palatine process of maxilla)
- posteriorly, muscular soft palate
Vestibule
the part of the nasal cavity that lies just superior to the nostrils, within the flared wings of the external nose. “Porch, entranceway”
Lined with skin containing sebaceous glands, sweat glands and numerus hair follicles.
Vibrissae
- Nose hairs
- filter large particles like insects and lint
Respiratory Mucosa
- Pseudostratified ciliated columnar epithelium
- scattered goblet cells
- underlying connective tissue lamina propria w/ tubular alveolar glands
- mucous cells:
- secrete mucous
- Serous cells:
- secrete watery fluid containing digestive enzyme
- mucous cells:
Nasal glands and goblet cells
(respiratory mucosa)
- Each day they secrete a quart of mucous contaning lysozyme.
- Lysozyme is an enzyme that digests and destroys bacteria
- sheet of mucous traps inhaled dust, bacteria, pollen, viruses, and other debris from the air.
- Cilia moves sheets of mucous to posterior pharynx where it swallowed and broken down by digestive juices in the stomach
Nasal Mucousa
- Richly supplied with sensory nerve endings
- sneeze reflex is stimulated when irritating particles (dust, pollen) contact this sensitive mucosa.
The nose in cold temperatures
Vascular plexus engorge with warm blood to be able to continue to heat incoming air. Because of the abundance and superficial location of these vessels, nose bleeds are often common and profuse.
The Nasal Conchae
mucosa-covered scroll-like structures projecting medially from each lateral wall of the nasal cavity
- superior concha of ethmoid bone
- middle concha of ethmoid bone
- inferior concha (separate bone)
- *meatus: *groove inferior to each concha
Function:
- increased surface area traps particualte matter
- moisten/heat during inhalation
- reclaim moisture and heat during exhalation
Paranasal sinus
- a ring of air-filled cavities surrounding the nasal cavity
- lined with same mucosa and perform same functions as nasal cavity.
- suctioning effect by nose blowing helps drain them
- located in
- frontal bone
- sphenoid bone
- ethmoid bone
- maxillary bone
sinusitis
- inflammation of the paranasal sinuses
- caused by viral, bacterial, or fungal infections
- passages become blocked, vaccuum formed and sinus headache occurs
- if infection persists, inflammatory fluid exerts painful pressure
- Serious cases can be treated by promoting drainage and antibiotics
Pharynx
- funnel-shaped passageway that connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly
- descends from base of skull to 6th cervical vertebrae
- common passageway for food and air
- commonly called the throat
Nasopharynx
- Directly posterior to nasal cavity
- serves only as air passageway
- soft palate and uvula prevent food from entering
Pharyngeal Tonsils
- Adenoids
- lymphoid organ tissue that destroys pathogens entering the nasopharynx in the air
pharyngotympanic (auditory) tube
- drains the middle ear
- opens into each lateral wall of nasopharynx
tubal tonsil
- a ridge of pharyngeal mucosa posterior to the pharyngotympanic tube
- provides the middle ear some protection against infections that may spread from pharynx
Oropharynx
- lies posterior to the oral cavity
- extends inferiorly from soft palate/uvula to epiglottis/hyoid bone
- air and food pass through
- stratified squamous epithelium
Fauces
- “throat”
- the archlike entranceway to the oropharynx directly behind the mouth
epithelium of the pharynx
- Nasopharynx: Ciliated pseudostratified epithelium
- Oropharynx: protective stratified squamos epithelium
- Laryngopharynx: stratified squamos epithelium
Palatine Tonsils
- paired lymph nodes
- lateral to the walls of the fauces
- oropharynx
Lingual tonsil
- unpaired
- covers the posterior surface of the tongue
- oropharynx
Laryngopharynx
- common passageway for air and food
- from hyoid to inferior border of cricoid
- directly posterior to the larynx and continous with:
- esophagus: conducts food and fluid to stomach
- larynx: conducts air to respiratory tract
Larynx
- Voice Box
- From 4th cervical vertebra to 6th cervical vertebra
- attaches to hyoid bone superiorly and opens into laryngopharynx
- inferiorly it is continuous with trachea
Functions of the Larynx
- produces vocalizations
- provides an open airway
- acts as a switching mechanism to route air and food into the proper channels
- inlet (superior opening) is closed during swallowing and open during breathing
9 Cartilages of Larynx
- Thyroid Cartilage
- Cricoid Cartilage
- Arytenoid Cartilages (2)
- Corniculate Cartilages (2)
- Cuneiform Cartilages (2)
- Epiglottis
Thyroid Cartilage
(Larynx)
- large, shield-shaped cartilage formed by two cartilage plates
- Laryngeal prominence:
- Adam’s Apple
- Larger in males than in females because males sex hormone stimulates its growth during puberty
Cricoid Cartilage
(Larynx)
- The only laryngeal cartilage that forms a complete ring
- Shaped like a signet ring, wide posteriorly and narrow anteriorly
- perched atop the trachea
Arytenoid Cartilages
(Larynx)
- Most important of paired larygeal cartilages
- anchor the vocal cords
Epiglottis
(Larynx)
- Means “upon the tongue”. “Guardian of the airways”.
- composed of elastic cartilage and is almost entirely covered by a mucosa.
- stalk attaches anteriorly to the internal aspect of the angle of the thyroid cartilage
- projects superoposteriorly and attached to the posterior aspect of the tongue
- during swallowing the entire larynx is pulled superiorly and the epiglottis tips inferiorly to cover and seal the laryngeal inlet
Vocal folds
aka True vocal cords
- paired vocal ligaments that run anteriorly from the arytenoid cartilages to the thyroid cartilage.
- composed largely of elastic fibers
- covered in avascular mucus that make the folds look pearly white
Vocal Folds Function
- Air exhaled from lungs
- Folds vibrate in in a wave motion and clap together
- Basic sounds for speech are produced
Rima Glottidis
(vocal folds)
- medial opening between the vocal folds through which air passes
glottis
- vocal folds and rima glottidis together form this