respiratory system Flashcards
A series of organs responsible for taking in oxygen and expelling carbon dioxide.
respiratory system
what are the functions of the respiratory system
- Supply the body’s need for oxygen and to give off carbon dioxide (as it is a waste product and not needed in the body).
2.Maintaining homeostasis and a normal pH
- pH 7.35-7.45
- Adjust the CO2 levels of the body through breathing to maintain.
- The faster the breathing, it increases the pH and reduces the acidity.
- The slower the breathing, it decreases the pH and increases the acidity.
- Immune defense against bacteria and viruses.
- has numerous cilia, hair-like structures which is responsible to trap the viruses and the bacteria.
what is the normal pH of the respiratory system
pH 7.35-7.45
briefly explain the anatomical classification
- Upper respiratory tract
Sphenoid sinus
Frontal sinus
Nasal cavity
Pharynx - Lower respiratory tract
Larynx
Trachea
Bronchi
Lungs
briefly explain the functional and histological classification
- Conducting Portion
- serves as passageways for air to and from the alveoli
- organs involved:
Nasal cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchiole
Terminal bronchiole - Respiratory Portion
- where gas exchange occurs.
- organs involved:
Respiratory bronchioles
Alveolar ducts
Alveoli
what are the conducting portion and respiratory portion
CONDUCTING
1. Nasal cavity
- Nasal vestibule
- Nasal mucosa
- Olfactory mucosa
2. Nasopharynx
3. Oropharynx
4. Larynx
- Epiglottis
- Vocal cords (folds)
5. Trachea
6. Bronchi
- Bronchioles
- Terminal bronchioles
RESPIRATORY
1. respiratory bronchioles
2. alveolar ducts
3. alveoli
it is a hollow organ that serves as the primary entry point for air into the respiratory system
nose
- internal space is divided into two nasal cavities (or nasal fossae) by the nasal septum, a structure composed of cartilage and bone.
three shelf-like structures that occupy the lateral wall of the nasal cavity
Nasal conchae
- its 3 layers
Superior nasal turbinate
Middle nasal turbinate
Inferior nasal turbinate
function of nasal conchae
increase the surface area of the nasal cavity, helping to warm, humidify, and filter incoming air before it reaches the lungs.
composition of external coverings of nasal cavity
nose (hollow organ)
external coverings such as
- skin
- sweat glands
- sebaceous glands
- hair
external opening of the nasal cavity which serves as a passageway of inhaled air and shares moist stem and warm humidity
nostrils
mucus membrane of the nasal cavity
internal covering
space or cavity at the entrance of the nose
vestibule
made up of bones and partially hyaline cartilage
roof and floor
forms the middle wall of each of the nasal cavity
septum
the first and most superior part of the upper respiratory tract
nasal cavity
what are the 3 regions the nasal cavity is divided into based on the type of epithelial coverings
Nasal vestibule
Nasal mucosa region
Olfactory mucosa region
most anterior part of the nasal cavity
nasal vestibule
covered by:
external - skin
internal - keratinized stratified squamous epithelium and vibrissae (stiff hairs)
*Vibrissae - entraps dust particles and prevents it from entering the lungs
entraps dust particles and prevents it from entering the lungs
vibrissae
in the nasal vestibule, where can the sebaceous gland be found
roof of the vibrissal follicles
type of epithelium that covers the nasal mucosa region
pseudostratified ciliated epithelium (respiratory epithelium), which contains:
- ciliated columnar cells
- goblet
- serous cells
- brush cell
- basal cells
- granule cell
what are venous plexuses in the nasal conchae
vascular networks in the lamina propria of the nasal conchae
that help warm and humidify incoming air
*it is alternatively filled with blood from small arteries which directly supply to the venous plexus
briefly explain
- basal cells
- goblet cells
- ciliated columnar cells
- source cells
transes
function of olfactory mucosa
a site for odorant chemoreception
*Chemoreception:
to perceive environmental chemical compounds and to convert them into external signals into intracellular messages
to perceive environmental chemical compounds and to convert them into external signals into intracellular messages
chemoreception
Example: In the nose, olfactory receptors detect odor molecules and send signals to the brain to recognize different smells.
briefly explain how chemoreception happens in olfactory mucosa
- Odorant Molecules Contact the Olfactory Epithelium
- Example: Coffee molecules enter the nasal cavity and reach the olfactory epithelium. - Binding to Olfactory Receptors
- The molecules bind to the cilia of olfactory receptor cells in the olfactory mucosa. - The signal is sent from the olfactory bulb → olfactory tract.
- The olfactory tract links the smell to the olfactory nerves, which process it as a memory or perception (e.g., recognizing the smell of coffee).
where is the olfactory mucosa located and what is it composed of
located:
in the roof of the nasal cavity and is covered by pseudostratified columnar epithelium
composed of:
Olfactory receptor neuron
Supporting cell
Basal cell
Lamina Propria
- Bowman glands
- Olfactory fila
- Blood vessels
what are olfactory mucosa’s 3 types of cell and its function
- Olfactory receptor neurons
The receptors that respond to the odorous substances by generating an action potential. - Supporting cells
Provides structural support and functions to support the olfactory basal cells. - Basal cells
Stem cells that can differentiate into olfactory cells and supporting cells.
Bilateral cavities in some of the bones of the skull that arise during the embryonic development as invaginations of the nasal mucosa.
paranasl sinuses
name according to the bone they are located:
- Frontal
- Maxillary
- Ethmoidal
- Sphenoidal
A funnel-shaped fibromuscular tube.
Pharynx (Nasopharynx and Oropharynx)
- tube common to the digestive and respiratory tract
- conduct air from the nasal cavity and oral cavity to the larynx
Conducts air from the pharynx to the trachea.
Larynx
- supported by a set of cartilaes of complex shape
- covered by ciliated, pseudostratified respiratory epithelium
- contains several structures such as
epiglottis
vocal cords
nine pieces of cartilage located in its wall
briefly explain the structure of the larynx and voice box
transes
the difference between vestibular folds (false vocal folds) and vocal cords
VF - pseudostratified ciliated columnar epithelium and contain seromucous glands for lubrication
VC - stratified squamous epithelium to withstand friction and vibration during phonation
*Lining of VF is thicker and pinker due to the presence of the seromucous glands. Whereas the lining of the VC is thin and lighter.
briefly explain its location/ coverings of
- Nasopharynx
- Oropharynx
- Pharyngeal tonsil
- Palatine tonsils
Nasopharynx
- lined by respiratory epithelium.
Oropharynx
- lined by nonkeratinized stratified squamous epithelium.
Pharyngeal tonsil
- an unencapsulated patch on lymphoid tissue
- located in the posterior aspect of the nasopharynx
Palatine tonsils
- located at the junction of the oral cavity and the oral pharynx.
a thin leaf-like plate structure that projects upward behind the tongue and hyoid bone.
Epiglottis
- Stands in front of the laryngeal inlet and bends posteriorly to cover the inlet of the larynx when food is swallowed.
what are the 2 types of epithelia covers the epiglottis
- stratified squamous on the lingual surface facing the oropharynx
- respiratory epithelium on the laryngeal surface facing the larynx.
Downward projections of the epithelial layer into the underlying connective tissue.
rete ridges
- aka rete pegs
It is a flexible tube formed of cartilage and fibromuscular membrane.
Trachea
- extends from the larynx, at the cricoid cartilage, to the bifurcation of the bronchi.
- lined by pseudostratified ciliated columnar epithelium and reinforced by 10 to 12 C-shaped hyaline cartilage rings.
- epithelium is composed of several layers of:
goblets cells
ciliated columnar cells
basal cells
occasionally neuroendocrine cells (aka neuroendocrine system)
Smooth muscle located between the open ends of the C-shaped cartilage rings.
Trachealis muscle
- Trachealis muscle fibers attach directly to the perichondrium of the cartilage tgt with CT, which stabilizes the cartilage’s open ends
- contraction and expansion of smooth muscle help to adjust the airflow through the trachea
what are the 4 histologic layers of trachea
- Mucosa
- Submucosa
- Cartilage and muscle layer
- Adventitia
[refer to transes]
A pair of conical organs that occupy the greater part of the thoracic cavity.
Lungs
- the left and right lung is separated by the heart and other structures in the mediastinum.
- separated by fissures into lobes.
it is a double layer of fibrous tissue that envelopes each lung.
Pleura
it is the outer layer of the pleura that adheres to the thoracic wall.
Parietal pleura
it is the inner layer that adheres to the substances of the lungs.
Visceral pleura
it is the space between the parietal and visceral pleura which contains small amounts of serous fluids.
Pleural cavity
what does parietal and visceral pleura made up of
CT that has as abundance in elastic fibers and small amounts of cellular elements
- mainly fibroblast and macrophages
lining of the free surface of the pleura which is responsible for a minimal amount of fluid in the pleural cavity.
Mesothelium
- term of the epithelial layer of the serous membrane or the peritoneal pleural and pericardium.
- line the body cavities and cover the organs that project into the body cavities.
- producing lubricating fluid that reduces friction during movement of the organs.
- composed of a single layer of flat cells with centrally located nuclei.
pleura spaces is composed of?
CT
(refer to image on transes)
Reactive mesothelium
Clusters or clumps
Pale cytoplasm
Prominent nucleoli
Diffuse cell borders
Generations of branches of the bronchus.
Bronchial Tree
Bronchus
↓
Secondary (lobar) bronchus
↓
Tertiary bronchi (segmental) bronchi
↓
Smaller bronchi
↓
Bronchioles
The primary bronchi, which begin at the bifurcation of the trachea and lead to the right and left lungs.
Extrapulmonary Bronchi
-called “extrapulmonary” bronchi because they are positioned outside
right vs left primary bronchus
Right:
- wider and shorter and more vertical than the left one
- gives rise to three secondary (lobar) bronchi
Left:
- narrower and less vertical than the right one
- gives rise to two secondary (lobar) bronchi
Refers to all the bronchi that is within the lungs consists of secondary and tertiary bronchi.
Intrapulmonary Bronchi
- lined by respiratory epithelium, and the bronchial glands (seromucous glands) are found in the submucosa.
- skeletal support for each intrapulmonary bronchus is provided by several hyaline cartilage plates instead of C-shaped cartilage rings.
Intralobular airways with diameters of 1 mm or less, formed after about the tenth generation of branching.
Bronchioles
- they lack:
both mucosal glands, cartilage, or lymphoid nodules
- lined by:
ciliated columnar (large bronchioles) or cuboidal epithelium (small bronchioles) with decreased numbers of goblet cells and increased numbers of Clara cells.
they are secretory cells that are scattered among ciliated cells and often project into the lumen of the bronchioles.
clara cells
- dome-shaped cells
- without cilia
- contain apical granules (visible only with a special stain)
Non ciliated bronchiolar secretary cells.
clara cells
[- special cells found in the small airways (bronchioles) of the lungs.]\
function:
Functions:
1.Protection - reduces substances including glycosaminoglycans and the clara cells secretory proteins to help form the lining of the bronchiole.
- Dense secretory cytoplasmic granules - detoxify harmful substances when inhaled in the lungs.
[Detoxification -break down and neutralize harmful substances inhaled into the lungs] - Also functions as the progenitor cells that can differentiate into other epithelial cell types. Especially the repair of the airway injury.
[Repair and Regeneration - can change into other lung cells to help repair damaged airways after an injury]
they are the smallest and last of the conducting portion of the respiratory system and they have no gas exchange function.
Terminal bronchioles
- Give rise to respiratory bronchioles, which connect to the alveolar ducts, alveolar sacs, and alveoli.
The first airways that function in gas exchange.
Respiratory Bronchioles
- lined by cuboidal cells and have gradually increasing numbers of alveoli.
- connect to alveolar ducts
Arise from respiratory bronchioles.
Alveolar Ducts
- have more alveoli and some cuboidal epithelium on the walls as compared to respiratory bronchioles.
- they terminate as blind pouches with clusters of alveolar sacs.
composed of two or more alveoli that share a common opening.
Alveolar sac
these are rich in capillaries which makes gas exchange more efficient
alveolar ducts and alveoli
Thin-walled pouches, which provide the respiratory surface area for gas exchange.
Alveoli
- wall of the alveolus is formed by a delicate layer of CT with reticular and elastic fibers covered by type I and type II pneumocytes.
- type I pneumocytes lie on a basal lamina, which is fused with the basal lamina surrounding the adjacent capillaries to form a blood-air barrier.
important structure for oxygen and carbon dioxide exchange.
Blood-Air Barrier
what separates the neighboring alveoli
by alveolar septa
- which contain elastic connective tissue and may have capillaries within them.
difference between Type I and Type II Pneumocytes
Type I Pneumocytes
- aka type I alveolar cells.
- covers 95% to 97% of the alveolar surface
- squamous cells with a flat, dark, oval nucleus.
- tight junctions between type I pneumocytes help prevent movement of extracellular fluid into the alveolar sacs.
- unable to divide; however, can be regenerated from type II pneumocytes
Type II Pneumocytes
- cover about 3% to 5% of the alveolar surface and form tight junctions with type I pneumocytes
- undergo mitosis to regenerate and also can form type I pneumocytes.
They originate in bone marrow and circulate in blood as monocytes.
Alveolar Macrophage
- aka dust cells
- bcm mature and migrate into the CT of the alveolar septa and into the lumina of the alveoli from blood capillaries.
- move around on the epithelial surfaces and help to clear particles, as well as excessive surfactant, out of the respiratory spaces.
Columnar cell with numerous microvilli. It is a chemosensory receptor because of its association with different apparent nerve endings.
Brush cells
- found in the nasal mucosa region
Can be found in the basal layer of the pseudostratified or stratified epithelia. Nucleus are round or oval and located in the basement membrane
Basal cells
- found in the nasal mucosa region
It is a special vascular arrangement in the laminated proprietary of the nasal conchae. It is alternative,y filled with blood from small arteries directly from the venous plexus
Venous plexus
Conduct arise from the nasal cavity and oral cavity to the larynx
Pharynx (nasopharynx and oropharynx)
Term of epithelial layer of the serous membrane or the peritoneum pleura and pericardium.
Mesothelium
