Respiratory System Flashcards
Internal respiration
Also called cellular respiration
The utilization of oxygen in the metabolism of organic molecules
External respiration
Exchange of oxygen and CO2 between an organism and the external environment
Functions of the Resp System
Provide O2
Eliminate CO2
Form speech sounds (phonation)
Defend against microbes (host defence)
Trap and dissolve blood clots arising from systemic (usually leg) veins
Modulate concentration of biologically active molecules
What type of epithelium is respiratory epithelium?
Pseudostratified ciliated columnar epithelium
Respiratory epithelium
Pseudostratified ciliated columnar epithelium
Rests on thick basement membrane
Several cell types (columnar, basal, etc)
Ciliated columnar cells are most abundant
Goblet cells and intraepithelial lymphocytes and dendritic cells are also present
Lamina propria is well vascularized
Upper airway
Nose to vocal cords
Humidifies and warms inspired air
Nasal turbinates
Increase surface area in the nose
Superior, middle and inferior ones
Project into the nasal passages from the side wall of the inside of the nose
Olfactory epithelium
Basal cells, supporting cells, olfactory neurons
Lies on the roof of the nose above the top turbinate
To the brain through the cribiform plate in the ethmoid bone
Pseudostratified epithelium
Dendrites of olfactory neurons have cilia with membrane receptors for odor molecules
4 paranasal sinuses and their location
Frontal: above the eyes
Maxillary: under the eyes
Ethmoid: between the eyes
Spheoidal: behind the eyes
Sinuses
Air filled spaces
Lined by ciliated epithelium
Active mucociliary clearance to clear the main nasal passages
Lighten the skull (easier to be upright), provide resonance to the voice
Which sinus has the opening at the top? What problems does this cause?
Maxillary sinus
Mucus can be retained in the sinus
Can result in infection
3 major structures of the larynx
Epiglottis
Arytenoids
Vocal cords
Arytenoids
A pair of small three-sided cartilage structures to which the vocal folds are attached
Extrinsic vs intrinsic muscles of the larynx
Ex: change larynx position in swallowing
In: alter relative position (and tension) of vocal cords in production of sound
How many lobar bronchi are there?
1 for each lobe!
2 on the left, 3 on the right
Right lung sections
Upper, middle and lower lobes
Oblique and horizontal fissue
Left lung sections
Upper and lower lobe
Oblique fissure
Functions of conducting zone
Pathway for air flow
Defends against microbes, toxic chemicals and other foreign material via mucociliary clearance
Warms and moistens air
Phonation (vocal cords)
What do bronchioles lack?
Supporting cartilage and glands
What type of epithelium is present in very small bronchioles?
Simple cuboidal cells with cilia
Terminal bronchiole composition
Only one or two layers of smooth muscle cells surrounded by connective tissue
Epithelium contains ciliated cuboidal cells and many low columnar nonciliated cells
Clara cells
Nonciliateded
Only found towards the periphery
Secrete components of surfactant
Detoxify potentially harmful compounds in the air
Produce secretory component for the transfer of IgA into lumen
Type 1 vs Type 2 epithelial cells
1: squamous for gas exchange
2: make surfactant, rounded shape
3 important parameters for efficient gas exchange in lungs
- Large driving force (partial pressure gradient)
- Large surface area
- Distance needs to be small
Respiratory distress syndrome of the newborn
Type 2 alveolar cells mature at 24 weeks
Babies born before this time do not have enough surfactant to overcome surface tension forces
We have artificial surfactant to give them
What is surfactant made of?
Mixture of phospholipids and proteins, including DPPC
DPPC molecules align themselves on alveolar surface, with hydrophobic portions attracted to each other and hydrophilic portions repelled
2 types of circulation to the lungs
- Pulmonary circulation: from right heart, for gas exchange
2. Bronchial circulation: from aorta and provides nourishment to lung tissue
Pleurisy
Inflammation of the pleura
Often caused by viral infections
Inflammed pleural layers rub against each other resulting in pain
Pleural effusion
Excess of fluid in pleural cavity
Muscles of normal inspiration
External intercostals
Diaphragm
Accessory muscles of inspiration
Sternocleidomastoid
Scalenus
Accessory muscles of expiration
Internal intercostals Abdominal muscles (main): rectus abdominus, internal and external obliques, transversus abdominis
What nerve innervated the diaphragm
Phrenic nerve
Submucosal glands
Contain both serous and mucus cells
Present whenever there is cartilage
Serous cells secrete watery fluid containing anti inflammatory and anti oxidant compounds which helps flush the mucus out of the glands
Volume of the conducting zone and alveolar region
CZ: 150 mL
AR: 2.5-3 L