Respiratory system Flashcards
Two centers in the stem that control breathing
Pons and underneath medulla
Pons is responsible for what in breathing
Long deep breaths and intensity
Its main function is to control the rate or speed of involuntary respiration.
What center will cause us to exhale
Pneumotaxic center
Involuntary respiration is controlled by ___ center in the upper brain stem. It controls ____
respiratory center
The respiratory centers contain chemoreceptors that detect pH levels in the blood and send signals to the respiratory centers of the brain to adjust the ventilation rate to change acidity by increasing or decreasing the removal of carbon dioxide (since carbon dioxide is linked to higher levels of hydrogen ions in blood).
Peripheral chemoreceptors are found in
There are also peripheral chemoreceptors in other blood vessels that perform this function as well, which include the aortic and carotid bodies
Function of medulla in breathing
Its main function is to send signals to the muscles that control respiration to cause breathing to occur.
Two regions in medulla that control breathing
There are two regions in the medulla that control respiration:
The ventral respiratory group stimulates expiratory movements.
The dorsal respiratory group stimulates inspiratory movements.
Two regions in pons and their role
The apneustic center sends signals for inspiration for long and deep breaths. It controls the intensity of breathing and is inhibited by the stretch receptors of the pulmonary muscles at maximum depth of inspiration, or by signals from the pnuemotaxic center. It increases tidal volume
.
The pnuemotaxic center sends signals to inhibit inspiration that allows it to finely control the respiratory rate. Its signals limit the activity of the phrenic nerve and inhibits the signals of the apneustic center. It decreases tidal volume.
The apneustic and pnuemotaxic centers work against each other together to control the respiratory rate. They relay the signal to medulla, who will in turn control the breath
Who receives signal from chemoreceptors
Apneustic and pnuemotaxic receptors
What can
override the “automatic”
control of breathing
the cerebral cortex
what actions are performed during respiration
- External respiration
- Transport of gases by
the blood - Internal respiration
- Regulation of
respiration
3 divisions of respiratory system
– Upper respiratory (larynx,esophagus,nose,pharynx)
– Lower respiratory tract (trachea,lungs)
– Accessory structures
Diaphragm is ___ muscle
Skeletal
Larynx is involved in
Sound production
On left side on the lung you have only __ lobes, when in the right it is ___
Left-2
Right-3
As you get lower the trachea and to the lungs who do the cell change
Cartilage change for smooth muscle
What is muscles are involved in inhalation
External intercostais and diaphragm, scalenes and sternocleidomastoids
What muscles are involved in exhalation
Internal intercostais
Abdominal muscles
What structures are actually involved in external respiration
• Alveolar sacs. • capillaries • Pulmonary Arterioles • Pulmonary vein
Parts in pharynx
nasopharynx
oropharynx
Laryngopharynx
Role of nose
Conditioning of the air (warmed and humidified)
Microorganisms and other particles that are not supposed to get in are trapped in mucus
Sound production
What is cleft palate
Palatine bones- form hard palate
This is a disease characterized by failure to unite completely and only partially separate the nose and the mouth, producing difficulty in swallowing and speech
Cause of cleft palate
Cause-genetic (mutant gene, trisomy 13)
non-genetic (teratogenic- corticosteroids, benzodiazepines,
anticonvulsants),
Developmental defect resulting from
decreased migration of neural crest cells
What can be done to decrease the cleft palate
by taking multivitamin
with folic acid.
Pharynx connects ___ and ___
Upper and lower airways
Pharynx starts where and is made from
Made from muscles
Starts at the base of skull
Why do we have sinuses?
- Maybe for lightening the skull, so it is not so heavy
- Maybe immunity
- maybe in conditioning
in nasopharynx there is a connection to
Middle ear
Larynx is producing the sound for our voice , but it is helped by
Nose and Speech-Pharynx changes shape
to produce certain vowel
sounds.
Trachea connects
The larynx to the bronchi and from the larynx to the primary bronchi
Obstruction of trachea causes ___
Death
What is embedded in cartilage c rings
Smooth muscle
What is the main tissue type in trachea
hyaline cartilage
Pseudostratified epethilia-ciliated
What happens to bacteria that get to trachea
They got trapped in mucus in the airway and then it is sweeped up the trachea to the larynx and then you swallow it and it is killed in the acidic of the stomach
Trachea branches in
Primary bronchi and then in secondary and then bronchioles
Three layers in bronchials and what specific cells it has
epithelial, smooth muscles,
connective
Goblet cells and ciliated cells
Terminal bronchiole leads to
respiratory bronchial and then alveolus
Clusters of alveoli are called
alveolar sacs
What are the pores of kohn
The pores of Kohn (also known as interalveolar connections) are discrete holes in walls of adjacent alveoli
Respiratory
membrane is
—the
barrier between which
gases are exchanged by
alveolar air and blood
respiratory membrane consists of
alveolar epithelium,
capillary endothelium,
and their joined
basement membranes
The surface of the
respiratory membrane
inside each alveolus is
coated with
a fluid - Surfactant—that reduces surface tension-produced by Type II cells(septal cells)
Types of cells in alveoli
There are three major types of alveolar cell. … Type I cells are squamous, thin and flat and form the structure of the alveoli. Type II cells release pulmonary surfactant to lower surface tension. Type II cells can also differentiate to replace damaged type I cells.
What happens during inspiration
During inspiration, the diaphragm contracts
and moves downwards, and the thoracic
cavity increases in volume. This decreases
the intra-alveolar pressure so that air flows
into the lungs. Inspiration draws air into the
lungs
What happens during expiration
During expiration, the relaxation of the diaphragm and elastic recoil of tissue decreases the thoracic volume and increases the intra-alveolar pressure. Expiration pushes air out of the lungs.
Why do we need 2 gradients for respiration
One in which the pressure within alveoli of lungs is
lower than atmospheric pressure to produce inspiration
• One in which the pressure in alveoli of lungs is higher
than atmospheric pressure to produce expiration
Pressure gradients are established by
changes in
size of thoracic cavity that are produced by
contraction and relaxation of muscles
what is PB
Atmospheric pressure (PB) is the air pressure of the atmosphere outside the body’s airways.
What is PA
Alveolar pressure-intrapulmonary pressure—the pressure at the far end of
the internal airways.
What is PIP
Intrapleural pressure (PIP)-created by two membranes that surround the lungs. It
is the fluid pressure of the pleural fluid between the parietal pleura (outer
membrane attached to the chest wall) and visceral pleura (membrane
surrounding lung)
Pleural space is
thin fluid-filled space between the two pulmonary pleurae
parital-outter layer
visceral-inner layer
pariatal is connected to diaphragm
Air moves into lungs when ___ pressure drops below
___pressure
alveolar
atmospheric
What is compliance
ability of pulmonary tissues to stretch, making inspiration
possible
Surfactant is classified as what type of molecule and is formed from___, and function
Surfactant a lipoprotein is formed from protein and phospholipid
secretions by type II cells in the wall of the alveolus
• It acts to reduce surface tension and prevents alveolar collapse during
exhalation
Explain in detail the function of surfactant
water molecules want to shrink together because water
molecules are attracted to each other-this would decrease
the size of the alveolus
• Surfactant acts to decrease attraction between water
molecules
• Surfactant molecules are interspersed between water
molecules and in doing so promotes expansion of the
lungs, and acts against the tendency to recoil
What are primary phagocytes in the innate immune system
Alveolar Macrophages
Function of Alveolar Macrophages
Clearing the air space of infectious, toxic or allergic particles
secretion of lysozyme, antimicrobial peptides and proteases
• through processes of phagocytosis
• alveolar macrophages can eliminate the small inocula of typical
microbes which are aspirated daily in the normal host
Factors that determine the amount of oxygen
that diffuses into blood:
The total functional surface area of the respiratory
membrane
• The respiratory volume
• Alveolar ventilation
Structural factors that facilitate oxygen diffusion
from alveolar air to blood
Cappillary bed
• Walls of the alveoli and capillaries form only a very
thin barrier for gases to cross
• Alveolar and capillary surfaces are large
• Blood is distributed through the capillaries in a thin
layer so each red blood cell comes close to alveolar
negative feedback control of respiration
Increased cellular respiration during exercise causes a rise in plasma Pco2—which is detected by central chemoreceptors in the brain and perhaps peripheral chemoreceptors in the carotid sinus and aorta.
• Feedback information is relayed to integrators in the brainstem that respond to the increase in Pco2 above the set point value by sending nervous correction signals to the respiratory muscles, which act as effectors.
• The effector muscles increase their alternate contraction and relaxation, thus increasing the rate of respiration. As the respiration rate increases, the rate of CO2 loss from the body increases and Pco2 drops accordingly. This brings the plasma Pco2 back to its set point value.
Changes in the Po2, Pco2 and pH of arterial blood influence ____
medullary
rhythmicity area
Pco2 acts on central chemoreceptors in medulla—if it increases, result is faster
breathing; if it decreases, result is slower breathing
• A decrease in blood pH (less Co2) stimulates peripheral chemoreceptors in the
carotid and aortic bodies, and even more so, the central chemoreceptors (because
they are surrounded by unbuffered fluid) to slow breathing
• Arterial blood Po2 presumably has little influence if it stays above a
certain level
What is happening in asthma, bronchitis and emphysema in lungs
Bronchitis- extra secretion of mucus
Asthma- smooth muscle contract too much, edema of respiratory mucosa and excessive mucus production obstruct airways
Emphysema- after years of smoking- enlargement and destruction of alveolar walls
