Respiratory system Flashcards
Functions of the respiratory system
- Aids in sense of smell in nasal cavity
- Produces sounds for speaking, singing and other forms of communication
- Moves air along respiratory passageways to and form gas-exchange surfaces of the lungs
- Provides large area for gas exchange between air and circulating blood
- Protects respiratory surfaces from dehydration, temperature changes and pathogens
Upper respiratory system
- nose
- nasal cavity
- paranasal sinuses
- pharynx
Lower respiratory system
- larynx
- trachea
- bronchi
- lungs (bronchioles and alveoli)
Respiratory defense system
Nasal cavity
mucous cells and mucous glands
cilia
Nasal cavity
Nasal hairs , at the opening of the nostrils trap large particles of dust that might otherwise be inhaled
Mucous cells and mucous glands
Produce mucus that bathes exposed surfaces
cilia
sweep mucus and trapped debris and microorganisms toward pharynx to be swallowed to acids in stomach or coughed out
Mucociliary escalator
Flow of mucus/ trapped debris
sticky mucus produced by mucous cell and mucous glands
trap debris particles
Moved by beating cilia
where is the debris on the mucociliary swept to ?
towards pharynx and swallowed to acids in stomach or coughed out
Alveolar macrophages
Engulf small particles that reach lungs
Air enters the nose through the ______
nares
Olfactory tract
Detect the sense of the smell and convey it to the brain
The rest of the nasal cavity is lined with ______
respiratory mucosa
respiratory mucosa
moistens air and traps incoming foreign particles
Cavities within bones surrounding the nasal cavity are called ______
sinuses
Functions of the sinuses
- lighten the skull
- act as resonance chambers for speech
- produce mucus that drains into the nasal cavity
Pharynx
throat
throat
pharynx
three regions of the pharynx
- Nasopharynx
- Oropharynx
- Laryngopharynx
Where are the tonsils located in
pharynx
Larynx
voice box
function of larynx
helps to route the air and food into proper channels
plays a role in speech
Larynx is made of
eight rigid cartilages, epiglottis
Epiglottis
Protects the superior opening of the larynx
Routes food to the posteriorly situated esophagus and routes air toward the trachea
When swallowing, the epiglottis rises and forms a lid over the opening of the larynx
Larynx
houses the vocal cords- mucosal folds supported by elastic ligaments
The slit between the vocal cords is called
glottis
When air passes through the _______, the vocal cords______, producing sound
glottis, vibrate
The ______ the tension in the vocal cords, the _____ the pitch
greater, higher
Trachea
windpipe
Trachea is lined with
ciliated mucosa
Ciliated mucosa in the trachea
Cilia beat continuously in the opposite direction of incoming air
Expel mucus loaded with dust and other debris away from lungs
Walls of the trachea are reinforced with _________ which keeps it ______
C-shaped hyaline, patent
Tranchea branches into two bronchi
right main bronchus , left main bronchus
Right main bronchus
Creates more likely pathway for foreign objects
-> wider, shorter and at a steeper angle than the left bronchi
number of right lung lobes
3
number of left lung lobes
2
Each lung is divided into lobes by ______
fissures
The walls of the sac and the capillaries are both made of
simple squamous epithelium
Gas exchange occurs
between air in the alveoli and blood in the capillaries
Gas exhange occurs in the lungs: Oxygen diffuses across the _________ and enters the ________, and carbon dioxide diffuses from the ______ into the _______
alveolar wall , bloodstream, blood alveoli
Alveoli are lined with ______, a film of _______ that lowers the _________ and prevents __________.
surfactant , lipoprotein, surface tension of water, the alveoli from closing
Main cell of alveoli
pneumocytes Type 1
Function of alveolar macrophages
patrol epithelium, phagocytizing particles in alveoli
structure of type 1 pneumocytes
unsually thin, simple squamous epithelium
function of pneumocytes type 2
produce surfactant, a liquid that helps to keep alveoli open by reducing surface tension
Respiratory membrane are formed
by alveolar and capillary walls
site of gas exchange
respiratory membrane
Layers of respiratory membrane
- Alveolar cell layer
- Capillary endothelium
- Fused basement membranes between alveolar and endothelial cells
alveolar cell layer
squamous epithelial cells lining the alveoli
What covers the outer surface of the lungs
Serosa
Serosa layers
- (inner layer) pulmonary (visceral) pleura covers the lung surface
- parietal pleura (outer layer) lines the walls of the thoracic cavity (chest cavity)
What pleural fluid does?
It fills the area of the pleura to allow gliding and decrease friction during breathing
Space between the layers
pleural space
Main purpose of respiration
to provide oxygen to the cells at a rate adequate to satisfy their metabolic needs
Pulmonary ventilation
moving air into and out of the lungs
External respiration
Gas exchange between pulmonary blood and alveoli
Gas transport
Transport of oxygen and carbon dioxide via the bloodstream
Internal respiration
Gas exchange between blood and tissue cells in systematic capillaries
Four events of respiration
- Pulmonary ventilation
- External respiration
- Gas transport
- Internal respiration
Pulmonary ventilation is a _______ process that depends on __________ in the __________
mechanical, volume changes, thoracic cavity
Volume changes lead to
___________ , which lead to ____________.
pressure changes, the flow of gases to equalize pressure
Two phases of pulmonary ventilation
Inspiration , expiration
inspiration
inhalation, flow of air into lungs
expiration
exhalation, air leaving lungs
Primary respiratory muscles
the diaphragm
external intercostals
Accessory respiratory muscles
The sternocleidomastoid,
the pectoralis major,
the trapezius
when is assessory respiratory muscles activated
when respiration increases significantly
What happens when Inspiration occurs
diaphragm and external intercostal muscles contract
the size of the thoracic cavity increases
external air is pulled into the lungs as a result of increase in intrapulmonary volume and decrease in gas pressure
air is sucked into the lungs
What happens when expiration occurs
largely a passive process that depends on natural lung elasticity
As muscle relax, air is pushed out of the lungs as a result of decrease in intrapulmonary volume and increase in gas pressure
forced expiration can occur mostly by contraction of internal intercostal muscles to depress the rib cage
Normal breathing moves about _____ml of air with each breath
500 ml
respiratory volume is
tidal volume
What factors affect respiratory capacity
- age
- sex
- a person’s size
- physical condition
Volumes during ventilation
tidal volume
vital capacity
inspiratory and expiratory reserve volume
tidal volume
the amount of air that moves in and out with each normal breath
Vital capacity
the maximum volume that can be moved in plus the maximum amount that can be moved out during each breath
Inspiratory and expiratory reserve volume
the increased volume of air moving in or out of the body with forced inspiration and expiration
Vital capacity is the sum
of tidal + inspiratory reserve + expiratory reserve volumes
Residual volume
the air remaining in the lungs after exhalation
Nonrespiratory air movements can be caused by
reflexes or voluntary actions
Examples of nonrespiratory air movements
cough and sneeze crying laughing hiccup yawn
Sounds that can be heard with a stethoscope
- bronchial sounds - produced by air rushing through lung passageways such as trachea and bronchi
- Vesicular breathing sounds
Bronchial sounds is produced
produced by air rushing through lung passageways such as trachea and bronchi
Vesicular breathing sounds
soft sounds of air filling alveoli
what happens during external respiration
- Air in the lungs has high PO2 and low PCO2
- Blood arriving in pulmonary arteries has low PO2 and high PCO2
- Concentration gradient causes O2 to enter blood and CO2 to leave blood
Carbon dioxide transport in blood
Transported in the plasma as bicarbonate ion
a small amount is carried inside red blood cells on hemoglobin, but at different binding sites from those of oxygen
Oxygen transport in blood
Most oxygen travels attached to hemoglobin and forms oxyhemoglobin
A small dissolved amount is carried in the plasma
What happens during internal respiration
Carbon dioxide diffuses out of tissue to blood (loading)
Oxygen diffuses from blood into tissues (unloading)
Breathing is controlled by the _______ and by _______
nervous system , certain chemicals
Neural centers (nervous control of breathing)
control rate and depth are located in the mendulla oblongata and pons - in the brain stem
where are the neural centers located at
mendulla oblongata and pons in the brain stem
How inspiration occurs
respiratory control center in the brain automatically send out nerve signals to the diaphragm and the external intercostal muscles of the rib cage, causing inspiration to occur.
Chemoreceptors
Sensory receptors that are sensitive to the chemical composition of fluids
Two sets of chemoreceptors sensitive to pH can cause breathing to ________
speed up
Two sets of chemoreceptors are
mendulla oblongata of the brain stem
carotid bodies of the carotid arteries and aortic bodies of the aorta
Process of removal of CO2 from the blood
Production of CO2 during cell respiration
Formation of acid and decreased pH
Activation of chemoreceptors
Respiratory center increases the rate and depth of breathing
Remove CO2 from the blood
