what is respiration
process in which body allows for oxygen delivery in cells to break down glucose and CO2 removal from cells out of body that is exhaled out of the lungs and is all done by respiratory system
requirements for respiration to occur
1 surface area or respiratory surface (for large amounts of gas exchange at fast enough rates to meet bodies needs )
2 moist environment (so O2 and CO2 can be dissolved in water)
what are the stages of respiration
breathing, external respiration, internal respiration, cellular respiration
first stage of respiration and funtion
breathing-inspiration (breathing) aka moving air from external environment into lungs and expiration (exhaling) aka moving air from lungs back into external enviroment
second stage of respiration and function
external respiration- exchange of oxygen and carbon dioxide between air and blood
third stage of respiration and function
internal respiration- exchange of oxygen and carbon dioxide between body tissues and cells
fourth stage of respiration and function
cellular respiration- series of energy releasing chemical reactions that break down glucose to produce ATP or energy that can be used around body.
what is the main principle organ in respiration
the lungs, located deep in the body
what are lungs protected by
thoracic cavity
what is the thoracic cavity
a bone and muscular structure used to protect the lungs
where does thoracic originate from
greek word meaning chest place
what is the respiratory tract
passageway that air moves from external environment to respiratory surface
what does upper respiratory tract include
nose, mouth, nasal passages, pharynx, epiglottis, larynx and trachea
what is the nasal passage
first organ of respiration, main function is to warm, moisten and clean incoming air. lined with mucus producing cells that trap foreign particles and ciliated particles which move these particles. (these particles can include bacteria and dust)
what are the turbinate bones
very thin bones, that project into nasal cavity and increase surface area of cilia, for warming air and removing particles
what is the pharynx
second organ of respiration. known as throat, passageway for air getting into respiratory system as well as passageway for food and water to get into digestive system
what is the epiglottis
third organ of respiration, flap of cartilage that lies behind tongue and above the larynx that closes over opening of trachea (glottis).
what is epiglottis function
When a person swallows epiglottis prevents food and water from entering trachea and passing into lungs. When a person is at rest epiglottis is up right, allowing air to pass to lower respiratory tract
What is the larynx
“voice box'“ made from cartilage and contained vocal chords
how do vocal chords work
when you breath, there is a large gap between them but when you speak, muscles around them contract causing them to come closer together and vibrate- producing sound or pitch
what is pitch
determined on length of vocal cords which determine a higher or lower pitch. (longer the chords the lower or deeper the pitch.
what is the trachea
“windpipe” that extends from larynx to the bronchi that is strengthened by cartilage arches that prevent it from collapsing.- open section of semicircle cartilage fases the esophagus to allow it to expand for the swallowing of food
structures of the lower respiratory tract
lungs, bronchi, bronchioles, alveoli and capillaries
primary organ of respiration and what does it contain
lungs-contain the bronchi, bronchioles and alveoli.
how are lungs divided
divided into regions called lobes.
number of lobes per lung
right contains 3 lobes and left contains 2 lobes to have space for the heart.
what is the pleural membrane
thin, double layered membrane that surrounds each lung (outer membrane attaches to chest wall and inner membrane attached to outside of lung
what does pleural membrane do
they adhere to each other allowing lungs to expand and draw in air when volume of chest cavity is increased as well space between membranes contains fluid to reduce friction during inhalation
what are the bronchi
the branching of the trachea (2 bronchi) that enter left and right lung
what are bronchi made of
contain c shaped cartilage rings that provide support as part of the bronchus wall
what does bronchi branch into
smaller network of fine tubes called bronchioles within each lung
what are bronchi and bronchioles lined with
cilia and mucous producing cells
what do cilia do in the bronchi and bronchioles
movies foreign particles upward to upper resp. tract to be ejected by coughing, sneezing or swallowing
what does mucous do in the bronchi and bronchioles
captures and traps particles and pathogens
structure of alveoli
cluster of tiny sacs and the end of each bronchiole which forms spongy lung tissue. composed of single layer of cells for rapid gas exchange occurring in external respiration. surrounded by network of capillaries.
function of alveoli
functional part units of lungs. During inhalation alveoli are bubble shaped but during expiration tiny sacs collapse.
what causes alveoli to not stick together
film of fat called lipoprotein preventing membranes from sticking
what are capillaries
tiny blood vessels that surround the alveoli, only one cell thick and connect arteries and veins
concentration of oxygen in capillaries and alveoli
air that enters alveoli have a higher concentration of oxygen then blood in capillaries. oxygen diffuses out of alveoli and into blood of capillaries
what transfers the oxygen
diffusion transports most of oxygen but about 30% of oxygen is transported by facilitated diffusion where protein molecules “carry” oxygen across cell membrane. not requiring more energy but speeding up process
where does external respiration take place
in the lungs
process of external respiration
oxygen diffuses into the blood of capillaries to begin journey to heart and to be pumped into tissues
carbon dioxide diffuses from blood in capillaries to alveoli in lungs to be released into external environment
where does internal respiration take place
takes place in body tissues
process of internal respiration
oxygen diffuses from the blood into oxygen-poor tissues
carbon dioxide diffuses from tissue to blood -to heart
first step of oxygen transport
oxygen moves from atmosphere (high partial pressure) to alveoli then diffuses into blood and dissolves in the plasma
what increases solubility of oxygen into the blood
hemoglobin
what is hemoglobin
respiratory pigment of red blood cells the increase the oxygen carrying capacity of blood (20mL—100mL)
what does hemoglobin consist of
4 polypeptides composed of heme (iron containing pigment) and globin(protein component)
bond between oxygen and hemoglobin
when oxygen dissolves into plasma, hemoglobin forms weak bond with oxygen to form oxyhemoglobin
what does the amount of oxygen binding depend on
partial pressure . -in lungs around 13.3 KPa, thus blood leaving lungs is nearly saturated in oxygen
what happens to partial pressure as it enters capillaries
as it enters capillaries in tissues, partial pressure drops to about 5.3 KPa, (drop in pressure causes dissociation or split of oxygen from hemoglobin and oxygen diffuses into tissues.)
solubility of carbon dioxide
20 times more soluble than oxygen (approximately 23% of CO2 is carried in blood by hemoglobin, 7% is carried by plasma, 70% is dissolved and carried in in blood as bicarbonate ions (H2CO3))
reaction of CO2 and H2O in blood
carbon dioxide and water combine to form bicarbonate ions with enzyme carbonic anhydrase
concentration of carbon dioxide in blood from tissues
the concentration decreases (CO2) in plasma, maintaining low partial pressure so that CO2 continues to diffuse into blood from tissues
what do acids in the blood do
can create problem and change pH of blood resulting in death and must be buffered
what happens to unstable carbonic acid
it dissociates to bicarbonate ions and hydrogen ions, then hemoglobin binds with hydrogen to act as a buffer
what happens to hemoglobin and hydrogen
once the venous (deoxygenated) blood reaches lungs oxygen dislodges H+ and hemoglobin and free H+ and bicarbonate ions combine to form CO2 and water again. Carbon dioxide diffuses from blood into alveoli to be exhaled
what controls air pressure in lungs
the diaphragm and rib muscles contracting and relaxing
what is the diaphragm
dome shaped layer of muscle that separates thoracic cavity (region of lungs) from abdominal cavity (region of stomach and liver)
what are rib muscles
INTERCOSTAL MUSCLES- found between ribs and along ventral or inside surface of ribs
what is inspiration
(inhalation)
process of inhalation
begins with nerve stimulus that causes external intercostal muscles of ribs to contract, lifting rib cage up and out and at the same time diaphragm contracts to pull downward.
what do the intercostal muscles contracting and the diaphragm contracts to pull downwards heffect
this causes an increase in volume of thoracic cavity and increase of gas molecules spread apart (less outward pressure) This change in pressure causes the walls of the lungs to expand outward into the thoracic cavity and air to rush into the lungs form the external.
what is expiration
exhalation
actions of diaphragm and intercostal muscles
diaphragm and external intercostal muscles relax and internal intercostal muscles contract - reducing volume of thoracic cavity
what does the change in pressure during exhalation cause
pressure will increase in lungs and air will be forced out of lungs to the low pressure of the environment
what is pneumothorax
when air accumulates inside chest space between plural membranes that line the lungs and inner chest wall
effects of pneumothorax
pressure of air causes lung to collapse, normally caused by puncturing injury or lung damage (treatment is inserting a needle or chest tube between ribs to get rid of excess air)
what are breathing movements controlled by
chemoreceptors (nerve receptors, in medulla oblongata and detects levels if CO2)
tidal volume
volume of air inhaled and exhaled on a normal breath
inspiratory reserve volume
additional amount of air that can be taken into lungs beyond regular tidal inhalation
expiratory reserve volume
additional amount of air tha can be expelled