gaseous exchange Flashcards
what is breathing
the mechanical process whereby air moves in and out of the lungs-> inhalation, exhalation
what is gaseous exchange
exchange of O2 and CO2 across a gaseous exchange surface
cellular respiration
gradual release of energy from organic compounds (glucose) in the presence of O2
why is gaseous exchange is necessary, name 2 things
1- absorb O2 from the atmosphere, made available for cellular respiration
2- CO2 that cells release during respiration are removed thro gaseous exchange
why shouldnt CO2 accumulate
it can become toxic to the body, it can lower pH of body fluids which then impacts enzyme action
def for gaseous exchange surface
boundary betw external enviro and internal gaseous exchange system of organism
def diffusion
process gaseous exchange occurs via, it is the movement of molecules from an area of high concentration to an area of low concentration (across a gradient) until equilibrium is achieved
name 5 req for gaseous exchange
LaT PerM VenTraP
1- large surface area for max gaseous exchange: allow sufficient O2 diffuse in, CO2 diffuse out
2- surface must be moist: prev desiccation of gaseous exchange tissue
3- surface must be thin and permeable: quick diffusion
4- have transp systems : efficient transp of gases, eg blood
5- have adequate ventilatory mechanisms: ensure O2 rich air brought in, CO2 rich air driven out
name the 5 rq for gaseous exchange in mammals
LaT PerM VenTraP
1- large: bronchiole divide into many alveoli
2- thin + permeable: alveoli have Thin squamous epithelium cells
3- Moist: alveoli have thin layer of moisture
4- ventilated: inhalation and exhalation during breathing
5- protection : ribs protect the lungs
6- transp system: circulatory system
what is each nasal cavity divided into and what sep by
into 3 passages sep by 3 curved turbinate bones
what cells are the nasal passages lined with
lined by ciliated columnar epithelial cells with goblet cells (note: goblet cells secrete mucus)
what do goblet cells do
they secrete mucus
what is the pharynx lined with
lined with mucous membrane
what shape and material is the trachea and why
it is C-shaped cartilage, the opening part faces towards back and press against oesophagus, this allows oesophagus to expand as food moves down through oesophagus
what is the trachea lined with
like all other air passages, lined with mucous membrane or ciliated columnar epithelial cells that secrete mucus
what is the bronchi held open by
by O-shaped cartilage rings
what does the mucus in the air passages do name 3 things
1- traps dust + germs
2- antiseptic: prev inhaled germs from multiplying
3- moistens incoming air -> prev desiccation: drying out of gaseous exchange air
name the adaptation of the nasal cavity and its function
it is lined with small hairs: and filters larger dust particles from inhaled air
name the 3 adaptations and its functions of the air passages being lined with ciliated columnar epithelial cells
1- supplied with superficial capillaries: warms incoming air
2- has goblet cells: secrete mucus that-> 1) traps dust,2) antiseptic, 3) prev desiccation
3- cilia perform sweeping movements: carry dust and germ-carrying mucus out
name an adaptation of the glottis (opening to the trachea)
it is closed by the epiglottis (a leaf shaped cartilage) that closes the opening to the trachea when swallowing : prev chocking
name 2 adaptations of the trachea
1- C-shaped cartilage rings support the trachea walls: supports + keeps trachea open
2- ‘open’ sides of C-shaped rings are in contact with esophagus: allowing the esophagus to stretch during swallowing
what are the 4 steps during inhalation
DETA + LeDVIP, inhalation -> contract + incre
1-Diaphragm contracts + flattens, thoracic cavity length incre )top to bottom
2- External intercostal muscles : contracts + rib cage lifted, distance incre (side to side, front to back)
3- Thoracic cavity: volume incre , thus interpleural pressure decre
4- thus atmospheric pressure greater than intrapleural pressure, causing O2 rich air to be pulled into air passages
what are the 4 steps during exhalation
DETA + LeDVIP, exhalation ->relax + decre
1- Diaphragm relaxes + arched, thoracic cavity length decre
2-External intercostal muscles: relax + rib cage lowered , distance of thoracic cavity decre
3- Thoracic cavity: volume decre, thus interpleural pressure incre,
4- thus atmospheric pressure less than interpleural pressure, causing CO2 rich air to be forced out of lungs
what are the 3 adaptations of lungs along with their functions
1- lungs are spongy and elastic: allows it to expand + contract easily during breathing
2- lungs surrounded by double membrane with intrapleural fluid betw 2 membranes: prev friction during breathing
3- bronchioli eventually end in millions of alveoli
