gaseous exchange

Question 1

what is breathing

Answer 1

the mechanical process whereby air moves in and out of the lungs-> inhalation, exhalation

Question 2

what is gaseous exchange

Answer 2

exchange of O2 and CO2 across a gaseous exchange surface

Question 3

cellular respiration

Answer 3

gradual release of energy from organic compounds (glucose) in the presence of O2

Question 4

why is gaseous exchange is necessary, name 2 things

Answer 4

1- absorb O2 from the atmosphere, made available for cellular respiration
2- CO2 that cells release during respiration are removed thro gaseous exchange

Question 5

why shouldnt CO2 accumulate

Answer 5

it can become toxic to the body, it can lower pH of body fluids which then impacts enzyme action

Question 6

def for gaseous exchange surface

Answer 6

boundary betw external enviro and internal gaseous exchange system of organism

Question 7

def diffusion

Answer 7

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

Question 8

name 5 req for gaseous exchange

Answer 8

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

Question 9

name the 5 rq for gaseous exchange in mammals

Answer 9

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

Question 10

what is each nasal cavity divided into and what sep by

Answer 10

into 3 passages sep by 3 curved turbinate bones

Question 11

what cells are the nasal passages lined with

Answer 11

lined by ciliated columnar epithelial cells with goblet cells (note: goblet cells secrete mucus)

Question 12

what do goblet cells do

Answer 12

they secrete mucus

Question 13

what is the pharynx lined with

Answer 13

lined with mucous membrane

Question 14

what shape and material is the trachea and why

Answer 14

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

Question 15

what is the trachea lined with

Answer 15

like all other air passages, lined with mucous membrane or ciliated columnar epithelial cells that secrete mucus

Question 16

what is the bronchi held open by

Answer 16

by O-shaped cartilage rings

Question 17

what does the mucus in the air passages do name 3 things

Answer 17

1- traps dust + germs
2- antiseptic: prev inhaled germs from multiplying
3- moistens incoming air -> prev desiccation: drying out of gaseous exchange air

Question 18

name the adaptation of the nasal cavity and its function

Answer 18

it is lined with small hairs: and filters larger dust particles from inhaled air

Question 19

name the 3 adaptations and its functions of the air passages being lined with ciliated columnar epithelial cells

Answer 19

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

Question 20

name an adaptation of the glottis (opening to the trachea)

Answer 20

it is closed by the epiglottis (a leaf shaped cartilage) that closes the opening to the trachea when swallowing : prev chocking

Question 21

name 2 adaptations of the trachea

Answer 21

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

Question 22

what are the 4 steps during inhalation

Answer 22

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

Question 23

what are the 4 steps during exhalation

Answer 23

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

Question 24

what are the 3 adaptations of lungs along with their functions

Answer 24

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