Respiratory system

Question 1

what are the functions of the respiratory system?

Answer 1

-gas exchange-intake of O2 and removal of CO2
-regulates blood pH
-smell
-filters inspired air
-vocal sounds (phonation)
-excretes small amounts of water and heat

Question 2

what houses the lungs?

Answer 2

the thorax

Question 3

what are the respiratory system structural zones?

Answer 3

-upper respiratory tract
-lower respiratory tract

Question 4

what does the upper respiratory tract consist of?

Answer 4

-nose
-pharynx

Question 5

what does the lower respiratory tract consist of?

Answer 5

-larynx
-trachea
-bronchi
-lungs

Question 6

what are the respiratory system functional zones?

Answer 6

-conducting zone
-respiratory zone

Question 7

what does the conducting zone do?

Answer 7

-it is involved with bringing air to the site of external respiration and consists of the nose, pharynx,larynx,trachea,bronchi and bronchioles and terminal bronchioles

Question 8

what does the respiratory zone do?

Answer 8

-it is the main site of gas exchange and consists of the respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli

Question 9

where does air passing through the respiratory tract transverse?

Answer 9

-nasal cavity
-pharynx
-trachea
-primary (1) bronchi
-secondar (2) bronchi
-tertiary (3*) bronchi
bronchioles
-alveoli (150million/lungs)

Question 10

how is the nasal cavity?

Answer 10

-it has an external nose that is visible on the face
-has an internal nose with a large cavity beyond the nasal vestibule

Question 11

how is the nasal cavity divided?

Answer 11

-it is divided by the nasal septum into right and left nares

Question 12

what is the pharynx?

Answer 12

• a hollow tube that starts posterior to the internal nares and descends to the opening of the larynx in the neck

Question 13

how is the pharynx formed?

Answer 13

by a complex arrangement of skeletal muscles that assist in deglutition

Question 14

what are the functions of the pharynx?

Answer 14

it acts as:
-passageway
-resonating chamber
-housing for tonsils

Question 15

what’s the larynx?

Answer 15

-the voice box
-it is composed of 9 pieces of cartilage and forms a short passageway connecting the laryngopharynx with the trachea

Question 16

what is the trachea?

Answer 16

-a semi-rigid pipe made of semi circular cartilaginous rings
-it is 12cm long and extends from the inferior portion of the larynx

Question 17

where is the trachea located?

Answer 17

anterior to the oesophagus

Question 18

how is the trachea divided?

Answer 18

it is divided into right and left primary bronchi

Question 19

what are the 4 layers the trachea is composed of?

Answer 19

-one layer of mucous secreting epithelium,the mucosa
-three layers of CT (submucosa, hyaline,cartialge and adventitia)

Question 20

what does the respiratory tract cilia in the upper respiratory tract do?

Answer 20

-move mucous and trapped particles down toward the pharynx

Question 21

what does the respiratory tract cilia in the lower respiratory tract do?

Answer 21

-moves mucous and trapped particles up toward the larynx

Question 22

what changes happen to the bronchial tree?

Answer 22

changes that cause all the branches from the trachea to the terminal bronchioles conduct airways and do not participate in gas exchange

Question 23

what do respiratory bronchioles do?

Answer 23

-give way to alveolar ducts and the epithelial (simple cuboidal) changes to simple squamous which comprises the alveolar ducts, alveolar sacs and alveoli
-they also mark the start of the respiratory zone

Question 24

how is the pulmonary lobule?

Answer 24

each pulmonary lobule is wrapped in elastic connective tissue and contains a lymphatic vessel, an arteriole,a venule and a terminal bronchiole

Question 25

what are alveoli?

Answer 25

-cup shaped out pouching which participate in gas exchange -they have alveolar macrophages -there are fibroblasts which are reticular/elastic fibres -the alveolar sac comprises two or more alveoli that share a common opening

Question 26

what do alveolar macrophages do?

Answer 26

remove dust

Question 27

what is a type 1 alveoli cell?

Answer 27

-it is a simple squamous epithelial cell -it is the site of gas exchange

Question 28

what is a type 2 alveoli cell?

Answer 28

-it is a cuboidal epithelial cell -it has microvilli -it secretes surfactant -it decrease surface tension

Question 29

pneumothorax

Answer 29

air

Question 30

hemothorax

Answer 30

blood/pus

Question 31

how do the lungs receive blood supply?

Answer 31

via two sets of arteries: -pulmonary arteries -bronchial arteries

Question 32

what do the pulmonary arteries do?

Answer 32

carry deoxygenated blood from the right heart to the lungs for oxygenation

Question 33

what do the bronchial arteries do?

Answer 33

-branch from the aorta and deliver oxygenated blood to the lungs primarily perfusing the muscular walls of the bronchi and bronchioles

Question 34

what is ventilation-perfusion coupling?

Answer 34

the relationship between the air reaching the alveoli (ventilation) and the blood flow (perfusion) in the lungs

Question 35

why is ventilation-perfusion coupling important?

Answer 35

-blood flow to each area of the lungs matches the extent of airflow to the alveoli in that area

Question 36

what does vasoconstriction in the lungs in response to hypoxia do?

Answer 36

directs pulmonary blood from poorly ventilated areas of the lungs to well ventilated regions

Question 37

what does hypoxia cause in all other body tissues but the lungs?

Answer 37

-causes dilation of blood vessels to increase blood flow

Question 38

what can disruptions in ventilation-perfusion coupling lead to?

Answer 38

-conditions like hypoxia (low oxygen)

Question 39

what are the three main steps of the process of gas exchange?

Answer 39

-pulmonary ventilation-breathing -external pulmonary respiration -internal tissue respiration

Question 40

what happens in pulmonary ventilation-breathing?

Answer 40

-involves the movement of air between the atmosphere and the alveoli and consist of inhalation and exhalation -changes to intathoracic volume allow ventilation to take place

Question 41

what does the rate of airflow and effort required for pulmonary ventilation depend on?

Answer 41

-alveolar surface tension -compliance of the lungs -airway resistance

Question 42

what happens in external (pulmonary) ventilation?

Answer 42

-gas is exchanged between the alveoli and the blood

Question 43

what happens in internal (tissue) respiration?

Answer 43

gas is exchanged between the systemic capillaries and the tissues of the body

Question 44

what does the rate of pulmonary and systemic gas exchange depend on?

Answer 44

-Partial pressure difference of the gases- link to altitude sickness -Surface area available for gas exchange-link to emphysema -Diffusion distance-link to pulmonary oedema -Molecular weight and solubility of gases

Question 45

what is oxygenated Hb called?

Answer 45

-oxyhaemoglobin

Question 46

what is the most important factor that determines how much O2 binds to haemoglobin?

Answer 46

-the PO2, the higher the PO2 the more O2 combines with Hb

Question 47

what happens with oxygen transport in the blood?

Answer 47

in the blood -some O2 is dissolved in the plasma as a gas (about 1.5%,which is not enough to stay alive) -most O2 (about 98.5%) is carried attached to haemoglobin (Hb)

Question 48

what are the three different forms that CO2 is transported in, in the blood?

Answer 48

-7% is dissolved in the plasma as a gas -70% is converted into carbonic acid by carbonic anhydrase (CA) before dissociating into bicarbonate and protons -23% is attached to Hb forming carbaminohaemoglobin (Hb-CO2) but not at the same binding sites as oxygen

Question 49

what is the equation that shows how CO2 dissociates into bicarbonate and protons?

Answer 49

CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-

Question 50

what does Boyle's law explain?

Answer 50

-the volume-pressure relationship -it states that the pressure of a gas in a closed container is inversely proportional to the volume of the container

Question 51

how is the respiration controlled?

Answer 51

-some stimulus disrupts homeostasis by increasing the arterial blood Pco2 pr decreasing pH or Po2 -the receptors input nerve impulses to the control centre -there is then an output of nerve impulses to the effectors -there is then a decrease in arterial blood Pco2,increase in pH and increase in Po2 -there is then a return to homeostasis when the response brings arterial blood Pco2,pH and Po2 back to normal

Question 52

what is the control centre for the control of respiration?

Answer 52

-it is the inspiratory area in the medulla oblongata

Question 53

what is the effectors in the control of respiration?

Answer 53

-muscles of inhalation and exhalation which contract forcefully and frequently (hyperventilation)

Question 54

what are the receptors in the control of respiration?

Answer 54

-central chemoreceptors in the medulla -peripheral chemoreceptors in the aortic and carotid bodies