Respiratory Cardio-Vascular (RCV) II

Question 1

Describe the bronchioles - 5 points

Answer 1

The right and left main bronchi further divide into primary bronchi which further subdivide into secondary bronchi, there is 1 secondary bronchi per lobe of lung, secondary bronchi become tertiary bronchi, there is 1 tertiary bronchi per lung segment (subdivision of the lobes), these then divide further to become bronchioles and finally terminal bronchioles - all makes up the bronchial tree

Question 2

Describe the lobe situation of the lungs

Answer 2

3 lobes in the Right lung, 2 lobes in the Left lung

Question 3

Describe where the goblet cells and the cilia exist

Answer 3

only up till the larger bronchioles

Question 4

Describe the placement of the lungs within the body and its lining - 6 points

Answer 4

found within the thoracic cavity, covered by a pleural membrane (pleura), outer layer = parietal, inner layer = visceral, space between the 2 layers = pleural cavity, holds lubricating fluid secreted by the pleural membrane - helps reduce friction, fluid build up = pleural effusion

Question 5

Describe the mediastinum

Answer 5

where the lungs split into left and right

Question 6

Describe the surroundings of the lungs and describe the pleura

Answer 6

surrounded by ribs which extend from the 6th costal cartilage anteriorly to T10 posteriorly, pleura extends below by 5cm to 12th rib

Question 7

Describe where the apex of the lungs lie

Answer 7

superiorly

Question 8

Describe the fissures of the lungs

Answer 8

Both lungs have an oblique fissure which divides each lung into superior and inferior lobes, the Right lung also has a horizontal fissure subdividing the superior right one into 2 so it also has a middle lobe

Question 9

Describe the alveoli - 4 points

Answer 9

terminal bronchioles become respiratory bronchioles, they penetrate more deeply and then become alveolar ducts, alveolar sacs then surround each alveolar ducts creating a grape-like appearance which increases surface area to maximise gas exchange, the sacs also have a v thin simple epithelium and an elastic type membrane to aid gas exchange

Question 10

Describe the alveolar fluid - 2 points

Answer 10

alveoli secrete alveolar fluid to keep the surface moist, this contains surfactant which decreases the chances of the alveoli collapsing

Question 11

Macrophages

Answer 11

these are dust cells which remove debris from a region

Question 12

Describe the cell walls of the alveoli - 2 points

Answer 12

v thin and in close contact with the arterioles/venules to allow gaseous exchange - diffusion

Question 13

Describe pulmonary ventilation

Answer 13

mechanical flow of air in/out of the lungs

Question 14

Describe inhalation - 4 points

Answer 14

air moves into lungs when the pressure inside the lungs is less than the pressure outside, therefore increasing lung volume decreases the pressure and drives air in, volume of the lungs is increased by the downwards movement of the diaphragm and using the intercostal muscles to pull ribs up & out, continues until the pressures are equal inside & out

Question 15

Accessory muscles in inhalation - 3 points

Answer 15

associated with the movement of the rib cage and diaphragm, come into play during exercise to help increase the lung volume even further - diaphragm moves 1cm in resting respiration and 10cm in exercise conditions

Question 16

Describe exhalation - 5 points

Answer 16

air moves out the lungs when pressure inside is greater than the pressure outside (pressure gradient), elastic recoil of the fibres within the chest walls & lungs, there is also an inward pull of surface tension due to the film of alveolar fluid, diaphragm move up, intercostal muscles relax therefore the ribs move down and in hence decreasing the lung volume and increasing the pressure within the lungs and air is pushed out

Question 17

Tidal Volume - 4 points

Answer 17

volume of a breath, on average = 12/18 breaths a minute, moving 500mol of air into the lungs, about 70% of air intake reaches the alveolar, 30% remains in the airways

Question 18

Describe the movement of gases relating to partial pressure

Answer 18

each gas will move from an area where its partial pressure is greater to an area where it is less

Question 19

Describe the levels of the various gases throughout respiration and the effect of this

Answer 19

CO2 is higher in the pulmonary system than in lungs therefore moves from the blood into the lungs and is breathed out
O2 is higher in the alveolar than in the deoxygenated blood of the pulmonary vessels (because of inspiration) and so moves from the lungs into the blood vessels to be carried as oxygenated blood around the body

Question 20

nitrogen has a higher % within atmospheric air and can pass across respiratory membrane, what effect does it have …

Answer 20

no known effect on bodily function, v little dissolves into blood plasma

Question 21

Describe nitrogen narcosis

Answer 21

occurs in scuba divers if they approach the surface too quickly because the partial pressure of nitrogen is higher in a mixture of compressed air then air at sea level pressure meaning more nitrogen can dissolve in blood plasma producing this condition, if surface is approached slowly then the dissolved nitrogen can be exhaled however if approached too rapidly then the nitrogen comes out of solution and forms bubbles in tissues ‘decompression sickness’ - causes joint pain/dizziness/SOB

Question 22

3 things that affect blood O2 concentration in external respiration

Answer 22

Morphine - slows down pulmonary ventilation which can reduce O2 levels
Atmospheric pressure at high altitudes - causes diffusion of O2 at slower level so it decreases O2 levels
Pulmonary disorders - inhibit gaseous exchange so decrease O2 levels

Question 23

Describe Haemoglobin - 3 points

Answer 23

most O2 reaching bloodstream binds to Hb for transportation, some dissolves within oxyhemoglobin molecule and diffuses across tissue membranes, OxyHb releases O2 from blood across cell membranes to the cells and the cells in return release CO2 from their metabolic activity back into blood

Question 24

2 factors affecting O2 concentrations in internal respiration

Answer 24

Acidic Conditions and Carbon Monoxide

Question 25

Factor affecting O2 conc in internal resp - Acidic Conditions - 3 points

Answer 25

within cells, caused by build up of lactic acid as a result of metabolic activity in muscles, causes O2 to remain attached to Hb so less is released to cells and less energy is given to muscles hence causing cramp

Question 26

Factor affecting O2 conc in internal resp - Carbon Monoxide - 4 points

Answer 26

by product of faulty heaters, if inhaled then it binds with Hb and decreases its O2 carrying capacity, if not treated in time then it causes CO poisoning/death - treatment = giving patient pure O2 to increase the partial pressure available therefore more binding capacity and so more O2 available

Question 27

Describe the nervous stimulation of the respiratory system

Answer 27

Nerve impulses are involuntarily generated by the inspiratory centre in the brain, they trigger phrenic nerves of the diaphragm and intercostal nerves between the ribs, they cease after 2 seconds and the muscles relax, the expiratory area of the brain send impulses for the muscles to contract

Question 28

Pneumotaxic Area

Answer 28

sends impulses from the brain to stop the lungs over-inflating

Question 29

Apneustic Area

Answer 29

ensures sufficient length of inspiratory effort

Question 30

Hypoxic Hypoxia

Answer 30

less O2 can get to the bloodstream because of high altitude/obstruction/fluid in lungs

Question 31

Anaemic Hypoxia

Answer 31

decreased function of Hb possible due to CO poisoning/haemorrage

Question 32

Ischaemic Hypoxia

Answer 32

blood flow to tissue decreased so there is too little O2 delivered to cells

Question 33

Histoxic Hypoxia

Answer 33

delivery of O2 prevented by toxic agents

Question 34

6 factors affecting Respiration

Answer 34

Limbic Stimulation - anticipation of action/anxiety
Temperature - increased temp/fever/exercise increases respiration
Sharp Pain - can cause apnoea (cessation of breathing with shock of pain), prolonged pain = increased respiration
Irritation of airways - cessation of breathing to allow coughing/sneezing
Rise in BP - decreases respiration
Drop in BP - increases respiration

Question 35

5 reasons why smoking affects respiration

Answer 35

Nicotine - constricts terminal bronchioles so decreased air flow in/out of lungs
Carbon Monoxide - by-product, binds with Hb and decreases O2 carrying capacity
Irritants in smoke - swelling of mucus membranes so decreased air flow
Excess Mucus & Foreign Bodies - can’t be swept away easily because cilia = destroyed by smoke
Destruction of Elasticity of Fibres - prevents effective exhalation of air - greatest cause of COPD (Chronic Obstructive Pulmonary Disease)