1
Q
name the laryngeal cartilleges
A
- thyroid
- cricoid
- epiglottis
- arteynoid x2
- corniculate x2
- cuneform x2
2
Q
what makes up waldeyers ring?
A
- pharyngeal tonsils
- palatine tonsils
- lingunal tonsils
3
Q
At what spinal level is the tip of the epiglottis?
A
C5
4
Q
At what spinal level is the inferior border of the cricoid cartillege?
A
C6
5
Q
what is the upper respiratory tract made up of?
A
- nasal cavity
- pharynx
- larynx
6
Q
How does the counter current exchange system prevent excessive heat loss from the body core?
A
- nasal membranes moisten and humidify the entering air, can heat inspired air from 6°C to 30°C
- inhaled air is then fully humidified to body temp as it passes through the trachea
- Expired air is always slightly below body temp as it gives up heat when it leaves the nasal passages
7
Q
what are the characteristics of the pharynx?
A
- divided by soft palette into nasopharynx and oropharynx
- contains lymphoid structures such as adenoids and tonsils
8
Q
At what vertebral level does the trachea begin?
A
C6
lower border of cricoid cartilege
9
Q
what are the lobes of the right and left lung?
A
- The right lung is divided into three lobes: upper, middle and lower
- The left lung has only two lobes: upper and lower
10
Q
what fissures are found on the lungs?
A
left lung: oblique fissure seperates the upper and lower lobe
right lung: horizontal fissure splits upper and middle lobe, oblique fissure seperates middle and lower lobes
11
Q
hoe does the trachea divide? (the tracheobronchial tree)
A
trachea -> 2 main bronchi -> 4 lobar bronchi -> 16 segmental bronchi -> bronchioles -> terminal bronchioles -> respiratory bonchioles -> alveoli
12
Q
describe the arrangment of muscle in tracheobronchioles tree?
A
. The bronchial smooth muscle is arranged in clockwise and anticlockwise helical bands and there is a matrix of elastic tissue supporting the muscles.
13
Q
describe the epithelium from the nasal cavity to the bronchioles?
A
cilliated columnar epithelial cells
14
Q
what happens to foreign particles which are unable to be expelled by the cillia?
A
- macrophages in the lower respiratory tract
- estimates to be 16 macrophages per alveolus in the human lung
- macrophages immobilise and destroy bacteria and carry out phagocytosis
15
Q
describe the role of goblet cells in the respiratory tract and where are they found?
A
- Goblet cells are found predominately in the epithelium from the nose to the bronchi (columnar tapering towards the base)
- function is the secretion of mucus
- Along with the cilia, mucus is part of the airway’s defence. Inhaled particles, macrophages, cell debris and bacteria are trapped in the sticky mucus to be swept away on the mucociliary escalator .
16
Q
what are clara cells?
A
- Clara cells are found mainly in the distal conducting airways, the terminal bronchioles and alveolar ducts
- non ciliated cells, have short microvilli
- granules which store Clara cell secretory protein (CCSP) and a solution similar to lung sufactant
17
Q
what are the functions of clara cells?
A
- control of inflammatory processes
- Assist in the mucociliary clearance of environmental particles
18
Q
describe type 1 alveolar cells (aka type 1 pneumocytes)
A
- large, flat, squamous cells with few organelles and thin cytoplasm
- cover majority of alveolar surface
- Their primary purpose is air–blood gas exchange
- narrow junctions between cells (prevents fluid entering alveolus)
19
Q
describe type 2 alveolar cells (aka type 2 pneumocytes)
A
- domed cuboidal cells in the alveolar epithelium
- containing lamellar bodies that secrete surfactant
- Surfactant is continuously synthesised and secreted by type II alveolar cells
- covers only a small portion of alveoli but surfacant forms a thin film which covers the whole alveolar surface
20
Q
what is the function of surfactant?
A
- reduces alveolar surface tension
- Prevent the basically spherical alveoli from collapsing during expiration as they have water-soluble and oil-soluble components
- Decrease the effort needed to expand the alveoli at the next inspiration (increase pulmonary compliance )
21
Q
How is the pons and medulla oblangata involed in controlling respiration?
A
- In medulla oblangata there is the medullary respiratory centre which is split into ventral and dorsal groups: ventral group controls the rythmcity of breathing
- in the pons the pontine respiratory centre communicates with the medullary centre to smooth respiration
22
Q
what factors can influence respiratory rate?
A
- peripheral chemoreceptors
- voluntary control
- pain
- emotion
- temprature
23
Q
Where are peripheral chemorecptors found?
A
- carotid and aortic bodies
24
Q
what is the function of chemorecetors?
A
- chemorecpetors detect a change in the blood
- lower oxygen, lower pH (increased H+) and increased CO2, causes chemoreceptors to send signals to stimulate the respiratory centre and increase respiration rate
- allowing you to breathe in more oxygen and breathe out more CO2
25
Where are central chemoreceptors found?
Medulla
26
what receptors are found in the lungs and what are their effect on respiration rate?
- irritant receptors, when stimulated they slow down respiration (supress respiratory centre)
- stretch receptors, hering- brever reflex, protective against over inflation of lungs and slows down respiration rate
27
What nerves innervate the diaphragm?
phrenic nerve which is formed in the neck within the cervical plexus and contains fibres from spinal roots C3,C4,C5.
28
How do glomus type 1 cells work?
- peripheral chemoreceptors
- a decrease in oxygen or an increase in CO2 causes the cell to become depolarised and an action potential is fired to the respiratory centre to increase respiration
29
how does pO2 change as it moves from the atmosphere through the tracheobronchile tree?
PO2 decreases from atmosphere to trachea and continues to decrease as it moves towards alveoli (oxygen cascade)
30
what are adaptations of red blood cells (erythrocytes)?
- biconcave - increase sa
- tiny diameter - move into tissues and small capillaries
- no organelles- more room for haemoglobin, doesnt use an oxygen
31
what are the characteristics of haemoglobin?
- globular protein
- 4 subunits
- each haemoglobin can carry 4 oxygen molecules
32
how to calculate total O2 delivered per min?
= cardiac output x O2 content
33
how does 2,3-DPG act on haemoglobin?
- when O2 binds beta chains move apart which makes space for 2,3- DPG to enter and decreases affinity for oxygen
34
explain the two types of metabolism in a red blood cell
1) oxidative glycolysis
2) anaerobic glycolysis -> produces 2,3-DPG
(when venous blood is deoxygenated anaerobic glycolysis increases)
35
what is the haldane effect?
deoxygenated Hb binds more H+ than oxy Hb and there for form carbamino Hb more readily
36
Where do the right and left cura of the diaphagrm arise from?
Right crus – Arises from L1-L3 and their intervertebral discs.
Left crus – Arises from L1-L2 and their intervertebral discs.
37
what is the action of external intercostal muscles?
Elevates the ribs, increasing the thoracic volume
38
what is the action of the internal intercostal muscles ?
reduces the thoracic volume by depressing the ribcage
39
What are the characteristics of the serous membrane which makes up the pleurae?
serous membrane is simple squamous cells supported bt connective tissue, this simple squamous epithelial layer is also known as the mesothelium.
40
What is the pleural cavity?
the potential space between the visceral and parietal pleurae, has a small volume of serous fluid
-> The serous fluid also produces a surface tension, pulling the parietal and visceral pleura together. This ensures that when the thorax expands, the lung also expands, filling with air.
41
What is the mechanism during inspiration and expiration?
- diaphragm contracts and moves down increasing the thorax ,volume with in lungs increases, lowering pressure so air moves in from high pressure to low pressure.
- expiration is the opposite
42
what is action of the sternocleidomastoid muscle and how does its origins relate to this?
- origines at sternum (manubrium) and clavicle then insterts at masteoid process
- this helps to increase volume of thorax
43
what is the origin of the scalene muscle and how does this relate to its action?
- originates at cervical vetebrae and inserts at first two ribs
- increases thorax volume
44
what is the action of pec minor, serratus anterior and errector spinal muscles in relation to breathing?
- increases volume of thorax to allow for inspiration
45
what muscles are involved in expiration?
- rectus abdominals
- external obliques
- internal obliques
- transversus abdominus
- latisumiss dorsi
- internal intercostals
46
what is the A band in a myofibril?
- remains constant
- myosin and actin found here
- total width of myosin
47
what is the sarcomere?
- the smallest unit of contraction in a myofibril, Z line to Z line
48
explain the sliding filament theory
1) Ca2+ binds to release troponin and tropomyosin complex (leaves free actin)
2)
- ATP binds to myosin head, dissociates to ADP +Pi and causes myosin head to move and bind to actin
- ADP + Pi leave myosin head causing 'power stroke'
- ATP binds to release myosin head from actin, it then dissociates and the process repeats, causing sarcomere to shorten
49
what is functional resiudal capacity?
Functional residual capacity (FRC) refers to the volume of air left in the lungs at the very end of normal expiration
50
what is forced expiratory volume?
which is the amount of air that can be forcibly expelled after a maximal inhalation in 1 second
51
what is the distinction between the O2 content of the blood and O2 saturation?
- O2 content refers to the amount of O 2 carried by 1 L of blood
- O2 saturation ( S ) is the percentage of O2 -carrying sites on the haemoglobin molecule occupied by O2 . Under normal physiological conditions, arterial O 2 saturation, S a O2 , would be approximately 100%
52
how is the lymphatic drainage of the lung organised?
- The channels providing lymphatic drainage in the lungs lie in the interstitial spaces between the alveolar cells and the endothelial cells of the alveolar capillaries
- these channels follow a network that follows the tracheobronchial tree to the hilium
53
How does plumonary odema occur?
- alveolar surfaces are constantly moistened by a net filtration fluid
- The lymphatics then drain any excess fluid
- pulmonary odema occurs when there is too much excess fluid for the lymphatics to drain
54
when needs to be considered for a drug to be administrated orally?
- most commonly used as it is the cheapest and most convinient
- how well the drug is absorbed into the systematic circulation from the GI lumen, and how it is metabolised
- could be used for local effect on GI tract
55
What are the two ways a drug can be administered intravenously?
- bolus - whole amount ofd rug is given in one go
| - infusion - when the total dose is given slowly over a period of time
56
What are the advantages and disadvantages of administrating a drug intravenously?
- rapid onset of action
- drugs that would otherwise be irritants can be administered this way, as plasma dilutes and veins are insensitive
- toxicity can be a problem due to rapid onset of therapeutic effect
- requires trained personnel and is expensive due to sterilisation
57
what does it mean for a drug to be administered subcutaneously?
- Subcutaneous injection is when the drug is injected just under the skin
- absorption is relativley slow
58
what is sublingual admiistration?
- the drug is held under the tounge
59
what happens to CO2 when it is absorbed into the blood plasma?
- just free in plasma
| - reacts with water in plasma to form carbonate ion and hydrogen ion, slow
60
what happens to CO2 when is absorbed into an erythrocyte?
- reacts with water and carbonic anhydrase catalyses the reaction to form carbonate ion and hydrogen ion
- > carbonate and chloride transporter moves carbonate ions out of the erythrocyte and chloride ions into the cell
- can form carbamino Hb
61
what are the advantage of inhalation of a drug?
- rapid absorption from lungs to systematic circulation
- for lung disorders, allows a large amount of drug to be delivered directly to target structures
- drug can be modified to determine how much maintains in lung and how much reaches systemic circulation
62
go on girl
you got this
63
what are the common structural features of viruses?
- genetic material is contained within a coat or capsid, made up of a number of individual protein molecules
- The complete unit of nucleic acid and capsid is called the ‘nucleocapsid’, and often has a distinctive symmetry
- in some the nucleocapsid is further surrounded by a membrane usually of host cell origin
64
what are the variables for effiency of transmission of a virus?
- how much of the virus you were exposed to
- how infectious is that virus
- how healthy are you
- at what stage of infection was the original host
65
how does an enveloped virus and a non enveloped virus differ when it comes to possible routes of transmission?
- non enveloped virus can withstand extreme pH, drying and detergents. Eneveloped viruses cannot.
66
what are fomites?
- infected inanimate objects
67
How are enveloped viruses spread?
- have to have an intact membrane and have to be wet
| - sneeze, blood, saliva or mucus
68
what are the classifications of a virus?
- order
- family
- subfamily
- genus
- species
69
what characteristics are considered to classify a virus?
- nature of virus genome
- size of virion
- presence or absence of envelope
- symmetry of capsid
70
what is the H zone in a myofibril and how does it change upon contraction?
- where only myosin is found
| - shortens upon contraction
71
what is the I band in a myofibril and how does it change upon contraction?
- where only actin is found
| - shortens upon contraction
medical sciences
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