Anatomy (pie for finals) Flashcards
1
Q
In general terms describe how we get O2 into the blood & CO2 out?
A
- We breathe air in via our nose (or our mouth)
- Air travels through the “respiratory tree”: a set of tubes which connect the nose/mouth with the millions of alveoli (air sacs) within the 2 lungs
- The surface of the very thin walled alveoli is covered with many thin walled capillaries
- This histological arrangement allows oxygen to be transferred by diffusion into the blood
- This, now oxygenated blood, is then returned to the heart to be pumped to all the other cells of the body
- This system also allows for the diffusion of CO2 from the blood into the alveoli to be breathed out of the body
2
Q
What 4 anatomical structures comprise the upper respiratory tract (URT)?
A
- Nasal cavities
- Oral cavity
- naso- oro- & laryngo- Pharynx
- Larynx
3
Q
Label all the anatomical structures shown in the pic
A
4
Q
What is the anatomical importance of the level of the C6 vertebrae
A
- The larynx becomes the trachea
- The pharynx becomes the oesophagus
5
Q
Where can the trachea be palpated ?
A
At the jugular notch of the manubrium
6
Q
Label the anatomical structures shown in the pic
A
7
Q
Define what is meant by the term ‘respiratory tree’
A
This describes the anatomy of the LRT airways from trachea to alveoli
8
Q
What makes up the LRT?
A
- Trachea
- Right & left main bronchi
- Lobar bronchi
- Segmental bronchi
- Bronchioles
- Alveoli
9
Q
Define what a lung lobe is and state how many there is
A
- The area of lung that each of the lobar bronchi supply with air is a lung lobe
- Remeber it as the word right has more letters so the right lung has more lobes
10
Q
Name the lung fissures
A
11
Q
Define what a bronchopulmonary segment is and state how many there is
A
- The area of lung lobe that each one of the segmental bronchi supply with air is a bronchopulmonary segment
- Each lung has 10 bronchopulmonary segments
12
Q
Each lung lobe and each bronchopulmonary segment has its own what?
A
- Own air supply (lobar or segmental bronchus)
- Blood supply
- Lymphatic drainage
- and nerve supply
13
Q
Define what the bronchial tree is
A
The bronchial tree is the branching system of trachea, bronchi, bronchioles, alveolar ducts, alveolar sacs, and alveoli that conducts air from the windpipe into the lungs.
14
Q
Label the structures of the bronchial tree shown
A
15
Q
What is the lining of the bronchial tree (except for the distal bronchioles & alveoli)?
A
Respiratory epithelium
16
Q
Describe the function in relation to the mucociliary escalator and structure of respiratory epithelium
A
Ciliated columnar epithelium which have:
- Mucous glands secrete mucous onto the epithelial surface
- And cilia (“eye lashes”) beat to sweep the mucous (plus any foreign bodies stuck in the mucous) superiorly, towards the pharynx, to be swallowed - known as the mucociliary escalator
17
Q
Describe, in general terms, the arrangement of hyaline cartilage and smooth muscle within the walls of the respiratory tree
A
Hyaline cartilage:
- It supports the walls of the trachea & all the bronchi. The amount of cartilage gradually reduces distally in the respiratory tree until, the most distal bronchioles and of the alveoli do not contain any cartilage
Smooth muscle:
- Smooth muscle in the walls of the airways becomes progressively more prominent distally
- Smooth muscle is the most prominent feature of the walls of the bronchioles
18
Q
What is the function of hyaline cartilage ?
A
To support the walls of the trachea & all the bronchi which assists with maintaining the patency of the airways (holding them open)
19
Q
Why must alveoli have neither cartilage nor smooth muscle?
A
Because this would impact on diffusion alveolar walls have to be extremely thin
20
Q
What is the function does smooth muscle in the walls of bronchioles enable ?
A
It allows bronchioles to constrict (become narrower) or dilate (become wider)
21
Q
State and explain the 5 main requirements for adequate diffusion of respiratory gases at the level of the alveolar wall
A
- Sufficient functioning lung tissue
- Sufficient O2 in the air we breathe in
- No CO2 in the air we breathe in
- Minimal thickness of the walls of the alveoli (air sacs) to facilitate gaseous diffusion
- Minimal tissue fluid in the tissue spaces around the alveolar capillaries to facilitate gaseous diffusion
22
Q
Summarise the main dangers to air moving freely through the upper and lower respiratory tracts i.e. the main things that may obstruct free movement of air in the resp tracts
A
The respiratory tract may become narrowed:
- The bronchioles may constrict (E.g. asthma)
- Swelling of the mucosa lining the inside of the respiratory tree & overproduction of mucous (E.g. asthma)
- A growing tumour may externally compress the tract at any point
Foreign bodies being inhaled into the respiratory tract - may partially or completely stop breathing
23
Q
Explain how the patency of the upper respiratory tract is maintained
A
- Bones forming the nasal cavities
- The nasal septum
- Skeleton of the larynx
24
Q
The 2 nasal cavities are separated from each other by an internal wall called the nasal septum, what forms the nasal septum ?
A
- Bony (posterior) part of the nasal septum ethmoid bone (superiorly) & vomer (inferiorly)
- Cartilaginous (anterior) part of the nasal septum
25
Describe what forms the nasal cavity
Each nasal cavity has:
* A relatively featureless medial wall
* An interestingly featured lateral wall
* A floor (formed from the palate)
* A roof (formed by the midline part of the floor of the anterior cranial fossa)
26
The skeleton of the larynx (voice box) is made up of what?
Several cartilages:
* The epiglottis
* The thyroid cartilage
* The cricoid cartilage
* The 2 arytenoid cartilages (posteriorly)
27
Label the anatomical structures shown in the pic
28
What are the 3 main functions of the larynx ?
1. Cartilages help to maintain the patency of the URT
2. Helps to prevent the entry of foreign bodies into the LRT (the vocal cords)
3. Produces sound (the vocal cords)
29
What is the inferior continuation of the larynx known as ?
The trachea
30
Label the anatomical structures shown in the pic
31
What is the narrowest part of the larynx and what is the clinical significance of it ?
* Narrowest part of the larynx = the rima glottis
* Clinical significance = large foreign bodies tend to block the URT at the rima glottidis
32
Label the anatomical structures shown in the pic
33
How do the vocal cords provide airway protection ?
* The vocal cords can approximate in the midline, closing the rima glottidis & preventing a foreign body being inhaled into the trachea
* A Cough reflex is then stimulated to expel the foreign body via the pharynx and oral cavity
34
How do the vocal cords (ligaments) influence voice production
Through Phonation (producing sound):
* Expire air across the vocal cords
* The cords vibrate to produce sound
35
Describe what the second phase of voice production is after phonation
Articulation (producing speech) = The sound is modified in the nose or mouth to produce vowels and consonants
36
How does the Heimlich manoeuvre aims to expel a foreign body out of the URT ?
1. It raises abdominal pressure which forces the diaphragm superiorly
2. Which will raise the pressure in the chest
3. Which will raise the pressure in the lungs
4. Which will force air from the lungs into the trachea
5. Which will force air through the rima glottidis to expel the foreign body out of the URT
37
How do we warm, humidify & “clean” the air we breathe in?
Warmed:
* The respiratory mucosa lining the walls of the nasal cavities has a very good arterial blood supply providing warmth
Humidified:
* The respiratory mucosa produces mucous providing moisture
Cleaned:
* The “sticky” mucous traps potentially infected particles whilst the cilia of the mucosa waft the mucous to the pharynx to be swallowed (into gastric acid)
* Additionally the tonsils located within the mucosa lining the pharynx produce white blood cells in the defence against infection
38
What anatomical structures greatly increase the surface area of the lateral walls of the nasal cavities and in doing so help bring the air breathed in, in contact with the walls and hence the respiratory epithelium for warming, humidification and cleaning ?
The conchae - through increasing surface area and producing turbulent flow
39
What is the main danger to the lungs via the chest wall?
Penetrating injuries
40
What comprises the chest wall?
* skin & fascia of the chest wall
* bones of the chest wall
* skeletal muscles of the chest wall
* the diaphragm (an internal chest wall)
* parietal pleura of the chest wall
41
What are the bones which make up the thoracic skeleton ?
* 12 pairs of ribs
* Intercostal spaces
* Costal margin
* 12 thoracic vertebrae
* Clavicle and scapula
* Sternum
* Manubrium, body, xiphoid, sternal angle
42
Of the 12 ribs which make up part of the thoracic skeleton, which are known as the true ribs, false ribs and floating ribs ?
* True ribs: 1-7 (attach via their costal cartilage to the sternum)
* False ribs: 8-10 (attach via their costal cartilage above to the sternum)
* Floating ribs: 11 & 12 (no attachment to sternum)
43
Label the anatomical structures shown in the pic
44
Label the bony features of a rib
45
Label the joints of the thoracic skeleton
46
What is found between the parietal and visceral layers of pleura ?
Pleural cavity - a space that surrounds the lung in 3 dimensions apart from where the main bronchus enters it
47
What are the 2 parts which make up the thorax?
Chest walls:
* Protect the heart & lungs
* Make the movements of breathing
* Breast tissue - lactation (lactare = to suckle)
Chest cavity:
* Within the chest walls
* Contains vital organs (also known as viscera)
* Also contains major vessels and nerves
* Consists of the mediastinum & the right & left pleural cavities
48
Go over this photo displaying the development of the lungs
49
Name the 3 layers of skeletal muscles located between the ribs & within the intercostal spaces
1. External intercostal muscles
2. Internal intercostal muscles
3. Innermost intercostal muscles
50
What is the function of the intercostal muscles and their attachments
* The layers of intercostal muscles attach between adjacent ribs
* They make the chest wall expand during breathing by pulling adjacent ribs upwards and outwards
51
Define what an intercostal space is and state how many there is
* They are the anatomical space found between each two ribs
* There are 11 pairs (right and left sided) intercostal spaces
52
What is found within the intercostal spaces?
The intercostal muscles and each space carries a neuro-vascular bundle (Vein, artery and nerve = VAN)
53
Where specifically in the intercostal space is the neuro-vascular bundle located ?
Between the internal and innermost intercostal muscle layers
54
What nerve is carried in the neuro-vascular bundle within the intercostal spaces ?
Anterior ramus of spinal nerve (**intercostal nerve**)
55
Describe the blood supply to the posterior and anterior parts of the intercostal spaces (i.e. the arteries and veins carried within the ant and posterior neurovascular bundles)
* The azygous vein drains the posterior parts of the intercostal spaces. Whilst the thoracic aorta supplies them
* The internal thoracic artery and veins (2) - supply the anterior parts of the intercostal spaces - course vertically either side of the deep surface of the sternum
56
Describe the structure of the diaphragm
* It is an internal part of the body wall which forms the floor of the chest cavity and the roof of the abdominal cavity
* It has 2 'openings' to allow structures to pass through
* Anatomically arranged as right & left “domes” the right dome is normally the more superior (due to the presence of the liver inferiorly)
57
What are the openings of the diaphragm ?
1. The caval opening (for the IVC)
2. The oesophageal hiatus (for the oesophagus & the vagus nerves)
3. The aortic hiatus (for the thoracic aorta, azygous vein & thoracic duct)
58
What are the attachments of the diaphragm ?
1. The sternum
2. The lower 6 ribs & costal cartilages
3. L1-L3 vertebral bodies
59
What spinal nerves together form the phrenic nerve ?
Anterior rami of cervical spinal nerves C3, 4, 5
60
Where in the neck and chest is the phrenic nerve located and what does it supply ?
* Found in the neck on the anterior surface of scalenus anterior muscle and in the chest (thorax) descending over the lateral aspects of the heart
* It supplies somatic sensory and sympathetic axons to the diaphragm & fibrous pericardium and somatic motor axons to the diaphragm
61
What is the neumonic used to remember that the diaphragm is supplied by the phrenic nerve ?
C3,4 & 5 keep the diaphragm alive!
62
Define what parietal and visceral pleura is
* The visceral pleura is the delicate membrane that covers the surface of each lung, and dips into the fissures between the lobes of the lung.
* The parietal pleura is the outer membrane which is attached to the inner surface of the thoracic cavity.
63
Define what the pleural cavity is
A vacuum containing pleural fluid
64
Label the surface anatomy in this pic
65
Label the quadrants and surface anatomy of the female breast
66
Label the surface anatomy shown
67
Label the surface anatomy shown in the pic
68
Label the anatomy shown in the pic
69
What pathology is shown here and what causes it ?
Paralysis of serratus anterior (usually through injury to the long thoracic nerve) results in a “winged scapula”
70
Label the anatomy shown in the pic
71
When do the subclavian vessels become the axillary ?
**Lateral to the lateral border of the 1st rib** (here the subclavian vessels are within the axilla and so change their names to the axillary artery & vein)
72
Label the anatomy shown in the pic
73
What is the most inferior region of the pleural cavity when standing upright ?
The costodiaphragmatic recess
74
Where is the costodiaphragmatic recess located and what may collect here ?
* Located between the diaphragmatic parietal pleura and the costal parietal pleura
* Abnormal fluid in the pleural cavity drains into the recess e.g. pleural effusion or haemothorax
* This causes the “blunting of the angles” & a fluid level seen on CXR
75
What is the most inferior region of the pleural cavity laterally ?
The costophrenic angle
76
What are the structures which comprise the root of the lung ?
* 1 main bronchus
* 1 pulmonary artery
* 2 pulmonary veins
* lymphatics
* visceral afferents
* sympathetic nerves
* parasympathetic nerves
77
Label the surface markings and hilum of the right lung
78
Label the surface markings and hilum of the left lung
79
When ascultating what are normal breath sounds described as?
Rustling in nature
80
What is the anatomical location to ascultate the apices of the lungs and also the location of the fissures of the lungs and the sternal angle ?
81
Summarise the anatomy of the steps involved in stimulating and generating a cough (including the nerves involved)
Stimulation of sensory receptors occurs in the mucosa any of the following; the Oropharynx, Laryngopharynx, Larynx or Respiratory tree (trachea to bronchioles)
The CNS then responds by rapidly coordinating the following:
1. A DEEP inspiration using the diaphragm (phrenic nerves), intercostal muscles (intercostal nerves) & “accessory muscles of inspiration”
2. Adduction of the vocal cords to close the rima glottidis (vagus nerves)
3. Contraction of the anterolateral abdominal wall muscles (intercostal nerves) to build up intra-abdominal pressure which pushes the diaphragm superiorly and builds up pressure in the chest/respiratory tree inferior to the adducted vocal cords
4. The vocal cords suddenly abduct to open the rima glottidis (vagus nerves)
5. The soft palate tenses (CN V) and elevates (vagus nerves) to close off the entrance into the nasopharynx and direct the stream of air (at ~100mph!!) through the oral cavity as a cough rather than through the nasal cavity as a sneeze!
82
Summarise the sensory nerve supply to the mucosa lining the nasal cavities, pharynx and larynx
* Nasal cavity - CN V1 & V2
* Pharynx - naso & oropharnyx CN IX, laryngopharynx CN X
* larynx CN X
83
Give a basic definition of the carotid sheath and list the structures enclosed within it
The carotid sheaths are protective “tubes” of cervical (neck) deep fascia which attach superiorly to the bones of the base of the skull and blend inferiorly with the fascia of the mediastinum
They contain:
1. The vagus nerve
2. The internal carotid artery
3. The common carotid artery
4. The internal jugular vein
84
Give a basic summary of the sensory & motor nerve supply to the lungs (via the pulmonary plexus)
* All motor axons (parasympathetic & sympathetics) travel from the tracheal bifurcation along the branches of the respiratory tree to supply all mucous glands & all bronchiolar smooth muscles
* The pulmonary visceral afferents travel from visceral pleura & respiratory tree to the plexus then follow the vagus nerve to the medulla of the brainstem
85
Summarise the mechanics of quiet inspiration
1. **Diaphragm contracts and descends** - Increasing vertical chest dimension
2. **Intercostal muscles contract elevating ribs** - Increasing A-P and lateral chest dimensions
3. **The chest walls pull the lungs outwards with them (pleura)** - because the parietal pleura is stuck to the chest walls (and as intercostals increase the wall dimensions) and creates a vacuum, this pulls the visceral pleura and therefore the lungs out with them
86
What is the main muscle of quiet respiration ?
The diaphragm
87
Appreciate that in deep (forced) inspiration a greater outflow of action potentials of longer duration, via the phrenic nerves , to the diaphragm, occurs, resulting in maximal descent of the diaphragm & maximally increased vertical chest diameter
88
Appreciate that increased recruitment of skeletal muscle fibres of the diaphragm & the intercostal muscles occurs in a forced inspiration
89
What are the muscles of normal (quiet) inspiration ?
Diaphragm & external intercostal muscles
90
What are the accessory muscles of deep (forced) inspiration and what is there use a sign of ?
1. Pectoralis major & minor
2. Scalenus
3. Sternocloidomastoid
The use of these muscles for inspiration is a sign of dysponea (breathlessness)
91
What are the muscles of active expiration ? ( they contract only during active expiration)
Note - Recall expiration is usually passive
Anterolateral abdominal wall muscles and internal intercostal muscles
92
What type of muscles are the intrinsic muscles of the larynx, what nerve are they supplied by and where do they attach?
* They are all skeletal (voluntary) muscles and are supplied by CN X
* They all attach between the cartilages of the larynx
93
Describe the route of the vagus nerve
1. It is a mixed cranial nerve which connect with the CNS at the medulla (oblongata) of the brainstem and passes through the jugular foramen
2. It then descend through the neck within the carotid sheath
3. In the chest they descend posterior to the lung root
4. They then pass through the diaphragm on the oesophagus and onto the surface of the stomach, here they finally divide into many parasympathetic branches for the foregut & midgut organs
94
What are the functions of the vagus nerve ?
Supplies somatic sensory & somatic motor axons to the larynx:
* sensory to the mucosa lining the larynx
* motor to the intrinsic muscles of the larynx
Supply parasympathetic axons to the chest organs (including the lungs via the pulmonary plexus)
Supplies many parasympathetic branches for the foregut & midgut organs
95
Label the anterolateral abdominal wall muscles
96
What are the attachments of the external oblique ?
Superiorly attach to the lower ribs and inferiorly attach to the pubic tubercle and iliac crest
97
What is the linea alba and what forms it ?
* It is a fibrous structure that extends from the xiphoid process of the sternum to the pubic symphysis
* It is formed by the aponeuroses of all the flat muscles become entwined in the midline, forming the linea alba. The aponeuroses (a broad, flat tendon), cover the vertical rectus abdominis muscle also before becoming entwined
98
What is the linea semilunaris and what forms it
* It is a vertical curved tendinous intersection found on either side of the rectus abdominis muscle.
* Formed by the layers of the rectus sheath (aponeuroses of the lateral abdo wall muscles)
99
What are the attachments of the internal oblique muscle ?
* Superiorly - lower ribs
* Inferiorly - iliac crest and thoracolumbar fascia
100
What are the attachments of the transverse abdominus muscle?
* Superiorly - lower ribs
* Inferiorly - iliac crests & thoracolumbar fascia
101
Describe the rectus abdominus muscle
* It is a long, paired muscle, found either side of the midline in the abdominal wall. It is split into two by the linea alba.
* It has tendinous intersections (divide each of 2 long flat muscles into 3 or 4 smaller quadrate muscles: the “6-pack” or “8-pack” (for improved mechanical efficiency)
* It is enclosed within the rectus sheath
102
What forms the rectus sheath ?
The aponeuroses of the 3 lateral abdominal wall muscles
103
What are the functions of the anterolateral abdominal wall muscles ?
* Maintain posture & support the vertebral column - through tonic (continuous low level) contractions
* Contractions to produce movements of the vertebral column (spine) - flexion; lateral flexion; rotations
* “guarding” contractions to protect the abdominal viscera
* Contractions increase intra-abdominal pressure to assist:
* defacation; micturition; labour, forced expiration
104
What is the safe triangle for carrying out needle aspiration (thoracocentesis) of a tension pneunothorax?
1. The anterior border of latissimus dorsi
2. The posterior border pectoralis major
3. Axial line superior to the nipple
105
Where should needle entry be for thoracentesis of a pneumothorax?
Into the **middle** of the intercostal space to avoid the NVB in the costal groove superiorly and the collateral NVB inferiorly
106
What innervates the anterolateral abdominal wall muscles ?
Thoracoabdominal nerves
