Anatomy of Thorax/ Histology Flashcards

1
Q

What are the differences between true, false and floating ribs?

A

True- Ribs 1-7- costal cartilage is attached directly to sternum
False- Ribs 8-10- Costal cartilage attaches to cartilage above it (cartilage creates costal margin)
Floating- Ribs 11, 12- Do not attach to sternum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What forms the superior thoracic aperture?

A

Superior margin of T1 ribs and manubrium of sternum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What forms the inferior thoracic aperture and what attaches to it?

A

Diaphragm attaches to it

Formed by inferior margin of floating ribs, costal margin and xiphoid process of sternum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How far up does the diaphragm sit?

A

Attached to T11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the diaphragm attach to?

A

Inferior thoracic aperture, xiphoid, lumbar vertebrae (1-3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What innervates the digaphram?

A
Phrenic Nerve (C3-C5)
C3, 4, 5, keep the phrenic nerve alive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What openings are in the diaphragm and what passes through at what level of the ribs?

A

Caval opening- inferior vena cava at T8, most anterior
Oesophageal Opening- Oesophagus T10
Aortic Hiatus- Aorta (most posterior) at T12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What muscles are in the thoracic wall, what movement does each muscle cause, and when is each set most active?

A

Internal intercostal- present anteriorly back to angle of ribs. Active during expiration. Pull ribs down
External- Active during inspiration. Pull inferior ribs upward and out.
Innermost intercostal- Incomplete and sparse, associated with internal layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where is the neurovascular bundles supplying the intercostal muscles found in terms of depth?

A

Between the internal and innermost intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What muscles are important for respiration?

A

Diaphragm moves down

External intercostal move ribs up and out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What accessory muscles aid in exhalation?

A
Internal intercostal muscles
Transverse Thoracis 
External Obliques
Internal Obliques
Rectus Abdominus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What accessory muscles aid in inhalation?

A

Pectoralis minor (via fixing upper limb to help lift ribs)
Sternocleidomastoid
Scalene
Serratus Anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where and what forms the intercostal neurovascular bundles, and where do the nerves stem from?

A

Run along costal grove at inferior posterior portion of rib.
VAN- Vein (superior- most protected)
Artery
Nerve
Anterior rami of T1-T11 form intercostal nerves
Anterior ramus of T12 forms subcostal (underneath rib 12)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where do the intercostal arteries stem from?

A

Posterior- originates from aorta and travels along with nerve
Anterior- originates from internal thoracic artery (branch of subclavian aka mammary)
They will anastomose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is the anastomosing of the anterior and posterior intercostal arteries important?

A

Important in aiding in blood flow to the lower body if there is a blockage of the aorta (blockage can’t be sudden)
Blood will move into anterior intercostal artery, meet with posterior and down, then re-join with aorta lower down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What cavities are found in the thoracic cavity, and what is found in them?

A

2 Pulmonary- hold lungs, left is smaller

Mediastinum- hold heart, oesophagus, aorta, trachea and separates two pulmonary cavities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What layers of the heart and what are their purpose(s), starting most superficial?

A

Fibrous pericardium- protective, anchors heart in place
Parietal serous - secrete fluid to reduce friction
Pericardial cavity
Visceral serous pericardium (epicardium)- secrete fluid to reduce friction
Myocardium- contains myocytes for contraction
Subendocardium- Purkinje Fibres are here, connects myocardium and endocardium
Endocardium- Simple squamous cells, helps reduce friction in chambers reducing turbulence, helps form valves
Membranes are continuous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What layers surround the lungs and what are their purpose, starting most superficial?

A

Parietal Pleura- anchors lungs to thoracic cavity
Pleural cavity- has fluid secreted by serous membrane (pleura)
Visceral Pleura- surrounds lungs
Membranes are continuous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is serous membrane?

A

Set of membranes (visceral and parietal) surrounding an organ that allows for lubrication between two membranes helping to reduce friction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the pleural recesses?

A

Potential spaces between the costal and diaphragmatic pleura that the lungs can move into during inspiration.
Visceral, parietal, costal, diaphragmatic, mediastinal, cervical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the costodiaphragmatic recess?

A

Between costal and diaphragmatic pleura there is a sharp angle at dome of thorax
It is potential space for lung to extend into.
Most inferior part of cavity and where liquid will build

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where is the safest place for a draining chest tube placement, and why?

A

Just above the 10th rib.
This is where the costodiaphragmatic recess is (where fluid will accumulate), so best for drainage
Above 10th rib- intercostal nerves run along costal groove inferior to ribs, and are more important in function than collateral branches that run superior to ribs.
Can angle needle up to try and avoid collateral branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What structures do you pass through in order to place a chest tube? Start most superficial.

A
Skin
Subcutaneous fat and Fascia
External, internal, innermost intercostal muscles (avoid collateral/ intercostal nerves)
Endothoracic Fascia
Costal parietal pleura
Costodiaphragmatic recess
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Starting at the sagittal plane of the body and moving laterally, what are surface landmarks?

A
Jugular notch at the manubrium down to sternal angle (where rib 2 attaches)
Midclavicular line 
Anterior axillary line 
Midaxillary line
Posterior axillary line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What fissures are found in the lungs?
Horizontal on right lobe- most superior, separating superior and middle lobes Oblique- separates middle/ inferior right lobe, and superior/inferior left lobe
26
What is the cardiac notch and lingula?
Cardiac notch is in left lobe where the heart sits | Lingula is a lipping of the inferior medial aspect of the superior left lobe
27
What hold the lobes in place?
The trachea and structures entering the lobes through the hilum
28
How do the borders of the right and left lungs differ?
Right has larger posterior border and straight anterior (costal) border.
29
What structures are found in the hilum of the lungs?
``` Bronchi Pulmonary arteries Pulmonary veins Nerves Lymphatics (can be quite distinctive and black at the hilum) ```
30
What is the arrangement of the structures within the hilum?
Superior- Pulmonary arteries Inferior- Pulmonary veins (2) Posterior- Bronchus is posterior to the structures and more superior in right lobe- may also see cartilage around them
31
Describe the bifurcations that help form the tracheobronchial tree, including first bifurcation location.
Trachea bifurcates at level of sternal angle into primary bronchi (forms carina) Primary bronchi branch into secondary (lobar) bronchi (3 right, 2 left) Secondary bronchi branch into tertiary (segmental) bronchi (10 right, 8 left) Tertiary bronchi supply bronchopulmonary segments
32
How does the primary bronchus or the right lung differentiate from the left?
Right bronchus is shorter and more vertical | This means if patients aspirate, object is more likely to move into this bronchi
33
What are the bronchopulmonary segments?
Discrete independently functioning area within the lungs. | They have independent bronchus, pulmonary arteries and veins.
34
How does blood move through the lungs?
Pulmonary arteries bring deoxygenated blood to lungs Arterioles -> capillaries Oxygen exchange results in offloading of CO2 and uptake of O2 Capillaries join -> venules -> veins (have segmental venules that come together to form lobar veins) -> lobar veins form pulmonary veins 2 pulmonary veins on left, 2 on right Pulmonary veins take oxygenated blood to the left atrium
35
How is lung tissue supplied?
Bronchiole arteries and veins
36
Where does the trachea begin and divide?
Begins at C6 below the cricoid cartilage of the larynx | Divides at T4 into two principle bronchi
37
What structures form the trachea?
C-shaped hyaline cartilage rings anteriorly joined by fibroelastic membrane Posterior gaps united by trachealis muscle Inner specialized mucous membrane contains cilia
38
What is the atrioventricular groove?
Separates the atria from the ventricle, wrapping around posterior portion Also called coronary sulcus
39
What separates the right and left ventricles from a superficial posterior and also an anterior view?
Posterior interventricular artery | Anterior interventricular artery (left anterior descending artery)
40
What portions of the heart does the left anterior descending artery supply?
Left and right ventricle Left atria Apex
41
How is the anastomoses of the heart relevant to the categorization of the coronary vessels?
Its very sparse | Coronary arteries are therefore deemed functional end arteries (like terminal arteries- not much of collateral supply)
42
How does blood from coronary supply travel back into the atrium?
Middle, small (right marginal vein), posterior cardiac, anterior interventricular veins -> great cardiac vein will all drain into the coronary sinus on posterior aspect of heart within the atrioventricular groove The anterior veins of right ventricle will drain directly into the right atrium
43
Which heart chamber forms most of the base of the heart and receives the pulmonary veins?
Left atrium | Remember the apex is at the bottom!
44
What venous system drains the intercostal veins?
``` Azygous vein (drains largely posterior intercostal veins into superior vena cava) Internal thoracic vein (drains breasts and intercostal veins into brachiocephalic vein) ```
45
What anatomical points can be found by identifying the location of the sternal angle?
- Marks the point where 2nd costal cartilage articulate with sternum - At level of T4-T5 intervertebral disc - The level of the transverse thoracic plane which divides the mediastinum into the superior and inferior mediastinum - It overlies the aortic arch on the left and the superior vena cava on the right. - It is roughly at the level of the bifurcation of the trachea and therefore superficial to the carina - Roughly at the level of the bifurcation of the pulmonary trunk. - Left recurrent laryngeal (under arch of the aorta) - Thoracic duct empties into left subclavian vein here
46
What is the physiological reason for possible splitting of the 2nd heart sound?
During inspiration the pulmonary valve closes later and the aortic valve closes earlier -due to increased pressure of lung expansion causing slower flow out of right ventricles
47
What is Virchow's Nodes?
Lymph node found at the venous angle | Swelling can be indicative of stomach cancer (70%), or breast, lung cancer
48
What changes in; circulation hormones, autonomic activity, and serum ion concentrations, impact firing rates of the SA node?
AN- sympathetic (tachycardia) and vagal stimulation (bradycardia) Hormones- Hyperthyroidism (tachycardia) and hypothyroidism (bradycardia). Nor/Adrenaline (tachycardia) [Ion]- hyperkalaemia (bradycardia) and hypokalaemia (tachycardia) due to impact on repolarization
49
What is ptosis and what can cause it?
Un-dilated pupil, droopy eye lid, drier face. | Related to a Pancoast tumour (lung cancer), or myasthenia gravis,
50
How does the vasovagal response relate to syncope?
Thing like fear and/or emotion cause stimulation of vagus nerve, resulting in fainting and slowed heart rate
51
What is carotid sinus syndrome?
Overactive carotid vagus nerve. Stimulation of vagus nerve causes fainting, slowed heart rate. Carotid sinus massage can be used to treat- but very dangerous.
52
How can you evaluate swallowing capabilities?
Barium swallowing test. | Allows you to visualize liquid moving down oesophagus into stomach using barium which shows up white on an x-ray.
53
What is the respiratory epithelium and what are exceptions?
Pseudostratified ciliated columnar epithelium cells and goblet cells Exception: Inferior pharynx has stratified squamous epithelium (protect from abrasion and chemical damage)
54
How do goblet cells differ as you descend through the respiratory tract?
Less present as the trachea descends. | They become Club cells at respiratory bronchioles, which help produce surfactant
55
What is the mucociliary escalator?
Self clearing mechanism Mucous traps particles and creates watery and viscous layers. Cilia project into watery layer, and they move in synchrony to move mucous away from lungs.
56
What disease is associated with the mucociliary escalator and how?
Cystic Fibrosis Chromosomal mutation in chloride channels of cells leads to more viscous mucous, making it difficult to move mucous up the mucociliary escalator
57
What supports the trachea?
Hyaline C-shaped cartilage | Smooth muscle attaches the edges of the C-shaped cartilage (trachealis muscle)
58
What layers, beginning in lumen, surround the trachea, and what are found in the layers?
Mucosa- Respiratory epithelium, cilia, goblet cells Submucosa- Nervous tissue and blood vessels. Rich in seromucous glands (produce watery and mostly mucous secretions, delivered to luminal surface by ducts- aids in humidification) Cartilage Layer- Hyaline, perichondrium, trachealis muscle Adventitia- loose connective tissue
59
Do C-shaped hyaline rings support the entire respiratory tract?
No At secondary bronchi they become small segmented plates, and stop completely at the bronchioles (more smooth muscles in walls)
60
What structures help form the bronchioles on a histological level?
No cartilage No submucosal glands Largely smooth muscle forming walls Large bronchioles have simple ciliated columnar epithelium with few goblet cells Smaller bronchioles have simple cuboidal with few ciliated cells and more club cells
61
What do Club cells do?
Form surfactant | Also serve as progenitor cells for ciliated/secretory epithelium
62
What is significant about the terminal bronchioles?
Last part of conduction system, helping move air from bronchioles to respiratory bronchioles
63
Describe the pneumocytes present in the alveoli.
Type 1 pneumocytes- gas exchange. Flattened squamous cells Type 2 pneumocytes- produce surfactant to prevent alveolar collapse. Type of progenitor cell that can replenish both 1 and 2 pneumocytes. Account for 60% of cells but cover 5% of surface area.
64
How many alveoli are in a human lung on average?
500 million
65
What is the blood-air barrier and what helps to form it?
Prevents blood and air from mixing. | Type 1 pneumocytes and endothelial cells of capillaries, with fused basement membranes
66
How does lung fibrosis impact the lung on a histological level?
Thickening of lung tissue / blood-air barrier resulting in increased space between t1 pneumocyte and capillary Creates inefficiency for gas diffusion
67
What cell type forms the endocardium?
Simple Squamous epithelium which is continuous with the endothelium of blood vessels
68
What structures/cells are found in the epicardium?
Known as visceral pericardium consisting of; External simple squamous epithelium (mesothelial cells of mesodermal origin) Internal areolar tissue (loose connective tissue). Neutrophils clear dead myocytes (which cant be replaced). Nerves and vessels supplying the heart are found here in areolar tissue, with lots of adipose surrounding it
69
What occurs when myocytes die?
Replaced by polymorphs (scar tissue), which can weaken heart. Myocytes are terminally differentiated
70
How do Purkinje Fibres appear histologically, and how do they differ from myocytes?
Many mitochondria, paler (due to fewer myofibrils), larger than myocytes, can conduct action potentials more quickly than myocytes . They radiate into the subendocardium of ventricular walls
71
What is the subendocardium?
Connective tissue layer within endocardium (below simple squamous epithelium) containing Purkinje Fibres
72
What is found within the intercalated discs connecting myocytes?
Gap junctions for ion movement | Desmosomes for mechanical connections of myocytes
73
How do muscular and elastic arteries differ?
Elastic: Numerous bundles of elastic fibres (elastic laminae) in media, deal with high pressures near heart Muscular: smaller arteries, thick tunica media with lots of smooth muscle and little elastic tissue (helps maintain BP), internal/external elastic laminae on either side of media
74
How do veins appear in cross-sections- touch on layers and what they are composed of.
Large tunica adventitia Adventitia is composed of collagen Thin tunica intima Relatively thin media with layer of smooth muscle cells
75
What structures/cells are found in the myocardium?
Cardiomyocytes form thick muscle layer (single, central nucleus, many mitochondria, glycogen rich, y-shaped) Intercalated discs join cardiomyocytes (formed using gap junctions, desmosomes, and adherens)