Thorax I Flashcards
1
Q
anterior posterior dorsal ventral lateral medial proximal distal
All body planes
A
2
Q
True Ribs
A
1-7
3
Q
False Ribs
A
8-10
4
Q
Floating Ribs
A
11-12
5
Q
The Thoracic Cage
A
6
Q
A
7
Q
A
8
Q
A
9
Q
Inferior Thoracic Aperture
A
10
Q
Posterior Anterior of Thoracic vertebrae
A
11
Q
Lateral View of Vertebrae
A
12
Q
Costovertebral joint
A
13
Q
Features of Typical Ribs
A
14
Q
Which of the ribs is atypical?
A
Ribs 1, 2, 10 11 and 12
Note how all contains the numbers 1, 2
1 is important clinically because of its close relationship to lower nerves of the brachial plexus and main vessels of arm
15
Q
True & False Ribs
How do all ribs articulate? and with what structure?
A
All ribs articulate posteriorly with the thoracic vertebrae
16
Q
What can happen if the first rib/clavicle is damaged…
A
The nerves of the brachial plexus can be compressed between the first rib and clavicle which can cause pain in the forearm, hand, wrist and can comprimise circulation in the upper limb
17
Q
Where are fractures most likely to occur in the ribs?
A
The weakest point in adult ribs vulnerable to fractures is the angle
18
Q
Clinical case: Cervical Rib
A
A rib arising from anterior tubercle of transverse process (TP) of C7
Can cause pressure on lower brachial plexus or subclavian artery
19
Q
The black boxes are fibres
Muscles of the chest wall: Pectoralis Major
A
20
Q
Deltoids _____ arm
Pectoralis Major ______ arm
A
Deltoids abduct arm
Pectoralis Major adducts arm
21
Q
Muscles of the chest wall: Pectoralis Minor
Function?
A
Depression of Scapula
22
Q
Muscles of the chest wall: Serratus anterior
Function?
A
Protraction and rotation of scapula
23
Q
Intercostal muscles
A
24
Q
Intercostal Membranes
A
25
Intercostal muscle fibre direction
26
Subcostalis
Internal surface of one rib to internal surface of another
27
Transversus thoracis
From xiphoid process and lower body of sternum to lower border of CCs 3-6
(costal cartilages?)
28
Functions of intercostal muscles
**•External intercostal muscles most active during inspiration (A)**
**•Interchondral portion of internal intercostal** also involved **(C)**
o Elevate ribs and sternum
**•Internal intercostal muscles most active during expiration (B)**
o Interosseous portion - the portion between the ribs
o Depress ribs and sternum
Most activity of intercostal muscle is to maintain tone in the intercostal space: ‘isometric’
29
The Diaphragm & structure
Most important muscle of respiration
**Thin muscular & tendinous septum**
**Separates** the thoracic cavity above & the abdominal cavity below
**Dome** shaped
30
Diaphragm consists of...
Peripheral muscular part & Centrally placed tendon
31
On contraction the diaphragm...
**pulls down its central tendon & increases the vertical diameter of the thorax**
32
Diaphragm Structure question
Answer in Picture
33
There are three main apertures in the diaphragm:
**Vena Caval foramen (T8)**
**Oesophageal hiatus (T10)**
**Aortic hiatus (T12)** (not a true aperture)
34
Mechanism of respiration
* Two phases of Inspiration & Expiration
* Alternate increase & decrease of capacity of thoracic cavity
* As there is only a single entrance (trachea), an increase in capacity of the thoracic cavity, results in air moving into the lungs under **atmospheric pressure**
35
Vertical diameter
**Changes in thoracic cage diameter**
changes are achieved through **the diaphragm**
36
Anteroposterior diameter
**Changes in thoracic cage diameter**
Downward sloping ribs raised at sternal end
First rib is fixed, intercostals contract bringing ribs closer together
External intercostals & interchondral part of internal intercostals and innermost intercostals
37
Transverse diameter
**Changes in thoracic cage diameter**
- Ribs articulate in front with the sternum & behind with vertebral column
- Curve downward & resemble bucket handles
38
The interchondral joints
small articulations between the apposed costal cartilages of the **ribs 7-10.**
39
The intercostal artery, vein & nerve (the neurovascular bundle) run along between the...
**Intercostal neurovascular bundle**
**Internal & innermost intercostal muscles**
_Protected by_ the **costal groove of the superior rib**
**V - Vein**
**A - Artery**
**N - Nerve**
40
How many intercostal spaces are there?
**_11 intercostal spaces_: name according to the rib superior**
41
Intercostal nerve enters space between
**Intercostal nerves**
**parietal pleura & internal intercostal membrane**
42
Intercostal nerves originates segmentally from...
**Intercostal Nerves**
**Anterior Rami T1-T11 of spinal nerve:**
## Footnote
* 1-6 intercostal spaces
* 7-9 pass deep to Costal Cartilages to enter anterior abdominal wall
* 10-11 pass directly to anterior abdominal wall
43
‘Subcostal nerve’
**Intercostal nerves**
**T12** intercostal nerve
44
**T1 intercostal nerve** has branch that joins to..
**Intercostal nerves**
**Brachial Plexus**
_It also has:_
**_No_ lateral cutaneous branch**
**_No_ anterior cutaneous branch**
45
Intercostal Nerve Diagram question
46
Blood supply via the anterior & posterior intercostal arteries originate from...
**Intercostal arteries**
...the internal thoracic artery (branch of the subclavian - anterior) & descending thoracic aorta (posterior) respectively
47
Each intercostal artery gives off branches to the...
...muscles, skin, parietal pleura & in the region of the breast in the female. The branches to the superficial structures are particularly large
48
49
50
Intercostal Artery & Vein Diagram
51
The azygous and hemi-azygous system of veins drains...
**Intercostal veins**
the intercostal spaces, as well as the pericardium & parts of the posterior abdominal region
52
Posterior intercostal veins drain into...
**Intercostal veins**
the azygous & hemi-azygous systems
53
Main azygous vein on **\_\_\_\_\_**
Superior (accessory) & Inferior hemiazygous (proper) on **\_\_\_\_\_**
**Intercostal veins**
Main azygous vein on **right**,
Superior (accessory) & Inferior hemiazygous (proper) on **left**
54
Azygous & Hemi-zygous veins are also important as they can be an...
**Intercostal Veins**
anastomotic pathway for venous return if IVC becomes blocked
55
* Azygous formed by union of right ______ \_\_\_\_\_& right ______ \_\_\_\_
* Inferior hemiazygous formed by union of left ______ \_\_\_\_\_ & left _____ \_\_\_\_
**Intercostal Vein**
* Azygous formed by union of **right** **ascending lumbar** & **right subcostal veins**
* Inferior hemiazygous formed by union of **left ascending lumbar** & **left subcostal veins**
56
57
58
Breast structure, where it overlies and parts rest
* Overlies the **2nd–6th rib**
* **_Two-thirds of it rests on pectoralis major_**, **_one-third on serratus anterior_**
* Lower medial edge just overlaps the **upper part of the rectus sheath**
59
**Structure of the Breast (go over lecture in this bit)**
* Modified sweat gland
* It is **conical** in shape
* It lies in **superficial fascia** of the front of chest
* It has a base, apex and tail (axillary tail)
* It extends from the lateral margin of the sternum to the midaxillary line
* It has no capsule
60
Blood supply to the Breast (Arterial)
Arterial
From the axillary artery, principally via its lateral thoracic and acromiothoracic branches:
1. Perforating branches of internal thoracic (internal mammary) artery
2. Mammary branches of lateral thoracic artery
3. Mammary branches of Intercostal arteries
61
Blood supply to the Breast (Venous)
**Venous**
1. Circular venous plexus are found at the base of nipple.
2. Veins of this plexus drain into axillary & internal thoracic veins.
62
Diagram
63
The largest lymph nodes are located where....
**Breast Lymphatics**
**peripheral lymphatics** connect with the **trunk , such as the groin, axillae and base of the neck**
64
Particular importance to the lymph nodes in the axilla...
**Breast Lymphatics**
1. Frequent development of cancer in the mammary gland
2. Subsequent dissemination of the malignant cells along lymph vessels to the nodes
65
**5** breast lymphatic groups which lie in the axillary fat:
**Breast lymphatic**
1. Pectoral (Anterior) group: which lies on Pectoralis Major along lateral thoracic vessels
2. Subscapular (Posterior) group: which lies on posterior wall of axilla on lower border of subscapularis along subscapular vessels
3. Brachial (Lateral) group: lies on lateral wall of axilla along the axillary vessels
4. Central group: lies in at the Center (base of axilla)
5. Apical group: lies at apex of axilla
66
Subclavian lymph trunk is formed by union of...
**Breast lymphatic**
...efferent lymph vessels of apical group.
* It usually opens in subclavian vein.
* On the left side it usually opens into thoracic duct.
