1- Organization of the thorax Flashcards
All structures in the bony landmarks are easily palpable except ___ and ____.
1st and 12th rib
The __________ is a readily palpable indentation at the superior border of the manubrium.
Jugular notch
Running a finger inferiorly from the jugular notch, the first palpable projection is the _______, which is connected to the ________ of the ____ribs.
Sternal angle;
costal cartilage, 2nd
The sternal angle is at the transverse level of _______; forming the _______ plane.
T4-T5 (specifically, the
intervertebral disc between T4 and T5);
transverse thoracic
The ________ is a is the triangular shaped bone
at the back of the shoulders.
It has 2 easily palpable
projections _______ and _______ that surround
the head of humerus.
Scapula;
Acromion
Coracoid process
For acromion and the coracoid process, which is more anterior?
Coracoid process.
Mnemonic: While spelling S ca pula, the C is in front of the A .
The Coracoid process is anterior to the Acromion.
Acromion arises from the spine (at posterior)
Which 4 surface lines you should remember?
- Anterior midline
- Posterior midline
- Mid-clavicular line
- Scapular line (middle of the scapular at the posterior)
A. Sternal line is equivalent anterior midline
B. Parasternal line is equivalent to mid-clavicular line.
Both wrong.
A. Sternal line is at the head of the clavicular; Anterior midline is really the midline
B. Parasternal line is the middle of sternal line and mid-clavicular line.
The _______th intercostal space of the _________ line is the apex of the heart where the heartbeat can be felt.
5th;
Mid-clavicular line
The ________ line passes through the inferior angle of
scapula. (Lowest part of the scapula, covered by latissimus dorsi.
Scapular
What is in between the manubrium and the sternum?
Manubriosternal joint
What is the part of the sternum and is at the level of T9?
Xiphoid process
What are the 3 lines in the axillary region?
Anterior axillary line,
Midaxillary line,
Posterior axillary line
The anterior axillary line is formed by the border of the __________.
Pectoralis major.
The posterior axillary line is formed by the _____ and ______ muscles.
Latissimus dorsi;
Teres major
When we ask the patient to put their hands on their waist, it will contract the _________ and make the _________ line more prominent.
Latissimus dorsi;
Posterior axillary line
What are the boundaries of the safety triangle?
○ Anteriorly: lateral border of pectoralis major
○ Posteriorly: lateral border of latissimus dorsi
○ Inferiorly: horizontal line from nipple (commonly the
5th intercostal space)
defines the safe site for
thoracocentesis,
In thoracocentesis, the needle run in the ___________ to prevent the VAN from being damaged .
It it also done in the safety triangle to prevent the ________, _____ and ____ from being damaged.
intercostal groove;
diaphragm, liver (right) or spleen (left)
What are the differences between true ribs and false ribs? What is the remaining ribs called?
● True ribs (1-7): connect directly to the sternum
● False ribs (8-10): costal cartilage connect to the cartilage of
the rib superior to them
● Floating ribs (11-12): Do not connect to the sternum at all
Typical ribs are ribs _____to _____. Which 6 structures to they have?
3-9
- Head: site of 2 facets for articulation
- Neck
- Tubercle
- Shaft (body)
- Angle: where fractures are most likely to occur.
- Costal groove: where intercostal veins, arteries and nerves run. (VAN)
Mnemonic: Typical structures in Thorax comes in multiples
of 3, typical ribs are 3-9, typical intercostal nerves are 3-6
Which 2 structures are behind the sternum?
- Arch of aorta
- Bifurcation of the trachea
(T4-T5)
What are the 5 structures of a thoracic vertebra?
- Vertebral body
- Superior articular facet
- Inferior articular facet
- Transverse process
- Spinous process
What are the key characteristics of a thoracic vertebra?
- Heart-shaped body (heart is located in the thorax);
Kidney-shaped body of lumbar vertebrae (kidneys in abdomen)
- Presence of transverse process
- Spinous process slants inferiorly (lumbar and cervical vertebrae have horizontal spinous processes)
For ribs 2-10, the transverse process, superior costal facet and the inferior costal facet of the vertebra above are connected to which structure of the rib respectively?
Transverse process: Tubercle
Superior costal facet: Inferior surface of head
Inferior costal facet of the vertebra above:
Superior surface of the head
Describe the movements of the thoracic cage in inspiration.
Inspiration:
Upward and outward movement of the rib cage and sternum, diaphragm and intercostal muscles contract, flattening of the diaphragm from 5th to 6th ribs.
Intrathoracic volume increases, pressure is lower than atm pressure and draws air into lungs.
About dermatomes:
A. There is some overlap of adjacent dermatomes, so there
would not be total loss of sensation upon damage of one
spinal nerve
B. Shingles (生蛇) go along dermatome area of a spinal nerve
C. Nipples are in T4 dermatome
D. Umbilicus is on T10
All
Which 3 major kinds of muscles are on the thoracic wall? List all the muscles involved.
- Chest muscles
- Pectoralis major
- Pectoralis minor
- Serratus muscles (Boxer’s muscle) - Rib to rib muscles
- External intercostal muscle becomes External intercostal membrane at the anterior side
- Internal intercostal muscle becomes Internal intercostal membrane at posterior side
- The transversus thoracis and the innermost intercostal muscles are a continuous layer
- Sternum to ribs muscles
- Transversus thoracis
What nerves innervate the pectoralis minor?
Medial and Lateral pectoral nerves (Brachial plexus)
The Serratus Anterior muscle inserts onto the external
surface of ______ parts of ribs 1-8 individually.
The muscle
originates from the anterior surface of medial border of
scapula.
It is innervated by the ____________ and acts to protect the scapula.
Damage of the nerve will cause ___________.
lateral;
Long Thoracic nerve;
Winged scapula
Mnemonic: SALT
○ Serratus Anterior muscle is innervated by Long
Thoracic nerve
What is the fibre direction of intercostal muscles?
Mnemonic: Fibre direction of intercostal muscles
○ Fibre direction of e xternal intercostal muscles =
direction of forearm when hands are in pock e ts (run
inferomedially)
○ Fibre direction of i nternal intercostal muscles and
i nnermost intercostal muscles = direction of forearm
when hands are on t i ts (run superomedially)
Blood supply of the thoracic wall can be divided into 2 parts:
- Posterior intercostal arteries which arise from the _________;
- Anterior intercostal arteries which arise from the ___________and then _________.
Thoracic aorta;
Subclavian artery > internal thoracic artery
The internal thoracic artery (branches from subclavian
artery ) run lateral to the _______________.
internal thoracic vein (drains into
subclavian vein )
Each intercostal space is supplied by?
a large posterior
intercostal artery
and a pair of anterior intercostal arteries
Each intercostal space is drained by?
posterior intercostal
veins (tributaries of azygos/hemiazygos venous system)
and anterior intercostal veins (tributaries of internal
thoracic veins )
The internal thoracic artery ends at ____th intercostal space and branches into _________ and __________.
6;
musculophrenic and superior epigastric artery
The _________ containing ___________ (superior to inferior) runs along the costal groove.
Neurovascular bundle;
- Intercostal veins (goes to azygous and hemiazygous veins)
- Intercostal arteries (anterior and posterior)
- Intercostal nerves
The ________ is the circular pigmented area of skin surrounding
the nipple.
Areola
Mammary glands are modified _____ glands. Glands consist
of ____________ and _________ that open onto the nipple.
Sweat;
Secretory lobules;
Lactiferous ducts
Breast cancer pulls on the _________ , resulting in
pitting of the skin, appearance like skin of an orange
suspensory ligaments (Cooper’s ligament)
What are the 3 major arterial supply to the breasts?
- Intercostal arteries
- Internal thoracic arteries
- Branches from axillary artery (lateral thoracic artery)
In breasts, most lymph drains to the ___________ (includes the pectoral , central axillary , subscapular and supraclavicular
nodes).
Axillary lymph nodes
*Breast cancer: spread of metastasis via lymphatic drainage
Venous drainage of the breast is mainly to the ________ vein ,
but there is some drainage to the _____ vein.
Axillary;
Internal thoracic
The transverse thoracic plane at the sternal angle (T4-T5) separates the _____ mediastinum and the _______ mediastinum.
Superior and inferior.
The inferior mediastinum is separated into _____, _______ and ______mediastinum.
Anterior, middle and posterior
前中後
When cut in coronal plane, which mediastinum can be seen?
Superior and inferior.
When cut in transverse plane, which mediastinum can be seen?
Anterior, middle and posterior
When cut in mid-sagittal plane, which mediastinum can be seen?
All 4
Thoracic duct and esophagus are in the ______ mediastinum.
Posterior
Which muscle causes a winged scapula?
- Weakness of serratus anterior.
- It is due to the damage of long thoracic nerve which innervates serratus anterior
muscles. - Normally when the arm is extended and pressing against the wall, serratus anterior
contracts to pull the originally flipped out scapula towards the body. But without
contraction of serratus anterior, the scapula appears to be winged.
In anesthesia during thoracentesis, the intercostal nerves superior and inferior to the
insertion site of needle have to be blocked. Explain the reason.
- Intercostal nerves have collateral branches, which travel above and along the rib.
- The cutaneous branches of one intercostal nerve and the collateral branch of the
superior one intercostal nerve together innervate the same area of skin. (overlapping
in sensory field) - Both of the nerves have to be blocked to eliminate all sensation of the insertion site
during thoracentesis.
