p.8
Breast Anatomy and Physiology
What is a supernumerary breast or nipple?
Having more than two breasts.
p.5
Muscular Components of the Thoracic Wall
What are the three major muscle groups that make up the intrinsic muscles of the thoracic wall?
Intercostals, Transversus thoracis, Subcostals.
What is the function of the thoracic cage in respiration?
Generating the negative pressure required for respiration.
p.10
Breast Anatomy and Physiology
What glands are located within the periphery of the areola?
Sweat and sebaceous glands, and the accessory glands of Montgomery.
p.6
Blood Supply of the Thoracic Wall
Which arteries supply each intercostal space?
A large posterior intercostal artery and a small pair of anterior intercostal arteries.
p.1
Surface Landmarks of the Chest
Why is the sternal angle an important landmark?
It is adjacent to the 2nd rib and used for orientation; it helps in identifying other ribs and thoracic vertebrae.
p.11
Blood Supply of the Thoracic Wall
Which veins are involved in the deep venous drainage of the breast?
Internal mammary veins, axillary veins, and posterior intercostal veins.
p.2
Surface Landmarks of the Chest
Where is the 2nd intercostal space located?
Below the 2nd rib and always below the nipple line.
p.1
Bony Components of the Thoracic Wall
What is the significance of the thoracic spine being kyphotic?
The apex of the kyphotic curve is at T7, making the thoracic cage widest in sagittal diameter at this level.
p.6
Muscular Components of the Thoracic Wall
What is the action of the external intercostal muscles?
Elevates the ribs, increasing the thoracic volume.
p.2
Bony Components of the Thoracic Wall
What are the three parts of the sternum?
Manubrium, body, and xiphoid process.
p.10
Clinical Significance of Thoracic Structures
What is Peau d’orange and what does it indicate?
A skin appearance like an orange, indicating a sign of breast cancer.
p.3
Bony Components of the Thoracic Wall
Until which rib does the length of ribs increase, and what happens afterward?
The length increases until the 7th rib; afterward, the length decreases.
p.3
Bony Components of the Thoracic Wall
What is the function of the head of a typical rib?
The head consists of the slightly enlarged posterior end, normally carrying 2 facets for the costovertebral joints, and attaches to two vertebrae: the vertebra of the same number and the vertebra immediately superior.
p.4
Bony Components of the Thoracic Wall
What type of joints are the 2nd to 7th sternocostal joints?
Synovial joints (Plane), which allow movement during breathing.
p.9
Surface Landmarks of the Chest
What is the Tail of Spence?
The superolateral extension of the breast.
p.4
Muscular Components of the Thoracic Wall
Which muscles are considered auxiliary breathing muscles in the anterior thoracic wall?
The pectoralis major and minor, and the serratus anterior.
p.8
Mediastinum Compartments
What mnemonic can help remember the contents of the posterior mediastinum?
DATE – Vivian Slapped Larry (Descending Aorta, Azygos and hemi-azygos veins, Thoracic duct, Esophagus, Vagus nerve, Splanchnic nerves, Lymphatics).
p.8
Mediastinum Compartments
What is the significance of the superior mediastinum?
It serves as a conduit space for structures from the neck and upper extremities/thorax.
p.10
Breast Anatomy and Physiology
What influences the size and pigmentation of the areola?
Direct hormonal influence.
p.11
Blood Supply of the Thoracic Wall
Which portions of the breast are supplied by the internal mammary artery?
The medial and inferior portions of the breast.
p.6
Muscular Components of the Thoracic Wall
What is the action of the internal intercostal muscles?
Interosseous part reduces the thoracic volume by depressing the ribcage; interchondral part elevates ribs.
p.6
Blood Supply of the Thoracic Wall
From where do the posterior intercostal arteries arise?
From the supreme/superior intercostal artery (a branch of the subclavian artery) for the 1st and 2nd intercostal spaces, and from the thoracic aorta for the 3rd-11th intercostal spaces.
p.2
Bony Components of the Thoracic Wall
What is the xiphoid process made of early in life?
Cartilage, which gradually becomes ossified starting during middle age.
p.3
Bony Components of the Thoracic Wall
How are ribs numbered?
In accordance with their vertebral attachments.
p.3
Bony Components of the Thoracic Wall
What is the angle of a rib?
The angle is the part with the greatest degree of rib curvature and is the most posterior extent of the thoracic cage, aligning with the medial border of the scapula.
p.4
Bony Components of the Thoracic Wall
What are the two points of articulation for a typical rib in the costovertebral joint?
The superior costal facet and the inferior costal facet of the same number.
p.3
Bony Components of the Thoracic Wall
What are the characteristics of the 1st rib?
The 1st rib is the shortest, broadest, flattest, and most sharply curved. It has only one articular facet, no costal groove, and its anteromedial part is covered by the clavicle. It also has two grooves for the subclavian vessels and a prominence called the scalene tubercle for the attachment of the scalene muscle.
p.4
Muscular Components of the Thoracic Wall
What is the function of the abdominal muscles in respiration?
They compress the abdominal cavity, pushing the diaphragm upwards and increasing intrathoracic pressure, leading to forced expiration.
p.4
Muscular Components of the Thoracic Wall
What is the role of the posterior thoracic wall muscles?
They increase thoracic volume and reinforce the thoracic wall.
p.5
Muscular Components of the Thoracic Wall
Which nerves innervate the internal oblique muscle?
Thoracoabdominal nerves [T7-T11] and subcostal nerve [T12].
What are the parts of the thoracic cage?
Anterior: Sternum; Posterior: 12 thoracic vertebrae connected by 12 pairs of ribs with their costal cartilages.
p.2
Surface Landmarks of the Chest
What does the anterior axillary line separate?
The anterior from the lateral chest walls.
p.5
Muscular Components of the Thoracic Wall
What action do the internal intercostal fibers perform during respiration?
Depress the rib during expiration.
p.12
Bony Components of the Thoracic Wall
How are ribs classified based on their attachment?
True ribs (1-7), False ribs (8-10), Floating ribs (11-12).
p.12
Muscular Components of the Thoracic Wall
What is the function of the scalene muscles?
Flexion of the upper spine and lifting of ribs during inspiration.
p.11
Innervation of the Breast
Which nerves provide innervation to the breast?
The lateral and anterior cutaneous branches of the 2nd to 6th intercostal nerves.
p.3
Bony Components of the Thoracic Wall
Describe the classification of ribs based on their attachment.
True ribs (1-7) are directly attached to the sternum by their cartilaginous portion. False ribs (8-10) attach to the costal cartilage of the rib above. Floating ribs (11-12) have no bony attachments to the sternum and end in the musculature of the lateral chest wall.
p.7
Blood Supply of the Thoracic Wall
From which arteries do the anterior intercostal arteries arise?
The musculophrenic artery and the internal thoracic artery.
p.3
Bony Components of the Thoracic Wall
What is the costal groove and what runs through it?
The costal groove is located at the lower edge of the rib, where the intercostal vessels and the intercostal nerve run.
p.3
Bony Components of the Thoracic Wall
Which ribs are considered atypical ribs?
The 1st, 2nd, and 10th-12th ribs.
p.7
Mediastinum Compartments
What anatomical landmark divides the mediastinum into superior and inferior compartments?
The transverse thoracic plane.
p.8
Mediastinum Compartments
Where does most lymphatic drainage in the superior mediastinum converge?
At the thoracic duct, which empties into the bloodstream at the left subclavian.
p.13
Breast Anatomy and Physiology
What is the significance of the Tail of Spence in breast anatomy?
The Tail of Spence is an extension of breast tissue into the axilla, important for breast examinations.
p.12
Surface Landmarks of the Chest
What is the significance of the sternal angle?
It is an important landmark adjacent to the 2nd rib, used for orientation.
What is the function of the thoracic cage?
Protection of organs, breathing, resisting negative internal pressures, supporting upper limbs, and providing attachment for muscles.
p.6
Muscular Components of the Thoracic Wall
What is the function of the transversus thoracis muscle?
Depresses ribs during expiration.
p.2
Bony Components of the Thoracic Wall
What is the superior aperture also known as?
Thoracic inlet or outlet, depending on orientation.
p.10
Breast Anatomy and Physiology
Where does mammary tissue develop?
Within the superficial fascia of the anterior chest wall.
p.9
Breast Anatomy and Physiology
Why do males typically lack prominent breasts?
Males lack hormones for breast development.
p.9
Breast Anatomy and Physiology
What is the breast parenchyma made up of?
15 to 25 lobes of glandular tissue, each emptying into a separate milk duct terminating in the nipple.
p.13
Muscular Components of the Thoracic Wall
Describe the role of the scalene muscles in respiration.
The scalene muscles lift the ribs during respiration.
p.13
Mediastinum Compartments
What are the contents of the inferior middle mediastinum?
Heart, pericardial cavity, roots of the great vessels, phrenic nerve.
p.7
Mediastinum Compartments
Where is the thymus located in children and how does it change with age?
In children, a substantial portion of the thymus is located in the anterior mediastinum. As individuals age, the thymus regresses and may be entirely found in the superior mediastinum.
p.8
Breast Anatomy and Physiology
What supports the breasts?
Skin and connective tissues.
p.6
Muscular Components of the Thoracic Wall
Describe the location and action of the subcostal muscles.
Located on the inferior surface of the lower ribs, extending to the superior border of the rib 2 or 3 levels below it. They have the same action as the internal intercostals.
p.12
Bony Components of the Thoracic Wall
What is the superior aperture?
A kidney-shaped opening at the superior border of the thoracic cage.
p.11
Blood Supply of the Thoracic Wall
Which anterior perforating branches of the internal mammary artery are the most significant?
The 2nd and 3rd anterior perforating branches.
p.10
Breast Anatomy and Physiology
What types of muscles are found in the nipple and what are their functions?
Longitudinal muscles for nipple retraction and circular muscles for nipple erection.
p.11
Clinical Significance of Thoracic Structures
What is the significance of venous networks in the breast?
They are important hematogenous routes for metastasis of breast cancer.
p.11
Lymphatic Drainage of the Breast
What is the purpose of a sentinel node biopsy in breast cancer?
To determine whether early breast cancer has spread to the axillary lymph nodes.
p.9
Breast Anatomy and Physiology
What type of gland is the mammary gland classified as?
Specialized sweat gland: apocrine.
p.13
Mediastinum Compartments
What are the contents of the superior mediastinum?
Subclavian and carotid vessels, brachiocephalic vein, subclavian vein, jugular vein, thoracic duct, vagus, phrenic, cardiac, and left recurrent laryngeal nerves.
p.8
Mediastinum Compartments
Name three major vessels found in the superior mediastinum.
Subclavian vessels, carotid vessels, brachiocephalic vein.
p.9
Breast Anatomy and Physiology
How do the size and shape of the breast vary?
With individual race and age, and may have some degree of asymmetry.
p.9
Breast Anatomy and Physiology
Describe hemispherical breasts.
Most common type of breast shape.
p.9
Breast Anatomy and Physiology
Describe conical breasts.
More evident in individuals with smaller breasts.
p.8
Breast Anatomy and Physiology
What is a secondary role of the breasts?
They are a major female sexual characteristic.
p.5
Muscular Components of the Thoracic Wall
What is the function of the rectus abdominis muscle?
Depresses ribs; inserts in the xiphoid process and the 5th-7th costal cartilages.
p.6
Muscular Components of the Thoracic Wall
Where does the transversus thoracis muscle originate and insert?
Originates from the posterior aspect of the sternum and inserts into the 2nd-6th costal cartilages.
p.12
Surface Landmarks of the Chest
What does the anterior axillary line separate?
The anterior from the lateral chest walls.
p.6
Muscular Components of the Thoracic Wall
What is the innervation of the intercostal muscles?
Intercostal nerves (T1-T11).
p.2
Bony Components of the Thoracic Wall
What structures pass through the superior thoracic aperture?
Structures from the neck to the chest and from the upper extremity to the chest.
p.11
Blood Supply of the Thoracic Wall
Which artery supplies the lateral and upper portions of the breast?
The lateral thoracic artery.
p.1
Surface Landmarks of the Chest
What are intercostal spaces used for?
They are landmarks for interventional procedures for the lungs.
p.10
Clinical Significance of Thoracic Structures
How can you differentiate between physiologic and pathologic nipple retraction?
By stimulating the nipple; a physiologic retraction will appear normal after stimulation, while a pathologic one will not.
p.10
Breast Anatomy and Physiology
What are Cooper's ligaments and their function?
Connective tissue that traverses the fat and separates the breast lobules.
p.3
Bony Components of the Thoracic Wall
What happens to the costal cartilage as it approaches the sternum?
The costal cartilage comes back a little superiorly, and the end portion of each rib is oriented differently, going up toward their connection to the body of the sternum.
p.7
Blood Supply of the Thoracic Wall
What do the anterior intercostal arteries supply?
The anterior parts of the 1st-9th intercostal spaces.
p.7
Blood Supply of the Thoracic Wall
Which veins are responsible for the drainage of the anterior intercostal arteries?
The internal thoracic veins and the musculophrenic veins.
p.7
Mediastinum Compartments
What are the borders of the mediastinum?
Superior: Thoracic inlet, Inferior: Diaphragm, Lateral: Pleura, Anterior: Sternum, Posterior: Thoracic vertebrae.
p.9
Surface Landmarks of the Chest
Which muscles do the breasts rest on?
Pectoralis major, serratus anterior, external oblique, and rectus abdominis.
p.8
Mediastinum Compartments
What happens to the thymus as an individual ages?
The thymus regresses and can be found in the superior mediastinum.
p.8
Mediastinum Compartments
What is the primary role of the anterior mediastinum?
It is filled with connective and fatty tissues to protect the heart.
p.8
Mediastinum Compartments
What is the primary role of the posterior mediastinum?
It serves as a passageway for structures between the thorax and abdomen.
p.5
Muscular Components of the Thoracic Wall
Where are the intercostal vessels and nerves located?
In the space between the internal and innermost intercostal muscles.
p.2
Surface Landmarks of the Chest
What is the midclavicular line used for?
Access to the pleural cavity or subclavian vessels.
p.11
Blood Supply of the Thoracic Wall
What is the primary source of blood supply to the breast?
The majority of the blood supply comes from the internal mammary artery.
p.12
Surface Landmarks of the Chest
What is the midclavicular line?
A vertical line crossing the midpoint of the clavicle, just medial to the nipple.
p.1
Surface Landmarks of the Chest
What does the clavicle separate?
The neck from the thorax.
p.12
Bony Components of the Thoracic Wall
What are the three parts of the sternum?
Manubrium, body, and xiphoid process.
p.11
Innervation of the Breast
Which nerve is most constant in providing innervation to the nipple?
The 4th intercostal nerve.
p.9
Breast Anatomy and Physiology
What might prominent breasts in males indicate?
Hormonal imbalance or liver pathology.
p.13
Muscular Components of the Thoracic Wall
What is the function of the transversus thoracis muscle?
Depresses ribs during expiration.
p.9
Surface Landmarks of the Chest
From which ribs does the breast extend?
From the 2nd or 3rd rib to the level of the 6th or 7th rib.
p.3
Bony Components of the Thoracic Wall
What is the mnemonic for remembering the order of structures in the costal groove?
VAN: Vein superiorly, Artery, Nerve.
p.7
Mediastinum Compartments
What is the function of the mediastinum?
It serves as a protective pathway for structures traversing from the neck to the abdomen.
p.9
Breast Anatomy and Physiology
Where is the nipple-areola complex found?
At the tip of the breast.
p.5
Muscular Components of the Thoracic Wall
Which muscles are responsible for elevating the 1st and 2nd ribs during inspiration?
Anterior scalene (1st rib), Middle scalene (1st rib), Posterior scalene (2nd rib).
p.5
Muscular Components of the Thoracic Wall
Describe the action of the external oblique muscle.
Contralateral rotation of the torso; covers the lower 8 ribs.
p.12
Surface Landmarks of the Chest
What are intercostal spaces used for?
They are landmarks for interventional procedures for the lungs.
p.2
Surface Landmarks of the Chest
What does the midsternal line separate?
The left and right sides of the chest.
p.10
Breast Anatomy and Physiology
How does the areola change during pregnancy?
It increases pigmentation due to hormonal imbalance.
p.10
Breast Anatomy and Physiology
Why does the areola have differing colors?
For higher visibility for the infant.
p.6
Blood Supply of the Thoracic Wall
What is the arterial supply of the thoracic wall?
Derived from the thoracic aorta, subclavian artery, and axillary artery.
p.11
Innervation of the Breast
What is the role of the 2nd intercostal nerve, also known as the intercostobrachial nerve?
It is responsible for cutaneous sensation from the upper medial aspect of the arm and axilla floor.
p.3
Bony Components of the Thoracic Wall
How does the posterior level of ribs compare to the anterior level?
The posterior level is higher since the ribs move inferiorly as they come anteriorly.
p.4
Bony Components of the Thoracic Wall
What are the characteristics of the 2nd rib?
It has 2 articular facets and a rough surface on the superior part called the tuberosity for serratus anterior.
p.4
Bony Components of the Thoracic Wall
What type of joint is the 1st sternocostal joint?
Synchondrosis, which is immobile.
p.9
Surface Landmarks of the Chest
What defines the extent of dissection during breast surgeries?
The breast extends medially from the edge of the sternum, then laterally to the anterior axillary line.
p.8
Mediastinum Compartments
Which nerves are contained in the superior mediastinum?
Vagus, phrenic, cardiac, and left recurrent laryngeal nerves.
p.4
Muscular Components of the Thoracic Wall
What is the role of the scalene muscles in respiration?
They lift the ribs during inspiration due to their attachment to the 1st rib.
p.8
Mediastinum Compartments
How can you locate the superior mediastinum?
Draw a line from the sternal angle posteriorly to the junction of T4-T5. Above the line is the superior mediastinum.
p.4
Muscular Components of the Thoracic Wall
Where does the rectus abdominis insert?
In the xiphoid process and the 5th-7th costal cartilages.
p.8
Breast Anatomy and Physiology
Where are the breasts located?
On the anterior chest wall.
p.12
Surface Landmarks of the Chest
What does the suprasternal notch indicate?
The superior border of the sternum.
p.2
Surface Landmarks of the Chest
What is the xiphoid process used as a landmark for?
Cardiac interventional procedures and ultrasound of the heart.
p.12
Surface Landmarks of the Chest
What is the xiphoid process used for?
It is used as a landmark for cardiac interventional procedures and ultrasound of the heart.
Which organs are protected by the thoracic cage?
Heart, lungs, great vessels, esophagus, trachea, and partially the stomach, liver, kidneys, and spleen.
p.5
Muscular Components of the Thoracic Wall
What is the primary function of the intercostal muscles?
They are primary respiratory muscles, responding in elevation and depression of the thoracic cage, maintaining tension.
p.1
Surface Landmarks of the Chest
What is the importance of knowing surface landmarks on the thoracic cage?
They assist physicians in clinical assessment and serve as guides for interventional procedures.
p.10
Breast Anatomy and Physiology
What substances does the areola secrete to facilitate breastfeeding?
Lubricants and pheromones.
p.1
Surface Landmarks of the Chest
What does the suprasternal notch indicate?
The superior border of the sternum where the two clavicles meet.
p.2
Bony Components of the Thoracic Wall
What anatomical landmark marks the attachment of the 2nd rib?
The sternal angle (Angle of Louis).
p.11
Blood Supply of the Thoracic Wall
Where are the branches of the lateral thoracic artery frequently found?
From 1-2.5 cm from the skin surface.
p.11
Blood Supply of the Thoracic Wall
What forms collaterals around the areola?
Branches of the internal mammary artery and lateral thoracic artery.
p.13
Muscular Components of the Thoracic Wall
Where does the rectus abdominis muscle insert?
In the xiphoid process and the 5th-7th costal cartilages.
p.13
Mediastinum Compartments
What are the boundaries of the mediastinum?
Superior: Thoracic inlet, Inferior: Diaphragm, Lateral: Pleura, Anterior: Sternum, Posterior: Thoracic vertebrae.
p.13
Mediastinum Compartments
What are the contents of the inferior posterior mediastinum?
Descending aorta, azygos and hemi-azygos veins, thoracic duct (lower part), esophagus, vagus nerve, splanchnic nerves, lymphatics.
p.4
Muscular Components of the Thoracic Wall
Which muscles cover the eight lower ribs?
The external oblique muscles.
p.4
Muscular Components of the Thoracic Wall
Which muscles are part of the posterior thoracic wall?
The trapezius, latissimus dorsi, serratus posterior, rhomboids, and levator scapulae.
p.12
Surface Landmarks of the Chest
What does the nipple line correspond to posteriorly?
The T4 level, used for determination of dermatomal levels.
p.5
Muscular Components of the Thoracic Wall
What is the orientation of the external intercostal fibers?
Infero-anteriorly, like fibers of the external oblique.
p.2
Surface Landmarks of the Chest
What do the anterior and posterior axillary lines delineate?
The borders of the lateral chest wall.
p.12
Surface Landmarks of the Chest
What does the midsternal line separate?
The left and right sides of the chest.
p.11
Blood Supply of the Thoracic Wall
Where do the anterior perforating branches of the internal mammary artery exit?
Approximately 2 cm laterally to the sternum.
p.6
Blood Supply of the Thoracic Wall
What are the branches of the internal thoracic arteries?
Superior epigastric and anterior intercostal arteries.
p.10
Clinical Significance of Thoracic Structures
What can happen if a malignant tumor invades Cooper's ligaments?
The ligaments can shorten, leading to changes in the skin such as Peau d’orange.
p.4
Bony Components of the Thoracic Wall
How does the 2nd rib differ from the 1st rib?
The 2nd rib is thinner, longer, and less curved compared to the 1st rib.
p.3
Bony Components of the Thoracic Wall
What is the tubercle of a rib and where is it located?
The tubercle is found behind the neck of the rib and contains an articular facet which is part of the costotransverse joint lying between the rib and transverse process of the vertebra.
p.7
Blood Supply of the Thoracic Wall
Which intercostal spaces are supplied by the internal thoracic artery?
The 1st-6th intercostal spaces.
p.9
Surface Landmarks of the Chest
Where are the breasts located in relation to the muscles?
Subcutaneously, resting on the fascia of the chest and abdominal muscles.
p.8
Mediastinum Compartments
What does the anterior mediastinum contain?
Lymphatic tissues, parasternal lymph nodes, and the thymus in children.
p.8
Mediastinum Compartments
What structures are contained in the middle mediastinum?
Heart, pericardial cavity, roots of the great vessels, and phrenic nerve.
p.10
Breast Anatomy and Physiology
What is the retromammary space and its significance?
It allows the breast to move freely over the chest wall and is the location where breast implants are inserted.
p.3
Bony Components of the Thoracic Wall
What is unique about the 12th rib?
The 12th rib is not always present.
p.4
Bony Components of the Thoracic Wall
Describe the tubercle of the 10th-12th ribs.
The tubercle is not prominent and does not articulate with the transverse process of its corresponding vertebra.
p.4
Bony Components of the Thoracic Wall
What is the function of the sternocostal ligaments?
They reinforce the sternocostal joints.
p.13
Mediastinum Compartments
What are the contents of the inferior anterior mediastinum?
Lymphatic tissues, parasternal lymph nodes, thymus in children.
p.4
Bony Components of the Thoracic Wall
What is the only bony articulation of the thorax to the shoulder girdle?
The sternoclavicular joint.
p.13
Surface Landmarks of the Chest
Identify the surface landmarks of the female breast.
Nipple-Areola Complex, Areas of Breasts and the Tail of Spence.
p.9
Breast Anatomy and Physiology
Describe pendulous breasts.
Hanging, more common in obese and elderly individuals.
p.8
Mediastinum Compartments
What is the primary role of the middle mediastinum?
It protects and houses the heart and great vessels.
