Session 1.2b - Grey's Anatomy for Students - Regional Anatomy - Thorax - Pectoral Region Flashcards
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The cylindrical thorax consists of:
- a wall,
- two pleural cavities,
- the lungs, and
- the mediastinum
Give some functions of the thorax.
- houses the heart and lungs
- acts as a conduit for structures passing between the neck and abdomen
- plays a principal role in breathing
Give some functions of the thoracic wall.
- protects the heart and lungs
- provides support for the upper limbs
What helps provide support for the upper limbs, as well as the thoracic wall?
Muscles anchored to the anterior thoracic wall
What defines the pectoral region?
- Muscles anchored to the anterior thoracic wall and their associated
- – connective tissue
- – nerves
- – vessels
- Overlying skin
- Superficial fascia
The pectoral region is external to the ___
anterior thoracic wall
What does the pectoral region anchor?
The upper limb to the trunk
What does the pectoral region consist of?
- a superficial compartment
- a deep compartment
What is in the superficial compartment of the pectoral region?
Skin
Superficial fascia
Breasts
What is in the deep compartment of the pectoral region?
Muscles and associated structures
Nerves, vessels and lymphatics in the _______ compartment emerge from the ____ ____, the ______, and the _____
superficial; thoracic wall, axilla, neck
What does the breast consist of?
Mammary glands and associated skin and connective tissues
What are mammary glands?
Modified sweat glands
Where are the mammary glands?
In the superficial fascia anterior to the pectoral muscles and the anterior thoracic wall (Fig. 3.16).
Fig. 3.16
Label and caption the image
- Secretory lobules
- Areola
- LYMPHATIC AND VENOUS DRAINAGE PASSES FROM LATERAL AND SUPERIOR PART OF THE BREAST INTO AXILLA
- Axillary process
- PECTORAL AXILLARY NODES
- LATERAL AXILLARY NODES
- Lateral thoracic artery
- CENTRAL AXILLARY NODES
- APICAL AXILLARY NODES
- Pectoral branch of thoraco-acromial artery
- Internal thoracic artery
- Pectoralis major muscle
- Secretory lobules
- Suspensory ligaments
- Lactiferous sinuses
- Retromammary space
- PARASTERNAL NODES
- Mammary branches of internal thoracic artery
- LYMPHATIC AND VENOUS DRAINAGE PASSES FROM MEDIAL PART OF THE BREAST PARASTERNALLY
- SOME LYMPHATIC AND VENOUS DRAINAGE MAY PASS FROM INFERIOR PART OF THE BREAST INTO THE ABDOMEN
Breasts
What do the mammary glands consist of?
A series of ducts and associated secretory lobules.
What do the mammary gland ducts converge to form?
15 to 20 LACTIFEROUS DUCTS
Where do the lactiferous ducts open onto?
Independently onto the NIPPLE.
What is the nipple surrounded by?
A circular pigmented area of skin termed the AREOLA.
What surrounds the ducts and lobules of the mammary gland?
A well-developed, connective tissue stroma
What do the ducts and lobules condense to form?
In certain regions, these condense to form the suspensory ligaments of breast
What are suspensory ligaments of breast continuous with?
The dermis of the skin
What do the suspensory ligaments of breast do?
Support the breast
What happens to the suspensory ligaments of the breast in carcinoma?
Creates tension on these ligaments, causing pitting of the skin.
What is the predominant component of breast in nonlactating women?
Fat
What is the predominant component of breast in lactating women?
Glandular tissue is more abundant here
What does the breast lie on?
Deep fascia related to the pectoralis major muscle and other surrounding muscles
What is the layer of loose connective tissue that separates the breast from the deep fascia called?
The RETROMAMMARY SPACE
What does the retromammary space do?
Provides some degree of movement over underlying structures.
What part of the breast extends vertically from ribs II to VI?
The base, or attached surface
The base, or attached surface, of each breast extends where?
- vertically from ribs II to VI,
- transversely from the sternum to as far
- laterally as the midaxillary line
What is the arterial supply to the breast?
The breast is related to the thoracic wall and to structures associated with the upper limb; therefore, vascular supply and drainage can occur by multiple routes (Fig. 3.16):
- axillary artery
- internal thoracic artery
- 2nd to 4th intercostal arteries
What is the lateral arterial supply to the breast?
From vessels from the axillary artery
Which vessels from the axillary artery supply the breast?
Superior thoracic
Thoraco-acromial
Lateral thoracic
Subscapular
What is the medial arterial supply to the breast?
From branches from the internal thoracic artery
Other than the axillary and internal thoracic artery, what arteries supply the breast?
The second to fourth intercostal arteries via branches that perforate the thoracic wall and overlying muscle.
How do the 2nd-4th intercostal arteries supply the breast?
Via branches that perforate the thoracic wall and overlying muscle.
What is the venous drainage to the breast?
Veins draining the breast parallel the arteries
Where do veins draining the breast ultimately drain into?
The axillary, internal thoracic, and intercostal veins.
What is the innervation of the breast?
Innervation of the breast is via anterior and lateral cutaneous branches of the 2nd to 6th intercostal nerves.
What is the innervation of the nipple?
4th intercostal nerve.
What is the lymphatic drainage of the breast?
- lymphatic vessels
- parasternal nodes
- intercostal nodes
What is the main lymphatic drainage of the breast?
Approximately 75% is via lymphatic vessels
Where do the lymphatic vessels drain?
Laterally and superiorly into AXILLARY NODES (Fig. 3.16).
After the lymphatic vessels, where does most of the remaining drainage of the breast go?
Into parasternal nodes
Where are parasternal nodes?
Deep to the anterior thoracic wall
What are the parasternal nodes associated with?
The internal thoracic artery
A little bit of drainage of the breast may occur here ___?
Via lymphatic vessels that follow the lateral branches of posterior intercostal arteries and connect with intercostal nodes situated near the heads and necks of ribs.
Where do axillary nodes drain into?
Subclavian trunks