UPPER LIMB Introduction Organization Function By Dr Mujahid

UPPER LIMB Ø Introduction Ø Organization Ø Function By: Dr. Mujahid Khan

Introduction Ø The upper limb is a multijointed lever that is freely movable on the trunk at the shoulder joint Ø At the distal end of the upper limb is the prehensile organ, the hand.

Introduction Ø Much of the importance of the hand depends on the pincerlike action of the thumb, which enables one to grasp objects between the thumb and index finger Ø The upper limb is divided into the shoulder (junction of the trunk with the arm), arm, elbow, forearm, wrist, and hand.

BREAST Introduction: Ø Breasts are specialized accessory glands Ø Secrete milk Ø Present in both sexes Ø Similar in males and immature females

Anatomy of Breast Ø Has nipples Ø Surrounded by a colored area of skin “Areola” Ø Consist of a system of ducts embedded in connective tissue

At Puberty Ø Gradually enlarge Ø Assume their hemispherical shape under the influence of ovarian hormones Ø The ducts elongate in size

Extension Ø Base extends from 2 nd to the 6 th ribs Ø From lateral margin of sternum to midaxillary line Ø Greater part of a gland lies in superficial fascia

Axillary Tail Ø Extends upward and laterally Ø Pierces the deep fascia at the lower border of pectoralis major muscle Ø Then enters the axilla

Formation Ø Each breast consists of 15 -20 lobes which radiate out from the nipple Ø The main duct from each lobe opens separately on the summit of the nipple called Ampulla Ø Base of nipple is surrounded by AREOLA Ø Tiny tubercles on the areola produced by the underlying areolar glands

Fibrous Septa Ø Lobes of the glands are separated by fibrous septa Ø Are well developed in the upper part of the gland Ø Extend from skin to the deep fascia Ø Serve as a suspensory ligament

Retromammary Space These are the connective tissues which separate the breasts from the deep fascia covering the underlying muscles

Young & Old Ø Breasts tend to protrude forward from a circular base in young women Ø They tend to be pendulous in older women Ø They reach their maximum size during lactation

Early Pregnancy Ø In the early months of pregnancy, there is a rapid increase in length and branching in the duct system Ø The secretory alveoli develop at the ends of the smaller ducts and the connective tissue becomes filled with expanding and budding secretory alveoli

Early Pregnancy Ø The vascularity of the connective tissue also increases to provide adequate nourishment for the developing gland Ø The nipple enlarges, and the areola becomes darker and more extensive as a result of increased deposits of melanin pigment in the epidermis Ø The areolar glands enlarge and become more active

Late Pregnancy Ø During the second half of pregnancy, the growth process slows Ø The breasts continue to enlarge, mostly because of the distention of the secretory alveoli with the fluid secretion called colostrum

Postweaning Ø Once the baby has been weaned, the breasts return to their inactive state Ø The remaining milk is absorbed, the secretory alveoli shrink, and most of them disappear Ø The interlobular connective tissue thickens

Postweaning Ø The breasts and the nipples shrink and return nearly to their original size Ø The pigmentation of the areola fades, but the area never lightens to its original color

Postmenopause Ø After the menopause, the breast atrophies Ø Most of the secretory alveoli disappear, leaving behind the ducts Ø The amount of adipose tissue may increase or decrease

Postmenopause Ø The breasts tend to shrink in size and become more pendulous Ø The atrophy after menopause is caused by an absence of ovarian estrogen and progesterone

Blood Supply Ø Perforating branches of the internal thoracic artery and the intercostal arteries Ø Axillary artery via lateral thoracic and thoracoacromial branches

Lymph Drainage Ø Important clinically because of frequent development of a cancer Ø Subsequent dissemination of the malignant cells along the lymph vessels to the lymph nodes

Division Breast is divided into 4 quadrants for lymph drainage

The lateral quadrants of the breast drain into the anterior axillary or pectoral group of lymph nodes

The medial quadrants drain by means of vessels that pierce the intercostal spaces and enter the internal thoracic group of nodes