ANA 201 Upper Limb 2 (Axilla, Brachial Plexus And Breast) Flashcards
(99 cards)
1
Q
What bones is the axilla made up of?
A
Clavicle, humerus, upper thoracic wall (ribs) and scapula
2
Q
What muscles make up the anterior wall of axilla?
A
Pectoralis major and minor
Subclavius
clavipectoral fascia
3
Q
What muscles make up the posterior wall of axilla?
A
Subscapularis
Long head of triceps
Latissimus dorsi
Teres major
4
Q
What muscles make up the medial wall of axilla?
A
Thoracic wall
Part of the serratus anterior
5
Q
What structures make up the apex of axilla?
A
It is bounded by the clavicle bone anteriorly,
First rib medially and
Upper border of scapula posteriorly
6
Q
Which artery enters the axilla?
A
The axillary artery
7
Q
How does the axillary artery enter the axilla?
A
The subclavian artery, becomes the axillary artery as it crosses the lateral margin of 1st rib and enters the axilla
8
Q
Main blood vessel supplying the upper limb
A
Subclavian artery
9
Q
How does the axillary vein become the subclavian vein?
A
Similarly, the axillary vein becomes the subclavian vein as it passes over the lateral margin of rib I and leaves the axilla to enter the neck.
10
Q
What forms the floor of the axilla?
A
The floor of the axilla is formed by fascia and a dome of skin that spans the distance between the inferior margins of the walls.
It is supported by the clavipectoral fascia.
11
Q
Axillary contents
A
- The three cords of the brachial plexus and their branches
- The axillary arteries and its branches
- The axillary vein and its tributaries
- The axillary lymph nodes
- Fibro-fatty tissue
- The axillary tail of Spence of mammary gland in females
12
Q
What is the major blood supply for the distal upper arm?
A
axillary artery
13
Q
What are the 3 parts of the axillary artery?
A
1.the first part is proximal to pectoralis minor (extends from the lateral border of 1st rib to medial border of P.minor)
2.the second part is posterior to pectoralis minor (behind the P. minor)
- the third part is distal to pectoralis minor (the longest part, extending from the lateral border of P.minor to the lower border of teres major muscle
14
Q
Where does the axillary nerve leave the axilla
A
The quadrangular space
15
Q
How does the axillary artery become the brachial artery?
A
The axillary artery become the brachial artery at the inferior margin of the Teres major
16
Q
What is the brachial plexus
A
The brachial plexus is a network of nerves that is responsible for the cutaneous and muscular innervations of the entire upper limb with two exceptions;
●The trapezius muscle which is innervated by the SPINAL ACCESSORY NERVE and
●An area close to the axilla which is innervated by the INTERCOSTALBRACHIALIS NERVE
17
Q
Where does the brachial plexus begin
A
The brachial plexus begins in the neck extending through the axillary inlet into the axilla where almost all the branches of the plexus arises after it has crossed the first rib.
18
Q
How are the cord of the brachial plexus named?
A
Lateral, medial and posterior to the axillary artery
19
Q
Branches of the brachial plexus
A
Supraclavicular
Infraclavicular
20
Q
What are the supraclavicular branches of the brachial plexus
A
- Long Thoracic Nerve (C5-C7)
- Dorsal scapular nerve (C5)
- Suprascapula nerve (C5-C6)
- Nerve to subclavius (C5-C6)
21
Q
Long Thoracic Nerve (C5-C7)
A
Long Thoracic Nerve (C5-C7)- passes through the cervicoaxillary canal and posterior to other BP components to supply the serratus anterior muscle.
22
Q
Dorsal scapula nerve C5
A
Dorsal Scapular nerve (C5)- pierces the middle scalene muscle and runs deep to supply the levator scapulae, enters the deep surface of the Rhomboids muscle supplying it.
23
Q
Suprascapula C5, C6
A
Suprascapular Nerve (C5-6)- passes laterally through the posterior triangle of the neck and through the suprascapular foramen to enter the posterior scapular region;
supplies the supraspinatus, infraspinatus muscles and glenohumeral joint.
24
Q
Nerve to subclavius C5 C6
A
originates from the superior trunk of the brachial plexus;
Passes anteroinferiorly over the subclavian artery
•Innervates the subclavius muscle.
25
Infraclavicular (lateral cord) branches of the plexus
Lateral cord
1. Lateral pectoral nerve C5-C7
2. Musculocutaneous nerve C5-C7
3. Lateral root of median nerve C5-C7
26
Infraclavicular (medial cord) branches of the plexus
1. Medial root of median nerve C8-T1
2. Medial pectoral nerve C8-T1
3. Medial cutaneous nerve of the arm C8-T1
4. Medial cutaneous nerve of the forearm C8-T1
5. Ulnar nerve C8-T1
27
Lateral pectoral nerve
is the most proximal of the branches from the lateral cord.
It innervtes the **pectorialis major** muscle.
28
Lateral Pectoral Nerve (C5-C7)
is the most proximal of the branches from the lateral cord, passes anteriorly, together with the thoraco-acromial artery, to penetrate the clavipectoral fascia that spans the gap between the subclavius and pectoralis minor muscles.
It innervtes the **pectoralis major muscle.**
29
Musculocutaneous Nerve (C5-7)-
is a large terminal branch of the lateral cord, passes laterally to penetrate the coracobrachialis muscle and pass between the biceps brachii and brachialis muscles in the arm, and innervates all three flexor muscles in the anterior compartment of the arm.
Innervates the **coracobrachialis muscle, biceps brachii and brachialis muscles**
It continues as the lateral cutaneous nerve of the forearm.
30
Lateral Root of Median nerve (C5-7)-
is the largest terminal branch of the lateral cord and passes medially to join a similar branch from the medial cord to form the median nerve.
31
Medial Root of Median Nerve (C8-T1)
It joins the lateral roots from the lateral cord to form the median nerve (C5-T1).
The median nerve is formed anterior to the third part of the axillary artery by the union of lateral and medial roots originating from the lateral and medial cords of the brachial plexus.
32
Innervation of the median nerve
It passes into the arm anterior to the brachial artery, through the arm into the forearm where branches innervate most of the muscles in the anterior compartment of the forearm (except for the flexor carpi ulnaris muscle and the medial half of the flexor digitorum profundus muscle, which are innervated by the ulnar nerve).
the three thenar muscles associated with the thumb;
*the two lateral lumbrical muscles associated with movement of the index and middle fingers;
*the skin over the palmar surface of the lateral three and one-half digits and over the lateral side of the palm and middle of the wrist.
33
Medial Pectoral Nerve (C8-T1)
receives a communicating branch from the lateral pectoral nerve and then passes anteriorly between the axillary artery and axillary vein.
innervates the **pectorialis minor muscle and part of the pectorialis major muscle** too.
34
Medial Cutaneous Nerve of the arm (C8-T1)
supplies the skin of the medial side of the arm and superior part of the forearm and also the floor of the axilla.
35
Medial cutaneous nerve of the forearm CB-T1
innervates the skin on the medial side of the forearm.
Known as the “fools nerve”.
36
Ulnar Nerve (C8-T1)
a large terminal branch of the medial cord.
Transverse the arm into the forearm without branching.
innervates **one and a half muscles in the anterior compartment of the forearm (flexor carpi ulnaris, flexor digitorum profundus).**
innervates also all the **intrinsic muscles of the hand except (3 thernar muscles and 2 lumbricals).**
It innervates **skin over the palmar surface of the little finger, medial half of the ring finger, and associated palm and wrist, and the skin over the dorsal surface of the medial part of the hand.**
37
What are the anterior muscles of the arm?
Coracobrachialis
Brachialis
Bicep brachii
38
What spans the gap between the subclavius and pectoralis minor muscles?
Clavipectoral fascia
39
What is the clavipectoral fascia pierced by?
the cephalic vein
the lateral pectoral nerve
and branches of the thoracoacromial artery.
40
What is the largest terminal branch of the lateral cord?
Lateral Root of Median nerve (C5-7)
41
Which nerve is known as fools nerve?
Medial cutaneous nerve of the forearm C8-T1
42
The Axilla almost disappears when the arm is fully
Abducted
43
Purpose of the Axilla
Provides a passageway for vessels and nerves to reach the upper limb
44
What makes up the lateral wall of the Axilla?
Intertubercular sulcus/ shaft of the humerus I
Coracobrachialis muscle (tendon)
Short head of the Bicep brachii (tendon)
45
The apex of the Axilla is also known as the
Cervicoaxillary canal
46
What is the position of the Axillary vein and artery to each other?
At the axillary inlet, the axillary vein is anterior to the axillary artery which in turn is anterior to the trunks of the brachial plexus
47
Difference between branches and tributaries
Branches divide, tributaries meet
48
Which part of the Axilla is the longest part?
3rd part
49
What branch arises from the first part of the axillary artery and what does it supply?
Superior thoracic artery which supplies the first intercostal space
50
What branches arise from the second part of the axillary artery and what do they supply?
the thoraco-acromial artery a branch which pieces the clavipectorial fascia and divides into four branches thus;
i. The deltoid branch which lies in delto-pectoral groove.
ii. The clavicular branch which supplies sternoclavicular joint and subclavius muscle
iii. The pectoral branch which supplies the pectoral muscles
iv. The acromion branch which takes part in the anastomosis over the acromial process
The lateral thoracic artery, which runs along the lateral border of the** P. minor muscle and supplies the anterior and medial walls**. In females branches emerge from the inferior border of the P. major and contribute in the **supply of the breast.**
51
the thoraco-acromial branch of the second part of the axillary artery divides into four branches thus;
i. The deltoid branch which lies in delto-pectoral groove.
ii. The clavicular branch which supplies sternoclavicular joint and subclavius muscle
iii. The pectoral branch which supplies the pectoral muscles
iv. The acromion branch which takes part in the anastomosis over the acromial process
52
What branches arise from the third part of the axillary artery and what do they supply?
i. The subscapular artery; is the largest branch of the axillary artery and is the major blood supply to the **(i) posterior wall of the axilla.
**It also contributes to (ii) the blood supply of the **posterior scapular region.**
(iii) It divides into its two terminal branches, the
circumflex scapular artery and the thoracodorsal artery
ii. the anterior circumflex humeral artery, (i) It passes anterior to the surgical neck of the humerus and (ii) anastomoses with the posterior circumflex humeral artery.
(iii) Supplies branches to surrounding tissues, which include the glenohumeral joint and the head of the humerus.
iii.The posterior circumflex humeral artery; a much larger artery than the anterior circumflex humeral and (i) accompanies the axillary nerve through the quadrangular space.
(ii) Supplies the glenohumeral joint and surrounding muscles i.e **teres major, minor and long head of triceps brachii.**
53
Where does the axillary vein begin and what is it a continuation of?
The axillary vein begins at the lower margin of the teres major muscle and is the continuation of the basilic vein
54
What is the basilic vein?
which is a superficial vein that drains the posteromedial surface of the hand and forearm and penetrates the deep fascia in the middle of the arm.
55
How does the axillary vein become the subclavian vein?
The axillary vein passes through the axilla medial and anterior to the axillary artery and becomes the subclavian vein as the vessel crosses the lateral border of 1st rib at the axillary inlet.
56
Discuss the axillary vein?
Tributaries of the axillary vein generally follow the branches of the axillary artery. Other tributaries include brachial veins that follow the brachial artery, and the cephalic vein.
57
Discuss the cephalic vein?
The cephalic vein is a superficial vein that drains the lateral and posterior parts of the hand, the forearm, and the arm.
In the area of the shoulder, it passes into an inverted triangular cleft (the clavipectoral triangle) between the deltoid muscle, pectoralis major muscle, and the clavicle.
In the superior part of the clavipectoral triangle, the cephalic vein passes deep to the clavicular head of the pectoralis major muscle and pierces the clavipectoral fascia to join the axillary vein.
Many patients who are critically unwell have lost blood or fluid, which requires replacement. Access to a peripheral vein is necessary to replace the fluid. The typical sites for venous access are the cephalic vein adjacent to the anatomical snuffbox or the antecubital veins, which lie within the superficial tissues of the cubital fossa.
58
What are the tributaries of the axillary vein?
cephalic vein
thoraco-acromial vein
lateral thoracic vein
subscapular vein
anterior humeral circumflex
posterior humeral circumflex
59
five principal groups of the axillary lymph nodes
apical, pectoral, subscapular, humeral, and central
60
The 3 cords of the brachial plexus are named according to their relationship with which part
Second part of the axillary artery
61
Type of brachial plexus
When the contribution from C4 is more than that of T1, the root of the plexus starts from C4 and ends at C8.
•This type of brachial plexus is termed prefixed.
•When the contribution from T2 is more and the superior root is C6, it is termed postfixed.
62
Why are brachial plexus injuries important? How are they caused?
Brachial plexus injuries are important because they affect movements and cutaneus sensations in the upper limb.
•Diseases, stretching and wounds in the posterior triangle of the neck or in the axilla may produce brachial plexus injuries.
63
What causes injury to the superior parts of the bp (C5 and C6)
1. An excessive increase in the angle between the neck and the shoulder.
2. A person who is thrown from a motorcycle or a horse and lands on the shoulder in a way that widely separates the neck and shoulder.
Injury to the superior trunk of the plexus is apparent by the characteristic position of the limb ("waiter's tip position"), in which the limb hangs by the side in medial rotation.
3. Upper brachial plexus injuries can also occur in a newborn when excessive stretching of the neck occurs during delivery.
64
terms are used to describe superior brachial plexus injuries
1. Erb palsy (paralysis)
2. Erb- Duchenne palsy (paralysis)
3. Duchenne-Erb palsy (paralysis)
4. Upper radicular syndrome.
65
In what way can the inferior part of the brachial plexus be injured?
1. During a breech birth when the infant’s limb are pulled over the head.
•These events injure the inferior trunk of the brachial plexus (C8-T1) and may pull the dorsal and ventral roots of the spinal nerves from the spinal cord.
•The short muscles of the hand are affected, and a claw hand results.
2. Person falling and holding onto tree branch
66
Branches of the posterior cord of the brachial plexus
Upper subscapular (C5-C6)
Lower subscapular nerve (C5-C6)
Thoracodorsal nerve (C6-C8)
Radial nerve (C5-8,T1)
Axillary nerve (C5-C6)
67
Upper/superior subscapular (C5-C6)
is short, passes into the **subscapularis** muscle innervating it
68
Lower/inferior Subscapular Nerve (C5-6)
innervates the teres major muscle as well as the **inferior part of the subscapularis muscle**.
69
Thoracodorsal Nerve (C6-8)
the longest of the 3 side branches of the posterior cord, it passes vertically along the posterior axillary wall and innervates** latissimus dorsi.**
70
Radial Nerve (C5-8, T1)
is the largest terminal branch of the brachial plexus.
Supplies **1. all the extensor muscles of the posterior compartment of the upper limb
2. skin on the posterior aspect of the arm and forearm**
71
Axillary Nerve (C5-6)
a terminal branch of the posterior cord, passes inferiorly and laterally along the posterior wall of the axilla to exit the axilla through the quadrangular space .
●It passes posteriorly around the surgical neck of the humerus.
●**innervates the teres minor and the deltoid muscle**
72
What are mammary glands?
The mammary glands are modified sweat glands in the superficial fascia anterior to the pectoral muscles and the anterior thoracic wall.
Usually accessory to reproduction in females and are rudimentary and almost functionless in men, consisting of only few ducts.
73
Discuss the gross anatomy of the female breast
The roughly circular base of the female breast extends transversely from the lateral border of the sternum to the mid-axillary line where it covers the 2nd to the 6th ribs.
The nipple is situated on the 4th intercostal space about 10cm from the median plane.
A small part of the mammary gland may extend along the inferiorlateral aspect of the P.Major muscle towards the axilla to form the axillary tail of Spence.
About 2/3rd of the breast lies on deep fascia related to the pectoralis major muscle while the other 1/3rd rest on the fascial covering the serratus anterior muscle.
A layer of loose connective tissue (the retromammary space) separates the breast from the deep fascia and provides some degree of movement over underlying structures.
74
Purpose of the retromammary space
Loose connective tissue that separates the breast from the deep fascia and provides some degree of movement over underlying structures.
75
Purpose of the suspensory ligaments (of Cooper)
The mammary gland is firmly attached to the dermis of the overlying skin by skin ligaments the suspensory ligaments (of Cooper) of the breast.
76
Discuss the lactiferous ducts
The lactiferous ducts give rise to buds that form 15 to 20 lobules of glandular tissue, which constitute the gland.
Each lobule of the breast is drained by a lactiferous duct that usually opens independently on the nipple.
Deep to the areola, each duct has a dilated portion, the lactiferous sinus, in which a small droplet of milk accumulates or remains in the nursing mother.
77
Discuss the AREOLA
it contains numerous sebaceous glands that enlarges during pregnancy.
Secrets an oily substance which gives a protective lubricant to the areola itself and the nipple.
It is particularly subject to chaffing and irritation as mother and baby begins the nursing experience.
78
Discuss the nipple
these are cornical or cylindrical prominence in the centre of the areola with no fat, hair or sweat gland.
In nulliparous woman, it is usually at the level of the 4th intercoastal space but, however, the position of the nipple varies.
It is composed mainly of circularly arranged smooth muscle fibre that compresses the lactiferous gland during lactation and erects the nipple in response to stimulation. i.e. when a baby begins to suckle or from a touch.
Made of smooth muscle
79
Meaning of nulliparous
used to describe a woman who hasn't given birth to a child. It doesn't necessarily mean that she's never been pregnant — someone who's had a miscarriage, stillbirth, or elective abortion but has never given birth to a live baby is still referred to as nulliparous
80
Discuss the ARTERIAL SUPPLY of the breast
i. Lateral thoracic and thoracoacromial arteries
ii. Posterior intercoastal arteries a branch of the thoracic aorta in the 2nd, 3rd and 4th intercoastal spaces.
iii. Medial mammary branch of perforating branches & anterior intercoastal branches of the internal thoracic artery.
81
Describe the VEINOUS SUPPLY of the breast
Veinous drainage of the breast is mainly by the axillary vein with some assistance from the internal thoracic vein.
82
How do cancer cells spread?
cancer cells spread (metastasize) via lymphatics
83
Describe the drainage of the superficial lymphatics of the skin of the breast
The superficial lymphatics from skin over the breast except the nipple and areola drain radially into axillary, supraclavicular and internal mammary group of lymph nodes.
84
Describe the drainage of the deep lymphatics of the breast
The deep lymphatics from the nipple, areola and parenchyma drains as follows;
75% of lymph especially from the lateral quadrant of the breast drains mostly into anterior (pectoral), some into posterior (subscapular) and apical group of axillary lymph nodes.
These also communicate with the lateral and central groups as well.
Most of the remaining 25% lymph, particularly from the medial quadrants drain to the parasternal nodes or to the opposite breast while lymph from the lower quadrants drain to the inferior phrenic (abdominal) nodes.
Lymph from the axillary nodes drains into the infraclavicular and supraclavicular nodes which now drains into the subclavian lymphatic trunk that also drains lymph from the upper limb.
Lymph from the parasternal nodes enters into the Bronchomediasternal trunk which drains lymph from the thoracic viscera.
85
Discuss the nerve supply to the breast
Nerve supply to the breast is derived from the Anterior and Lateral Cutaneous branches of the 4th -6th intercostal nerves.
The branches of the intercostal nerve passes through the deep fascia covering the pectorialis major muscle to reach the skin, including the breast in the subcutaneous tissue overlying this muscle.
86
What is Polymastia?
Polymastia; this is a condition when there is an extra number of breast.
Polymastia may occur superior or inferior to the normal breast and could occasionally develops in the axilla or anterior abdominal wall.
The extra breast may consist of only rudimentary nipple and areola, which may be mistaken for a mole (nevus) until they change pigmentation with the normal nipple during pregnancy.
Polymastia may occur anywhere along the line extending from the axilla to the groin as this is the location where the embryonic mammary ridge develops from.
87
What is Polythelia?
Polythelia; means exceeding the normal number of nipples.
88
What is Amastia?
In either sex, there may be no breast or there could be a nipple and no glandular tissue
89
What is gynaecomastia?
Gynaecomastia; this is a situation of the enlargement of the male breast which commonly occur in puberty but could accompany aging and drug related e.g. after treatment of prostate cancer with Diethylstibesterol.
It could also occur by a sudden change in the metabolism of sex hormones by the liver.
Approximately 40% of post-pubertal males with Klinefelter’s syndrome (xxy trisomy) exhibits gynaecomastia.
90
Where does breast cancer develop?
Breast cancer develops in the cells of the acini, lactiferous ducts, and lobules of the breast.
91
a diagnosis of breast cancer is confirmed by
a biopsy and histologic evaluation.
92
Meaning of staging the tumor
size of the primary tumor;
exact site of the primary tumor;
number and sites of lymph node spread;
organs to which the tumor may have spread.
93
Purpose of CT scan
Computed tomography (CT) scanning of the body may be carried out to look for any spread to the lungs (pulmonary metastases), liver (hepatic metastases), or bone (bony metastases).
94
What is a mastectomy and it's risks? (Describe a winged scapula)
A mastectomy (surgical removal of the breast) involves excision of the breast tissue to the pectoralis major muscle and fascia.
Within the axilla the breast tissue must be removed from the medial axillary wall.
Closely applied to the medial axillary wall is the long thoracic nerve.
Damage to this nerve can result in paralysis of the serratus anterior muscle producing a characteristic 'winged' scapula.
It is also possible to damage the nerve to the latissimus dorsi muscle, and this may affect extension, medial rotation, and adduction of the humerus.
95
Symptoms of breast cancer
Changes in skin texture
discharge from nipples
retraction or indentation of nipple
atypical fullness and or puckering
96
Which sight of the breast is most susceptible to tumors
Axillary tail of Spence
97
What is the montegomery tubercle on the nipple
Enlarged sebaceous glands during pregnancy
98
Describe peau d'orange
Subcutaneous lymphatic obstruction and tumor growth pull on connective tissue ligaments in the breast resulting in the appearance of an orange peel texture (peau d'orange) on the surface of the breast.
Further subcutaneous spread can induce a rare manifestation of breast cancer that produces a hard, woody texture to the skin (cancer en cuirasse).
99
Which group of lymph nodes is most prone to metastasis?
anterior group of axillary lymph nodes
