Pectoral Region Flashcards
Pectoral region: name subcutaneous nerves
Supraclavicular
Pectoral
Intercostal
Pectoral region: supravlavicular nerves
3 cutaneous nerves - common trunk from plexus = under SCM Ventral rami of C3 + 4 Post. triangle, under platysma Over clavicle Supply skin over ICS 1 + 2 Medial, intermediate + lateral branches
Pectoral region: pectoral nerves
Lateral = more med. - from lat. cord Medial = more lat. - from med. cord
Typical IC nerve: structure
Spinal cord Dorsal + ventral roots Spinal ganglion Dorsal + ventral rami Dorsal ramus = lat. + med. branches Ventral ramus = lat. cutaneous + ant. cutaneous Lat. = ant. + post. Ant. = lat. + med.
Important dermatomes
T2 = 2nd ICS T4 = nipple T6/7 = xiphoid prcoess T10 = umbilicus
Pectoral region: subcutaneous blood vessels
Thoraco-acromial a. - deltoid + pectoral br.
ITA - perforating br.
Cephalic v.
Pectoral muscles: name
Pec. major
Pec. minor
Serratus ant.
Subclavius
Pectoralis major: origin
Sternal end of clavicle
Sternum to 7th rib
Cartilages of true ribs
Aponeurosis of ext. obliques
Pectoralis major: insertion
Lat. lip of intertubercular sulcus (humerus)
Pectoralis major: innervation
Med. + lat. pectoral nerve
Pectoralis major: function
Flex, adduct + medially rotate arm
Pectoralis minor: origin
Outer surface of upper margin of ribs 3-5
Pectoralis minor: insertion
Coracoid process
Pectoralis minor: innervation
Med. pectoral nerve
Pectoralis minor: function
Lower lat. angle + protract scapula
Serratus anterior: origin
Lat. surface of upper 8/9 ribs
Serratus anterior: insertion
Costal surface of medial border of scapula
Serratus anterior: function
Protracts + rotates scapula
Holds it against thoracic wall
Serratus anterior: innervation
Long thoracic nerve
Subclavius muscle: function
Anchors + depresses clavicle
Extrathoracic muscles: name
Serratus anterior
External oblique
Rectus abdominis
External oblique muscles: origin
External surfaces of ribs 5-12
External oblique muscles: insertion
Linea alba
Pubic tubercle
Ant. half iliac crest
Rectus abdominis: origin
Pubic symphysis + pubic crest
Rectus abdominis: insertion
Xiphoid process
Cartilages 5-7
Primary inspiratory muscles
Rest + deep
Diaphragm + IC muscles
Secondary inspiratory muscles
Deep
Neck = SCM + scalenus
Thorax = pec. major, minor + serratus ant.
Back = latissiumus dorsi
Primary expiratory muscles
None
Passive
Secondary expiratory muscles
Forced
Thorax = thoracicus transversus
Abdomen = rectus abdominis + obliques
Clavipectoral fascia: penetrating structures
Cephalic v.
Thoraco-acromial a.
Lat. pectoral n.
Lymph vessels
Clavipectoral fascia: arrangement
Deep to pec. major From clavicle Encloses subclavius Single Pec. minor Unites Suspensory ligament of axilla Floor of axilla 1st-2nd cartilages to med. aspect of coracoid process = costocaracoid membrane
Mammary gland: surface anatomy
Vert. = 2nd-6th ribs Horz. = parasternal border to MAL Covers pec. major + serratus ant. Inferomedial quadrant = ext. oblique Nipple varies, usually 4th ICS
Mammary gland: structure
15-20 lobules = lactiferous ducts + sinuses
Retinacula cutis = suspensory ligaments - skin to deep fascia
Fat between tissue
Areola + nipple = involuntary m. + lymphatics - opening of ducts
Axillary tail = upwards + laterally to 3rd rib in axilla - enters in deep fascia
Mammary gland: blood supply
Laterally:
- axillary artery
- superior, lateral, thoraco-acromial + subscapular
Medially:
- ITA
- 2nd-4th IC a.
Mammary gland: venous drainage
Axillary
IT v.
IC v.
Mammary gland: lymphatic drainage
Lat. + sup. = axillary nodes
Med. = parasternal nodes
Inf. = into abdomen
