Thorax 3 - GA Flashcards
What are the main muscles of inspiration?
→ external intercostal muscle
→ scalene muscles
What are the origins of the external intercostal muscles?
originates from the sharp inferior costal border of one rib
What are the insertions of the external intercostal muscles?
insert along the outer lip of the superior border of the immediate rib below
What is the innervation for external intercostal muscles?
intercostal nerves
What are the different parts of the scalene muscles?
→ anterior
→ middle
→ posterior
What is the origin of the anterior scalene muscle?
anterior tubercles of transverse processes of cervical vertebrae C3-C6
What is the insertion of the anterior scalene muscle?
scalene tubercle of 1st rib
What innervates the anterior scalene muscle?
anterior rami of 4th-6th cervical nerves
What is the origin of the middle scalene muscle?
posterior tubercles of transverse processes of C2-C7
What is the insertion of the middle scalene muscle?
superior surface of 1st rib
What innervates the middle scalene muscle?
anterior rami of 3rd-8th cervical nerves
What is the origin of the posterior scalene muscle?
posterior tubercles of transverse processes of C4-C6
What is the insertion of the posterior scalene muscle?
external surface of 2nd rib
What innervates the posterior scalene muscle?
anterior rami of 4th-6th cervical nerves
What do the external intercostal muscle do?
contraction moves ribs up + out
What do the scalene muscles do?
contraction raises 1st + 2nd ribs up in deep inspiration
What are the muscles of expiration?
→ internal intercostal muscles
→ abdomen muscles
What are the origins of the internal intercostal muscles?
inferior border of the ribs
What are the insertions of the internal intercostal muscles?
superior borders of the ribs immediately below
What innervates the internal intercostal muscles?
intercostal nerves
What do the internal intercostal muscles do?
→ depresses ribs at their costovertebral joints
→ moves ribs down + in
What are the different abdomen muscle involved in expiration?
→ rectus abdominis
→ transversus abdominis
→ internal oblique
→ external oblique
What do the abdominal muscles do in expiration?
→ helps move ribs down + in expiration
→ assists in forced expiration e.g. coughing + sneezing
What artery is the main supply for the thorax? Where does it stem from?
thoracic arteries, stem from the respective subclavian arteries
What does the internal thoracic artery split off into?
→ pericardiacophrenic artery
→ perforating branches of the internal thoracic arteries
→ musculophrenic artery
→ superior epigastric artery
What does the pericardiacophrenic artery supply?
pericardium + diaphragm
What do the perforating arteries of the internal thoracic arteries supply?
→ pectoralis major
→ breast
→ overlying skin
What does the musculophrenic artery supply?
→ intercostal muscles
→ diaphragm
→ abdominal muscles
How do the veins relate to the thoracic arteries?
accompanying veins of the same name run alongside the arteries to drain them
How is the pectoral region divided?
→ superficial part : consisting of skin, fascia + breast tissue
→ deeper part : 3 muscles of the anterior thorax
What are the 3 muscles of the pectoral region?
→ pectoralis major
→ pectoralis minor
→ subclavius
What is the origin of the pectoralis major?
medial half of clavicle + anterior surface of sternum, costal cartilages 1-7, aponeurosis of external oblique
What is the insertion of the pectoralis major?
lateral lip of inter tubercular sulcus of humerus
What innervates the pectoralis major?
medial + lateral pectoral nerves
What is the action of the pectoralis major?
adduction, medial rotation + flexion of the humerus at the shoulder joint
What is the origin of the subclavius?
rib 1 at junction between rib + costal cartilage
What is the insertion of the subclavius?
groove on inferior surface of middle third of clavicle
What innervates the subclavius?
nerve to subclavius
What is the action of the subclavius?
pulls clavicle medially to stabilise sternoclavicular joint + depresses tip of shoulder
What is the origin of the pectoralis minor?
anterior surfaces of the 3rd, 4th, 5th ribs + deep fascia overlying the related intercostal spaces
What is the insertion of the pectoralis minor?
coracoid process of scapula
What innervates the pectoralis minor?
medial pectoral nerves
What is the action of the pectoralis minor?
depresses tip of shoulder + protracts scapula
What are the key features of the breast tissue?
→ suspensory ligaments of breast → adipose tissue → lactiferous sinuses → lactiferous ducts → lobules of mammary gland → areola → nipple
What is the innervation for the breast?
→ lateral cutaneous branches of 4th + 5th intercostal nerve
What is the arterial blood supply for the breast?
→ pectoral branches of thoracoacromial artery
→ lateral mammary branches of lateral thoracic artery
→ medial mammary branches of perforating branch of internal thoracic artery
What is the lymphatic drainage for the breast?
→ interpectoral nodes → anterior axillary nodes → superficial lymph vessels of thoracic wall → infraclavicular nodes → parasternal nodes
What is the venous drainage for the breast?
→ internal thoracic vein + lateral thoracic vein ??
What are the 2 main classes of back muscles?
→ extrinsic
→ intrinsic
What are extrinsic back muscles?
muscles where the area of origin + area of insertion are different
What are intrinsic back muscles?
area of insertion + are of origin are both in the back
How are back muscles further classified?
→ superficial
→ intermediate
→ deep
What innervates extrinsic back muscles?
anterior spinal nerve rami
What innervates intrinsic back muscles?
posterior spinal nerve rami
Which groups of back muscles are extrinsic?
superficial + intermediate
Which groups of back muscles are intrinsic?
deep
What is the general action of the superficial back muscles?
moves shoulder joint
What are the superficial back muscles?
→ levator scapulae muscle → rhomboid major → rhomboid minor → latissimus dorsi → trapezius
What are the origins of the trapezius?
skull, ligamentum nuchae + spinous processes of C7 to T12
What is the insertion of the trapezius?
clavicle, acromion, spine of scapula
What innervates the trapezius?
accessory nerve
What is the action of the trapezius?
elevation, rotation, retraction, + depression of the scapula
What are the origins of the latissimus dorsi?
spinous processes of T6-T12, thoracolumbar fascia, Lilian crest + inferior 3 ribs
What is the insertion of the latissimus dorsi?
Fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus
What innervates the latissimus dorsi?
Thoracodorsal nerve
What is the action of the latissimus dorsi?
Extension, adduction and medial rotation of the upper limb
What are the origins of the levator scapulae?
Transverse processes of the C1-C4 vertebrae
What is the insertion of the levator scapulae?
Medial border of the scapula
What innervates the levator scapulae?
Dorsal scapular nerve
What is the action of the levator scapulae?
Elevation of the scapula
What are the origins of the Rhomboid major?
Spinous processes of T2-T5 vertebrae
What is the insertion of the Rhomboid major?
Medial border of the scapula, between the scapula spine and inferior angle
What innervates the Rhomboid major?
Dorsal scapular nerve
What is the action of the Rhomboid major?
Retracts and rotates the scapula
What are the origins of the Rhomboid minor?
Spinous processes of C7-T1 vertebrae
What is the insertion of the Rhomboid minor?
Medial border of the scapula, at the level of the spine of scapula
What innervates the Rhomboid minor?
Dorsal scapular nerve
What is the action of the Rhomboid minor?
Retracts and rotates the scapula
What are the intermediate back muscles?
→ serratus posterior superior
→ serratus posterior inferior
What are the origins of the serratus posterior superior?
nuchal ligament + spinous processes of C7-T3
What are the insertions of the serratus posterior superior?
external surfaces of 2nd-5th ribs
What innervates the serratus posterior superior?
anterior rami of 2nd-5th thoracic nerves
What is the action of the serratus posterior superior?
elevates ribs at their costovertebral joints
What are the origins of the serratus posterior superior?
spinous processes of T11-L2 vertebrae
What are the insertions of the serratus posterior superior?
external surfaces of 9th to 12th ribs
What innervates the serratus posterior superior?
anterior rami of 9th to 12th thoracic rami
What is the action of the serratus posterior superior?
depresses ribs at their costovertebral joints
What are the 5 main different groups of deep muscle groups?
Spinotransversales Erector Spinae Transversospinales Segmental Suboccipital
How are the muscle fibres of the spinotransversales orientated?
Orientated superior laterally, most superficials muscles of the deep back muscles
What does unilateral contraction of the spinotransversales do ?
Head turns to the side of the muscle that contracts, e.g. right contracts, head turns to right
What does bilateral contraction of the spinotransversales do?
Extends the neck + points the face towards the sky
What are the different spinotransversales muscles?
Splenius Capitis
Splenius cervicis / colli
What is the origin of the Splenius capitis?
Lower aspect of the ligamentum nuchae + the spinous processes of C7-T3/4 vertebrae
What is the insertion for Splenius capitis?
Mastoid process + occipital bone
What is the action of the Splenius capitis?
Rotates head to the same side
What innervates the Splenius capitis?
Posterior rami of spinal nerves C3 and C4
What is the origin for the Splenius cervicis?
Spinous processes of T3-T6 vertebrae
What is the insertion for Splenius cervicis (colli)?
Transverse processes of C1-3/4
What is the action of Splenius cervicis (colli)?
Rotate head to the same side
What innervates the Splenius Cervicis (colli)?
Posterior rami of the lower cervical spinal nerves
What groups of muscles does the erector spinae divide into?
Spinalis Thoracis
Longissimus Thoracis
Iliocostalis Thoracis
What happens after the erector spinae divides into 3 muscle blocks?
Will further divide into lumborum, Thoracis, cervicis (colli) or capitis muscle fibres depending on what part of the vertebral column they attach to superiorly.
What does bilateral contraction of the erector spinae muscles do?
Extension of the spinal chord
What does unilateral contraction of the erector spinae muscles do?
Flex trunk laterally to the side of muscle contraction (e.g. right contraction = bend to the right)
What is the general origin of the erector spinae muscles?
Common tendinous origin of the erector spinae
What is the insertion of Iliocostalis erector spinae?
Costal angle of the ribs + the cervical transverse processes
What is the insertion of longissimus erector spinae?
Lower ribs, the transverse processes of C2-T12, and the mastoid process of the skull
What is the insertion of spinalis ?
Spinous processes of C2, T1-T8 and the occipital bone of skull
What direction do the tranversospinales fibres travel in?
Upwards + medially = superomedially
What does unilateral contraction of the transversospinales muscles do?
Vertebral column rotates to the opposite side of the muscle contraction
What are the different groups of transversospinales muscles?
Semispinales
Multifidus
Rotatores
What is the origin of the semispinalis?
Transverse processes of C4-T10
What is the origin of multifidus?
Sacrum, iliac spine, common tendinitis origin of erector spinae, lumbar vertebrae T1-T3 and C4-C7
What is the origin of rotatores?
Vertebral transverse processes
What is the insertion of transversospinales?
Spinous processes of C2-T4 and to occipital bone of skull
What is the insertion of the multifides?
Spinous processes of vertebrae
What is the insertion of rotatores?
Lamina + spinous processes of the immediately superior vertebrae
What is the action of the semispinalis?
Extends and contra laterally rotates the head + vertebral column
What is the action of the multifidus?
Stabilises the vertebral column
What is the action of the rotatores?
Stabilises the vertebral column + has propioceptive function
What are the segmental muscles?
Levatores Costarum
Interspinales
Intertransversarii
What is the origin of the levatores costarum?
Transverse processes of C7-T11
What is the origin of the interspinales?
Spans between adjacent spinous processes
What are the origins of the intertransversarii?
Spans between adjacent transverse processes
What is the insertion of levatores costarum?
The rib immediately below
What is the insertion of interpspinales?
Spins between adjacent spinous processes
What is the insertion of intertransversarii?
Spans between adjacent transverse processes
What is the action of the levatores costarum?
Elevates the ribs
What are the actions of the interspinales + intertransversarii?
Stabilise the vertebral column
What are the sub occipital muscles?
Rectus capitis + obliquus capitis
What is the origin of the rectus capitis + obliquus capitis?
Upper cervical vertebrae (C1/C2)
What is the insertion of the rectus capitis + obliquus capitis?
Occipital bone
What is the action of the rectus capitis + obliquus capitis?
Extension + some rotation of the head
What innervates the rectus capitis + obliquus capitis?
Posterior ramus of C1 spinal nerve
What is the diaphragm?
Thin broad musculoskeletal-tendonous sheet
What does the diaphragm do?
Assist with inspiration + expiration
What is the general structure and shape of the diaphragm?
2 domes
