Anatomy Flashcards
Branches of the bronchi
Right and left bronchi, lobar, segmental bronchi
What level does the larynx become trachea and pharynx become oesophagus
C6
What does the chest cavity contain
Mediastinum and right and left pleural cavity
Function of pleural fluid
Lubrication and provide surface tension
What causes the visceral and parietal pleura to stick together
Surface tension
What are lung lobes
Area of lung that each lobar bronchi supply with air
Right side - Upper, middle and lower
Left - Upper and lower
What are bronchopulmonary segments
Area of lung that each of the segmental bronchi supply with air. 10 in each lung
What fissues seperated the lobes
Horizontal fissure (only right side) and oblique fissures
Classification of the ribs
True (1-7), false (8-10) and floating ribs (11-12)
Where does the head of the rib articulate
Head of the rib articulates with the body of vertebrae of same number and superior body
Where does the rib tubercle articulate
Articulates with transverse process of vertebrae of same number
Joints of thoracic skeleton
Sternocoastal joint, Costochondral joint, Costovertebral
Skeletal muscles between ribs and intercoastal space
External, internal and innermost intercoastal muscles
How many intercoastal spaces
11
Nerve supply to intercoastal space
Anterior rami of spinal nerve, intercoastal nerve
Blood supply to posterior intercoastal space
Thoracic aorta and drained by Azygous vein
Blood supply to anterior intercoastal space
Internal thoracic artery and internal thoracic vein
What forms the intercoastal artery
Anastomose between thoracic aorta posteriorly and inner thoracic artery anteriorly
Where do bronchial arteries arise from
Anterior branches of thoracic aorta
Why is right dome of diaphragm higher
Due to presence of liver
What vertebral bodies diaphragm attaches to
L1 to L3 vertebral bodies
Nerve supply to diaphragm
Phrenic nerve, C3, 4 and 5 anterior rami
Route of Phrenic nerve to diaphragm
C3, 4 and 5 anterior rami. Anterior surface of scalenus anterior muscle. Lateral aspect of the heart supplying somatic sensory and sympathetic axons to diaphragm and fibrous pericardium, somatic motor to diaphragm
What innervates the nipples and umbilicus
Nipples - T4, Umbilicus - T10
What quadrants can the breast be divided into
Superolateral, superomedial
Inferolateral, inferomedial
Lymph drainage of breasts
Unilateral drainage from lateral quadrants to axillary nodes. Bilateral drainage from medial quadrants to parasternal nodes
What level is sternal angle
Coastal cartilage 2, T4 vertebrae
What vein can be found in the delto-pectoral groove
Cephalic vein
Function of superficial fascia
Fatty tissue, provide insulation
Function deep fascia
Fibrous, tough and protective in nature
What causes winged scapula
Paralysis of serratus anterior often due to injury to the long thoracic nerve
Where does the pectoralis minor attach
Coracoid process and ribs 3-5
Where does fluid from haemothorax or pleural effusion generally drain to
Costodiaphragmatic or costophrenic recess
Where can the apex of lung be auscultated for
Superior to medial 1/3rd of clavicle
Level of horizontal fissures
Rib 4
Level of oblique fissures
Rib 6
Auscultation of middle lobe
Between ribs 4 and 6, midclavicular and midaxillary line
Auscultation of lung base
T11 scapular line
Origin of pectoralis major
Clavicular head originates on the clavicle, sternocoastal head on the sternum and costal cartilage 1 to 6. This inserts into the intertubercular groove of humerus.
What nerve supplies pectoralis major
Pectoral nerve from brachial plexus
Actions of pectoralis major
Adduction and medial rotation of upper limb at shoulder joint. Accessory muscle of inspiration
Origin of pectoralis minor
Coracoid process of scapula
Insertion of pectoralis minor
Ribs 3-5 midcalvicular line
Actions of pectoralis minor
Stabilize scapula, accessory muscle of inspiration
Nerve supply of pectoralis minor
Pectoral nerve from brachial plexus
Origin and insertion of serratus anterior
Origin on ribs 1-8 anterior axillary line and inserts in the medial border of deep (anterior) surface of scapula
Main actions of serratus anterior
Stabilize and protraction of scapula
Nerve supply of serratus anterior
Long thoracic nerve from brachial plexus
CNS coordination of coughing
Deep inspiration using diaphragm (phrenic nerve C3,4,5), intercostal muscles (intercostal nerves) and accessory muscles on inspiration
Adduction of vocal cords to close rima glottidis (vagus nerve)
Contraction of anterolateral abdominal wall (intercostal nerve) to build-up abdominal pressure which pushes diaphragm up and builds pressure in the chest inferior to adducted vocal cords. The vocal cords suddenly abduct to open rima glottidis (vagus nerve).
The soft palate (CN V - Trigeminal) and elevates (Vagus nerve) to close off the entrance into nasopharynx and direct stream of air through oral cavity rather than nasal cavity as a sneeze
What nerves are involved in sneezing
CN V - Trigeminal and CN IX - Glossopharyngeal
What nerves are involved in coughing
CN IX - Glossopharyngeal and CN X - Vagus nerve
What are the carotid sheaths
Protective deep fascia that contains the vagus nerve, internal carotid artery, common carotid artery and internal jugular vein
Route of Phrenic nerve to diaphragm
Anterior rami of C 3,4,5. Anterior surface of scalenus anterior muscle. In the thorax descending over lateral aspect of fibrous pericardium anterior to lung root
Muscles of quiet inspiration
External, internal and innermost intercoastal muscles
Accessory muscles of inspiration
Pectoralis major and minor, Sternocleidomastoid, Scelenus anterior, middle and posterior
What ribs do Pectoralis minor pull
Ribs 3-5 superiorly towards the coracoid process of scapula
Where does the sternocleidomastoid attach
Sternum/clavicle and mastoid process of temporal bone
What supplies the vocal cords
Somatic motor nerves part of CN X - Vagus nerve
Vagus nerve connections in brainstem
Medulla oblongata at brainstem. Exit cranium at jugular foramen
Location of vagus nerve at root lung
Posterior to root lung whereas Phrenic nerve is anterior to lung root
Where does the aponeurosis of left and right external oblique meet
Linea alba
Where does external oblique attach inferiorly
Iliac crest and pubic tubercle
What is the attachment of muscle fibre to aponeurosis called
Linea semilunaris
Inferior attachment of internal obliques
Iliac crest and thoracolumbar fascia of lower back
Inferior attachment of transverse abdominus
Iliac crest and thoracolumbar fascia
What do the tendinous intersections of rectus abdominus do
Divide the 2 long flat muscles into 3 or 4 quadrate muscles
How is the thoracoabdominal nerve formed
7 to 11 intercoastal nerve travel anteriorly then their terminal branches leave the intercoastal space in plane between transverse abdominus and internal oblique muscles as thoracoabdominal nerve
What nerve arises from T12 anterior ramus
Subcostal nerve
What nerve arises from one half of L1 anterior ramus
Iliohypogastric nerve and Ilioinguinal nerve from the other half
Openings of diaphragm
Caval opening for SVC, oesophageal hiatus and aortic hiatus
What makes up the rectus sheath
Aponeuroses of transverse abdominus, internal and external obliques
What happens when air enters pleural cavity
Vacuum is lost and elastic lung recoil towards lung root making expiration harder.
Small vs large pneumothorax
Small < 2 cm
Large > 2 cm
What in tension pneumothorax
Torn pleura can create a one-way valve that permits air to enter pleura but not leave. This increases pleural pressure with every breath applying increased tension to mediastinal structures causing a mediastinal shift and decreases in lung volume of unaffected lung
Level of sternal angle
T4
How can tension pneumothorax cause hypotension
It can cause SVC compression, leading to decrease venous return; this causes hypotension
Management of large pneumothorax
Thoracentesis/needle aspiration/pleural tap in 4th-5th intercostal space, midaxillary line
What is a safe triangle
Triangular region in the axilla formed by anterior boundary of latissimus dorsi, posterior boundary of pectoralis major and axial line superior to nipples. It is a safe region for thoracentesis and chest drains. Insert the needle posterior to rib to avoid the neurovascular bundle
Emergency management of tension pneumothorax
Large gauge cannulae inserted into pleural cavity via 2nd or 3rd intercoastal space, midclavicular line on side of tension pneumothorax
What factors cause development of herniae
Weakness of one structure, commonly part of body wall
Chronic cough, increases ipsilateral pressure
Paraoesophageal vs sliding hiatus hernia
Paraoesophageal hitus hernia - Herniated part of stomach becomes parallel to oesophagus in chest
Sliding hiatus hernia - Herniated part slides though oesophageal hiatus into chest with gastro-oesophageal junction
Inguinal ligaments attach where
Between ASIS and pubic tubercle
Describe the inguinal canals
4cm long passageways through anterior abdominal wall in inguinal regions. Deep ring superior to midpoint of inguinal ligament and superficial ring superolateral to pubic tubercle
What does the inguinal canal contain in adults
Spermatic cord or round ligament of uterus
Embryonic developmental outpouching of parietal peritoneum in the testes
Processus vaginalis
What is the cremasteric fascia
Covering of skeletal muscle fibres from internal oblique
What is the external spermatic fascia
Covering of external oblique aponeurosis
What is the superficial ring of inguinal canal
Defect in external oblique aponeurosis where the testis pass into the superficial fascia of scrotum
Layers the spermatic cord passes through, posterior to anterior
Visceral peritoneum, parietal peritoneum (processus vaginalis), transversalis fascia (internal spermatic fascia), transverse abdominus, internal oblique (cremasteric fascia), external oblique aponeurosis (external spermatic fascia)
What is the spermatic cord
Vas defernece, testicular artery and pampiniform plexus, sympathetic nerves, lymphatic vessels, internal spermatic fascia, cremasteric fascia and external spermatic fascia
Direct vs indirect hernia
Direct - Peritoneum is pushed though posterior wall of inguinal canal and directly out of superficial ring into scrotum
Indirect - Peritoneum is pushed through deep ring into inguinal canal and then though superficial ring into scrotum
How to clinically differentiate direct and indirect
Place a finger on deep ring and ask the patient to cough. If it’s a direct hernia, the lump will reappear. It it’s indirect, won’t appear
Significance of internal thoracic artery
Branch of subclavian artery
Anterior parts of intercoastal space are supplied via anterior intercoastal branches. This artery can be mobilised form its attachment to sternum, sectioned inferiorly and anastomosed to a coronary artery distal to occlusion
