Exam II Flashcards
The larynx connects what two features?
lower part of the pharynx and the trachea
Funx of the larynx
- prevents food from entering airway during swallowing
- regulates air flow into lungs
- functions in vocalization (voice box)
At what vertebral level is the larynx found and how long is it?
- Found b/w CV 3 and CV6
- 5cm long in adults
Part of the thyroid cartliage that articulates with the cricoid cartilage
Inferior horn of the thyroid cartilage
Part of thyroid cartilage for attachment of inferior constrictor, sternothyroid, and thyroid muscles
Oblique line of the thyroid cartilage
Cricoid cartilage
most inferior of the laryngeal cartilages
Epglottic cartilage
single spoon shaped cartilage behind the root of the tongue and body of hyoid bone. attached to laryngeal prominence of thyroid cartilage by thyroepiglottic ligament
Arytenoid Cartilages
- paired cartilages; pyramidal in shape
- each cartilage contains: A) vocal process: attachment of vocal ligament. B) muscular process: attachment to instrinsic muscles of larynx
Corniculate cartilages
paired cartilages lying on apices of arytenoid cartilages and enclosed in aryepiglottic folds
Cuneiform cartilages
paired; lie in the aryepiglottic folds (functionally insignificant)
-may ossify and be mistaken for fracture on xray
Cricothyroid joint
synovial b/w cricoid cartilage and inferior horn of thyroid cartliage. permits rotation of thyroid cartilage (associated with changing pitch)
Cricoarytenoid Joint
synovial b/w upper border of cricoid cartilage and base of arytenoid. permits gliding and rotation of arytenoid on cricoid
Thyrohyoid membrane
from thyroid cartilage to hyoid bone; pierced by internal laryngeal nerve and superior laryngeal vessels
Median Cricothyroid lig
from arch of cricoid cartilage to thyroid cartilage
Vocal Lig
from thyroid cartilage to vocal process of arytenoid; vibrates during speech
Conus Elasticus (cricocervical membrane/lateral cricothyroid ligament)
membrane from cricoid cartilage to vocal ligament
Quadrangular Membrane
connects epiglottic cartliage to arytenoid on each side
- sup margin: forms aryepiglottic lig in aryepiglottic fold
- inf margin: forms vestibular lig in vestibular fold
Larynx contains two pairs of folds…
- vestibular folds (false): protective funx, helps to initiate cough
- vocal folds (true): contain the vocal lig and vocalis muscle
Rima Vestibuli
space b/w vestibular folds
Rima Glottidis
space b/w vocal folds; narrowest part of laryngeal cavity
3 Cavities of the larynx divided by vestibular and vocal folds
- laryngeal vestible: from laryngeal inlet to vestibular folds
- Laryngeal ventricles: lie b/w vestibular folds and vocal folds
- Infraglottic cavity: from vocal folds to inf border of cricoid cartilage
Larygeal Saccule
‘oil can’ of the vocal folds; contains glands which lubricate the vocal folds
-lubricant becomes depleted in hoarseness
Extrinsic Muscles
those which move the larynx as a whole. they can be divided into elevators and depressors
Extrinsic Elevators
Thyrohyoid, stylohyoid, mylohyoid, digastric, stylopharyngeus, palatopharyngeus
Extrinsic Depressors
omohyoid, sternohyoid, sternothyroid
Intrinsic Muscles of larynx (all are recurrent laryngeal N besides cricothyroid which is external laryngeal N)
- Cricothyroid: increases tension of vocal cords and increases pitch
- Posterior Cricoarytenoid: abducts vocal folds
- Lateral Cricoarytenoid: adducts vocal folds (whispering)
- Transverse Arytenoid: adducts vocal folds; coughing
- Oblique Arytenoid: adducts vocal folds; coughing
- Aryepiglottic: (continuation of oblique aryt.) closes laryngeal inlet
- Thyroepiglottic: opens larygeal inlet
- Thyroarytenoid: shortens and relaxes cords by drawing them forward (lowers pitch)
- Vocalis: adjusts tension on cords during phonation; fine tuning control of cords (lowers pitch)
Movements of Vocal folds:
- impt in phonation b/c they control air passing through rima glottidis
- size and shape of glottidis is altered by arytenoids
- glottidis is wide during inspiration and narrow during expiration and phonation
Voice Sexual Dimorphism
- males have longer vocal cords
- size of resonating chamber
- thickness of vocal cords
Most impt nerve of the larynx?
Recurrent Laryngeal Nerve (innervates all but 1 intrinsic muscle)
-sensory to the mucosa of the larynx below the vocal fold
Internal Laryngeal N.
- branch of sup. laryngeal
- sensory to mucosa above vocal folds
- pierces thyrohyoid membrane along with superior laryngeal A.
External Laryngeal N.
- branch of sup. laryngeal
- motor to cricothyroid and inferior constrictors
Blood Supply to Larynx
- superior laryngeal A: from superior thyroid A
2. inferior laryngeal A: from inferior thyroid A
3 main funx of lymphatic system
- picks up proteins too large for capillaries and brings them to bloodstream
- returns excess tissue fluid to the bloodstream
- produces lymphocytes
Lymph Nodes
Swellings found along the lymphatic system; produce lymphocytes and act as filters for lymph, preventing foreign bodies from entering bloodstream
Afferent lymph vessel
drain lymph to a node
Efferent lymph vessel
drain lymph from a node
Superficial nodes of the head
occipital, mastoid, parotid
Superficial nodes of neck
submandibular, submental, anterior cervical, superficial cervical
Deep cervical nodes
- located within carotid sheath and follow course of internal jugular vein
1. jugulodigastric: drains tongue and palatine tonsil
2. jugulo-omohyoid: also drains tongue (found near intermediate tendon of omohyoid)
Where do all lymphatics of head and neck drain into?
all drain directly or indirectly into the deep cervical nodes
Efferents of deep cervical nodes
- Right jugular trunk: drains into junction b/w internal jug and subclavian vein
- Left jugular trunk: drains into thoracic duct (largest lymphatic duct in body)
Submental Nodes
afferents drain central portions of lower lip, floor of mouth, and tip of tongue
Submandibular nodes
afferents drain the cheek, side of nose, upper lip, lateral lower lip, gums, and margin of the tongue
How does the spread of cancer relate to drainage of affected region?
spread of cancer follows lymphatics which drain affected region. ex: cancer of central lip will follow dif path than cancer of lateral lip
Lymphogenous metastasis
spread of cancer via lymphatic system
Signal (sentinal node)
- enlarged supraclavicular node, usually on left side
- often 1st indication of a visceral tumor or thorax/abdomen
Lymphoma
-a primary tumor of the lymph nodes
Hodgkins: type of lymphoma
Non-Hodgkins: another type w/ a poorer prognosis
Filariasis
parasitic infection of lymph nodes (worms; transmitted via mosquito)
Nodes in Diagnosis
Enlarged node and…
- tender/painful: indicates infection
- hard/painless: indicates cyst development or cancer
Breast is derived of.. (3)
mammary glands, fat, fibrous tissue
Location of breasts
b/w 2nd and 6th ribs b/w sternum and midaxillary line
location of the nipple
level of the 4th intercostal space
Axillary process of breast
portion of breast extending back into armpit; frequent site for cancer
Suspensory ligaments of breast
strong fibrous septa which support the breast. run from skin to deep layer of superficial fascia
Mammary gland
- modified sweat gland in superficial fascia, containing 15-20 lobes of glandular tissue
- each lobe of glandular tissue opens onto tip of nipple through lactiferous duct
Lactiferous sinus
expansion of lactiferous duct; serves as a reservoir for milk during lactation
Blood supply of Breast
internal thoracic, thoracoarcomial, lateral thoracic, and intercostal arteries
Lymphatic drainage of breast
axillary, parasternal, nodes of opposite breast, nodes of anterior abdominal wall
-75% of lymph from breast drains into axillary nodes
Breast Cancer
- most common cancer in women
- spreads to lymphatics before blood
- spreads to axilla first
- posterior intercostal veins drain to azygous and hemiazygous systems
- connections to vertebral venous plexus allows spread to vertebral column and brain
Clinical signs of breast cancer
- dimpling: due to invasion of suspensory ligament
- inverted nipple: due to invasion of the lactiferous ducts
- leathery thickening of the skin
- BC is one cause of midthoracic back pain in females
Sternum
- contains bone marrow and is major site of RBC production
1. manubrium: wides and thickest part; upper border forms jugular notch
2. body: articulates with 2nd-7th costal cartilages
3. xiphoid process: cartilagnous at birth and ossifies throughout life (could develop a bifid xiphoid or a xiphoid foramen)
Sternal angle
formed by articulation of manubrium and body; found at disc level b/w TV4 and TV5
Superior Thoracic Aperture (thoracic inlet)
superior opening of the thoracic cage and is bound by:
-manubrium, 1st rib, and 1st thoracic vertebra
Inferior Thoracic Aperture (thoracic outlet)
inferior opening of the thoracic cage and is bound by:
-xiphoid, costal margin, 12th rib, distal end of 11th rib, 12th thoracic vertebra
True Ribs
ribs 1-7 articulate with the sternum directly with their own costal cartilages
False Ribs
- ribs 8-10: articulate with sternum indirectly by attaching to costal cartilage of rib above
- ribs 11 and 12: not connected to sternum (floating ribs)
Typical ribs (3-9)
head, neck, tubercle, angle, shaft, costal groove (partially shields intercostal vein and artery)
Funx of thoracic cage
- protect thoracic and upper abdominal organs
- muscle attachments
- respiration
External Intercostal Muscles
- 2nd most impt for inspiration
- elevates the ribs during inspiration
- begin at tubercle of rib and end at costochondral joint
- run downward and forward (hands in pocket)
Internal Intercostal Muscles
- depresses ribs in forced expiration
- begin at the sternum and end at the angle of the ribs
- run downward and backward
Other muscles of thoracic wall
- all funx in forced expiration
1. innermost intercostal
2. subcostalis
3. transversus thoracis
What is the funx of all intercostal muscles?
prevent the pushing in or drawing out of intercostal spaces during respiration
Anterior aspect of thoracic wall blood supply
Internal thoracic Artery and its branches:
- pericardiophrenic A: pleura, pericardium, and diaphragm
- Anterior intercostal A: supply upper 6 intercostal spaces, anastomose with posterior intercostal A
- Musculophrenic A: lateral terminal branch of internal thoracic A
- Superior Epigrastric A: medial terminal branch of internal thoracic A
Posterior aspect of thoracic wall blood supply
- superior intercostal A (from costocervical trunk): branches into 1st and 2nd posterior intercostal A
- 3rd-11th Posterior Intercostal A: arise directly from the troracic aorta
- Subcostal A: lies below 12th rib and arises from thoracic aorta
Venous drainage of thoracic wall
- Anterior: drained by internal thoracic vein into the brachiocephalic vein
- Posterior: drained by the azygos system
Right Side Azygos System
- 1st posterior intercostal drains into brachiocephalic
- 2nd and 3rd posterior intercostal veins join to from superior intercostal vein; drains into azygos vein
- 4th-11th posterior intercostal and subcostal vein drain directly into the azygos
Left Side Azygos System
- 1st posterior intercostal drains into brachiocephalic
- 2nd and 3rd posterior intercostal veins join to form the superior intercostal vein; drains into left brachiocephalic
- 4th-8th posterior intercostal join to form the accessory hemiazygos; drains into azygos
- 9th-11th posterior intercostal veins and subcostal form the hemiazygos vein; drains into azygos
Nerves of the Thoracic Wall
- Intercostal Nerves: the anterior primary rami of the first 11 thoracic spinal nerves
- Subcostal Nerve: the anterior primary ramus of the 12th thoracic spinal nerve
Funx of the endothoracic fasci:
to prevent the innermost intercostal muscle from rubbing against the parietal pleura
Typical intercostal space contains…
intercostal Vein, artery and Nerve (VAN)
3 subdivisions of thoracic cavity
- 2 pleural cavities, each surrounding a lung
2. 1 mediastinum: area b/w the pleural cavities containing the heart, great vessels, trachea, esophagus etc
Pleura
thin membrane which lines inner surface of thoracic cavity and covers surface of lung
- parietal pleura: lines inner surface of thorax
- blood supply from intercostal arteries, internal thoracic A, and superior phrenic A
- innervated by intercostal nerves, subcostal nerve, and phrenic nerve (highly sensitive to pain) - visceral pleura: intimately invests the lung
- blood supply from bronchial artery
- no sensory innervation
Pleural Cavity
potential space b/w the parietal and visceral pleurae
Pleural Fluid
lubricates pleurae to minimize friction b/w parietal and visceral layers; easing movement of the lungs
4 parts of Parietal pleura
- costal pleura
- mediastinal pleura
- diaphragmatic
- cervical (covers apex of lung)
Pleural Recesses
- spaces found b/w two folds of parietal pleura; allow expansion of the lung during inspiration
1. costodiaphragmatic: fluid may accumulate here
2. costomediastinal
Pneumothorax
Pleural cavities filled with air (potential space –> real space)
- trauma (sucking chest wound)
- disease
- congenital weak spot
Tension pneumothorax
instead of a hole, a flap is present on the visceral pleaura
- air enters cavity on inspiration but cannot exit on expiration
- pleural cavity inflates, pushing the mediastinum to the opposite side and compressing the other lung
Hemothorax
- pleural cavity fills with bood
- hemopneumothorax
- conditions result in atelectasis (lung collapse)
Pleuritis
inflammation of pleura leading to adhesions b/w parietal and visceral pleura
- painful due to parietal
- pain is referred to shoulder via phrenic N
- pain radiates along supraclavicular nerves
- produces sound that can be heard on auscultation known as pleural friction rub
Importance of Sternal Angle landmark
- boundary b/w superior and inferior mediastinum
- articulation of 2nd rib and sternum
- aortic arch
- bifurcation of trachea into left and right main bronchi TV4 and TV5
- upper border of the pulmonary trunk
Superior mediastinum contents:
sup vena cava, brachicephalic veins, arch of aorta, thoracic duct, trachea, esophagus, thymus, vagus N, left recurrent laryngeal nerve, phrenic nerve
Subdivisions of Inferior mediastinum and their contents:
- Anterior Mediastinum: thymus, lymph nodes (paresternal nodes), sternopericardial ligaments
- Middle: heart, pericardium, roots of great vessels, main bronchi, phrenic N
- Posterior: esophagus, thoracic aorta, azygos vein, hemiazygos vein, thoracic duct, vagus N, splanchnic nerves
Trachea
- begins at inferior border of cricoid cartilage CV6
- 15-20 C shaped rings: prevent trachea from collapsing
- posterior gap is covered by smooth muscle known as trachealis muscle
- 9-15cm in length
Carina
prominent ridge located within trachea at bifurcation to separate openings of right and left main bronchi
Right main bronchus
shorter, wider and more vertical than the left main broncus
- passes under the arch of the azygos vein
- 3 lobar bronchi divide into 10 segmental bronchi
Left Main bronchus
longer, narrower, and more horizontal than the right main
- anterior to the esophagus
- 2 lobar bronchi divide into 10 segmental bronchi
Blood supply and Innervation of trachea
Blood -Inferior thyroid A -Bronchial A Innervation -Vagus N (parasymp and pain fibers) -Sympathetic trunk
Hilum
-opening on the mediastinal surface where vessels, nerves, and bronchi pass
Root of the lung
- formed by the structures which pass through the hilum; connects to the hear and the trachea
- bronchi, pulmonary V and A, bronchial vessels, nerves, lymphatics
Pulmonary ligament
pleura descending from the root of the lung
Right lung
- Sup lobe: above horizontal fissure
- Middle lobe: b/w horizontal and oblique fissure
- Inf lobe: below the oblique fissure
Characteristics of the Right lung
groove for azygos, groove for esophagus, cardiac impression, groove for superior vena cava, groove for right brachiocephalic vein
Characteristics of the Left Lung
lingula, cardiac notch, cardiac impression, groove for the aorta, groove for the left subclavian A
Bronchopulmonary segments
functional independent units of the lung, each consisting of:
- segmental bronchus
- branch of pulm A
- segment of lung tissue
- surrounding septum
Blood Supply of Lungs
A: bronchial A from thoracic aorta
V: bronchial V to the azygos and accessory hemiazygos
innervation of the lungs
anterior and posterior pulmonary plexuses formed by fibers from the:
- vagus (parasympathetic and sensory)
- sympathetic trunk (T2-T5, sympathetic and sensory)
Sympathetic activation of lungs
produces bronchial dilation and vasoconstriction and decreases glandular secretion
Parasympathetic activation of lungs
produces bronchial constriction and vasodilation and increases glandular secretion
Asthma
- obstructive airway disease (coughing, wheezing, difficulty breathing)
- caused by spasms of smooth muscle in segmental bronchi and bronchioles accompanied by excessive secretion of mucus
1. Extrinsic: triggered by allergens
2. Intrinsic: non-allergenic stimuli (stress, cold, exercise)
Lymph drainage from lungs
drains into pulmonary and bronchopulmonary nodes in the hilum –>tracheobronchial nodes
Bronchogenic carcinoma
- primary tumor of the bronchus
- directly related to cigarette smoking and air pollution
- highly metastic: spreads quickly to lymph nodes and enters blood stream
- often causes enlargement of sentinal node
Lung cancer may affect
- Phrenic N: resulting in paralysis of half the diaphragm
2. recurrent laryngeal N: at apex of lung resulting in paralysis of half the larynx
What does the diaphragm separate?
the thorax from the abdomen
Which dome of the diaphragm is higher? Why?
the right dome is higher because it overlies the liver
What are the two parts of the diaphragm?
- muscular part
- sternal part: from xiphoid process
- costal part: from lower 6 costal cartilages
- lumbar part: from lumbar vertebrae 1-3 and medial and lateral arcuate ligaments - central tendon
3 openings of the diaphragm
- Caval opening: at TV8 within central tendon; holds inferior vena cava and right phrenic nerve
- Esophageal hiatus: at TV10; holds the esophagus and the ant and post vagal trunks
- Aortic hiatus: at TV12; holds aorta, thoracic duct, and azygos vein
Blood Supply to the Diaphragm
- Musculophrenic A from the internal thoracic A
- Pericardiophrenic A from internal thoracic A
- Superior Phrenic A from the Aorta
- Inferior Phrenic A from the Aorta
Innervation of Diaphragm
- Phrenic N: motor to diaphragm and sensory to central part
2. Intercostal Nerves: sensory to peripheral part
Hiatal Hernia
- due to weakness in wall of diaphragm around esophageal hiatus
- upper part of the stomach slides into thoracic cavity through opening
- > 50 y/o
- major cause of gastroesophageal reflux
- SOT adjustment for treatment
3 major movements of during inspiration
- Piston movement: diaphragm contracts; resulting in increase of vertical diameter of thorax
- Bucket handle movement: elevation of ribs 7-10; resulting in an increase in the transverse diameter of thorax
- Pump handle movement: elevation of ribs 2-6; resulting in an increase in the antero-posterior diameter of thorax
Forced expiration
coughing, sneezing, and clearing the airway are done so by contraction of the internal intercostals, innermost intercostals, and muscles of the anterior abdominal wall
hiccups
spasmodic contraction of the diaphragm caused by irritation of the phrenic N
-pericarditis, pleuritis, peritonitis
Pericardium
fibroserous sac that encloses the heart and great vessels; occupies the middle mediastinum
Fibrous Pericardium
- dense outer part
- blends with the central tendon of the diaphragm
- connected to the back of the sternum by 2 sternopericardial ligaments (cardiac seat belt)
Serous Pericardium
- parietal layer: lines the inner surface of the fibrous
2. visceral layer: closely adheres to outer surface of heart (epicardium)
Pericardial Cavity
potential spaces b/w the parietal and visceral layers of the serous pericardium; contains serous fluid
Heart
a) epicardium: equivalent to visceral layer of serous
b) cardiac muscle fibers arranged in a spiral
c) endocardium: smooth endothelium lining the inside of the heart/walls of the chambers
d) chambers: 4 chambers in the heart
Cardiac Tamponade
- fluid leaking rapidly into the unyielding fibrous pericardium which compresses the heart and impedes venous return
- superior vena cava is particularly vulnerable to compression and cardiac tamponade
- one of the causes for a prominent external jugular vein and eventually all veins of the face and neck over time
Transverse pericardial sinus
subdivision of the pericardial sac which lies posterior to the aorta and pulmonary trunk and anterior to the superior vena cava and left atrium
Oblique pericardial sinus
subdivision of the pericardial sac which lies posterior to the heart. it is surrounded by the left and right pulm veins and inferior vena cava
Blood Supply of the pericardium
- pericardiophrenic A: most impt
- bronchial A
- esophageal A
- coronary A (supplies visceral layer of serous pericardium only)
Innvervation of the Pericardium
Phrenic N: sensory
Sympathetic trunk: vasomotor
vagus
Pulmonary embolism
- obstruction of a pulm A by a blood clot
- clot forms in the systemic venous system and passes through vena cava and so on
- embolus will block a pulm A or one of its branches and blood flow to the lung will be blocked
- resulting in acute respiratory distress and/or heart failure where death can occur in minutes
Each valve of the heart consists of 3 major components
- valve orifice
- fibrous ring (anulus)
- cusps: flaps to close the valve when necessary
Semilunar
lack chordae tendineae and papillary muscles
- Pulm valve: a, l, r cusps
- Aortic valve: p, l, r cusps
Mitral (bicuspid)
a and p cusps
Tricuspid
a, p, and septal cusps
Lub-Dup
two stroke beat produced by the heart
- Lub: contraction of the ventricles and closure of the tricuspid and mitral
- Dup: produced by closure of the pulm and aortic valves
Pulm Valve
- behind medial end of 3rd left costal cartilage
- most audible over the 2nd left intercostal space
Aortic valve
- located behind the left half of the sternum medial to the 3rd intercostal space
- most audible over the right 2nd intercostal space
Mitral valve
- behind the left half of the sternum medial to the 4th costal cartilage
- most audible over the left 5th intercostal space at midclavicular line
Tricuspid valve
- behind the right half of the sternum medial to the 4th intercostal space
- most audible over the left 5th intercostal space at border with sternum
Orientation of the heart
obliquely in the thorax
from base to apex: forward, downward, and to the left
Surfaces of the heart
- Anterior: formed mostly by the RV
- Diaphragmatic: formed by the RV and LV
- Left Pulmonary: mostly the LV
- Right Pulmonary: mostly the RA
RA structures
- right Auricle
- Pectinate: prominent ridges on ant wall
- Crsita terminalis: vertical muscular ridge marking the termination of the pectinate muscles. Runs from the opening of the SVC to that of the IVC. Marked externally by the sulcus terminallis
- Sinus of VC: smooth wall post to the crista terminalis. Represents embryonic sinus venosus
- Fossa Ovalis: depression remnant of the foramen ovale, an opening which closes at birth (not closed in 25% of adults)
Atrial septal defect
- Probe patent foramen when defect is small
- clinical atrial septal defect when the defect is larger
- blood is shunted from the LA to the RA causing dilation of the RA, RV, and pulm trunk
Openings of the RA
- Sup and inf vena cava
- Coronary sinus
- anterior veins of the RV
- RV via tricuspid
RV structures
- Trabeculae carneae: interconnecting muscular ridges
- Papillary Muscles: 3 (a, p, and septal), cone-shaped muscles connecting to the chordae tendineae
- Chordae tendineae: attach the papillary muscles to the cusps of the tricuspid (prevent eversion of valve during ventricular contraction)
- Conus Arteriosus: upper portion of the RV
- Supraventricular crest: muscular ridge separating the conus arteriosus from the rest of the RV
- Moderator band (septomarginal trabecula): transmits the right bundle branch of the conduction system
Openings of the RV
- RA via tricuspid
- Pulm trunk via pulm valve
LA structures
- left auricle
2. pectinate muscles: few found in auricle, rest of LA is smooth
Openings of the LA
- Pulm veins (4 usually)
- LV via the mitral/bicuspid valve
LV structures
- Trabeculae carneae: finer and more numerous than RV
- Papillary muscles: a and p
- Chordae tendineae: attach papillary muscles to cusps of mitral valve
- aortic vestibule: smooth walled portion below cusps of aortic valve
Openings of the LV
- LA via the mitral/ bicuspid
- Aorta via the aortic valve
Septal Walls of heart
- Interatrial septum: b/w the two atria (atrial septal defects)
- Atrioventricular Septum: small portion above septal cusp of tricuspid and below anterior cusp of mitral
- Membranous Interventricular Septum: thin, smooth, fibrous
- Muscular Interventricular septum: very thick
Enlargement of the heart (2 ways)
- Muscular hypertrophy: elasticity is lost in blood vessels and more force is required to push blood through arteries. walls of heart grow thicker
- dilation of a chamber
- septal defects
- valve incompetency of the mitral valve
Structure of semilunar
- nodules: small central thickenings of free edge
- lunules: thin, crescentic part of cusps
- sinuses: the space b/w the cusps and the walls of the vessel
Fibrous skeleton of the heart
connective tissue framework of heart composed of:
- fibrous rings (anuli): form the foundation of each of the heart valves
- Left and Right fibrous trigones: connect the rings together; strongest part of fibrous skeleton
- Membranous part of septal wall
Funx of the fibrous skeleton
- provide a structural framework for the valves
2. insulate electrical impulses of the conduction system in the atrial wall from those in the ventricular wall
Right coronary A
- sinuatrial nodal A
- right marginal A
- posterior interventricular A
Left coronary A
- anterior interventricular A
- circumflex A: passes posteriorly to anastomose with the right coronary A. Gives branch to the left marginal A
Coronary Artery Dominance
- which coronary artery gives rise to the posterior interventricular A
- Right coronary dominance in 70% of people
- Left coronary dominance in 30% of people
Right coronary A supplies…?
RA, most of RV, diaphragmatic surface of LV, posterior 1/3 of interventricular septum, conduction system to proximal parts of right and left bundle branches
Left coronary A supplies…?
LA, most of LV, part of RV, anterior 2/3 of interventricular septum
Where do coronary anastomoses occur?
- right coronary and circumflex arteries
2. anterior and posterior interventricular arteries
Coronary Sinus
- larges vein of the heart found within coronary sulcus and drains into RA
- receives blood from: great cardiac V, middle cardiac V, small cardiac V, posterior V of left ventricle, and oblique vein of left atrium
Anterior veins of the RV
drain directly into the RA
Venae cordis minimae
smallest veins of the heart; run w/in the walls of the heart and drain into RA
Athersclerosis
- deposition of lipid plaques on the inner walls of arteries
- results in narrowing of lumen
Angina Pectoris
- substernal chest pain upon exertion
- symptom of partial occlusion of coronary A branches
- occurs due to insufficient blood flow to heart tissue
Myocardial Infarction
- occurs when a coronary artery branch becomes completely occluded
- portion of the heart supplied by the A dies and is converted to fibrous scar tissue
Most common sites for heart attack (major)
- Anterior interventricular A (40-50%)
- Right coronary A (30-40%)
- Circumflex A (15-20%)
Lymphatic drainage of the heart
subepicardial lymphatic plexus to tracheobronchial node
Innervation of the heart
Cardiac plexus
- Superficial cardiac plexus: beneath the arch of the aorta and anterior to the pulmonary trunk
- Deep cardiac plexus: posterior to the aortic arch
- sympathetic: cervical and thoracic cardiac nerves (T1-T4)
- parasympathetic: from the vagus
Parts of the conduction system
- SA Node: pacemaker of the heart, located near the crista terminalis
- AV Node: in the septal wall above opening for the coronary sinus in the RA
- Atrioventricular Bundle:
a) Right bundle branch: enters the septomarginal trabecula of the Right ventricle
b) Left bundle branch: enters the papillary muscles of the left ventricle - Subendocardial plexus of conduction cells (purkinje): joined by branches of the left and right bundle branch
Pathway of the conduction impullse
SA node –>atrial wall –> AV node –> AV bundle and branches –> Subendocardial plexus –> myocardium of the ventricles
Ligamentum Arteriosum
remnant of the embryonic ductus arteriosus connecting the arch of the aorta to the left pulm artery or to the pulm trunk
Esophagus
Cervical, thoracic (longest), and abdominal
- upper 1/3 striated muscle
- middle 1/3 both striated and smooth muscle
- lower 1/3 smooth muscle
Where does the esophagus begin and end?
laryngopharynx at CV 6 and joins the stomach at cardioesophageal junction
Blood supply to the esophagus
- Inferior thyroid A
- Bonchial A
- Esophageal A
- Left Gastric A
- Inferior phrenic A
Venous drainage of esophagus
- Esophageal veins (into adjacent systemic veins)
2. Left gastric vein (into the portal vein)
Innervation of the esophagus
- Vagus nerve
a) motor to supply upper 1/3 and part of middle 1/3 striated muscle
b) parasympathetic fivers supply the smooth muscle portion lower 1/3 and part of middle 1/3 - Sympathetic from thoracic cord level
- Pain fibers in sympathetic trunk
Parts of the aorta
- Ascending aorta (in middle mediastinum)
- Aortic Arch (in superior mediastinum)
- Descending Aorta
a) Thoracic Aorta (in posterior mediastinum) at TV4
b) Abdominal Aorta (in abdomen)
Where does the thoracic aorta become the abdominal aorta?
at the aortic hiatus at TV12
Branches of the thoracic Aorta
- Parietal Branches (supply body wall)
a) 3rd - 11th intercostal arteries
b) subcostal arteries
c) superior phrenic arteries - Visceral branches (supply thoracic viscera)
a) bronchial arteries
b) pericardial arteries
c) mediastinal arteries
d) esophageal arteries
Impt anastomoses
- b/w the ant and post intercostal A
2. b/w the sup and inf epigastric A
Where does the thoracic duct begin?
in the abdomen at the junction of the three abdominal trunks (intestinal, lumbar, descending intercostal) called the cisterna chyli
Pathway of the thoracic duct
begins in abdomen at cysterna chyli –> passes through aortic hiatus of diaphragm –> upward through the posterior mediastinum b/w the aorta and azygos vein –> crosses over to the left at TV5 or TV6 –> passes posterior to the left subclavian vein and empties into the junction of the left internal jugular and subclavian veins
Thoracic duct drains lymph from all over the body except what?
- right upper extremity
- right thoracic cavity
- right side of the head and neck
Functional components of the phrenic N
Phrenic N (C3-5)
- Motor to diaphragm
- Sensory (pain fibers from the diaphragm, pericardium, pleura, and peritoneum)
- Sympathetic
Accessory Phrenic N
variation which arises from C5 and is a branch of the nerve to the subclavius
Sympathetic Trunk
- extends from base of skull to the coccyx on both sides of the vert column
1. Gray Rami communicantes: postganglionic sympathetic fibers and are connected to every spinal nerve (cell bodies found in sympathetic trunk)
2. White Rami Communicantes: preganglionic sympathetic fibers and are limited to spinal cord segments T1-L2 (cell bodies located in the lateral horn/ intermediolateral column)
Cervicothoracic (stellate) ganglion
formed by the fusion of the inferior cervical with the first thoracic ganglion
Splanchnic Nerves
- Major visceral branches of the sympathetic trunk which supply the abdominal viscera
1. Greater splanchnic (T5-T9)
2. Lesser splanchnic (T10-T11)
3. Least splanchnic (T12) - all 3 pierce the crura of the diaphragm to reach the abdomen
Vagus nerve in the thorax
Right vagus enters thorax in front of right subclavian A
-right recurrent laryngeal hooks around the right subclavian artery and ascends into the neck
Left vagus enters thorax b/w the left common carotid and left subclavian arteries
-left recurrent larygeal hooks around the arch of the aorta and ascends into the neck
Functional components of the vagus N
- Motor to muscles of the pharynx and larynx - not to thorax
- Sensory to thoracic and abdominal viscera
- Parasympathetic to thoracic and abdominal viscera
Esophageal Plexus
- formed from the vagus nerve along the esophagus
- plexus comes together to form the ant and post vagal trunks near the esophageal hiatus
Autonomic Plexuses
Each plexus receives sympathetic fibers from the sympathetic trunk and parasympathetic fibers from the vagus
- Cardiac Plexus: related to the arch of the aorta; controls the heart rate and is divided into superficial and deep parts
- Pulmonary plexus: related to the root of the lung
- Esophageal plexus: formed along the esophagus
- Thoracic aortic plexus: network of nerves along the thoracic aorta and its branches