Cardioresp Anatomy Flashcards
Sternum location and its parts
Lies anterioly in the midline of the thoracic cage. Three pa-ts manubrium, body and xiphoid process
Manubrium
Superior boarder has a notes - suprasternal (jugular notch). Articulates with clavicle at sternoclavicular joint nd first rib. Articulates with body at marubiosternal joint aka sternal angle /angle of Louis
Body of sternum
Articulates with ribs 2-7 o (2nd rib with eternal angle)
Xiphoid process
Inferior to one body. small and variable in shape. Seventh rib articulates with part of inferior body an superior part of xiphoid process.
What are anterior parts of the ribs composed of?
Costal cartilage _ ribs articulate with them at costochondral joints
True vs false Ribs and why
True ribs 1-7 I the costal cartilages articulate directly with sternum at stennocostal joints. False ribs 8-10 units and join 7th costal cartilage. Ribs 11-12 do not articulate with the sternum - “floating’
Where do ribs articulate posteriorly
Articulate posteriorly with the toracic vertebrae at cast vertebral joints
Typical us atypical ribs.
3-9 are typical ribs - have a head neck tubercle and body.
I-2 and 10-12 are atypical
What nerves is the skin of the thoracic wall innovated by?
Spinal nerves T1 - T12 . Adermatatome is an area of skin innovated by a single spinal ne-ve.
Spaces between ribs are inte-costal muscles, they contain:
Three lagers of inte-costal muscles (external, internal and inne-rmost)
And an intercostal neurovascular bundles comprising an intercostal nerve, artery and vein.
External intercostal muscle fibre orientation
Antero-inferior. Contraction pulls its superior, hence most active in inspiration
Internal intercostal fibre orientation
Perpendicular to external inte-costal, in postero-inferior direction. Contraction pulls ribs inferiorly so most active in expiration.
Innermost intercostal fibre orientation.
Same direction as those of internal intercostal.
Where is the endothoracic fascia?
Deep to innermost intercostal and superficial to parietal pleura
where does intercostal neurovascular bundle lie
In the plane between internal and innermost intercostal muscles. Lies along inferior border of rib superior to the space. Lies in a shallow costal groove on deep surface of the RI’s
What does intercostal neuromuscular bundle supply?
Intercostal muscles, overlying skins and underlying parietal pleura.
Anterior and posterior intercostal arteries
Supply anterior and posterior parts of intercostal spaces respectively. Anterior arteries branches of internal thoracic artery (branch of subclavian artery). Posterior arteries are branches of descending aorta in the poste-ion tho-ax.
intercostal veins.
Drain into internal thoracic vein and posterior intercostal veins drain into azygous
What is the pleura?
Two layers of membranes covering lungs and structures passing into and out of them (blood vessels + main bronchi)
,parietal pleura lines inside of thorax
Visce-al pleura covers surface of lungs and extends into the fissures
A thin pleural cavity lies between parietal and visceral pleura.
Parts of the parietal pleura
Cervical-covers apex of lung
Costal - lies adjacent
Mediastinal-lies adjacent to the heart
Diaphragmatic - lies adjacent to the Diaphragm
What is the costodiaphragmatic recess
A ‘gutter’ around periphery of the diaphragms where costal pleura becomes continuous with diaphragmatic. A smaller costomediastinal recess lies in junction of costal and mediastinal pleura. These ape potential spaces that the lungs expand into during deep inspiration
Innovation of the parietal pleura
Intercostal nerves that innovate one overlying skin of the chest wall. Somatic sensory fibres in these nerves carry sensation to our consciousness. Injury to parietal pleura is typically very painful
Innovation of the visceral pleura
Autonomic sensory ne-ues (visceral afferents). Usually does not reach ou-conscious perception.
Most superior part of the lung
Apex (projects into the roof of the neck above the clavicle
Lobes of the right lung
Three lobes - superior, middle and inferior
Lobes of the left lung.
Superior and inferior( anterior extension of superior lobe - the lingula - extends over the heart )
Fissures of the lungs
Both lungs have an oblique fissure. (Separates superior inferior in left lung. And the inferior in right lung.
Right lung has a horizontal fissure separating superior and middle.
Surfaces of lung
Costal - adjacent to ribs.
Mediastinal - adjacent to heart
Diaphragmatic - inferior surface of lung
Borders of the lung
Anterior - sharp and tapered
Posterior - thick and rounded
Inferior - sharp and tapered.
Hilum of the lung
Region of mediastinal surface of the lung where pulmonary artery, veins and main bronchus enter and exit the lung. (In right lungs pulmonary artery lies to ante-ion main bronchus (superior in left lung)
Bifurcation of the trachea
Level of sternal angle; internally this point is called carina. Right main bronchus is sho-ter wider descends more vertically (foreign body more likely to enter it)
Bronchial tree
Each main (primary) bronchi divides into lobar (secondary) bronchi, one for each lung lobe. These divide to give -ise to segmental (tertiary), bronchi (approx 10 in each lung) each supplies a functionally independent region of the lung called a bronchopulmonary segment 10 in each lung. Segmental bronchi within each segment divide into bronchioles that become smaller witheach division. Smallest bronchioles conduct air to and from alveoli.
What do walls of trachea and bronchi contain us walls of bronchioles
Trachea and bronchi - contain smooth muscle and cartilage, bronchioles - only contain smooth muscle. Contraction & relaxation of smooth muscle under autonomic control.
What are the walls of the pharynx composed of ?
Oute- layer circular muscle and an o inner layer of longitudinal muscle.
The external circular muscle layer of the pharynx wall is composed of.
Three constrictor muscles the superior, middle and inferior constrictors that overlap. They contract superior to inferior so that swallowed food moves down pla-yax towards the oesophagus.
How does food move during swallowing
Food in oral cavity pushed into the oropharynx by the tongue. Soft palate rises and closes off nasopharynx from the oropharnx. Food enters laryogopharynx and constriction of the muscles of pla-nyeal wall move good into oesophagus. The epiglottis closes off the laryngeal inlet + prevents foodfliquids entering the larynx
What parts make up the pharynx?
Nasopharynx - posterior to the nasal cavity
Orophargnx - posterior to the oral cavity
Laryngopharynx - posterior to larynx
What type of tissue make up the tonsils ?
Collections of lymphoid tissue
Where are the pharyngeal and tubal tonsils ?
Found in nasopharynx. Pharyngeal fossil (adenoid) lies in the root of the nasopharynx. The tubal tonsil surrounds the opening of tube the auditory ( which connects the nasopharynx to the middle ear )
Palatine and lingual tonsils.
The palatine tonsil lies next to the pharyngeal wall in oropharynx. Lingual tonsil is a collection of lymphoid tissue on the posterior aspect of the tongue
Nerve innovation of the pharynx
Sensory fibres from the glossopharyngeal nerve and motor fibres from the vagus nerve
Nerves that lie dose to the posterior pharyngeal wall.
Cervical part of the sympathetic trunk and superior cervical ganglion. Superior laryngeal nerve - this branch of the vagus ne-ve descends over the posterior aspect of the internal carotid artery. Passes between the inferior and middle constrictors of the pharynx to the larynx.
Hypoglossal ne-ve. This lies close to the vagus nerve
Glossopharangeal nerve. From the posterior aspect, deep it lies to the internal carotid artery.
Gag reflex
Protects the airway. Mediated by glossopharyngeal and vagus nerves. Stimulation carried to CNS and muscles contract
Normal nerve innovation in swallowing
Vagus nerve coordinates contraction of the pharyngeal muscles and soft palate and conveys sensation from large , waist glossophangeal nerve provides sensory innovation to pharynx.
Cartilages of the larynx
Nine- thee unpaired and three paired.
Larynx unpaired cartilages
Epiglottis, thyroid and cricoid cartilage.
Larynx three paid cartilages.
Much smaller than unpaired. Aryteroids, the cuneiforms and corniculate cartilages
Thyroid cartilage
Two flat cartilages (laminae) meet in anterior midline to form laryngeal prominence
Superior and inferior Norns
Extensions formed from laminate that project superiorly and inferiorly
Superior norms attach to the hyoid bone.
Inferior horns articulate with cricoid cartilage below.
Cricothyroid membrane
Connects inferior border of thyroid and superior border of the cricoid. This is pierced to create an emergency airway.
Epiglottis
Attached to superior aspect of thyroid cartilage, where the two thyroid Latina e meet. During swallowing, it covers entrance to larynx and protects from entry of foods or liquid.
.
Aryteroids-
Sit on superior surface of cricoid cartilage. They articulate with cricoid cartilage at small joints. Vital fo-pronation, as vocal cords attach to them. Movements of them move the vocal cords.
Vocal folds
Two pairs of folds that project into the cavity. Vestibular folds ( false vocal cords) superio-ly and the vocal folds (tree vocal cords) inferiorly
Vocal ligaments
Attached anteriorly to the internal aspect of one laryngeal prominence and posteriorly to the aryteroid cartilages.
Vocal cords
Space between the few vocal cords is the rima glottidis. Addiction Closes this abduction opens it.
Two groups of muscles that act on the larynx
Extrinsic muscles-suprahyoid and infrahgoid muscles. Do not move individual cartilages, but rather move the larynx as one with speech + swallowing
Intrinsic muscles - move the laryngeal cartilages which in turn move the vocal cords. Injury to the nerves that innovate the intrinsic laryngeal muscles therefore affect speech.
Intrinsic muscles that move the vocal co-ds
- Left and right cricothyroid muscles-tension on vocal cords.
Left and right posterior cricoanyteroids _ each attached to inns lateral arteroid. These muscles abduct the vocal cords and open rima glottidis.
Transve-se arytenoid - unpaired muscle. adducts vocal folds and close rima glottidis.
Superior laryngeal ne-ve
Innovates cricothyroid muscle and is senso-y to langue above vocal folds
Recurrent laryngeal nerve
Innervotes all intrinsic muscles except cricothyroid and is sensory to larynx below Vocal folds
Blood supply of the lungs
Bronchial arteries from the descending aorta. Bronchial veins return blood to azygos
Autonomic nerves that innovate the lungs:
Parasympathetic fibres stimulate constriction of bronchial smooth muscle (broncoconstriction)and secretion from the glands of the bronchial tree.
Sympathetic fibres stimulate relaxation if the bronchial smooth muscle (bronchodilation) and inhibit secretion from the glands
Visceral afferents
(Visceral sensory fibres) accompany sympathetic and parasympathetic nerves and relay sensory information from lungs and visceral pleura to the CNS (not usually conscious perception).
What is innervated by somatic sensory fibres carried in the intercostal nerves
Parietal pleura
Where does lymph from the lungs drain
Into the venous system via the thoracic duct or right lymphatic duct
What is the space between the parietal pleura and the inferior boarder of the lung
Costodiaphragmatic process
Apex of the lung
Projects into lower neck, superior to the medial end of the clavicle
Inferior boarder of the lung
6th rib anteriorly (midclavicular line)
8th rib laterally (midaxillary line)
10th rib posteriorly (at vertebral column)
Parietal pleura extends to the
8th rib (modclavicular line)
10th rib anteriorly (midaxillary line)
12th rib posteriorly (at vertebral column)
Oblique fissure location
Extends from 4th rib posteriorly to 6th intercostal cartilage anteriorly - runs deep to the 5th rib
Horizontal fissure of the right lung location
Extends anteriorly from the 4th costal cartilage and intersects oblique fissure
Diaphragm
Broad thin domed sheet of skeletal muscle. Separates thoracic and abdominal cavities. Superior surface adjacent to parietal pleura. Openings in it allow passage of structures between thorax and abdomen. Function is intergalactic to mechanics of breathing.
Attachments of the diaphragm
Xiphoid process, costal margin ( and to the tips of the 11th and 12th ribs) and the lumbar vertebrae. Central part of the diaphragm is not muscular but fibrous -the central tendon.
Movements of the diaphragm in breathing
Contracts during inspiration, muscle fibres of left and right domes pulled towards peripheral attachments and domes flatten. Increases thoracic volume for lungs to expand.
Relaxed during expiration, domes superiorly, decreasing thoracic volume and drives air from the lungs.
Nerve innervation of the diaphragm
Right and left phrenic nerves innervate right and left sides. They are somatic nerves formed in the neck by fibres from the c3, c4 and c5 spinal nerves so contain motor and sensory fibres.
Role of the pleural fluid in ventilation
Creates surface tension between parietal pleura lining the thoracic cavity and the visceral pleura on the surface of the lung. Keeps the pleura in contact with each other and prevents lung from collapsing away from thoracic wall when it changes volume.
How does contraction of the intercostal muscles help increase thoracic volume
External intercostals pull ribs superiorly and laterally and the ribs pull sternum superiorly and anteriorly, increasing the AP and lateral dimensions of the thoracic cavity.
Extra muscles in use in forced breathing
Sternocleidomastoid, pectoralis major and minor, serrated anterior
Where does the mediastinum extend from
Superior thoracic aperture superiorly to the diaphragm inferiorly. Sternum anteriorly to the thoracic vertebrae posteriorly
What does the mediastinum contain
Heart and pericardium.
Great vessels that enter and leave the heart
Veins that drain the chest wall
Trachea and the main bronchi
The oesophagus
Nerves (somatic and autonomic)
Lymphatics
The thymus gland
Two parts of the mediastinum
Superior and inferior , line between these ribs from sterns lang,e anterirly to the t4/t5 junction posteriorly.
Divisions of the inferior mediastinum
Anterior middle ( obtains heart inside the pericardial sac, the pulmonary trunk and the ascending aorta) and posterior compartments.
Contents of the superior mediastinum
Arch of the aorta and its three branches
Superior vena cava and it’s tributaries- left and right brachiocephalic veins
Trachea
Oesophagus
Phrenic nerves
Thoracic duct
Thymus gland
Three ‘parts’ of the aorta
Ascending, arch and descending
Ascending aorta
Short, first part , gives rise to the coronary arteries which supply myocardium
Descending (thoracic) aorta
Descends through posterior mediastinum and into the abdomen posterior to the diaphragm.
Three major branches of the aortic arch that supply the upper body
Brachiocephalic trunk -bifurcates into the right common carotid artery ( supplies right side of head and neck ) and the right subclavian artery which supplies the right upper limb.
The left common carotid artery (supplies left side of head and neck)
Left subclavian artery supplies the left upper limb
Receptors in the arch of the aorta
Aortic bodies contain chemoreceptors. These monitor arterial oxygen and co2. Visceral sensory information travels back to the CNS along the path of the vagus nerve and results in reflex responses that regulate ventilation.
Ligamentum arteriosum
A fibrous, cordlike connection between pulmonary trunk and arch of the aorta. Remnant of the duct is afteriosus, a foetal circulatory shunt. ( it diverts most blood entering pulmonary trunk directly to the aortic arch. This closes when baby starts to use their lungs at birth. And blood in the pulmonary trunk enters the lungs)
Two veins carrying deoxygenated blood to the right atrium
Superior and inferior vena cava
Superior vena cava (SVC)
Returns blood to the heart from the head
Superior vena cava (SVC)
Returns blood to the heart from the head, neck and upper limbs , lies in the superior mediastinum. Formed by union of left and right brachiocephalic veins.
Each brachiocephalic vein is formed by the union of the internal jugular vein (which drains head and neck) and the subclavian vein (which drains the upper limb)
Inferior vena cava (IVC)
Returns blood to the heart from all regions inferior to the diaphragm. Thoracic part of the IVC is very short ( enters the right atrium as soon as it enters the thorax through the diaphragm. )
Trachea
Conducts air to and from the left and right main bronchi. Semi-ridged due to c shaped incomplete cartilage in its walls.
Extends from the larynx in the midline of the neck into the superior mediastinum and is palpable superior to thr surasternal notch.
It terminates at the level of the sterns angle by bifurcation into the left and right main bronchi.
Oesophagus
Muscular tube extending from pharynx in the midline of neck to stomach. Peristalsis moves food down it. In superior mediastinum, the oesophagus lies in the midline of the thorax, posterior to the trachea. It descends into the posterior mediastinum.
Where do the phrenic nerves enter the thorax
They descend through the neck and enter the thorax through the superior thoracic aperture. They course over the pericardium and pierce through the diaphragm.
Left and right vagus nerves
Arise from the brain stem and contain somatic sensory, somatic motor and parasympathetic fibres. They innervate structures of the thorax and abdomen in addition to the head and neck.
They descend through the neck alongside the internal carotid artery and internal jugular vein and enter the thorax via the superior thoracic aperture.
They each give rise to a recurrent laryngeal nerve which ascend back up into the neck to innervate the muscles of the larynx.
Left recurrent laryngeal nerve
Loops under the arch of the aorta before ascending back up the left side of the neck (along the trachea) to the larynx.
Right recurrent laryngeal nerve
Descends anterior to the right subclavian artery and then loops under the inferior border of the artery before ascending back up to the right side of the neck ( between trachea and oesophagus) to the larynx.
Vagus nerves
Contribute parasympathetic fibres to the heart, lungs and oesophagus
They transverse the diaphragm and convey parasympathetic fibres to most of the abdominal viscera.
Thoracic duct
Major channel for lymphatic drainage. It ascends through the posterior mediastinum and into the superior mediastinum where it empties into the venous system at the union of the left internal jugular vein and left subclavian vein.
Thymus gland
A lymphoid organ. It lies anteriorly in the superior mediastinum. It is important in children but atrophied with age, eventually becoming fatty.
Pericardium and it’s two layers
A tough fibrous sac that encloses the heart like a loose fitting bag. It is loose to allow for the movement of the heart within it.
Outer fibrous layer attached superiorly to the great vessels and inferiorly to the central tendon of the diaphragm.
A thin inner serous layer which has two parts : the parietal layer lines the inner aspect of the fibrous pericardium, and the visceral layer covers the surface of the heart. The two layers are continuous with each other.
Space between the two layers of serous pericardium
The pericardial cavity. Contains a small amount of pericardial fluid that lubricates the serous membranes and allows them to slide over each other with movement of the heart. Left and right phrenic nerves give rise ti sensory branches that innervate the fibrous pericardium
Apex of the heart
Projects to the left of the sternum towards the left lung. Formed by the left ventricle. It lies at the 5th intercostal space in the midclavicular line.