Cardiorespiratory anatomy Flashcards
what are the three parts of the sternum?
manubrium, body and xiphoid process (xiphisternum)
superior border of the manubrium?
suprasternal (jugular) notch
what joint is between the clavicle and manubrium?
sternoclavicular joint
what joint is between the manubrium and body of the sternum?
manubriosternal joint/ sternal angle/ angle of Louis
which ribs does the body articulate with?
2-7
which rib articulates with the sternum at the sternal angle?
second
which rib articulates with the inferior part of the body of the sternum and the superior part of the xiphoid process?
7
what is the costal margin?
cartilaginous arch formed by the medial margins of the cartilages of ribs 7-10
which bone marks the upper border of the thorax?
clavicle
which bones does the clavicle articulate with?
sternum medially
acromium laterally
what is just below the lateral part of the clavicle?
coracoid process of the scapula
what is the xiphisternum made up of?
cartilage
why can’t the first rib be palpated?
lies deep to the clavicle and pec major
how many ribs do we have?
12
how many true, false and floating ribs do we have?
which ribs fall in each category?
7 true ribs, 1-7 as directly articulate with sternum
3 false ribs, 8-10 as they do not directly articulate with sternum
2 floating ribs, 11 and 12, do not connect with sternum at all, only vertebral column
what is the midclavicular line?
vertically down, halfway between the sternoclavicular joint and acromioclavicular joint
continues to halfway between the ASIS and pubic tubercle
passes through the nipple in a male
what is the midsternal line?
suprasternal notch through umbilicus
which three lines run on the side of the body?
midaxillary line
anterior axillary line
posterior axillary line
which joints are between ribs and their costal cartilages
costochondral
which joints are between the costal cartilages and the sternum
sternocostal
what happens to the costal cartilages of ribs 8-10
unite and join the seventh costal cartilage
false ribs
the costal cartilages of which ribs form the costal margin
7-10
which ribs do not articulate with the sternum?
11 and 12
which joints are between the ribs and thoracic vertebrae?
costovertebral
which ribs are typical or atypical and why?
3-9 are typical. have a head, neck, tubercle and body (shaft)
1,2, 10, 11, 12 are atypical for various reasons
how many thoracic vertebrae are there?
12
where do the head and tubercle of the ribs articulate on the vertebrae?
head - vertebral body
tubercle - transverse process
which structures form the superior thoracic aperture?
manubrium, first ribs, first thoracic vertebra
which spinal nerves innervate the skin of the thoracic wall?
T1-T12
how are skeletal muscles of the anterior chest wall innervated?
somatic motor fibres in spinal nerves T1-T12
how are sweat glands and smooth muscles of blood cells and hair follicles in the skin innervated?
sympathetic fibres
what is a dermatome?
area of skin innervated by a single spinal nerve
what does the breast contain?
variable amounts of fat
glandular/ secretory tissue arranged in lobules
ducts which converge on the nipple
connective tissue and ligaments
blood vessels
lymphatics
what is the area of pigmented skin surrounding the nipple?
areola
arterial supply of the breast
branches from the:
internal thoracic artery (from subclavian)
axillary artery
where does the internal thoracic artery lie?
deep to the lateral edge of the sternum - paired artery
venous drainage of the breast
axillary and internal thoracic veins
nerves suppling the breast
somatic nerves and sympathetic fibres via the intercostal nerves
somatic sensory fibres innervate the skin of the breast
sympathetic fibres innervate smooth muscle in the blood vessel walls and nipple
lymphatic drainage of the breast
axillary lymph nodes
name the 5 groups of lymph nodes in the axilla
central, pectoral, humeral, subscapular, apical
which regions do the axillary lymph nodes drain?
breast, upper limb, chest wall, scapular region, abdominal wall
which lymph nodes are involved in the spread of breast cancer and why? where are they located?
apical nodes in the apex of the axilla
receive lymph from all other lymph nodes in the axilla
they drain most of the lymph from the breast
name the layers of intercostal muscles from superficial to deep
external, internal, innermost
name three accessory muscles of breathing
pectoralis major, pectoralis minor, serratus anterior
what is the primary function of the accessory muscles of breathing?
move the upper limb
what is the most superficial muscle of the anterior chest wall?
pec major
which muscle is lateral and superior to pec major?
deltoid
origin of pec major
clavicular part: anterior surface of medial half of clavicle
sternocostal part: anterior surface of sternum, costal cartilages of ribs 1-6
abdominal part: anterior layer of rectus sheath
insertion of pec major
crest of greater tubercle of humerus
location of pec minor in relation to pec major
deep to pec major
origin of pec minor
anterior surface, costal cartilages of ribs 3-5
insertion of pec minor
medial border and coracoid process of scapula
origin of serratus anterior
superior part: ribs 1-2, Intercostal fascia
middle part: ribs-3-6
inferior part: ribs 7-8/9 (variably extends to rib 10 (+ external oblique muscle))
insertion of serratus anterior
scapula
(superior part: anterior surface of superior angle
middle part: anterior surface of medial border
inferior part: anterior surface of inferior angle and medial border)
action of pec major
adduction and internal rotation of the humerus at the shoulder joint
action of pec minor
protract the scapula
action of serratus anterior
protract the scapula
what is a sign of respiratory distress?
use of accessory muscles of breathing: pec major, pec minor, serratus anterior
what is shingles and how does it present?
red, painful and itchy rash
typically over chest or abdomen on one side of the body only
strip like distribution - affects dermatomes
caused by a reactivation of the herpes zoster virus in people who have previously had chicken pox
virus lies dormant in the dorsal root ganglion and when reactivated, it causes a rash and pain in the dermatome associated with the affected spinal nerve
what condition can be caused by the removal of lymph nodes, and how does it present?
lymphoedema
fluid accumulation and swelling in the affected upper limb
main vein that drains the superficial part of the upper limb
cephalic vein
which groove does the cephalic vein lie in?
delto-pectoral groove
components of the intercostal neurovascular bundle
intercostal nerve, intercostal artery, intercostal vein
what does pec major have on its deep surface?
neuromuscular bundle
which nerve supplies both pec major and pec minor?
medial pectoral nerve
which nerve only supplies pec major?
lateral pectoral nerve
name the intercostal muscles, superficial to deep
external intercostal, internal intercostal, innermost intercostal
orientation of external intercostal muscles
antero-inferiorly
action of external intercostal muscles
pull ribs superiorly
when are the external intercostal muscles most active?
inspiration
what happens to the external intercostal muscles anteriorly?
muscle becomes membranous and forms the external intercostal membrane
orientation of internal intercostal
postero-inferior
action of internal intercostal muscles
pull ribs inferiorly
when are the internal intercostal muscles most active?
expiration
what happens to the internal intercostal muscles posteriorly?
become membranous and forms the internal intercostal membrane
orientation of innermost intercostal muscles
postero-inferior
what lies deep to the innermost intercostal and superficial to the parietal pleura?
endothoracic fascia
name the layers from superficial to deep, from the skin to the lung
skin
superficial fascia
(serratus anterior)
external intercostal
internal intercostal
innermost intercostal
endothoracic fascia
parietal pleura
pleural cavity
visceral pleura
lung
where do the intercostal neuromuscular bundles lie relative to the intercostal muscles?
between the internal and innermost intercostal muscles
what does the intercostal neurovascular bundle supply?
intercostal muscles, overlying skin, underlying parietal pleura
where does each intercostal neurovascular bundle lie?
inferior border of the rib superior to the intercostal space
in the shallow costal groove on the deep surface of the rib
in medical procedures that involve piercing the intercostal space (e.g chest drain), where is the incision made and why?
middle to lower part of the intercostal space
avoid the intercostal vessels and nerve
smaller collateral branches run in the same tissue plane, but in the lower part of the intercostal space
origin of anterior intercostal arteries
internal thoracic artery (which is a branch of the subclavian)
origin of posterior intercostal arteries
descending aorta
where do anterior intercostal veins drain into?
internal thoracic vein
where do posterior intercostal veins drain into?
azygos system of veins
what type of nerves are the internal intercostal nerves?
somatic - contain motor and sensory fibres
also carry sympathetic fibres
what do the intercostal nerves innervate?
intercostal muscles, skin of the chest wall, parietal pleura
what do the pleurae cover?
lungs and structures passing into and out of the lungs (pulmonary blood vessels and the main bronchi)
what does the parietal pleura line?
inside of the thorax
what does the visceral pleura line?
surface of the lungs
extends into fissures
what lies between the pleurae?
pleural cavity
name the different regions of the parietal pleura
cervical parietal pleura - covers apex of the lung
costal parietal pleura - lies adjacent to the ribs
mediastinal parietal pleura - lies adjacent to the heart
diaphragmatic parietal pleura - adjacent to the diaphragm
are the parietal and/ or visceral pleura visible with the naked eye?
the parietal pleura is visible but the visceral pleura is not
what do pleural cells produce?
pleural fluid
what is the gutter around the periphery of the diaphragm where the costal pleura becomes continuous with the diaphragmatic pleura?
costodiaphragmatic recess
which recess lies at the junction of the costal and mediastinal pleura?
costomediastinal recess
innervation of parietal pleura
intercostal nerves that innervate the overlying skin of the chest wall
somatic sensory fibres
does injury to the parietal pleura reach our consciousness?
yes
innervation of visceral pleura
autonomic sensory nerves (visceral afferents)
does injury to the visceral pleura reach our consciousness?
no
which arteries are found on the deep surface of the anterior thoracic wall?
internal thoracic arteries (also called internal mammary arteries)
origin of the internal thoracic arteries
subclavian artery
function of the internal thoracic arteries
supply the breast and anterior chest wall
course of the internal thoracic artery
runs down the inside of the thorax and abdomen to connect with the external iliac artery just above the groin
what is the name for the most superior part of the lung?
apex
how many lobes does the right lung have? what are they called?
three
superior, middle and inferior
how many lobs does the left lung have?
name them
two
superior and inferior
what is the name of the anterior extension of the superior lobe of the left lung that extends over the heart?
lingula (latin for small tongue)
which fissure(s) do the left and right lung have?
both have oblique
right has horizontal too
surface markings of the horizontal fissure
below the 4th costal cartilage
surface markings of the oblique fissure
starts posteriorly at the 4th rib, runs along the 5th rib and ends at the tip of the 6th rib anteriorly
what does the oblique fissure separate in the left and right lungs?
left - superior and inferior lobes
right - separates the superior and middle lobes from the inferior lobe (so is located between the middle and inferior lobe)
what does the horizontal fissure separate?
superior and middle lobe
where is the costal surface of the lung?
adjacent to the ribs
where is the mediastinal surface of the lungs?
adjacent to the heart
where is the diaphragmatic surface of the lungs?
inferior surface of the lung
name the borders of the lung
anterior, posterior and inferior
lower limit of the lung at the
a) mid clavicular line - anteriorly
b) mid-axillary line - laterally
c) vertebral column - posteriorly
with regards to the ribs
a) 6th rib
b) 8th rib
c) 10th rib
lower limit of the pleural space
a) mid clavicular line - anteriorly
b) mid-axillary line - laterally
c) vertebral column - posteriorly
a) 8th rib
b) 10th rib
c) 12th rib
what is the continuing potential space between the ribs and diaphragm called, and where does it extend to?
costo-phrenic space
two ribs lower than the lower limit of the lung
which structures leave indentations on the lung surface?
on the left and right lung
rib markings on the costal surfaces
left ventricle and descending aorta on the mediastinal surface of the left lung
superior vena cava and azygos vein on the mediastinal surface of the right lung
what is the root of the lung and what does it contain?
lies between the heart and lung
comprises of
- pulmonary artery
- pulmonary veins
- main bronchus
what encloses the root of the lung?
pleura
where is the one place where the lung has all its connections with the body?
hilum
what are the lung hila?
region on the mediastinal surface of the lung where the pulmonary artery, pulmonary veins and main bronchus enter and exit the lungs
how can the bronchi be distinguished in the lung hilum?
cartilage, which is not present in the blood vessels
what is the relation between the the main bronchus and pulmonary artery at the hilum of the right lung?
main bronchus lies anterior to the pulmonary artery
what is the relation between the main bronchus and the pulmonary artery at the hilum of the left lung?
main bronchus lies inferior to the pulmonary artery
how many pulmonary veins so we have in each hilum, and how many altogether?
2 in each hilum
4 altogether
where are the pulmonary veins usually located in both hila?
most anteriorly and inferiorly
other structures present in the lung hilum?
bronchial artery
lymphatics
branches of the vagus, parasympathetic nerve and the sympathetic chains
at which level does the trachea bifurcate? what joint can be found here?
T4
sternal angle
in which main bronchus is a foreign body more likely to become lodged, and why?
right main bronchus
it is shorter, wider and descends more vertically than the left main bronchus
what is the bronchial tree?
branching system of tubes that conduct air into and out of the lungs
describe the bronchial tree
trachea - right and left main bronchi - lobar bronchi - segmental bronchi - terminal bronchioles - respiratory bronchioles - alveoli
how many lobar bronchi are in each lung, and what is the naming based on?
the number of lobes in each lung
right - 3
left - 2
what does each segmental bronchus supply?
a functionally independent region of the lung called a bronchopulmonary segment
how many bronchopulmonary segments are there in each lung?
10 in the right
8 in the left
can a lung segment be resected without affecting the rest of the lung? why
yes
they are supplied by their own segmental bronchus and blood vessels
state whether bronchioles, trachea and bronchi have smooth muscle and/ or cartilage
trachea have smooth muscle and cartilage
bronchioles only have smooth muscle
is the contraction and relaxation of smooth muscle under somatic or autonomic control?
autonomic
where do the bronchial arteries arise from?
descending aorta
function of the bronchial arteries
supply oxygenated blood to trachea, bronchi and bronchial tree
where do the bronchial veins drain into?
azygos system of veins
action of parasympathetic fibres on the lungs
bronchoconstriction
secretion from the glands of the bronchial tree
action of sympathetic fibres of the lungs
bronchodilation
inhibit secretion from the glands of the bronchial tree
what relays sensory information from the lungs and visceral pleura to the CNS? do these sensations reach our consciousness?
visceral afferents (visceral sensory fibres)
no
how does lymph from the lungs eventually drain into the venous system?
thoracic duct or right lymphatic duct
is the diaphragm skeletal or smooth muscle?
skeletal
function of the diaphragm
ventilation
attachments of the diaphragm
xiphoid process
costal margin
lumbar vertebrae
what is the central tendon?
central, fibrous part of the diaphragm
what happens to the diaphragm during inspiration?
contracts
muscle fibres of the right and left domes are pulled towards their peripheral attachments, and the domes flatten
increases the intrathoracic volume for the lungs to expand
what happens to the diaphragm during expiration?
relaxes
domes superiorly
intrathoracic volume decreases
air is expired from the lungs
what are the names of the two phrenic nerves?
right and left
are the phrenic nerves somatic and autonomic?
somatic (contain both motor and sensory fibres)
which spinal nerve segments form the phrenic nerve?
C3, C4 and C5 (keep the diaphragm alive!)
in which directions do the dimensions of the thoracic cavity change during ventilation, and why?
vertically - contraction and relaxation of the diaphragm
laterally - contraction of the intercostal muscles which move the ribs
antero-posteriorly - movement of the sternum secondary to movement of the ribs
how is the pleural fluid integral to ventilation?
creates surface tension between the parietal and visceral pleurae
keeps the lung and thoracic wall together
therefore, when the thoracic cavity changes volume, the lung changes volume with it
prevents lung collapsing
what happens if surface tension between the pleurae is broken e.g by puncture wound?
pneumothorax
ventilation becomes dysfunctional
describe the process of inspiration
diaphragm and external intercostal muscles contract
intrathoracic volume increases
- external intercostals pull the ribs superiorly and laterally
- ribs pull the sternum superiorly and anteriorly
lungs increase in volume with the thoracic wall due to surface tension
pressure in the lungs decreases below atmospheric pressure
air is drawn into the lungs
describe the process of expiration
diaphragm and external intercostal muscles relax
internal intercostals contract
intrathoracic volume decreases
- internal intercostals pull the ribs inferiorly
- ribs pull the sternum inferiorly and posteriorly
lungs decrease in volume
pressure in the lungs increases above atmospheric pressure
air is expelled from the lungs
in normal quiet breathing, are inspiration and expiration active or passive?
inspiration is active (result of muscle contraction)
expiration is passive (due to elastic recoil of the lungs)
which muscle is the main driver of normal quiet breathing?
diaphragm
which muscle does active expiration use?
internal intercostal
which muscles are involved in very vigorous or forced breathing? e.g exacerbations of asthma or COPD
accessory muscles of breathing
which are the accessory muscles of breathing?
sternocleidomastoid
pec major
pec minor
serratus anterior
presentation of pleuritic chest pain
sharp and well localised
worse on inspiration
what is a pneumothorax? when does a tension pneumothorax develop?
presence of air in the pleural cavity
when air keeps entering the pleural cavity but cannot escape
compresses heart, great vessels and lungs
presentation of a pneumothorax
severe respiratory distress
what is a haemothorax?
collection of blood in the pleural cavity
occurs secondary to trauma when blood vessels are torn or cut
what is pleural effusion?
presence of excess fluid in the pleural cavity
how is a pleural effusion treated?
chest drain
what is malignancy of the pleura called?
mesothelioma
what is a pulmonary embolism, and how does it develop?
clot in the pulmonary circulation
clot usually forms in the deep veins in one of the legs and is carried in the venous circulation back to the right side of the heart and into the pulmonary trunk
symptoms of dyspnoea
shortness of breath
use of accessory muscles - fixing of upper limbs steady e.g by holding onto chair
allows the upper limb muscles that attach to the chest wall to move the ribs and aid ventilation
injury to which spinal segments causes paralysis of the diaphragm? is the paralysis ipsilateral or contralateral?
C3, 4 or 5
ipsilateral
how does contraction of the diaphragm assist in returning blood to the heart
when people breathe in, the diaphragm descends, which decreases the intrathoracic pressure and improves the intra-abdominal pressure
this compresses the blood in the inferior vena cava (IVC) and forces it upward into the right atrium and helps to fill the heart
which part of the thoracic cavity lies between the lungs and contains all the thoracic viscera apart from the lungs?
mediastinum
superior border of the mediastinum
thoracic aperture
inferior border of the mediastinum
diaphragm
anterior border of thee mediastinum
sternum
posterior border of the mediastinum
thoracic vertebrae
structures in the mediastinum
heart and pericardium
great vessels that enter and leave the heart
veins that drain the chest wall
trachea and main bronchi
oesophagus
somatic and autonomic nerves
lymphatics
thymus gland
which two compartments is the mediastinum initially divided into?
superior and inferior
where does the line between the superior and inferior mediastinum run anteriorly and posteriorly
sternal angle anteriorly to T4/ T5 junction posteriorly
what are the divisions of the inferior mediastinum?
anterior, middle and posterior
boundaries of the anterior mediastinum
posterior aspect of the sternum
anterior aspect of the pericardial sac
name something contained in the anterior mediastinum
thymus gland in children and its remnant in adults
not many interesting things are contained here!
contents of the middle mediastinum
heart inside the pericardial sac, pulmonary trunk, ascending aorta
boundaries of the posterior mediastinum
posterior aspect of the pericardial sac and the vertebrae
contents of the superior mediastinum
arch of the aorta and its three branches
superior vena cava and its tributaries - the left and right brachiocephalic veins
trachea
oesophagus
phrenic nerves (left and right)
vagus nerves (left and right)
thoracic duct
thymus gland
names of the three parts of the aorta in the thorax
ascending, arch, descending
which part of the aorta gives rise to the coronary arteries?
ascending
in which direction does the arch of the aorta curve?
posteriorly
in which region of the mediastinum does the descending aorta travel through?
posterior
branches of the arch of the aorta
brachiocephalic trunk, left common carotid, left subclavian
what does the brachiocephalic trunk divide into?
right common carotid and right subclavian
what does the right common carotid supply?
right side of the head, neck and brain
what does the right subclavian supply?
right upper limb
what does the left common carotid supply?
left side of the head, neck and brain
what does the left subclavian artery supply?
left upper limb
order of branches of the aortic arch from the body’s left to right
left subclavian, left common carotid, right common carotid, right subclavian (last two from brachiocephalic trunk)
what are aortic bodies and where are they found?
peripheral chemoreceptors in the arch of the aorta
what do aortic bodies monitor?
arterial oxygen and carbon dioxide
which nerve carries visceral sensory information from the aorta to the CNS? what is the result
vagus
reflex responses that regulate ventilation
what is the ligamentum arteriosum?
fibrous, cord-like connection between the pulmonary trunk and the arch of the aorta
what is the ligamentum arteriosum a remnant of?
ductus arteriosus, a foetal circulatory shunt
function of the embryological ductus arteriosus?
diverts most of the blood entering the pulmonary trunk directly to the aortic arch
when does the ductus arteriosus close?
when a baby starts to use their lungs at birth
where does the superior vena cava drain?
head, neck and upper limbs
where do the SVC and its tributaries lie?
superior mediastinum
the union of which veins forms the SVC?
left and right brachiocephalic veins
the union of which veins forms each brachiocephalic vein?
internal jugular vein and subclavian vein
what does the internal jugular vein drain?
head and neck
how can we remember what the brachiocephalic vein drains?
brachium = arm
cephalic = head
where does the IVC drain?
all regions inferior to the diaphragm (abdomen, pelvis and lower limbs)
main branches of the left subclavian artery
vertebral artery, the internal thoracic artery, the thyrocervical trunk, the costocervical trunk, and the dorsal scapular artery
main branches of the left common carotid
external carotid artery
internal carotid artery
what gives the trachea its semi-rigid structure?
C-shaped, incomplete rings of cartilage in its walls
where does the trachea extend from?
larynx in the midline of the neck to the superior mediastinum
where does the trachea terminate?
T4/ T5
what is the oesophagus and where does it extend from?
muscular tube that extends from the pharynx in the midline of the neck to the stomach
function of the oesophagus
move bolus distally by waves of contractions of smooth muscle
does the oesophagus lie anterior or posterior to the trachea?
posterior
path of the phrenic nerves
descend through the neck and enter the thorax through the superior thoracic aperture
course over the pericardium and pierce the diaphragm
what type of nerves are the phrenic nerves?
somatic
diaphragm is skeletal muscle so makes sense
motor innervation by phrenic nerves
diaphragm
sensory innervation by the phrenic nerves
pleura, peritoneum and pericardium (three P’s)
where do the left and right vagus nerves arise from?
brainstem
which fibres do the vagus nerves contain?
somatic sensory, somatic motor, parasympathetic
functions of the vagus nerves
sensory: innervates the skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. provides visceral sensation to the heart and abdominal viscera.
special sensory: provides taste sensation to the epiglottis and root of the tongue.
motor: provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx.
parasympathetic: innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm.
path of the vagus nerve?
descend through the neck alongside the internal carotid artery and internal jugular vein
enter the thorax via the superior thoracic aperture
each gives rise to a recurrent laryngeal nerve which ascend back up into the neck to innervate the muscles of the larynx
the left RLN loops under the arch of the aorta before ascending back up the left side of the neck (alongside the trachea) to the larynx
the right RLN descends anterior to the right subclavian artery and then loops under the inferior border of the artery before ascending back up the right side of the neck (between the trachea and oesophagus) to the larynx
the vagus nerves descend in the thorax posterior to the root of the lung
they contribute parasympathetic fibres to the heart, lungs and oesophagus
they traverse the diaphragm and convey parasympathetic fibres to most of the abdominal viscera
what is the major channel for lymphatic drainage from most regions of the body?
thoracic duct
where does the thoracic duct empty into the venous system?
union of the left internal jugular vein and left subclavian vein (to form left brachiocephalic vein)
where does the thymus gland lie? can we see it in the cadaver
anteriorly in the superior mediastinum
no
what is the pericardium?
tough, fibrous sac that encloses the heart
why is the pericardium loose?
allow for the movement of the heart within it
layers of the pericardium
tough, outer fibrous layer
thin inner serous layer with two parts that are continuous with each other
- parietal layer
- visceral layer (on the surface of the heart)
potential space between the two layers of serous pericardium
pericardial cavity
what does the pericardial cavity contain, and what is the function of it?
pericardial fluid
lubricates the serous membranes and allows them to slide over each other with movements of the heart
innervation of the fibrous pericardium
left and right phrenic nerves give rise to sensory branches
where do the phrenic nerves pass in relation to the lung hila on both sides?
in front
where do the vagus nerves pass in relation to the lung hila on both sides?
behind
in which direction does the base of the heart face?
posteriorly
the base is the posterior surface of the heart
where does the inferior surface of the heart lie, and what is it also called?
central tendon of the diaphragm
diaphragmatic surface
where does the anterior surface of the heart face, and what is it also called?
sternum and ribs
sternocostal surface
where do the left and right sides of the heart face, and what are the names of these surfaces?
the lungs
pulmonary surfaces
which chambers of the heart corresponds to the base/ posterior surface?
left atrium
part of the right atrium
which chambers of the heart corresponds to the inferior/ diaphragmatic surface?
left ventricle, part of the right ventricle
which chamber of the heart corresponds to the anterior/ sternocostal surface
right ventricle
which chamber of the heart corresponds to the left pulmonary surface?
left ventricle
which chamber of the heart corresponds to the right pulmonary surface?
right atrium
which chamber forms the apex of the heart?
left ventricle
where is the apex beat palpable?
left 5th intercostal space, midclavicular line
which structures correspond to the right border of the heart?
right atrium, superior vena cava, inferior vena cava
which structures correspond to the left border of the heart?
left ventricle, left pulmonary artery, left auricular appendage
which chambers correspond to the inferior border of the heart?
right ventricle and part of the left ventricle
surface landmarks of the right border of the heart
lies lateral to the right sternal edge, from the right 3rd costal cartilage to the right 6th costal cartilage
surface landmarks of the left border of the heart
left 2nd intercostal space to the left 5th intercostal space in the midclavicular line
surface landmarks of the superior border of the heart
lies along the line connecting the superior extents of the right and left borders
i.e from the right 3rd costal cartilage to the left 2nd intercostal space
surface landmarks of the inferior border of the heart
lies along the line connecting the inferior end of the right border with the apex
mostly formed by the right ventricle
what are the auricles/ auricular appendages?
outpouchings from the walls of the right and left atria
named because of their ear-like appearance
what is patent ductus arteriosus?
the ductus arteriosus remains open after birth
pressure in the aorta exceeds pressure in the pulmonary trunk
blood flows through a patent ductus arteriosus from the aorta into the pulmonary trunk
over time, increased flow through the pulmonary vessels can lead to pulmonary hypertension
why does hoarseness result from cancer at the apex of the lung?
involves the recurrent laryngeal nerve, which supplies most of the muscles of the larynx
nerve injury results in weakness or paralysis of the ipsilateral intrinsic laryngeal muscles, which move the larynx and the vocal cords
hoarseness results as the patient can no longer fully adduct their vocal cords
what is pericardial effusion, and what can cause it?
increase in fluid volume in the pericardial space
inflammation of the pericardium (pericarditis)
accumulation of blood (due to trauma)
what is cardiac tamponade?
pericardial effusion means heart is compressed and unable to fill properly
where do the left and right coronary arteries arise from?
ascending aorta
where do cardiac veins return venous blood to?
coronary sinus, which enters the right atrium
what does the right coronary artery supply?
parts of the conducting system of the heart, right atrium, right ventricle, part of left ventricle, part of interventricular septum
which valve lies deep to the atrioventricular groove?
tricuspid
the AV groove is between the right atrium and ventricle
where does the right coronary artery lie?
atrioventricular groove
which artery supplies the inferior border of the heart?
right marginal artery
which artery is a continuation of the right coronary artery?
posterior inter ventricular artery
where does the PIV run?
inferior surface of the heart
in the posterior intrventricular sulcus
what does the PIV supply?
both ventricles
name two main branches of the RCA
right marginal artery
posterior interventricular artery
what does the left coronary artery supply?
parts of the conducting system, left atrium, most of the left ventricle, part of the right ventricle, part of the interventricular septum
name three main branches of the left coronary artery
anterior interventricular artery (LAD)
circumflex
left marginal artery
name the two terminal branches of the left coronary artery
anterior interventricular artery (also called the left anterior descending - LAD)
circumflex
what is the short segment of the LCA called before it divides?
left main stem
where does the anterior interventricular artery/ LAD run?
anterior interventricular sulcus towards the apex
what does the LAD supply?
both ventricles
where does the circumflex run?
around the heart onto the inferior/ diaphragmatic surface
what does the circumflex supply?
left atrium, part of the right ventricle and left ventricle
where does the left marginal artery arise from?
circumflex
what does the left marginal artery supply?
left ventricle
what is right dominant circulation, and is it rarer or more common?
PIV arises from the right coronary artery
therefore, the left ventricle is supplied by both the left and right coronary arteries
more common (90% of hearts)
what is left dominant circulation, and is it rarer or more common?
PIV arises from the circumflex artery
therefore, the left ventricle is only supplied by the left coronary artery
rarer (30% of hearts)
in what percentage of hearts are there two, parallel branches of the PIV?
20%
function of heart valves?
unidirectional flow of blood through the chambers inside the heart
name three vessels from which the right atrium receives blood from
SVC
IVC
coronary sinus
what separates the atria?
interatrial septum
name some features of the right atrium
interatrial septum
fossa ovalis
crista terminalis
what is the fossa ovalis?
depression in the interatrial septum
remnant of the foetal foramen ovale
function of the foramen ovale in a foetus
shunts oxygenated blood from the right atrium to the left atrium, bypassing the lungs
what is the difference between the auricular appendages of the atria and the atria?
different embryological origins
what is the crista terminals?
muscular ridge separating the smooth walled posterior part of the right atrium from the anterior part, which has a ridged, muscular wall
what are the ridges on the right atrial wall, and where do they extend into?
pectinate muscles
right auricle
significance of the crista terminalis
separates two parts of the right atrium with different embryological origins
what does the pulmonary trunk divide into?
left and right pulmonary arteries
where is the pulmonary valve located?
entrance of the pulmonary trunk
what separates the ventricles?
interventricular septum
name some features of the right ventricle
trabeculae carneae, papillary muscles, chordae tendineae, moderator band
what are trabeculae carneae?
muscular ridges on the internal wall of the right ventricle
what are papillary muscles?
modified regions of trabeculae carneae, which project into the lumen of the ventricle
what are chordae tendineae?
fibrous cords which connect the tips of the papillary muscles to the tricuspid valve
what is the moderator band?
modified region of the trabeculae carneae which connects the interventricular septum to one of the papillary muscles
how many pulmonary veins does each lung give off, and how many do we have in total?
2, so then 4
describe the internal wall of the left atrium
smooth-walled posterior part
anterior part bearing pectinate muscles
what are the first branches from the aorta?
coronary arteries (NOT brachiocephalic trunk)
aortic valve function
prevents back flow of blood into the left ventricle from the aorta
features of the left ventricle
similar to right ventricle
- trabeculae carneae
- papillary muscles, two in the left ventricle
- chordae tendineae that connect the tips of the papillary muscles to the mitral valve
function of papillary muscles and chordae tendineae
normal functioning of the atrioventricular valves
they do not close the valves
allow the closed valves to resist the pressure generated inside the ventricles during contraction and prevent them from being forced open
when the ventricles contract, the papillary muscles also contract
the papillary muscles tense the cords, which pull on the valve cusps and prevent them everting into the atria
why are the aortic and pulmonary valves called semilunar valves?
their cusps are semi-circular (half-moon) shaped
how many cusps does each semilunar valve have?
three
do coronary arteries fill during ventricular systole or diastole?
diastole
where do we auscultate the aortic valve?
2nd intercostal space, just right of the sternum
where do we auscultate the pulmonary valve?
2nd intercostal space, just left of the sternum
where do we auscultate the tricuspid valve?
4th intercostal space, just left of the sternum
where do we auscultate the mitral valve?
left 5th intercostal space, midclavicular line
what is the heart’s pacemaker?
SAN
where is the pacemaker of the heart located?
superior end of the crista terminalis
rate of generation of impulses of the SAN
70 per minute
what do impulses from the SAN stimulate?
atrial contraction
where are impulses conducted after the SAN?
AVN
where is the AVN?
inferior end of the interatrial septum
from the AVN, what do the conducting fibres form?
atrioventricular bundle (Bundle of His)
what does the Bundle of His divide into?
left and right bundle branches
what do the bundle branches give rise to
Purkinje fibres
function of Purkinje fibres
stimulate contraction of the left and right ventricles
in what percentage of people is the SAN supplied by the right coronary artery? and left coronary artery?
60%
so then 40%
which artery is the AVN usually supplied by?
PIV
(which usually arises from the RCA)
which artery usually supplies the Bundle of His?
LCA
effect of sympathetic stimulation of the heart
increases heart rate and force of contraction
effect of parasympathetic stimulation of the heart
decreases heart rate and force of contraction
what is a myocardial infarction
death of a region of myocardium secondary to occlusion of the coronary vessel that supplies it
what usually causes an MI?
atherosclerosis within the coronary arteries
what is stenosis of the vessels of the heart?
narrowing of the lumen
what are cardiomyopathies?
diseases of myocardium
what is heart failure?
the heart does not pump efficiently
symptoms of heart failure
tiredness, shortness of breath, leg swelling
what is cardiac arrest?
cessation of cardiac contraction
name two causes of cardiac arrest
MI
conduction system abnormalities
what happens at T4?
separates the superior and inferior mediastinum
trachea bifurcates
end of the aortic arch
name contents of the posterior mediastinum
descending (thoracic) aorta
azygos veins
oesophagus
thoracic duct
sympathetic trunk and splanchnic nerves
posterior intercostal vessels and nerves
name branches of the descending aorta as it passes through the posterior mediastinum
posterior intercostal arteries which supply the intercostal spaces
bronchial arteries - lungs
oesophageal branches - oesophagus
pericardial branches - pericardium
phrenic branches - diaphragm
at which level does the aorta pass through the diaphragm?
T12
at which level does the azygos system arise?
L1/ L2
where do the azygos veins return blood to?
superior vena cava
describe the azygos system of veins with regards to the vertebral bodies
an azygos vein on the right side of the vertebral bodies
a shorter hemiazygos vein on the left side of the vertebral bodies
one or more veins connecting the above veins to each other
which vessel drains the posterior chest wall?
azygos system of veins
from which vessels does the azygos system receive blood from?
posterior intercostal veins, oesophageal veins, bronchial veins
in the posterior mediastinum, where does the oesophagus lie in relation to the aorta?
to the right
arterial supply of the oesophagus
oesophageal arteries from the descending aorta
how is blood from the oesophagus returned to the azygos system?
oesophageal veins
at which level is the oesophageal hiatus?
T10 (oesophagus has 10 letters)
main vessel of the lymphatic system
thoracic duct
what forms the right edge of the heart?
right atrium, superior vena cava, right brachiocephalic vein
what forms the left edge of the heart?
left ventricle, left auricular appendage, left pulmonary artery, arch of the aorta, left subclavian artery
which sinus separates the areas where the arteries leave the pericardial sac and the veins enter the pericardial sac?
transverse sinus
lies between the pulmonary artery and aorta anteriorly and pulmonary veins and superior vena cava posteriorly
describe the oblique sinus
a cul-de-sac extending superiorly from the inferior vena cava between the two left pulmonary veins on one side and the two right pulmonary veins on the other. Its anterior wall is formed by the posterior wall of the left atrium, between the four pulmonary veins.
what is the sulcus terminalis?
groove between the right atrium and auricular appendage
corresponds to the crista terminalis internally
what is immediately deep to the sulcus terminalis?
crista terminalis
in which chamber is the moderator band?
right ventricle
where does the thoracic duct lie?
between the azygos vein and the aorta
where does the phrenic nerve run in relation to the hilum of the lung?
anterior
where does the vagus nerve run in relation to the hilum of the lung?
posterior
where does lymph from the lower limbs, pelvis and abdomen flow towards?
cisterna chyli (sac like swelling that gives rise to the thoracic duct)
where does the thoracic duct drain lymph from?
lower limbs, pelvis, abdomen, intercostal spaces, lymph nodes, left side of the head and neck, left upper limb
where does the thoracic duct terminate?
opens into the venous system at the junction between the left internal jugular vein and left subclavian vein to form the left brachiocephalic vein
how is lymph drained from the right side of the head and right upper limb?
lymphatic ducts that enter the venous system at the junction of the right internal jugular and right subclavian veins
which nerve is immediately distal to the ligamentum arteriosus?
left recurrent laryngeal nerve
path of the left recurrent laryngeal nerve
runs under the arch of the aorta and ascends to innervate most of the muscles of the larynx
which structures lie posterior to the oesophagus?
azygos vein
vertebral column
descending aorta
thoracic duct
where does the azygos vein drain into?
posterior aspect of the superior vena cava
where do the trunks of the sympathetic chain lie?
posterior thoracic wall, either side of the vertebral column and posterior to the parietal pleura
what is a ganglion?
collection of cell bodies outside the CNS
which veins drain into the azygos veins?
intercostal veins for the lower part of the thoracic wall
describe the sympathetic trunks
thin, longitudinal fibre tracts regularly interspersed with ganglia
ganglia are connected by axons and dendrites
where do the sympathetic trunks run from?
skull base to coccyx
where do the cell bodies of preganglionic sympathetic neurones lie?
T1-L2/3
where do sympathetic fibres leave the spinal cord?
from its ventral aspect (anterior)
enter spinal nerves T1-L2/3
name the abdominopelvic splanchnic nerves and give their spinal levels?
greater: T5-T9
lesser: T10-11
least: T12
lumbar: L1-L2
where are the greater, lesser and least splanchnic nerves formed in the mediastinum?
posterior mediastinum
what structures does the posterior intercostal spaces contain behind the parietal pleura?
intercostal muscles
a posterior intercostal artery
a posterior intercostal vein
a posterior intercostal nerve
orientation of the structures in the posterior intercostal space from superior to inferior
vein, artery, nerve
(VAN down)
which nerves convey postganglionic sympathetic fibres to the thoracic viscera?
cardiopulmonary splanchnic nerves
which nerve conveys parasympathetic fibres to the thoracic viscera?
vagus
name three thoracic autonomic plexuses
cardiac, pulmonary, oesophageal
where does the cardiac plexus innervate?
function?
SAN
sympathetic - increase heart rate and force of contraction
parasympathetic - decrease heart rate and force of contraction
where does the pulmonary plexus innervate?
function?
bronchi
sympathetic - relaxes bronchi
parasympathetic - constricts bronchi
where does the oesophageal plexus innervate?
function?
oesophagus
sympathetic - inhibit peristalsis
parasympathetic - stimulate peristalsis
function of visceral afferents
relay sensory information from the thoracic viscera back to the CNS along the paths of the vagus and thoracic splanchnic nerves
where is cardiac pain referred to?
central chest, left side of neck, left arm
why is cardiac pain referred to the central chest, left side of neck and left arm?
these skin dermatomes are also innervated by T1-T5
where is diaphragm pathology referred to and why?
shoulder, also innervated by C3-5
what is an aortic dissection?
longitudinal tear in the aortic wall that allows blood to collect between the intima and media
symptoms of Horner’s syndrome?
three signs
- ptosis: drooping upper eyelid
- miosis: small pupil
- anhidrosis: lack of sweating on one side of the face
cause of Horner’s sydrome
interruption to the sympathetic nerves that innervate the head
a cancer in the apex of the lung that invades the sympathetic chain can cause Horner’s syndrome on the ipsilateral side of the head
what is hiatus hernia?
abdominal segment of the oesophagus moves proximally through the oesophageal opening in the diaphragm and into the chest
hiatus hernia symptoms
heartburn, acid reflux
name some structures in the neck
structures of the respiratory tract - pharynx, larynx, trachea
structures of the GI tract - pharynx, oesophagus
glands - thyroid and parathyroid
arteries and veins serving the neck and head, including the brain
nerves serving the head and neck, upper limbs, thoraco-abdominal viscera (via vagus) and diaphragm (via phrenic)
muscle groups - muscles moving the head and neck, moving the larynx in speech and swallowing, and that form the floor of the mouth
platysma muscle - thin, subcutaneous muscle deep to the skin of the neck
in which direction does platysma run from super to inferior?
outwards
which muscle is thin and deep to the skin of the neck
platysma
which muscle lies deep to platysma?
sternocleidomastoid
how many cervical vertebrae are there
seven
which joints join cervical vertebrae?
facet joints
where is the hyoid bone located?
anteriorly in the upper neck
inferior to the mandible
function of the hyoid bone
keep the pharynx open
provides an attachment point for several muscles in the neck and tongue
what is the larynx composed of?
skeleton of small cartilages connected by membranes and small joints
function of the larynx
protect the airway
voice box - phonation
which muscle separates the anterior and posterior triangles?
sternocleidomastioid
where is sternocleidomastioid attached to?
sternum, clavicle, mastoid process of the temporal bone
does sternocleidomastioid act unilaterally, bilaterally or both?
both
innervation of sternocleidomastoid
accessory nerve (CN XI)
boundaries of the anterior triangle of the neck
anterior - midline of the neck
posterior - anterior border of sternocleidomastoid
superior - lower border of the mandible
name structures inside the anterior triangle of the neck
trachea and larynx
thyroid gland, parathyroid glands and submandibular salivary gland
hyoid bone
suprahyoid muscles
infrahyoid muscles
common carotid artery and its terminal branches (external and internal carotid arteries)
branches of the external carotid artery to the head and neck
internal jugular vein
branches of the facial nerve (CN VII), glossopharyngeal (CN IIX), vagus (CN X), accessory nerve (CN XI), hypoglossal nerve (CN XII)
ansa cervicalis
in which triangle of the neck can you see the thyroid prominence?
anterior
function of the suprahyoid muscles
form the floor of the mouth
connect the hyoid to the mandible
move the hyoid and larynx in speech and swallowing
function of the infrahyoid muscles
connect the hyoid to the sternum and scapula
move the hyoid and larynx in speech and swallowing
‘strap’ muscles
which muscle is the most anterior of the strap muscles
sternohyoid
which muscle lies just lateral to sternohyoid?
omohyoid
which infrahyoid muscle connects the hyoid and sternum?
sternohyoid
origin - sternum
insertion - hyoid
what is the ansa cervicalis?
fibres from C1-C3 which innervate the infrahyoid muscles
boundaries of the posterior triangle of the neck
anterior - posterior border of sternocleidomastoid
posterior - anterior border of trapezius
inferior - clavicle
which muscles form the apex of the posterior triangle?
sternocleidomastoid and trapezius
name structures in the posterior triangle of the neck
muscles that move the head
subclavian artery and vein
external jugular vein
accessory nerve
roots of the brachial plexus
cervical plexus
phrenic nerve
function of the external jugular vein
drain the scalp and face
function of the brachial plexus
spinal nerves that supply the upper limb
which nerve fibres form the cervical plexus?
C1-C4
name the four suprahyoid muscles
mylohyoid
geniohyoid
stylohyoid
digastric
where do the suprahyoid muscles lie?
superior to the hyoid bone and form the floor of the mouth
are the hyoid muscles paired or unpaired?
paired
what happens when the suprahyoid muscles contract?
raise the hyoid bone and larynx during speech and swallowing
where do the infrahyoid muscles lie?
inferior to the hyoid bone just lateral to the anterior midline of the neck
function of infrahyoid bones
draw the hyoid bone and larynx inferiorly during speech and swallowing
name the infrahyoid muscles
sternohyoid, omohyoid, sternothyroid, thyrohyoid
which infrahyoid muscles lie superficially?
sternohyoid and omohyoid
function of sternohyoid
attach the hyoid to the sternum
function of omohyoid
attach the hyoid to the scapula
which infrahyoid muscles lie deep?
sternothyroid and thyrohyoid
function of sternothyroid
attach the sternum to the thyroid cartilage
function of thyrohyoid
attach the thyroid cartilage to the hyoid
where do the right and left lobes of the thyroid gland lie?
just lateral to the lower larynx and upper trachea
what structure joins the lobes of the thyroid gland?
isthmus
which muscle does the thyroid gland lie deep to?
sternothyroid
role of thyroid gland
produces hormones which play an important role in the regulation of metabolic processes
which gland regulates hormone secretion from the thyroid?
pituitary
blood supply of the thyroid gland
left and right superior thyroid arteries
left and right inferior thyroid arteries
origin of the superior thyroid arteries
branches of the external carotid arteries
origin of the inferior thyroid arteries
branches of the thyrocervical trunks (from the subclavians)
venous drainage of the thyroid gland
superior, middle and inferior thyroid veins
which glands are located posterior to the thyroid gland?
parathyroid glands
how many parathyroid glands are there usually?
4
which muscle lies deep to platysma?
sternocleidomastoid
names of the parathyroid glands
right and left superior and inferior glands
function of parathyroid glands
produce parathyroid hormone which plays a role in calcium regulation
blood supply of the parathyroid glands
inferior thyroid arteries
which additional thyroid arteryis present in some people?
thyroid ima artery
what do the common carotid arteries bifurcate into?
external and internal carotid arteries
where can pulsation of the internal carotid arteries be palpated?
immediately lateral to the larynx
what blood vessels can be found in the neck
common carotid arteries (bifurcate)
subclavian artery and branches
- e.g thyrocervical trunk
internal jugular vein
external jugular vein
what do the common carotid arteries bifurcate into?
external and internal carotid arteries
path of the internal carotid
does not give rise to any branches in the neck
enters the cranium and supplies the brain
path of the external carotid
gives rise to several branches that supply the head and neck, including the pharynx, scalp, thyroid gland, tongue and face
what structure can be found at the bifurcation of the common carotid artery
carotid sinus
function of the carotid sinus?
baroreceptors here monitor arterial blood pressure
this visceral sensory information is relayed back to the CNS via the glossopharyngeal nerve, rsulting in reflex responses that regulate blood pressure
how is visceral sensory information conveyed from the carotid sinus to the CNS?
glossopharyngeal nerve
origin of the thyrocervical trunk
subclavian artery
origin of the inferior thyroid artery
thyrocervical trunk
function of the subclavian artery
supply the upper limb
function of the internal jugular vein
drains blood from the brain and part of the face
which veins form the brachiocephalic veins?
internal jugular vein and subclavian vein
there are 2 brachiocephalic veins - left and right
e.g left internal jugular + left subclavian = left brachiocephalic vein
which vessels form the superior vena cava?
left and right brachiocephalic veins
function of the external jugular vein
drains blood from the scalp and face
where does the external jugular vein join the venous system?
joins the subclavian vein
name the nerves in the neck
facial (CN VII)
glossopharyngeal (CN IX)
vagus (CN X)
accessory (CN XI)
hypoglossal (CN XII)
phrenic (cervical 3-5)
innervation of platysma
facial nerve
sensory innervation of pharynx
glossopharyngeal
visceral sensory innervation of the carotid sinus
glossopharyngeal
motor innervation of the muscles of the pharynx
vagus
motor and sensory innervation of the larynx
vagus
in the neck, describe the path of the vagus nerve above AND below the bifurcation of the internal carotid
above
runs between the internal jugular vein and the internal carotid artery
below
runs between the internal jugular vein and common carotid artery
which structures are enclosed in the carotid sheath?
common carotid artery (CC)
internal carotid artery (I see = IC)
internal jugular vein (IV)
vagus nerve (10th cranial nerve)
mnemonic - I see 10CCs in the IV
innervation of sternocleidomastoid
accessory nerve
innervation of trapezius muscles
accessory nerve
motor innervation of the tongue
hypoglossal
does the hypoglossal supply any structures in the neck?
no, just travels through
where does the hypoglossal nerve lie in the neck?
lateral to the internal carotid artery and deep to the
sympathetic innervation of the head and neck
postganglionic fibres from the superior, middle and inferior cervical ganglia
risks of thyroidectomy
injury to the recurrent laryngeal nerves - inability to move the ipsilateral vocal cord which affects the quality of the voice
these nerves are close to the inferior thyroid arteries, which are ligated during this procedure
removal of the parathyroid glands - disturbs calcium homeostasis
what is carotid artery stenosis?
atheroma (fatty plaque) in carotid artery narrows the lumen (stenosis) and impedes blood flow to the brain
if the plaque breaks up, fragments of the plaque and thrombus will be carried up into the cerebral arteries, causing a stroke
what is carotid endarterectomy?
procedure to remove atheroma from the wall of the carotid artery
which vein is preferentially used for central line insertion?
internal jugular vein
what is the pharynx?
muscular tube that lies in the neck
forms part of the respiratory and gastrointestinal systems
name the parts of the pharynx
nasopharynx
oropharynx
laryngopharynx (hypopharynx)
where is the nasopharynx?
posterior to the nasal cavity
where is the oropharynx?
posterior to the oral cavity
where is the laryngopharynx?
posterior to the larynx
describe the anatomy of the walls of the pharynx
outer layer of circular muscle
inner layer of longitudinal muscle
describe the external circular muscle layer of the pharynx
three constrictor muscles that overlap each other
- superior
- middle
- inferior
which constrictor forms the posterior wall of the nasopharynx
superior
which constrictor forms the posterior wall of the oropharynx
middle
which constrictor forms the posterior wall of the laryngopharynx
inferior
in which direction do the constrictor muscles contract?
superior to inferior
what pushes food from the oral cavity to the oropharynx during swallowing?
tongue
what rises to close off the nasopharynx from the oropharynx?
soft palate
what closes off the laryngeal inlet and prevents food or liquids from entering the larynx?
epiglottis (one of the cartilages of the larynx)
sensory innervation of the pharynx
gloossopharyngeal nerve
motor innervation of the pharynx
vagus nerve
which nerves lie close to the posterior pharyngeal wall?
cervical part of the sympathetic trunk and superior cervical ganglion
superior laryngeal nerve
hypoglossal nerve
glossopharyngeal nerve
which nerve is the superior laryngeal nerve a part of?
vagus
path of the superior laryngeal nerve
descends over the posterior aspect of the internal carotid artery
passes between the inferior and middle constrictors of the pharynx to the larynx
function of the larynx
protect the airway
contributes to phonation/ speech
how many cartilages comprise the larynx?
9
how many unpaired cartilages are there?
3
how many paired cartilages are there?
3 (or rather, 6 due to 2 x 3)
how are the laryngeal cartilages joined?
membranes and very small joints
name the three unpaired cartilages of the larynx
epiglottis, thyroid cartilage, cricoid cartilage
are the paired cartilages larger or smaller than the unpaired cartilages?
smaller
name the paired cartilages
arytenoids, cuneiforms, corniculate cartilages
describe the anatomy of the thyroid cartilage
two flat cartilages (laminae) that meet in the anterior midline to form the laryngeal prominence
alternative name for the laryngeal prominence
Adam’s apple
what are the names of the posterior laminal extensions projecting superiorly and inferiorly from the thyroid cartilage?
superior and inferior horns
which bone does the superior horn of the thyroid cartilage attach to?
hyoid bone
what do the inferior horns of the thyroid cartilage articulate with below?
cricoid cartilage
what connects the inferior border of the thyroid and the superior border of the cricoid cartilage?
cricothyroid membrane
which membrane of the larynx is pierced to create an emergency airway?
cricothyroid
which cartilage is attached to the superior aspect of the thyroid cartilage, where the two laminae meet?
epiglottis
function of the epiglottis during swallowing
covers the entrance to the larynx (laryngeal inlet) and protects the airway from the entry of liquid or food
where are the arytenoids located?
superior surface of the cricoid cartilage
function of the arytenoids
phonation
movement of the arytenoids move the vocal cords
what are the names of the groups of muscles acting on the larynx?
extrinsic and intrinsic
what is the difference between extrinsic and intrinsic muscles of the larynx?
extrinsic muscles move the larynx as one
intrinsic muscles move the individual cartilages of the larynx relative to each other. by moving the cartilages, they move the vocal cords and this alters the quality of speech
which nerves are responsible for the gag reflex?
glossopharyngeal and vagus
describe the gag reflex
protects the airway
- back of the mouth, posterior wall of the pharynx or tonsils are stimulated
- this sensation is carried to the CNS via the glossopharyngeal nerve
- muscles of the soft palate and pharynx immediately contract via motor fibres in the vagus nerve
why may there be swallowing difficulties following a stroke?
stroke affects the regions of the brain involved in the control of swallowing
vagus disruption - dysfunctional swallowing
glossopharyngeal disruption - loss of sensation impairs the cough reflex
risk of aspiration of food
what is the dangly part at the back of the throat?
uvula
how can an emergency airway be created if the airway is obstructed above the level of the cricoid cartilage?
pierce the cricothyroid membrane
name some structures that are palpable on examination of the neck
hyoid bone
thyroid cartilage
cricoid cartilage
first tracheal cartilage
cricothyroid membrane
lobes of the thyroid gland
carotid pulse
what are tonsils?
collections of lymphoid tissue in the upper parts of the pharynx
what are the two types of tonsils found in the nasopharynx
pharyngal (adenoid) and tubal
where are the pharyngeal tonsils located?
roof of the nasopharynx
where are the tubal tonsils located?
surround the opening of the auditory tube
what is the auditory tube?
connects the nasopharynx to the middle ear
where does the palantine tonsil lie?
next to the pharyngeal wall in the oropharynx
where is the lingual tonsil?
posterior aspect of the tongue
what protects the larynx and airway from the entry of fluid or food?
epiglottis
what are the vocal folds?
folds of mucous membrane that project into the cavity of the larynx
name the two pairs of folds that project into the cavity of the larynx
vestibular folds
vocal folds
which of the folds are the true vocal cords, and which are the false vocal cords?
vestibular - false vocal cords
vocal - true vocal cords
which folds are superior and which are inferior?
vestibular folds are superior
vocal folds are inferior
what are the vestibular folds?
folds of mucous membrane that lie superior superior to the vocal folds
what are the vocal folds?
folds of mucous membrane that cover and protect the vocal ligaments - together they form the true vocal cords
what are the vocal ligaments attached to anteriorly?
internal aspect of the laryngeal prominence
what are the vocal ligaments attached to posteriorly?
arytenoid cartilages
What happens to the rima glottis when the true vocal cords are adducted?
Close
What happens to the rima glottis when the true vocal cords are abducted?
Opens
Does phonation require adduction or abduction of the true vocal cords?
Adduction
And closure of the rima glottis
To what extent is the rima glottis opened in whispering?
Small degree
To what extent is the rima glottis opened in normal breathing?
Partially
To what extent is the rima glottis opened in forced breathing?
Fully
Function of the intrinsic muscles of the larynx
Move the laryngeal cartilages and hence the vocal cords
Which recess can be found either side if the laryngeal inlet?
Pyriform fossa
Which nerve is responsible for general sensation and taste of the posterior third of the tongue?
Glossopharyngeal
Location of the cricothyroid muscle
Between the thyroid and the cricoid cartilage
Function of the cricothyroid muscle
Tips the thyroid cartilage anteriorly and inferiorly, placing tension on the vocal cords
Location of the posterior cricoarytenoids
Posterior surface of the cricoid
Function of the posterior cricoarytenoids
Abduct vocal cords and open rima glottis
Location of the transverse arytenoids
Posterior aspect of the larynx, connecting the two arytenoid cartilages
Function of the transverse arytenoids
Adduct the vocal folds and close the rima glottis
Where does the superior laryngeal nerve innervate?
Cricothyroid muscle
Sensory to the larynx above the vocal folds
Where does the recurrent laryngeal nerve innervate?
All of the intrinsic muscles except the cricothyroid
Sensory to the larynx below the vocal folds
Name the salivary glands that secret saliva into the oral cavity
Parotid, submandibular, sublingual
What type of fibres stimulate glandular secretion?
Parasympathetic
What is the carina?
Where trachea bifurcates
Which is the largest of the three paired salivary glands?
Parotid
Where does the parotid lie?
Posterior part of the mandible
Where is the parotid duct opening?
Adjacent to the upper second molar tooth
What epithelium are vocal folds covered with?
Stratified, squamous non-keratinising epithelium
What epithelium is most of the airway lined with?
Respiratory epithelium
Pseudostratified columnar ciliates with goblet cells
What is the aryepiglottic fold?
Folds of soft tissues that extend from the epiglottis anterosuperiorly to the arytenoid cartilage posteroinferiorly
Which nerve is the parotid gland closely related to?
Facial
What happens to the facial nerve in the parotid gland?
Divided into five branches with emerge to innervate the muscles of facial expression
Which blood vessel is the parotid gland associated with?
External carotid artery
Which nerve stimulates secretion from the parotid gland?
Glossopharyngeal parasympathetic fibres
Where does the submandibular duct open?
Floor of the mouth, under the tongue
Which nerve stimulates secretion from the submandibular gland?
Parasympathetic fibres from the facial nerve
Which nerve stimulates secretion from the sublingual glands?
Parasympathetic fibres in the facial nerve
Where are sublingual glands?
Floor of the mouth
Where do sublingual glands open?
Floor of the mouth
Path of the recurrent laryngeal nerve
Right side of the neck
- arises from vagus as it passes in front of the subclavian artery
- passes up in the groove between the trachea and oesophagus
Left side
- rln is much longer
- vagus passes over the arch of the aorta
- rln passes under the arch of the aorta, into the groove between the trachea and oesophagus
- enters the posterior aspect of the larynx
Where does the facial nerve exit the skull?
Stylomastioid foramina
Name the branches of the facial nerve
Mandibular, buccal, zygomatic, temporal, cervical
Why can vocal cord palsy result from thyroidectomy?
Recurrent laryngeal nerve lies close to the inferior thyroid artery, which is ligated during thyroidectomy
RLN innervates all but one of the intrinsic muscles of the larynx
If injured, intrinsic muscles of the ipsilateral side do not function
Vocal cords on the affected side cannot move
Hoarseness of the voice results
Name for visualisation of the larynx
Laryngoscopy
Usual presentation of malignancy of the larynx
Hoarseness of the voice
What is endotracheal intubation?
The passage of a semi-rigid tube into the trachea for ventilation
Which condition causes painful inflammation and swelling of the parotid gland?
Mumps
Which nerve is at risk by pathology of the parotid gland?
Facial (and its branches)
Which cranial nerve is the only one to have a contralateral effect?
CN 4
CN IV
Trochlear
Effect of pathology of the parotid gland
IPSILATERAL paralysis of facial muscles
Describe endotracheal intubation
Passage of a semi rigid tube into the trachea for ventilation
Commonly performed when patients have a general anaesthetic for surgery or when sedated in intensive care
Laryngoscope lifts th tongue and epiglottis to the vocal cords can be directly seen
Tube is passed between the vocal cords into the trachea
Correct placement into the trachea rather than oesophagus is confirmed by carbon dioxide reading on the anaesthetic machine and auscultation both lungs to ensure the tube is in the trachea and not one of the bronchi
