anatomy of the cardiorespiratory system Flashcards
where does the sternum lie anatomically?
anteriorly in the midline of the thoracic cage
what are the three parts to the sternum?
manubrium, body and xiphoid process
where in the sternum is the manubrium found
the most superior part
what is the name of the notch in the superior part of the sternum?
suprasternal (jugular) notch
what does the manubrium articulate with laterally?
the clavicle and the first rib
what is the name of the joint where the clavicle and the manubrium ariculate?
sternoclavicular joint
what does the sternum articulate with inferiorly?
body of the sternum
what is the joint where the manubrium and the sternum articulate called?
manubriosternal joint
what is the angle where the manubrium and the body articulate?
the sternal angle (angle of Louis)
what does the body articulate with?
- the manubrium superiorly
- xiphoid process inferiorly
- ribs 2-7
what does the second rib articulate with?
the sternum at the sternal angle
where is the xiphoid process?
inferior to the body
where does the seventh rib articulate?
inferior part of the body of the sternum and
the superior part of the xiphoid process
identify these on a skeleton
- clavicle (collarbone)
- manubrium, body, and xiphoid process of the sternum
- sternoclavicular joints
- suprasternal notch
- manubriosternal joint (the sternal angle) and the second rib
- costal margin.
what is the name of the cartilage found on the anterior part of the ribs?
costal cartilage
what is the name of the joint where the ribs articulate with their costal cartilages?
costochondral
what costal cartilage articulate directly with the sternum and what is the joint called?
ribs 1-7
sternocostal
joints
what costal cartilage join with the seventh costal cartilage?
8-10
what do the costal cartilage of ribs 7-10 form?
costal margin which is palpable
what is significant about ribs 11 and 12?
short and do not articulate with the sternum – they are ‘floating’ ribs
what do the ribs articulate with posteriorly and what is the name of the joint in which they articulate at?
thoracic vertebrae
costovertebral joint
how are adjacent ribs connected to eachother?
intercostal muscles
what are the two classification of ribs?
typical and atypical ribs
what are typical ribs?
look similar and share common
anatomical features
what are atypical ribs?
look different to typical ribs and / or lack some of the
features of typical ribs
what are the typical ribs? and what makes rhemtypical?
ribs 3 - 9 are typical ribs. they have a head, neck, tubercle, and body (shaft).
what are the atypical ribs? and what makes them atypical?
ribs 1 - 2 and 10 - 12 are atypical.
ribs 1, 11 and 12
are much shorter than typical ribs
what does the head of the rib articulate with?
vertebral body
what does the tubercle of the rib articulate with?
transverse process
what is the name of the space created by the manubrium, the first ribs and the first thoracic vertebra?
superior thoracic aperture
what is a dermatome?
an area of skin innervated by a single spinal nerve
what does each pair of thoracic spinal nerves supply?
a ‘strip’ of skin around the chest wall
what do the somatic thoracic spinal fibres innervate?
the skeletal muscles of the
thoracic wall
what do the sympathetic thoracic spinal nerves innervate?
sweat glands and the smooth muscle of
blood vessels and hair follicles in the skin (arrector pili)
what is the anatomical term for armpit?
anterior axilla
what is the part of the breast that is towards the armpit called?
axillary tail
what are some components of the breast?
● fat - variable amounts.
● glandular / secretory tissue arranged in lobules.
● ducts which converge on the nipple. the areola is the region of pigmented skin
that surrounds the nipple.
● connective tissue and ligaments.
● blood vessels and lymphatics.
what arteries supply the breast?
- internal thoracic artery (which arises from the subclavian artery)
- axillary artery.
where does the internal thoracic arterty go to?
the lateral edge of the sternum
what does the internal thoracic cavity give rise to and what does this supply?
anterior intercostal arteries
breast and the intercostal spaces
where does venous blood from the anterior intercostal arteries return to?
axillary and
internal thoracic veins
what type of nerves and fibres innervate the breasts?
somatic nerves and sympathetic fibres via the intercostal nerves
what do somatic sensory fibres innervate in the breast?
skin of the breast
what do sympathetic fibres innervate in the breast?
smooth muscle in the blood vessel walls and nipple
where does the lymph from the breast drain to?
lymph nodes in the axilla
what are the groups of lymph nodes in the axilla?
central, pectoral, humeral, subscapular, and apical
what regions fo the lymph nodes in the axilla drain?
breast, upper limb, chest wall, scapular region, and the abdominal wall
what is the function of the apical nodes?
receive lymph from all other lymph nodes in
the axilla
why are apical nodes often involved in the spread of breast cancer?
because they drain most of the lymph from the breast
how many layers of intercostal muscle are there and what are the names?
3
1. external intercostal is most superficial.
2. internal intercostal lies deep to the external intercostal.
3. innermost intercostal lies deep to the internal intercostal
what is the pectoralis major and what does it attach to?
- the most superficial muscle of the anterior chest wall
- attaches
to the upper humerus, the clavicle and the upper six ribs
what is the pectoralis minor and what does it attach to?
smaller muscle that lies deep to pectoralis major
attaches to
the scapula (shoulder blade) and ribs 3-5
what is the serratus anterior minor and what does it attach to?
superficial muscle that sweeps around the lateral aspect of the
thoracic cage
attaches to the scapula and the upper eight ribs
why is the usage of the prior three muscles a sign of respiratory distress?
their main function is to move the upper limb, but they can also move the ribs as they are attached to them and the muscles that are meant to move the ribs are fixed
what is shingles?
red, painful, and itchy rash, typically over the chest
or abdomen on one side of the body only
what do shingles affect that explains their stripy appearance?
dermatomes
what type of people does shingles affect and how does the infection work?
people who have had chickenpox
after an infection with chickenpox, the virus lays dormant in the dorsal root
ganglion. when reactivated, it causes a rash and pain in the dermatome associated with the affected spinal nerve
what is metastatis?
spreading (of cancer)
what condition can removing axillary nodes lead to and why?
axillary nodes drain lymph from the upper limb, their removal can
lead to fluid accumulation and swelling in the affected upper limb, a condition called
lymphoedema
what are intercostal spaces?
the spaces in between the ribs
what do the intercostal spaces contain?
- three layers of intercostal muscles
- the membranes associated with the intercostal muscle
- intercostal neurovascular bundle; an intercostal nerve, intercostal artery and an intercostal vein
what are the three types of intercostal muscle?
- external
- internal
- innermost
how do the external intercostal muscles run and how is this related to their function?
obliquely towards the armpits, where they attach to the rib below them pulling it up and out for inspiration
how do the inner intercostal muscles run and how is this related to their function?
obliquely towards the medial line, where they attach to the rib below them pull it down, and in for expiration
how do the innermost intercostal muscles run?
same as the inner intercostal muscles
where does the endothoracic facia lie?
deep to the innermost intercostal and superficial to the parietal pleura, which surrounds the lung
where do the neurovascular bundles lie within each intercostal space?
in the plane between the internal and innermost intercostal muscle.
they lie along the inferior border of the rib superior to the space
what do the neurovascular bundles of the intercostal spaces supply?
intercostal muscles, the overlying skin, and the underlying parietal pleura
how can where the neurovascular bundles on the ribs lie be told?
on the inferior border of the rib, there is a shallow costal groove
what do the anterior and posterior intercostal arteries supply?
the anterior and posterior parts of the intercostal space
where do the anterior intercostal arteries branch from?
internal thoracic artery (a
branch of the subclavian artery)
where do the posterior intercostal arteries branch from?
descending aorta in the
posterior thorax
where do the anterior intercostal veins drain into?
internal thoracic vein
where do the posterior intercostal veins drain into?
azygos system of veins
are intercostal nerves somatic or autonomic?
somatic, with sympathetic fibers
do intercostal nerves contain motor or sensory fibers or both?
both
what do the intercostal nerves innervate?
intercostal muscles, the skin of the chest wall and the parietal pleura
what are the two types of pleural membranes and where do they lie?
- the parietal pleura lines the inside of the thorax.
- the visceral pleura covers the surface of the lungs and extends into the fissures.
what is the pleural cavity?
the space that lies between the parietal and visceral pleura
which of the parietal or visceral pleura can be seen by naked eye?
parietal
what lies within the pleural cavity?
pleural fluid made by pleural cells
what are the four parts of the parietal pleura and where do they lie?
- the cervical pleura covers the apex of the lung.
- the costal pleura lies adjacent to the ribs.
- the mediastinal pleura lies adjacent to the heart.
- the diaphragmatic pleura lies adjacent to the diaphragm
what is the costodiaphragmatic recess?
a ‘gutter’ around the periphery of the diaphragm,
where the costal pleura becomes continuous with the diaphragmatic pleura
what is the name of the recess that lies at the junction of the costal and mediastinal pleura?
costomediastinal recess
what is the importance of the two recesses?
potential spaces that the lungs expand into during deep inspiration
what innervates the parietal pleura, and can injury to it be felt and why?
- the intercostal nerves that innervate the
overlying skin of the chest wall - pain can be felt as somatic sensory fibers there carry sensation to the consciousness
what innervates the visceral pleura, and can injury to it be felt and why?
- autonomic sensory nerves (visceral afferents)
- no pain as sensation from visceral afferents do not reach our conscious perception
where does the superior (apex) part of the lung lie?
projects into the root of the neck, above the clavicle
where does the base of the lung lie?
‘sits’ on the diaphragm
how many lobes are there in the right lung and what are their names?
3
a superior (upper), middle, and inferior (lower)
lobe
how many lobes are there in the left lung and what are their names?
superior and inferior lobe
which part of the lung extends over the heart?
an anterior extension of the superior lobe called the lingula
what is the costal surface of the lungs?
adjacent to the ribs
what is the mediastinal surface of the lungs?
adjacent to the heart
what is the diaphragmatic surface of the lungs?
inferior surface of the lung
what is the anterior border of the lungs in appearance?
sharp and tapered
what is the posterior border of the lungs in appearance?
thick and rounded
what is the inferior border of the lungs in appearance?
sharp and tapered
what is the hilum?
region on the mediastinal surface of the lung where the pulmonary artery, pulmonary veins and main bronchus enter and exit the lung
where does the root of each lung lie and what does it consist of?
- between the heart and the lung
- comprises the pulmonary
artery, pulmonary veins, and main bronchus
what encloses the root of each lung?
pleura
where are the positions of the pulmonary artery and the main bronchus at the right lung?
at the hilum of the right lung, the pulmonary artery lies anterior to the main bronchus
where are the positions of the pulmonary artery and the main bronchus at the left lung?
at the hilum of the left lung, the pulmonary artery lies superior to the main bronchus
where do the pulmonary veins lie in the left and right hila?
the two pulmonary veins are usually the most anterior and
inferior vessels
where does the trachea turn into the left and right main bronchi?
at the level of the sternal
angle
what is the bifurcation of the trachea marked by?
a ridge of cartilage called the
carina
why are foreign bodies more likely to enter the right main bronchus than the left?
the right main bronchus is shorter, wider and descends more vertically
what do the main (primary) bronchi divide into and how many are there at each lung?
- lobar (secondary bronchi)
- three in the
right lung and two in the left lung (one lobar bronchus for each lobe)
what do the lobar (secondary) bronchi divide into and how man are there in each lung?
- segmental (tertiary) bronchi
- approximately ten segmental bronchi in each lung
what is the name of the region that each segmental bronchus suppplies?
bronchopulmonary segments
what is the advantage to bronchopulmonary segments?
a segment may
be resected (surgically removed) without affecting the rest of the lung as they are supplied by their own segmental bronchus and blood vessels
what do the segmental bronchi divide into?
bronchioles, that become smaller with each division
where is the site of gas exchange?
alveoli
what do the walls of the trachea and bronchi contain?
smooth muscle and cartilage
what do the walls of the bronchioles contain?
smooth muscle
what supplies the lungs and where do they come from?
- bronchial arteries
- descending aorta
what do bronchial veins do?
return blood to the azygos system of veins
do somatic or autonomic nerves innervate the lungs?
autonomic
what do parasympathetic fibers in the lungs do?
stimulate:
1. constriction of bronchial smooth muscle (bronchoconstriction)
2. secretion from the glands of the bronchial tree.
what do sympathetic fibers in the lungs do?
- stimulate relaxation of bronchial smooth muscle (bronchodilation)
- inhibit secretion from the glands.
where does lymph from the lungs drain?
into the venous system via the thoracic duct or right lymphatic duct
where does the inferior border of the lungs lie?
- 6th rib anteriorly (midclavicular line)
- 8th rib laterally (midaxillary line)
3.10th rib posteriorly (at the vertebral column).
where does the patietal pleura extend to?
- 8th rib anteriorly (midclavicular line)
- 10th rib laterally (midaxillary line)
- 12th rib posteriorly (at the vertebral column).
where do oblique fissures extend to in terms of ribs in the left and right lungs?
from the 4th rib posteriorly to the 6th costal cartilage anteriorly; the fissure runs deep to the 5th rib
where does the horiaontal fissure extend to in terms of ribs in the right lung?
extends anteriorly from the 4th costal cartilage and
intersects the oblique fissure
what type of muscle is the diaphragm?
skeletal muscle
what is the superior (thoracic) surface of the diaphragm adjacent to?
parietal pleura
what travels through the apertures of the diaphragm?
aorta, inferior vena cava, and oesophagus (structures that pass through the thorax and abdomen)
what is the diaphragm attached to?
the xiphoid process, costal margin (and to the tips of the 11th
and 12th ribs) and the lumbar vertebrae
what is special about the central part of the diaphragm?
is not muscular, but fibrous - the central tendon
what happens to the diaphragm during inspiration?
contracts during inspiration, the muscle fibres of the right and left domes are pulled towards their peripheral attachments, and the domes flatten. this increases the intrathoracic volume for the lungs to expand
what happens to the diaphragm during expiration?
diaphragm relaxes and domes superiorly. this decreases the
intrathoracic volume and drives the expiration of air from the lungs
what innervates the diaphragm?
right and left phrenic nerves innervate the right and left sides of the diaphragm,
respectively
what type of nerves are phrenic nerves and where are they formed from?
somatic nerves, formed in the neck by fibres from the C3, C4 and C5 spinal nerves, and hence contain motor and sensory fibres
what are the three planes in which the thoracic cavity can move during ventilation?
- vertically - due to the contraction and relaxation of the diaphragm.
- laterally - due to contraction of the intercostal muscles which move the ribs.
- antero-posteriorly (AP) – due to movement of the sternum secondary to movement of the ribs.
what is the purpose of pleura and pleural fluid?
the fluid creates surface
tension between the parietal pleura and the visceral pleura, keeping the lung and thoracic wall ‘together’, so
when the thoracic cavity changes volume, the lung changes volume with it
describe the process of inspiration
1.the diaphragm and external intercostal muscles contract, increasing the intrathoracic volume (the external intercostals pull the ribs superiorly and laterally, and the ribs pull the sternum superiorly and anteriorly, increasing the AP and lateral dimensions of the thoracic cavity).
2. the lungs expand (increase in volume) with the thoracic wall (due to surface tension).
3. the pressure in the lungs decreases below atmospheric pressure and air is drawn into the lungs.
describe the process of expiration
- the diaphragm and external intercostal muscles relax, and the internal intercostals contract, decreasing the intrathoracic volume (the internal intercostals pull the ribs
inferiorly, and the ribs pull the sternum inferiorly and posteriorly, decreasing the AP and lateral dimensions of the thoracic cavity). - the lungs recoil (decrease in volume).
- the pressure in the lungs increases above atmospheric pressure and air is expelled
from the lungs.
what muscles are involved with normal breathing and which parts are active/passive?
inspiration is active and is mainly driven by movement of the diaphragm, but expiration is passive
what muscles are involved with vigorous breathing and is it active/passive?
active expiration uses the internal intercostal muscles
what muscles are involved with very vigorous breathing and is it active/passive?
active
the accessory muscles of breathing (sternocleidomastoid,
pectoralis major and minor, serratus anterior) contribute to the movement of the ribs and aid ventilation. the anterior abdominal wall muscles contribute to forced expiration
what is pleuritic chest pain and what does it feel like?
pain felt from the parietal pleura only, when it becomes inflamed or injured
feels typically sharp, well localised and worse on inspiration
what is pneumothorax?
the presence of air in the pleural cavity
what happens when pneumothorax occurs?
rapidly increasing volume of air progressively
compresses the lung, heart, great vessels and the opposite lung over to the contralateral side of the thorax, which can be fatal
what is haemothorax?
collection of blood in the pleural cavity and occurs secondary to trauma when blood vessels are torn or cut
what is pleural effusion and how is it treated?
- the presence of excess fluid in the pleural cavity
- chest drain is used to remove air and/or fluid from the pleural space
what is primary lung cancer?
cancer of the lung tissue or bronchi
what is secondary lung cancer?
cancer from
elsewhere that has metastasized to the lungs
what is malignancy of the pleura called?
mesothelioma
what is a pulmonary embolism?
a blood clot in the pulmonary circulation
how do pulmonary embolisms form?
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
what is dyspnoea? how does this affect the muscles of ventilation?
breathlessness or shortness of breath
accessory muscles of respiration are used
what is the mediastinum? what dos it contain?
part of the thoracic cavity that lies between the lungs that contains all the thoracic viscera apart from the lungs
where does the mediastinum extend from?
- superior thoracic aperture superiorly to the diaphragm inferiorly
- sternum anteriorly to the thoracic vertebrae posteriorly
specify the organs and structures within the mediastinum
- the heart and pericardium (the fibrous sac around the heart)
- the great vessels that enter and leave the heart
- the veins that drain the chest wall
- the trachea and main bronchi
- the oesophagus
- nerves (somatic and autonomic)
- lymphatics
- the thymus gland
where is the division for superior and inferior mediastinum?
from the sternal angle
anteriorly to the T4/T5 junction posteriorly
where does the inferior anterior mediastinum lie and what does it contain?
- lies between the posterior aspect of the sternum and the anterior aspect of the pericardial sac
- contains the thymus
gland in children and its remnant in adults
where does the inferior middle mediastinum contain?
heart inside the pericardial sac, the pulmonary
trunk, and the ascending aorta
where does the inferior posterior mediastinum lie?
between the posterior aspect of the pericardial sac
and the vertebrae