Cardiovascular/respiratory system Clinical skills Flashcards
what is the structure of the upper respiratory tract
nasal and oral cavities
pharynx
larynx
trachea
what is the structure of the lower respiratory tract
lower part of trachea
2 primary bronchi
lungs
alveoli - terminal branches of lungs
what are the nose hairs used for
removing bacteria
why is the nasal cavity vascularized
heats the air and humidifies it to make it easier to travel through airways and prevents the trachea from having spasms
where does mucus come from
goblet cells in the epithelium
unnatural production of goblet cells with asthma - results in excess mucus
mucus traps debris and prevents infection
where do the lympatic vessels drain into
submandibular node and then into deep cervical nodes
what are the 3 parts of the pharynx
nasopharynx - above soft palate and opens anteriorly into nasal cavities
cut off from oropharynx by soft palate during swallowing and contains eustachian tube opening
oropharynx
laryngopharynx - separates esophagus and trachea , innervated by vagus
(descending order)
what muscles surround the fascial tube of the pharynx
superior, middle, and inferior constrictor muscles
what is the larynx
attached to trachea and hyoid bone, mainly cartilaginous
innervated by vagus nerve
acts as an open valve to allow air to pass when breathing and protects trachea and bronchi during swallowing
also responsible for speech production and coughing
what is the trachea
membranous tube that is supported by c-shaped rings of hyaline cartilage
thyroid gland straddles the trachea while the common carotid arteries are lateral to the trachea
the oesophagus lies directly behind the trachea
what are the divisions of the bronchial tree
Conducting Zone
trachea into bronchi, which break into bronchiles and then terminal bronchioles
Transitional and respiratory zones
terminal bronchioles turn into respiratory bronchioles and then into alveolar ducts, then finally into alveolar sacs
what are thhe 4 parts of a lung
apex - top peak (into root of neck)
Base - concave surface that touches diaphragm
root - attachment for lung and point where hilum enters the lung
hilum - where the root attaches to the lung , contains main bronchus, vessels, nerves
what attaches the lungs to the pericardium
pulmonary ligaments
how many fissures and lobes do the lungs have
right lung - superior, middle, and inferior lobes
horizontal and oblique fissures
Left lung - superior and inferior lobes
only oblique fissure. also contains cardiac notch
Cause heart sits on left side
what are bronchopulmonary segments
further division of the lobes of the lungs
each segment gets a gaseous mixture from a single segment bronchus
important to identify tumours or lesions
what supplies blood to the lungs
pulmonary arteries - bring in deoxygenated blood and then oxygenated blood leaves thru pulmonary veins back to heart
bronchial arteries - supply blood to connective bronchial tissue, while brhonchial veins drain the blood from them
what is the pleura of the lungs
inner/outer pleura lying next to organs (inner) and against chest wall (outer)
separated by liquid which allows the two to slip over each other w no friction
what is ventilation
act of moving gas in or out of the lungs
what is respiration
exchange of gasses between environment and tissue cells
regulation of acid/base, metabolic, and defence functions of the respiratory system
what is anatomical deadspace
volume of air that does not participate in any gas exchange
what is alveolar dead space
air that reaches alveoli, but not the blood
mainly seen in forms of lung disease
what is physiological dead space
anatomical plus alveolar
what is tidal volume
regular breaths (volume of air displaced with regular breathing)
what is IRV
inspiratory reserve volume
max u can inhale
what is VC
vital capacity, max u can inhale after max expiration
what is RV
residual volume, deadspace air
what is ERV
expiratory reserve volume
max air u can expire after normal breathing
what is TLC
total lung capacity
how does transfer of gas occur
diffusion across the blood gas barrier
rate of diffusion dependant on gas and tissue properties (CO2 diffuses 20x faster than O2 cause it has much higher solubility
describe the stucture and function of alveoli
provide a large surface area for the diffusion of gas (50 to 100 square metres)
minimize the distance for diffusion
match ventilation and blood flow
capillary only wide enough for one RBC at a time, and they come into contact with many alveoli making em saturated with O2 quick
have capillaries wrapped around alveoli to maximize diffusion
what is the gas exchange ratio
v/q
ventilation/perfusion
perfusion will occur at the lowest part of the lung
important for maintaining partial pressure of O2 and CO2 levels in blood
what are the 3 elements in the control of breathing
sensors - gather info
central controller (brainstem, dorsal respiratory group in medulla is inspiration and ventral respiratory group in medulla is expiration) - coordinate info and send impulses
effectors (respiratory muscles) - cause ventilation
what is the apneustic centre
in lower pons, plays a role in abnormal ventilation in brain injury
what is the pneumotaxic centre
upper pons
can switch off or inhibit inspiration and regulate inspired volume and rate
how is voluntary breathing controlled
motor cortex can override brainstem and breathe on its own
pCO2 can be halved by hyperventilation
voluntary hypoventilation is hard to do
what muscles are responsible for breathing
external intercostals - fibres running forwards and downwards (inhalation)
internal intercostals - fibres running backwards and downwards (exhalation)
diaphragm - main muscle of respiration
connected via central tendon attaching to the xiphisternum (innervated by phrenic nerve from roots C3,C4,C5)
what passes through the diaphragm and where
i ate 10 eggs at 12
inferior vena cava at t8
esophagaus at t10
aorta at t12
what are the sensors that detect breathing rate changes
central chemoreceptors - respond to a change in the chemical composition of the blood or fluid around it, they sit near ventral surface of medulla and respond to changes in H+ (more h+, ventilation stimulated, less inhibits it)
peripheral chemoreceptors - in the carotid bodies at the bifurcation of common carotid arteries and the aortic arch, respond to decreases of pO2 and ph, and respond to increases of pCO2. less important than central
how do we achieve airflow in lungs
pressure inside the lungs has to be lower to force air in (diaphragm contracts)
pressure inside lungs has to be higher to force air out (diaphragm relaxes)
what encases the heart
mediastinum - space between the two pleural sacs
what is the pericardium
tough fibrous sac that surrounds the heart and protects it from sudden overfilling, with the apex of it having the aorta coming out alongside the SVC and the pulmonary trunk
base is fused with central tendon
what is the function of the heart
pump blood through vessels of the body, right heart gets and sends deoxygenated blood to lungs, left heart gets the oxygenated blood from lungs and sends to the body
what is the structure of the heart
4 chambers (2 atria and 2 ventricles)
each chamber wall has an endocardium (inner layer)
myocardium (middle layer w muscle)
epicardium (external layer)
what is the function of the right atrium
connects w IVC and SVC, receives blood from the body and pumps it down into Rventricle
what is the function of the right ventricle
pumps deoxy blood thru pulmonary trunk to send to lungs
wall is made up of papillary muscles which have chordae tendinae arrising from them, attaching to the AV valve
what is teh function of the left ventricle
the apex of the heart, the strongest area of the heart as it pumps blood to the entire body through the aorta
what is the function of the left atrium
recieve oxy blood from pulmonary veins
what are the AV valves called
right - tricuspid
left - mitral
both prevent backflow of blood and are controlled by the chordae tendinae/papillary muscles
what is the semilunar valve
in right its pulmonary valve, preventing backflow into Rventricle, sealed when blood flows backwards
in left its aortic valve, same properties
what supplies blood to the heart muscles
right/left coronary arteries (branches off the ascending aorta, and run in the coronary groove)
coronary sinus (opens into right atria to the left of IVC) and great cardiac vein drain the heart (mainly on the right side of heart.)
what are the two branches of the right coronary artery
right marginal branch - towards apex of heart
posterior interventricular branch - left side of heart
what are the two branches of the left coronary artery
anterior interventricular branch (apex)
circumflex branch (LV, LA, and left surface of heart
what are the 3 parts to the circulatory system
systemic circulation - supplies body as a whole
pulmonary system - supplies the lungs
coronary system - supplying the heart
trace the path of blood from IVC
IVC
RA
tricuspid valve
RV
pulmonary valve
pulmonary trunk/arteries
pulmonary veins
LA
mitral valve
LV
Aortic valve
Aorta
region of body (main artery)
arterioles
capillaries
venioles
veins
IVC or SVC
what is the function of capillaries
permit rapid exchange of substances between the blood and interstitial fluid
transport O2 to the muscles and transport nutrients/waste
what are the 3 components that regulate the CV system
control centre
effectors (heart, smooth muscles of vessels, and kidneys)
sensors
organized into a feedback loop
where is the control centre for the CV system
thru cardiovascular centre in the medulla oblongata (contains cardiac centre and vasomotor centre)
What is the cardiac centre
causes changes in heart rate and strength of contraction
causes increases by activating the cardiostimulatory pathways and decreases by activating the cardioinhibitory pathways (vagal nerve)
what is the vasomotor centre
causes change in blood vessel tone
causes vasoconstriction by activating the vasoconstrictor areas
causes vasodilation by activating the vasodilator areas
what are baroreceptors
pressure sensitive cells in the walls of carotid arteries and aortic arch, when they are stretched by force of BP they produce potentials to send to cardiovasular centre - carotid sinus receptors are more sensitive.
they exist in other vessels like VC and the chambers of the heart, and these are more sensitive to low-pressure changes caused by the effects of blood volume. they cause inhibition of the cardio-stim centre and lower BV and BP
whaat are central chemoreceptors for CV system
stimulated by an assortment of chemicals
when stimulated they send signals to CNS to activate local smooth muscle
central chemoreceptors are located on anterior surface of oblongata and are sensitive to H+ changes from CSF. they control the ventilation depending on if theres increased H+ (acidosis - increased vasoconstriction) or lower H+ (alkalosis - decreased vasoconstriction)
what are peripheral chemoreceptors for CV system
located in carotid bodies and aortic arch, respond to reductions in blood O2, or increases in blood CO2 and H+, and they stimmulate the vasopressor area and inhibit cardiostim centre
