Cardio-Respiratory System Flashcards
Shat vessels drain into the right atrium?
Superior and inferior vena cava
Does the right atrium contain oxygenated or deoxygenated blood?
Deoxygenated
Where does blood from the right atrium pass to?
The right ventricle
What is the name of the valve that exists between the right atrium and right ventricle?
Tricuspid valve
Where does blood drain from into the left ventricle?
Left atrium
The blood in the left ventricle is deoxygenated. T/F?
False - it is oxygenated
Which blood vesell does blood from the left ventricle empty into?
Aorta
How many times thicker is the left ventricle compared to the right ventricle?
Three times thicker
Through which valve does blood have to pass between the left atrium and left ventricle?
Bicuspid or mitral valve
What vessel leads from the right ventricle?
Pulmonary trunk
What is the valve called that blood must flow through when leaving the right ventricle?
The pulmonary valve
Where does blood pass to after leaving the heart from the right ventricle?
The lungs
What is the embryological remnant in the right atrium called?
Fossa ovalis
What does the embryological remnant in the right atrium represent in foetal life and what did this structure do during foetal life?
Foramen ovale - opening in the foetus that allowed blood to pass straight from the right atrium to the left atrium to avoid passing into the lungs
What is the purpose of the pulmonary valve?
To prevent the backflow of blood into the right ventricle as it passes into the lungs
Is the apex of the heart superior or inferior to the bulk of the heart?
Inferior
Is the base of the heart superior or inferior to the bulk of the heart?
Superior
What type of artery is the aorta?
Elastic artery
What are the major branches that arise from the aorta and pass into the neck and upper limbs?
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
From where do the coronary arteries arise?
The aorta
What is unique about the coronary arteries?
They are end- arteries - no other arteries supply this area
What would happen if the coronary artery were to be completely occluded?
Initially leads to ischaemia (reduced oxygen to tissues) and if completely blocked infarction (death) of the area that it supplies
How many nuclei are contained in a single cardiac myocyte?
One
What is the function of an intercalated disc?
To transmit the forces of contraction and action potential passage between myocytes ensuring synchronised contraction
What are the histological features of a cardiac myocyte?
Mononuclear Striated High numbers of mitochondria Intercalated discs Gal junctions
What nerves supply the heart?
Vagus nerve and thoracic spinal nerves
In the heart, where does the electrical impulse commence?
Sino-atrial node
Briefly describe the conducting system of the heart.
Under nervous control, impulses initiated at the SA node are propagated through the atrial musculature to the AV node then through the AV bundle and its branches to the myocardium, passing into the Purkinji branches
What is a moderator band?
It is a thickening of muscle present in the right ventricle and carries the right bundle branch to the anterior papillary musculature
How does the tricuspid valve prevent backflow of blood?
As pressure increases in the right ventricle, the valve leaflets of the tricuspid valve come together tightly. They are prevented from flapping back into the right atrium by chordae tendinae and papillary muscles anchoring the valve tightly in place
What is the pharynx?
A muscular tube which forms the superior part of the alimentary system posterior to the nasal and oral cavities, extending inferiorly past the larynx
What are the three main parts of the pharynx?
Nasopharynx
Oropharynx
Laryngopharynx
How does the pharynx terminate inferiorly?
Larynx
What are the three main layers of the aorta artery?
Tunica intima, media and externa
How many lobes do the right and left lungs have?
3 and 2 respectively
How far into the neck do the lungs pass?
1 inch above the medial third of the clavicle
What structure in the trachea maintains an open airway?
Cartilage
What epithelial specialisation is present in trachea to allow it to perform its function effectively?
Cilia that sweep mucous upward away from the lungs
What is the smooth muscle in the posterior aspect of the trachea called?
Trachealis
How would you differentiate between the right and left bronchi?
The right main bronchus is wider, shorter and runs more vertically than the left main bronchus
What is the hilum of the lungs?
The area of the lung where blood vessels and bronchus enters
What two structures indent a plastinated lung?
Heart
Aorta
Why is there no valve to prevent the back-flow of blood upon the entrance of the veins into the atria of the heart?
Because the contraction of the atria already constricts the entry points of these veins anyway
What are the structures which prevent the AV valves from being pushed upwards and backwards into the atria when the ventricles are contracting?
Chordae tendinae which attach to papillary muscles which are embedded in the ventricle walls
Which three lymph nodes primarily drain the heart?
Brachiocephalic
Posterior intercostal
Diagragmatic nodes
Where do the coronary arteries branch from?
From the very start of the aorta at the cusps of the aortic valve
Into which vein do the coronary arteries drain into?
The coronary sinus which drains into the right atrium
What are the layers of the heart in cross section?
Fibrous pericardium Parietal serous pericardium Pericardial space Visceral serous pericardium Myocardium Endocardium
What are the names of the two pleural recesses?
Costamediastinal recess
Costodiaphragmatic recess
What type of epithelium exists in the heart?
Simple squamous
What is the function of papillary muscles in the heart?
To limit the movement of the heart valves so as to prevent the backflow of blood
What structures attach the papillary muscles to the Av heart valves?
Chordae tendinae
How many pulmonary veins are there?
4
Which nerve provides parasympathetic innervation of the heart?
Vagus nerve
What spinal levels provide sympathetic innervation of the heart?
T1-4
Which artery does the anterior interventricular artery branch from?
Left coronary artery
Which artery supplies the posterior of the eft side of the heart?
Left circumflex artery
Which artery supplies the anterior side of the left atria and ventricle of the heart?
Anterior interventricular artery
Which artery of the heart muscle determines dominance?
Posterior interventricular artery
Which vessel sits within the coronary sulcus and what is its function?
Coronary sinus drains deoxygenated blood from the coronary arteries to the right atria
Which vein drains from the left atrium to the coronary sinus?
Great cardiac vein
Which vein drains blood from the posterior portion of the right atrium and ventricle?
Small cardiac vein
What are the three layers of arteries and veins?
Tunica externa
Tunica media
Tunica intima
What is the structure and function of the tunica externa?
It is the outer layer of a blood vessel composed of a loose, thick of connective tissue of collagen and elastin fibres with a network of nerve, lymphatic and capillaries
It functions to anchor the vessel to the surrounding structures and afford it some protection
What is the structure and function of the tunica media?
This is the middle layer of a blood vessel composed mainly of smooth muscle cells and elastic fibres
The outer external elastic lamina layer helps the artery recoil after it has been stretched and the inner layer of smooth muscle allows vasoconstriction and vasodilation to regulate blood pressure and rate of flow
What are the four components of the tunica intima (from most outer to inner)?
Internal elastic lamina
Lamina propria
Basement membrane
Endothelium
What type of epithelium exists in blood vessels?
Simple squamous
What is the function of the endothelium of blood vessels?
To regulate the diffusion of substances
To prevent substances from sticking to vessel walls
The size and thickness of arteries varies depending on their proximity to the heart. T/F?
True
How does the structure of the walls of arteries differ from other vessels?
They have a greater muscular and elastic thickness in their tunica media than in other vessels
How does the structure of capillaries differ from other blood vessels?
They lack a tunica intima and tunica externa
Veins generally have very thick walls in relation to their diameter. T/F?
False - they have thin walls with a large lumen
Arteries are more numerous than veins. T/F?
False the opposite is true
All veins have valves. T/F?
False
On a ,lateral view of the hilum of the lung the pulmonary arteries are superior to the veins and the bronchi are posterior to the blood vessels. T/F?
True
What is atelectasis?
Collapse of the lung
Where does the coronary sulcus sit in the heart?
On the posterior of the heart between the atria and ventricles
What vessel sits within the coronary sulcus of the heart?
Coronary sinus
In what part of the heart are the pectinate muscles contained?
Auricles
What is the most common congenital cardiac defect?
Ventricular septal defect
Why is a probe patent foramen ovale usually asymptomatic?
The higher pressure in the left atrium usually pushes the septum primum against the septum secundum to mechanically close the valve
What is the name of the smooth posterior part of the right atrium?
Sinus veranum
Which part of the right atrium is composed of a rough pectinate muscle wall?
Anterior part
What is the name of the part of the heart where the posterior and anterior walls merge?
Crista terminalis
Describe the foetal circulation
Oxygenated blood enters through the umbilical vein, some blood enters the liver and the rest enters the ductus venosus to by
Ass the liver and enter the IVC
The IVC enters the right atrium and most of the blood passes through the foramen ovale to the left atrium then left ventricle and aorta
Blood entering the right atrium from the SVC is poorly oxygenated, having just returned from the lungs
Some blood passes through the right atria to right ventricle, pulmonary trunk and then ductus arteriosus to enter the aorta
What is the name of the rough muscular walls of the ventricles of the heart?
Trabecular carnae
Where are the SA and AV nodes located?
Right atrium
