87 Questions
What is the primary role of the thyrocervical trunk in the blood supply to the head?
Supplies the neck
What is the benefit of the overlap in the arterial blood supply to the head?
Collateral blood flow to all areas
Which of the following arteries is NOT a primary source of blood supply to the head?
Aorta
What is the total number of main arteries that supply the head?
Four
Which artery is responsible for supplying the brain?
Internal carotid
What is the term for the connection between different blood vessels that allows for blood flow to continue even if one vessel is compromised?
Anastomosis
What is the route of the vertebral artery into the skull?
Through the foramen magnum
What is the function of the circle of Willis?
To ensure adequate blood supply to the brain even if one of its elements becomes compromised
What is the origin of the vertebral artery?
Subclavian artery
What is the destination of the merged vertebral arteries?
Basilar artery
What is the origin of the thyrocervical trunk?
Subclavian artery
What are the branches of the thyrocervical trunk?
Inferior thyroid artery, Ascending cervical artery, and Transverse cervical artery
What is the primary function of the internal carotid artery?
Supplying the brain, eyes, upper nose, and forehead
Which artery arises from just below the hyoid and descends to supply the thyroid gland?
Superior thyroid artery
Which two arteries arise from the first part of the subclavian artery?
Vertebral and thyrocervical arteries
What is the destination of the maxillary artery after it runs deep to the zygomatic arch?
It supplies the deep structures of the face
What is the path taken by the internal carotid artery to supply the brain?
Through the carotid canal at the base of the skull
What is the relationship between the branches of the external carotid artery?
They communicate between the left and right sides of the head
Which artery runs superiorly to supply the inferior aspect of the thyroid gland?
Inferior thyroid artery
What is the final destination of the blood drained from the brain tissues?
Sigmoid sinus
Which structure does the suprascapular artery pass behind?
Sternocleidomastoid
What is the name of the vein that drains the brain tissues into vessels close to the surface?
Superficial cerebral vein
What is the name of the sinus that exits through the jugular foramen?
Sigmoid sinus
What is the name of the artery that ascends between the anterior scalene and longus capitis?
Ascending cervical artery
What is the primary route of venous drainage for the anterior aspect of the face?
Internal jugular vein
What is the final destination of the venous blood from the head, neck, and brain?
Brachiocephalic vein
Which of the following veins is responsible for draining the brain?
Internal jugular vein
What is the relationship between the internal and external jugular veins?
Both veins ultimately drain into the brachiocephalic vein
What is the unique feature of the brachiocephalic veins compared to the brachiocephalic arteries?
There is one brachiocephalic vein on each side of the body
Which artery arises from the external carotid artery and supplies the thyroid gland?
Superior thyroid artery
Which arteries arise from the first part of the subclavian artery?
Vertebral and thyrocervical arteries
Which artery travels through the carotid canal at the base of the skull?
Internal carotid artery
Which artery supplies the eyes, upper nose, and forehead?
Ophthalmic artery
Which part of the subclavian artery gives rise to the vertebral and thyrocervical arteries?
First part
Which artery runs deep to the zygomatic arch before branching to provide blood to the deep structures of the face?
Maxillary artery
What is the significance of the vertebral artery entering the skull through the foramen magnum?
It supplies the brain with adequate blood flow
Which of the following arteries is NOT a branch of the subclavian artery?
Basilar artery
What is the primary function of the internal carotid artery in relation to the circle of Willis?
To provide a redundancy system for cerebral perfusion
What is the relationship between the vertebral arteries and the basilar artery?
The vertebral arteries merge to form the basilar artery
Which of the following arteries provides small spinal arteries to surrounding structures?
Vertebral artery
What is the significance of the overlap in the arterial blood supply to the brain?
It ensures adequate blood supply to the brain even in cases of compromise
Which artery arises directly from the aorta on the left side?
Common carotid artery
What is the name of the common branch that gives rise to the common carotid and subclavian arteries on the right side?
Brachiocephalic trunk
What is the destination of the blood supplied by the external carotid artery?
Face and neck
Which artery is responsible for supplying the arm?
Subclavian artery
What is the name of the branch that arises from the common carotid artery and supplies the thyroid gland?
Superior thyroid artery
What is the significance of the brachiocephalic trunk?
It supplies blood to both the arm and head
What is the position of the apex of the heart in relation to the body?
In the 5th intercostal space in mid-clavicular line
What is the function of the fibrous pericardium?
To anchor the heart and prevent it from moving excessively
What is the name of the valve that separates the right atrium and ventricle?
Tricuspid valve
What is the purpose of the chordae tendineae in the heart?
To anchor the valves to the papillary muscles
What is the embryonic remnant that connects the pulmonary trunk and aortic arch in fetal development?
Ductus arteriosis
What is the name of the artery that supplies the sinoatrial (SA) node?
Nodal branch
What is the orientation of the heart in the thoracic cavity?
A tipped pyramid with the base facing downwards
What is the function of the papillary muscles in the heart?
To prevent the valves from prolapsing into the atria
What is the name of the depression in the right atrium that is a remnant of the fetal foramen ovale?
Fossa ovalis
What is the purpose of the semilunar valves in the heart?
To prevent backflow from the ventricles into the atria
What is the main function of the fibrous skeleton of the heart?
To prevent over-dilation of the valve openings
Which branch of the left coronary artery runs in parallel with the left anterior descending artery?
Marginal branch
What is the function of the SA node?
To release electrical stimuli at a regular rate
Which nerve runs behind the root of the lung and has a branch called the left recurrent laryngeal?
Vagus nerve
What is the effect of the sympathetic nervous system on heart rate?
Increases heart rate
Which vessel is the largest in the coronary system?
Coronary sinus
What is the function of the AV node?
To transmit electrical stimuli to the bundle of His
Which of the following is NOT a branch of the arch of the aorta?
Coronary artery
What is the function of the parasympathetic nervous system on heart rate?
Decreases heart rate
Which vessel returns deoxygenated blood from the heart, neck, upper limb, and thoracic wall to the heart?
Superior vena cava
What is the name of the large vessel that runs posterior to the diaphragmatic surface between the atria and ventricles?
Coronary sinus
Which nerve runs in front of the root of the lung in close relation to the fibrous pericardium?
Phrenic nerve
What is the function of the fibrous skeleton in the heart?
To anchor the valve cusps and prevent over-dilation of the valve openings
Which branch of the vagus nerve scoops underneath the arch of the aorta?
Left recurrent laryngeal
What is the effect of the parasympathetic nervous system on the heart rate?
It slows the heart rate
What is the name of the artery that runs in parallel to the posterior interventricular artery?
Circumflex artery
Which vein drains the brain tissues into vessels close to the surface?
Dural sinus
What is the route of the blood flow from the abdomen and lower limbs back to the heart?
Inferior vena cava
Which part of the autonomic nervous system increases the heart rate and contractility?
Sympathetic nervous system
What is the name of the artery that arises from the left coronary artery and supplies the lateral aspect of the left ventricle?
Obtuse marginal artery
What is the main function of the pericardium?
To anchor the heart and prevent over-filling
Which valve is responsible for preventing back-flow from the left ventricle into the left atrium?
Mitral valve
What is the name of the surface of the heart that faces the lungs?
Pulmonary surface
Which of the following is NOT a function of the pericardium?
Supplying the heart with oxygen
What is the name of the valve that separates the right ventricle and pulmonary trunk?
Pulmonary valve
Where is the apex of the heart located?
In the 5th intercostal space in mid-clavicular line
What is the name of the embryonic remnant that connects the pulmonary trunk and aortic arch?
Ductus arteriosus
Which of the following is a characteristic of the atrioventricular valves?
They are anchored to the ventricular walls by chordae tendineae
What is the name of the muscles that contribute to atrial contraction?
Pectinate muscles
What is the name of the artery that supplies the sinoatrial (SA) node?
Nodal branch
Study Notes
Heart Structure and Function
- The heart is located in the middle mediastinum, central to the pleural cavities, and sits on the diaphragm.
- The apex of the heart is displaced to the left, in the 5th intercostal space in the mid-clavicular line.
- The heart has a tipped pyramid shape, with the diaphragmatic surface being the largest part of the LV.
- The anterior surface is the RV, and the pulmonary surfaces face the lungs.
Pericardium
- The heart is surrounded by the pericardium, which is a serous pericardium.
- The pericardium has three layers: parietal, visceral (epicardium), and fibrous pericardium.
- The fibrous pericardium is a strong, fibrous layer of connective tissue that attaches to the diaphragm and sternum.
Blood Flow Through the Heart
- The heart has a double pump, with oxygenated blood on the left and deoxygenated blood on the right.
- Deoxygenated blood enters the RA from the superior and inferior vena cava and coronary sinus.
- Blood flows through the tricuspid valve into the RV, then through the pulmonary valve into the pulmonary trunk.
- Oxygenated blood returns from the lungs through the pulmonary veins into the LA, then through the mitral valve into the LV.
- The LV contracts, pumping blood through the aortic valve and into the aorta for distribution to the body.
Heart Valves
- The heart has four valves: tricuspid, pulmonary, mitral, and aortic.
- The atrioventricular valves (tricuspid and mitral) have flexible leaflets, while the semilunar valves (pulmonary and aortic) are firmly closed during ventricular relaxation.
- The valves prevent backflow and ensure blood flows in the correct direction.
Heart Sounds
- Heart valves closing produce the "lub-dub" sounds.
- The sounds can be heard at different points on the chest, depending on the valve.
Right Atrium and Ventricle
- The right atrium has an auricle/appendage, pectinate muscles, and a fossa ovalis.
- The right ventricle has an AV orifice, AV valve, IV septum, chordae tendineae, and papillary muscles.
Left Atrium and Ventricle
- The left atrium has an auricle/appendage, pectinate muscles, and a fossa ovalis.
- The left ventricle has chordae tendineae, papillary muscles, trabeculae carnae, and an aortic valve.
Embryonic Remnants
- The foramen ovale is a remnant of fetal development, allowing blood to flow between the RA and LA.
- The ductus arteriosus is another remnant, allowing blood to flow between the pulmonary trunk and arch of the aorta.
Coronary Arteries
- The coronary arteries supply blood to the heart, arising from the aortic sinuses.
- They fill during ventricular diastole, when the valve is closed, and do not fill during ventricular systole.
- The arrangement of the coronary arteries is highly variable, and they are functional end arteries.
Cardiac Skeleton
- The cardiac skeleton is a connective tissue that anchors the valve cusps, prevents over-dilation of the valve openings, and provides a point of insertion for heart muscle bundles.
- It also provides electrical insulation.
Conducting System
- The SA node is the natural pacemaker, releasing electrical stimuli at a regular rate.
- The stimuli propagate through the atria to the AV node, then to the ventricles through the bundle of His and Purkinje fibers.
Autonomic Regulation of the Heart
- The heart rate is regulated by the autonomic nervous system (ANS).
- The parasympathetic nervous system slows the heart rate, while the sympathetic nervous system increases the heart rate and contractility.
The Cardiovascular System
- The cardiovascular system encompasses the heart, capillaries, arteries, and veins.
- The circulatory system includes the cardiovascular system and the lymphatic system.
Arteries and Veins
-
Arteries are thicker and hold their structure, while veins are thinner and can collapse.
-
The cardiovascular system includes large elastic conducting arteries, which branch into smaller arteries and arterioles.### Arteries of the Head and Neck
-
Most branches supplying the head and neck are branches of the first part of the subclavian artery.
Vertebral Artery
- The vertebral artery originates from the subclavian and proceeds superiorly within the vertebrae, providing small spinal arteries to supply surrounding structures.
- The vertebral artery then enters the skull through the foramen magnum.
Vertebral and Internal Carotid
- Both vertebral arteries merge to form the basilar artery.
- The basilar and internal carotids are the greatest contributors of blood to the brain, forming part of the circle of Willis, a redundancy system of vessels that ensures adequate blood supply to the brain.
Thyrocervical Trunk
- The thyrocervical trunk originates from the subclavian and branches into supplying the thyroid gland and muscles of the neck, including:
- Inferior thyroid artery
- Ascending cervical artery
- Transverse cervical artery
- Suprascapular artery
Branches of the External Carotid Artery
- The external carotid artery provides several branches that target the face and neck, including:
- Superior thyroid artery
- Ascending pharyngeal artery
- Lingual artery
- Facial artery
- Occipital artery
- Posterior auricular artery
- Maxillary artery
- Superficial temporal artery
Internal Carotid
- The internal carotid artery travels much deeper in the neck and has fewer branches.
- It contributes primarily to supplying the brain, after traveling through the carotid canal at the base of the skull.
- It also supplies the eyes, upper nose, and forehead via ophthalmic arteries.
Blood Drainage of the Brain
- The brain is drained into venous sinuses, including:
- Sigmoid sinus
- Superior petrosal sinus
- Ophthalmic vein
- Cavernous sinus
- Great cerebral vein
- Confluence of sinuses
- Straight sinus
- Superior sagittal sinus
- Inferior sagittal sinus
Venous Sinuses Exiting the Skull
- The network of sinuses drains into ever larger sized ones, which then ultimately drain into the sigmoid sinus that exits through the jugular foramen and is continuous with the internal jugular.
Venous Drainage of the Head and Face
- The veins of the face and scalp generally accompany the arteries and have the same name.
- The anterior aspect of the face, including muscles, is drained via a superficial network that ultimately drains into the internal jugular vein.
- The side of the face and scalp is drained into the external jugular vein.
Final Stages of Venous Drainage
- Ultimately, the internal and external jugular, as well as the vertebral veins, descend towards the base of the neck, where venous blood is delivered into the brachiocephalic vein.
- There is a brachiocephalic vein on each side of the body.
This quiz covers the origins and course of carotid arteries, distribution of major branches, anastomoses, and venous drainage patterns in the head and neck region.
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