Question

A 43-year-old man was washing his car when he suddenly complained of a severe headache and then slumped to the ground. His son, who had witnessed the episode, stated that his father grabbed his head with both hands and cried out in pain as he was falling. The son said that his father had no medical problems and exercised regularly. On examination in the emergency department, the patient was lethargic but responsive to deep pain stimuli. His pupils were dilated bilaterally and sluggishly reactive to light. CT scan of the head showed a significant intracranial hemorrhage. An angiogram demonstrated leakage of dye from the junction of the right internal carotid artery and the circle of Willis. The attending physician suspected a ruptured berry aneurysm.

1. Explain the most likely anatomical cause of the vessel rupture. [1 mark]

2. Clearly describe the blood supply to the brain. Include in your answer: the main arteries that supply blood to the brain, and the origins of these arteries; the major branches of these arteries and the territories they supply; and the formation of the circle of Willis. [10 marks]

3. Explain the bilateral pupil dilation and sluggish reaction to light. [2 marks]

4. List 4 main risk factors for an intracranial bleed/aneurysm. [2 marks]

5. Define and describe ‘end-arteries’ and explain the significance of these vessels in the brain.

please anyone help me to find out these answer regarding my case study? with reference, it's urgent, please.

Answer 1

Ans 1: Minute arteries bring blood to areas deep inside the brain. Hypertension can cause minute arteries to rupture, releasing blood into the brain tissue. An intracerebral hemorrhage is usually caused by rupture of tiny arteries within the brain tissue.

Ans 2: At the base of the brain, the carotid and vertebrobasilar arteries form a circle of communicating arteries known as the Circle of Willis. From this circle, other arteries—the anterior cerebral artery, the middle cerebral artery , the posterior cerebral artery arise and travel to all parts of the brain. Because the carotid and vertebrobasilar arteries form a circle, if one of the main arteries is occluded, the distal smaller arteries that it supplies can receive blood from the other arteries. The anterior cerebral artery extends upward and forward from the internal carotid artery. It supplies the frontal lobes, the parts of the brain that control logical thought, personality, and voluntary movement, especially of the legs. The middle cerebral artery is the largest branch of the internal carotid. The artery supplies a portion of the frontal lobe and the lateral surface of the temporal and parietal lobes, including the primary motor and sensory areas of the face, throat, hand and arm, and in the dominant hemisphere, the areas for speech. The posterior cerebral arteries stem in most individuals from the basilar artery but sometimes originate from the ipsilateral internal carotid artery. Small, deep penetrating arteries known as the lenticulostriate arteries branch from the middle cerebral artery Occlusions of these vessels or penetrating branches of the Circle of Willis or vertebral or basilar arteries are referred to as lacunar strokes.

Ans 3: The affected pupil does not immediately respond to direct or consensual light reflex; however, if light stimulus is prolonged, this pupil will slowly constrict to light and slowly dilate in the dark. Accommodation in the affected pupil is sluggish. The other pupil is of normal size and reacts to light.

Ans 4:

• Smoking. Smoking is linked to both the development and rupture of cerebral aneurysms. Smoking may even cause multiple aneurysms to form in the brain.
• High blood pressure. High blood pressure damages and weakens arteries, making them more likely to form and to rupture.
• Size. The largest aneurysms are the ones most likely to rupture in a person who previously did not show symptoms.
• Family history. A family history of aneurysm rupture suggests a higher risk of rupture for aneurysms detected in family members.

Ans 5:

An end artery/ terminal artery is an artery that is the only supply of oxygenated blood to a portion of tissue. Because vital tissues such as the brain or heart muscle are vulnerable to ischaemia, arteries often form anastomoses to provide alternative supplies of fresh blood.