Ch 10: HTN, Veins, Tumors Flashcards
Physio flashback! Describe the renin-angiotensin system.
- decreased GFR –> increased renin release
- renin cleaves angiotensinogen to angiotensin I
- ACE converts angiotensin I to angiotensin II
- angiotensin II causes vasoconstriction, direct sympathetic output, and increased adrenal aldosterone release (which increases sodium reabsorption)
- disease states that encourage this system (ex. renal artery stenosis) lead to HTN
What is the role of atrial natriuretic peptide (ANF)?
- antagonizes renin-angiotensin system by increasing urinary sodium excretion
- ANF is released by atrial distension (increased blood volume)
In patients with systemic HTN (no matter the cause), the end result of autoregulation is always _____.
increased peripheral resistance
Pt presents with elevated BP and a history of HA, weakness, dizziness. CT reveals mass in adrenal gland. Serum potassium is low, sodium is high, renin is low, and cortisol fluctuates widely throughout the day. What is the diagnosis and what hormone is being secreted by the tumor?
- Conn syndrome, an endocrine disorder in which the adrenal tumor secretes aldosterone
- hyperaldosteronism causes HTN, hypernatremia, and hypokalemia
What are the pathological changes occurring in arteries in hyaline arteriosclerosis?
- results from mild chronic HTN (benign)
- walls thickened by deposition of basement membrane and an accumulation of plasma proteins
- new layers of intimal elastic lamina
- increased connective tissue
Fun fact: when this results in loss of renal parenchyma, it is called benign nephrosclerosis
What are the pathological changes that occur in malignant HTN?
- results from elevated BP causing a sudden vascular compromise to end organs
- small arterioles show microaneurysms, focal hemorrhages, and scarring
- muscular arteries show:
1) segmental dilation due to necrosis of smooth muscle cells
2) influx of plasma proteins and deposition of fibrin (fibrinoid necrosis)
3) smooth muscle proliferation and an increase in number of layer of muscle termed ONION SKIN appearance
Fun fact: when this happens in the kidney, it is called malignant nephrosclerosis
An older patient has a history of chronic kidney disease. You find out the some of the arteries in their extremities are hard and dilated with concentric dystrophic calcification. What is going on?
Mönckeberg medial sclerosis:
- degenerative calcification of MEDIA of large and medium sized arteries
- usually not clinically significant
An 18 yo female comes to you complaining of episodes of severe pain in her fingers which usually corresponds with ice skating parties or snowball fights. Both hands are affected equally and she notices that her fingers also get extremely white and sometimes numb. What is going on, and what other systemic diseases might be associated with this?
- Raynaud phenomenon: vasospasm of the arteries and arterioles in the skin, potentially caused by dysregulation of vascular tone by sympathetic nerve activity or neurohumoral factors
- May occur as part of scleroderma or lupus
This condition causes a non-inflammatory thickening of large and medium sized vessels. It typically occurs in young women. It often causes renal artery stenosis. Microscopically, smooth muscle is replaced by fibrous tissue and myofibroblasts.
Fibromuscular dysplasia
Describe varicose veins and name sites besides the legs that they may occur.
- enlarged tortuous veins due to incompetence of valves and dilation of vessels
- risk factors include increased age, being female, having a family history, standing a lot, and obesity
- if severe, may lead to ulceration of overlying skin
- Also seen as hemorrhoids (anal/rectal veins), esophageal varices (lower esophageal veins), and varicocele (pampiniform plexus of scrotum)
Lymphatic obstruction can be precipitated by what factors? What are the consequences of this obstruction?
- lymphatics may be obstructed by scar tissue, intraluminal tumor cells, pressure from surrounding tumor tissue, or parasites (think filariasis)
- consequences are dilation of vessels (lymphangiectasia) and a grossly enlarged lymphedematous limb (elephantiasis)
A patient presents with painful purple nodules on their hands and feet. Upon investigation, you find that the nodules are derived from endothelial cells. What virus do you suspect is responsible and what may be in the medical history of the patient?
- Kaposi sarcoma, caused by HHV8
- commonly seen in immunosuppressed patients (AIDS, organ transplant)
A patient presents with a raised, painful lesion on the dorsal surface of their hand. Based on location, you suspect this is derived from a proliferation of normal neuromyoarterial receptors. What is the diagnosis? What can you see microscopically?
Glomus tumor
- branching vascular channels in connective tissue stroma
- aggregates of specialized glomus cells (round cells that reveal typical smooth muscle cell features)
Exposure to PVC, arsenic, and Thorotrast puts someone at risk for developing what?
- hepatic angiosarcoma
- in general, angiosarcomas are tumors of endothelial cells that undergo central necrosis and have malignant spindly cells that line vague channels
Name the three types of hemangiomas and describe each
1) capillary hemangioma - birthmarks, commonly on skin, vary from bright red to blue
2) juvenile/strawberry hemangioma - found on skin of newborns, usually regress within 5 years, endothelium-lined channels filled with blood
3) cavernous hemangioma - lesions of large vascular channels, red-blue soft spongy mass
