Chapters 15 & 16 - Bloodflow and Blood Pressure

Renin-Angiotensin-Aldosterone System

->Important regulator of BP ->The liver creates angiotensinogen ->renin is secreted by the kidneys in times of low fluid volume in nephron. Renin converts angiotensinogen into Angiotensin I. -> When angiotensin I reaches the lung, ACE converts it to Angiotensin II. ->Angiotensin II stimulates the adrenal gland to release Aldosterone which retains Na+ and water in the blood. -> Increase in Bloodpressure.

The goals of Medications for hypertension is to (2)

-Decrease Blood Volume -Decrease Arterial Resistance

Alcohol can inhibit _______ which is why it is a diuretic

ADH

Angiotensin II stimulates the adrenal glands to release __________ and also causes ____________ in blood vessels.

Aldosterone ; vasoconstriction

ADH

Anti Diuretic Hormone ->secreted when blood pressure falls due to lack of water or water loss. Makes the kidneys absorb water back from the urine. dehydration can happen in times of high salt serum levels and low water consumption.

Atherosclerosis vs Arteriosclerosis

Atherosclerosis usually pertains to the larger arteries in the body and is narrowing/hardening of arteries due to plaque build up. Arteriosclerosis (think arterioles) is an umbrella term that is hardening and thickening of small arteries and arterioles that usually is more related to Hypertension/diabetes rather then plaque build up. (medial layer is calcified) Both are usually used interchangeably nowadays but there is a distinct difference. Atherosclerosis is a specific kind of arteriosclerosis.

Arterial blood pressure is produced how?

By the force of the left ventricular contraction exceeding the resistance of the aortic valve to swing it open.

Blood pressure = ________ _______ X _______ _________

Cardiac Output ; Peripheral Resistance

The pathogenesis of Atherosclerosis?

Damage Inflammatory response Vessel wall permeablity LDL breach intima Leukocytes attracted Engulf lipids Platelets attracted Activate PDGF Stimulate smooth muscle proliferation PLAQUE

inotropy

Dealing with the contractility of the heart.

Fibrosis

Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process -scar tissue in a sense.

Humoral Factors

Humoral factors are factors that are transported by the circulatory system, that is, in blood, and include: Humoral immunity factors in the immune system, Hormones in the endocrine system, and other molecules.

How does primary hyperntension affect the heart over time?

Increased myocardial work due to the increased pressure the left ventricle must surpass to eject blood into circulation. Causes hypertrophy of the left ventricle which can lead to heart failure.

Coarctation of the Aorta

Infant Form - 70% of cases, congenital Adult form - 30% of cases narrowing of the aorta creating pressure gradient. Low blood pressure beyond the point of the coarctation and high blood pressure before it.

Foam cells

Macrophages that have engulfed lipids

Blood pressure regulation is affected by _________, _________, and ______ factors.

Neural ; humoral ; renal

Secondary Hypertension

Something else going on causing the HTN. ex] Kidney disease, Pheochromocytoma (Tumor of the medulla of the adrenal glands) Obesity and sleep apnea endocrine disorders. *most common form of HTN in young children <10.

The _____________ _______ in the brain governs daily variations of blood pressure in bodily function.

Suprachiasmatic Nuclei (part of the hypothalamus)

Monckeberg Medial Calcific Sclerosis

The middle muscular layer of vessels calcifies. This is uncommon and atherosclerosis is a much more common form of arteriosclerosis

Primary Hypertension

Unknown reason for HTN. Most common type of HTN.

Beta Blockers

Used to block Beta-adrenergic activity. Blocks the receptor so epinephrine and norepi can not bind. Negative Inotropic drug. Negative chronotropy druge Can affect Dromotropy of the heart as well.

Stroke Volume

Volume of blood pumped from the left ventricle per beat.

ACE inhibitors

block the effect of ACE in the lungs halting the Renin-angiotensin-aldosterone pathway in hopes of decreasing blood pressure.

How does HTN cause atherosclerosis?

chronic High pressure hitting the artery walls can potentially damage them which causes the breach in the wall that leads to our body attempting to heal it and form a plaque.

Chronotropy

dealing with the Heart Rate.

Dromotropy

dealing with the conduction speed of the heart.

Atheroma

degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue, and leading to restriction of the circulation and a risk of thrombosis.

Estrogen can protect against ________ ________ in women

heart attacks

How does Hypertension affect the kidneys over time?

increased blood pressure can cause autoregulation failure of the kidneys leading to ischemia and renal failure,

Coronary bypass

makes a new route for the blood to go to bypass the plaque or occlusion.

A blockage in a blood vessel is preceded by ___________ while a rupture or aneurysm is preceded by a _________ in the vessel.

narrowing ; weakness

Short term regulation of systemic blood pressure is due to release of certain ____________ such as ________ and ________.

neurotransmitters ; norepi ; epi

calcium channel blockers can reduce _________ __________

vascular resistance