Lecture 16 Baroreceptor Reflex, Cardiovascular Diseases Flashcards
GET IT THROUGH YOUR THICK SKULL
What is the formula for blood pressure?
BP= HR x SV x TPR
What are the controlling/ integrating centers of the medulla oblongata?
- Cardiac control centers: regulate cardiac rate
- Vasomotor control centers: control vasoconstriction/dilation of smooth muscle of peripheral vasculature
What are baroreceptors?
Where are they located?
They are stretch receptors that respond to blood pressure changes
Located in the aortic arch and carotid sinuses
True or False: Increase in BP stretches aortic and carotid sinus walls MORE, which results in a decreased frequency of APs along their sensory nerve fibers and vice versa
False: Change in BP is DIRECTLY proportional to change in frequency of APs
Which nerves do the sensory nerve activity from baroreceptors ascend from?
Vagus (CN X) and Glossopharyngeal (CN IX)
What does the baroreceptor reflex help maintain?
Helps maintain normal blood pressure on a beat-to-beat basis
What happens to BP when a person goes from laying to standing? (come back to this)
-500 to 700ml of blood in thoracic cavity rushes to veins of lower extremities resulting in decrease in venous return, to decrease in EDV to decrease in SV to decrease in CO to decrease in BP
- Decrease in EVERYTHING
What is hypertension?
Blood pressure in excess of normal range for age and gender
What are the blood pressure categories?
- Normal: <120 Systolic <80 diastolic
- Elevated: 120-129 S <80 D
-High BP stage 1: 130-139 S 80-89 D
- High BP stage 2: 140+ S 90+ D
Hypertensive Crisis: 180+ S 120+ D
What kind of hypertension do 90-95% of people with hypertension have?
Primary/ essential hypertension
What are some causes of Primary Hypertension?
- Obesity, insulin resistance, high alcohol intake, aging (ability of kidneys to excrete declines with age), sedentary lifestyle
- Increased salt intake: increases plasma osmolarity, ADH, H2O reabsorption, blood volume, cardiac output and blood pressure
- Genetics
- Increased stress (increases sympathetic activity and TPR, HR, BP)
Why is hypertension known as a “silent killer”?
Patients are often asymptomatic until substantial vascular damage occurs
What are some dangers of hypertension?
STROKKEEEE (explain tho)
- High arterial pressure increases the afterload which makes heart work harder and leads to changes in heart structure and function leading to congestive heart failure
- High BP may damage cerebral blood vessels leading to stroke
- High pressure contributes to development of atherosclerosis leading to heart disease and stroke
What is atherosclerosis the most common form of?
remember sclerosis: hardening of tissue or body part
Arteriosclerosis (hardening of arteries)
How does atherosclerosis begin?
Damaged endothelium from bloodborne chemicals, hypertension, or viral bacterial infections
Forms fatty plaques (atheromas) below endothelium within tunica media layer
