a&p 2 - quiz 11

Resistance to blood flow is due to friction between blood and the walls of the blood vessels. a. What three factors contribute to resistance? b. What factor is the most important in a healthy individual?

Blood viscosity Total vessel length Lumen diameter (most important)

What process is responsible for the movement of nutrients, wastes and gases across the capillary wall?

Diffusion

In a capillary, describe the areas where filtration and reabsorption take place.

Filtration- Arterial end Reabsorption- Venous end

How does the body handle filtrate that is not reabsorbed?

Fluid is picked up by lymphatic vessels and returned to the circulation.

What two pressures determine "bulk flow" in capillaries?

Hydrostatic pressure Osmotic pressure

If baroreceptors are stretched, will the cardioacceleratory center be stimulated or inhibited?

Inhibited

Blood pressure is highest in the aorta and lowest in the vena cava. Which type of artery offers the least resistance to blood flow? The greatest resistance?

Least resistance- aorta(large arteries) Greatest resistance- Arterioles

Where are the cardiovascular and vasomotor centers located?

Medulla

Where are chemoreceptors located? What type of stimuli do chemoreceptors respond to?

Near Baroreceptors in Aorta and Carotid Arteries; changes in chemical composition of blood

When we first get out of bed in the morning, blood pressure may fall. To restore normal BP, baroreceptors will _________ the cardioacceleratory center, ___________ the vasomotor center, and ______________ the cardioinhibitory center.

Stimulate, stimulate, and inhibit

If baroreceptors are stretched, has there been an increase or decrease in blood pressure?

increase

Where are baroreceptors located?

large arteries (aortic arch and carotid sinus)

Define acidosis

accumulation of acid or loss of base

Calculate net filtration pressure (NFP) at the venous end of this capillary: HP inside the capillary is 42 mm Hg HP in the IF is 0 mm HG OP inside the capillary is 22 mm Hg OP in the IF is 2 mm Hg

110mmHg

Calculate pulse pressure for this individual: Systolic Pressure = 150 mm Hg Diastolic Pressure = 90 mm Hg

60 mmHg

What does bulk flow determine in the body?

Amount of fluid in body compartments

Describe "vasomotor tone"? Which autonomic fiber is responsible for vasomotor tone?

Amount of tension in smooth muscle within blood vessel walls

Define hypercapnia

An excess of carbon dioxide in the blood

Define hypoxia

An insufficiency of oxygen in the body's tissues.

If the carbon dioxide levels of blood increase, which cardiovascular center will chemoreceptors stimulate

Cardioacceleratory and Vasomotor centers

Name the cardiovascular centers, and state which division of the autonomic nervous system each is associated with

Cardioinhibitory- parasympathetic(vagus) Cardioacceleratory- Sympathetics Vasomotor- Sympathetics

What type of stimuli do baroreceptors respond to?

pressure and stretch