A&P169 quiz3

Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by

diffusion.

Peripheral resistance

increases as blood viscosity increases

Surfactant helps to prevent the alveoli from collapsing by:

interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid.

Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation

lungs

Total blood vessel length, Blood

- A source of resistance related to distance blood has to travel through layers of fat to reach a destination

viscosity

- A source of resistance related to the thickness or "stickiness" of the blood

Resistance

- Opposition to flow (a measure of the amount of friction blood encounters as it passes through the vessels

Blood flow

- The volume of blood flowing through a vessel, an organ, or the entire circulation in a given period

Which of the following provide the greatest surface area for gas exchange?

: alveoli

The velocity of blood flow

: is slowest in the capillaries since the total cross-sectional area is the greatest

oxygen transport in blood

A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal

Total lung capacity

About 6000ml in an average male

Tidal volume -

About a pint's worth of air

Aldosterone

promote an increase in blood pressure.

Veins - Contain valves to assist blood flow back toward heart

Contain valves to assist blood flow back toward heart ,

Vital capacity

Maximum volume of air that can be exhaled after maximum inhalation

capillaries.

Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of:

Muscular arteries -

Smaller arteries that distribute blood to specific body organs,

Capillaries -

Smallest blood vessels with thin walls that allow exchange between blood and tissue cells,

Arterioles -

Smallest of the arteries that lead into capillary beds

Venules - Smallest veins leading away from capillaries

Smallest veins leading away from capillaries

Which of the following correctly describes mechanisms of CO2 transport

The chloride shift mechanism enhances CO2 transport.

Blood pressure ,

The force pre unit area exerted on a vessel wall by the contained blood

elasastic arteries -

Thick-walled large arteries near the heart that conduct blood continuously away from the heart

Which type of blood vessels contain valves and what is their function

Veins and venules contain valves to prevent blood from flowing backward. This is necessary because the venous vessels are a low-pressure system and the blood must sometimes flow against gravity, particularly in the limbs.

Functional residual capacity

Volume of air in lungs after normal tidal expiration

Inspiratory reserve -

Volume that can be forced in after a tidal inhalation,

The respiratory membrane is a combination of

alveolar and capillary walls and their fused basal lamina.

Fenestrated capillaries:

are not found in the brain

The nose serves all the following functions except:

as the initiator of the cough reflex.

Which of the following is not an event necessary to supply the body with O2 and dispose of CO2?

blood pH adjustment

The hepatic portal vein

carries nutrient-rich blood to the liver.

Most inspired particles such as dust fail to reach the lungs because of the:

ciliated mucous lining in the nose.

The pulse pressure

systolic pressure minus diastolic pressure.

The erythrocyte count increases after a while when an individual goes from a low to a high altitude because:

the concentration of oxygen and/or total atmospheric pressure is lower at high

Nerve impulses from ________ will result in inspiration

the dorsal respiratory group

The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is:

to secrete surfactant.

Factors that aid venous return include all except

urinary output

Which of the following is a type of circulatory shock

vascular, due to extreme vasodilation as a result of loss of vasomotor tone

Factors that influence the rate and depth of breathing include

voluntary cortical control