Physiology - Lecture 7 & 8

Cerebral blood flow stays nearly ________.

Constant

What is Angiogenesis controlled by?

Cytokines

Blood flow occlusion -> _____ Oxygen and ______ Carbon dioxide -> No production -> ______ vasodilation -> _______ blood flow.

Decrease Increase Increase Increase

Increase metabolic activity -> _____ Oxygen and _____ Carbon dioxide -> _______ vasodilation -> ______ blood flow

Decrease Increase Increase Increase

What is Angiogenesis?

Development of new blood vessels

When sounds disappear, the lowest pressure in the artery is _________ pressure.

Diastolic

Describe Venules

Receive blood from capillaries Thin exchange epithelium Little connective tissue Convergent pattern of flow

What factors can decrease plasma protein concentration?

Severe malnutrition or liver failure

_________ pump aids in lymph flow.

Skeletal muscle pump

Flow in _______ = Flow in all arterioles

Aorta

The ________ reflex controls blood pressure.

Baroreceptor

What are lymph nodes?

Bean shaped nodules of tissue with collection of immunologically active cells

Lymph capillaries are ________.

Blind-ended

If blood pressure is high, the firing of baroreceptors _________ and ________ the sympathetic output and ________ the parasympathetic output to _______ blood pressure.

Increases Inhibits Activates Decrease

Each side of the heart functions as an _____________.

Independent pump

Water movement due to osmotic pressure is from the _______ into the ________.

Interstitial fluid Capillary

What is the fluid movement of Absorption in capillaries?

Into

What is Bulk flow?

It is mass movement as a result of hydrostatic and osmotic pressure

What happens to the functionality of the baroreceptors if blood volume decreases?

It is unable to restore normal pressure causing dizziness

What is Hydrostatic pressure?

Lateral pressure of fluid pushing against vessel walls

Pulse can be felt as __________ pushes blood into the ________.

Left ventricle Aorta

How is arteriolar resistance influenced?

Local control, sympathetic reflexes and hormones

What is Hypotension?

Lower than normal MAP. Unable to supply oxygen to brain and feeling dizzy

What is the fluid inside a lymph vessel called?

Lymph

What is the relationship between MAP and Cardiac output and the resistance of arterioles?

MAP proportional to CO & Resistance

What is Pulse pressure?

Measure of strength pressure wave produced by ventricular contraction

What kind of receptors are Baroreceptors and where are they located?

Mechanoreceptors Carotid arteries and Aorta

What is capillary density related to of cells?

Metabolic activity

Blood distribution varies according to ______ of individual tissues.

Metabolic need

Describe Veins

More numerous than arteries Act as a Volume reservoir Thin walls of vascular smooth muscles Less elastic tissue Lie closer to body surface Contain one-way valves

Veins provide a _________ feedback in controlling blood pressure.

Negative

What net pressure value/effect will an increase in capillary hydrostatic pressure have?

Net Filtration

What net pressure value/effect will an increase of interstitial proteins have?

Net Filtration

What net pressure value/effect will a decrease in plasma protein concentration have?

Net filtration

Tonic ________ maintains arteriolar tone.

Norepinephrine

Lymphatic system allows for _______ movement of interstitial fluid into the circulatory system.

One-way

What is the function of Precapillary sphincters?

Open and close to direct blood flow to capillaries or venous circulation

What triggers the Baroreceptor reflex?

Orthostatic hypotension (low MAP)

Water movement due to hydrostatic pressure is _______ of capillary.

Out

What is the fluid movement of Filtration in capillaries?

Out

What happens to blood volume and MAP if the blood flowing in exceeds the blood flowing out?

Blood volume and MAP increases

Describe Metarterioles

Branches of arterioles Partial smooth muscle layer Precapillary sphincters

Coronary blood flows parallels the work of the _______.

Heart

Epinephrine binds beta 2 receptors to vascular smooth muscle of _____, _____, and ________.

Heart Liver Skeletal muscle arterioles

What does Arterial pressure signify?

Reflects driving pressure for blood flow MAP = Diastolic pressure + 1/3 (systolic pressure -diastolic pressure)

What is the kidney responsible for?

Removing excess fluid in volume

There is an adaptive integration between _______ and cardiovascular systems.

Respiratory

What is the main function of the Lymphatic system?

Returns fluid and proteins to circulatory system

What is the function of the endothelium?

Secrete paracrine signal molecules that regulate blood pressure, blood vessel growth and material absorption

What capillaries are found in the bone marrow, liver and spleen?

Sinusoids where blood cells and plasma proteins cross endothelium

Describe Arterioles.

Site of variable resistance. Part of microcirculation Less elastic and more muscular

How do arterioles perform variable resistance?

They direct the distribution of blood flow by selectively constricting and dilating

What kind of muscle do blood vessels contain?

Vascular smooth muscle

What is Myogenic autoregulation?

Vascular smooth muscle regulates its own state of contraction

Lymph vessels with semilunar valves empty into ________ circulation.

Venous

What function do systemic veins act as?

Volume reservoir where blood can be sent to the arterial side if blood pressure falls too low

What is muscle tone?

When blood vessels are in a state of partial contraction that depends on Calcium influx

What factors can increase capillary hydrostatic pressure?

Elevated venous pressure

________ releases epinephrine into blood.

Adrenal Medulla

If net value is negative, net _________ occurs

Absorption (venous)

What is Edema?

Accumulation of fluid in Interstitial space

Describe Arteries.

Act as a pressure reservoir. Thick layers of vascular smooth muscles Lots of elastic and fibrous connective tissue

Stretched vascular smooth muscle activate mechanically-gated ______ channels that ________ contraction.

Calcium Increase

Pressure wave disappears at the _________.

Capillaries

Baroreceptors produce ________ to brainstem.

Continuous (tonic) action potential

What type of capillaries form the blood-brain barrier with tight junctions?

Continuous capillaries

What are Pericytes?

Contractile cells that contribute to capillary impermeability. They secrete paracrine factors that promote vascular growth and differentiation

What is the function of Nitric oxide in blood flow?

Drug prolong NO activity Increase vasodilation Increase blood flow

Why does the diastolic pressure remain high?

Due to arteries ability to retain energy in elastic walls

Blood volume is relatively not constant. True or False?

False

Fastest flow of blood is in the capillaries and venules. True or False?

False

Kidney can conserve and increase blood volume. True or False?

False Only conserve

Which capillaries contain absorptive transporting epithelia?

Fenestrated capillaries

If net value is positive, net _______ occurs.

Filtration (arterial)

What is Hypertension?

Higher than normal MAP. Rupture of vessels, rupture in brain (cerebral hemorrhage)

Blood pressure is ______ in the arteries and ________ in the veins.

Highest Lowest

How is net pressure calculated?

Hydrostatic pressure - colloid osmotic pressure

Blood pressure is modulated by ______ and _________.

Hypothalamus Cerebral cortex

What is the function of Serotonin in blood flow?

Increase Vasoconstriction Decrease blood flow

What is Active hyperemia?

Increase in blood flow with increase in metabolic activity

What is Reactive hyperemia?

Increase in tissue blood flow by a period of low blood flowq

If CO increases and resistance stays the same blood volume _______ and MAP ________.

Increases

If CO stays the same and resistance increases blood volume _______ and MAP __________.

Increases

If blood volume increases, blood pressure _________.

Increases

Osmotic pressure is created by presence of proteins in the _________ but not the ________.

Plasma Interstitial fluid

What is the function of Kinins and Histamine blood flow?

Potent vasodilators Increase vasodilation Increases blood flow

What is Diastolic pressure?

Pressure during ventricular diastole

What is Systolic pressure?

Pressure during ventricular systole

Elastic walls of systemic arteries acts ___________.

Pressure reservoir

What can regulating angiogenesis do?

Prevent disease like inhibiting malignant tumor or promoting collateral circulation in coronary heart disease

Describe Capillaries.

Smallest vessels Primary site of gas exchange Walls lack smooth muscle Flat layer of endothelium and basal lamina Contain Pericytes

Blood pressure is estimated by ________.

Sphygmomanometry

If MAP is low what happens to sympathetic vein constriction, venous return, cardiac output, blood volume and MAP.

Sympathetic vein constriction increases Venous return increases Cardiac output increases Blood volume and MAP increases

Highest pressure in the artery is recorded as _________ pressure.

Systolic

What is the endothelium of blood vessels?

The inner lining of blood vessels

Korotkoff sounds

Thumping noise as blood squeezes through compressed artery

What is the function of the Cardiovascular control center (CVCC)?

To ensure adequate blood flow to the brain and heart by maintaining mean arterial pressure

In most capillaries, large molecules are transported by __________.

Transcytosis

What is the difference between paracellular pathway and endothelial transport?

Transport in paracellular is between endothelial cells while in endothelial it is through endothelial cells.