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.
