Download Chapter 20 - The Vascular System

CVS: The Vascular System
Arteries: _____________ that carry blood ________________the heart
Capillaries: _____________ that connect __________ with ________________; site of __________exchange
Veins:______________ that carry blood to the ___________________
How many miles of blood vessels does the adult human have? _____________
Arteries
Gross anatomy (fig. 19.1)
1. tunica interna (intima)
• _______________epithelium_
lines the ___________
(_____________)
• ______________membrane
• internal ______________lamina
2. tunica media
• ____________layer of
__________muscle with
________fibers (allows ____________
of the vessels)
• __________layer in artery wall
3. tunica externa
 ____________tissue with __________ & _____________ fibers
Classification
1. Elastic
 _________vessels near heart

large ________________ (so little _____________________to flow)

lots of ___________________ (so acts as ___________reservoir)
2. Muscular

__________________ to _____________ arteries

_________________ sized, more ____________ than elastic

delivers ________________ to body regions (__________, __________, etc.)
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3. Arterioles

_________arteries; heavily innervated

______________________become less obvious, may be only _____cell layer thick

____________________flow minute by minute to specific areas
Capillaries (fig. 19.1)
 Connect ____________ to_______________

The “business end” of the cardiovascular system

The site of ___________________ exchange

Lumen ~ ____________________ (___________________________)

Average length is ______ mm

Have no _______________ (only __________________ + basement membrane)

Only a few areas don’t have ________________ (____________________________________)

Provide ______________access to nearly every cell in the body
Classification (fig. 19.3)
1. Continuous
 most ___________________

Abundant in ___________and _______________

_______________cells have ______________junctions with small ____________________ (form
intercellular clefts)

allows some movement between ______________ and __________________
2. Fenestrated

_________junctions with ______________clefts present

________________cells have ______________ in their membranes

allows ______________ between lumen and tissue

found in ___________________________________________________
3. Sinusoidal

have large _________________ lumen

__________________basement membrane and ___________cleft between ___________ + ________ in
cells

leaky
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
found in _________________________
Capillary beds (fig. 19.4)
Metarteriole (______________shunt)
•
____________vessel that connects ____________________ to ________________
True capillaries
•
__________________ from the shunt and usually rejoin it
•
Actual ________________ vessels
•
_______________________ depending on organ being served
•
cuff of ___________muscle at root (precapillary sphincter)
•
sphincter ______________ and blood flows _________ capillary
•
sphincter _____________________ and blood _____________ the capillary
•
_______________________ depends on local chemical conditions and ______________ vasomotor
nerve fibers
Veins (fig. 19.1)
• ____________________lumen (so little____________ to flow)
•
generally follow the path of the___________________ back to _______________
•
Up to _____________of the blood will be in the veins (acts as a blood________________________)
Gross anatomy
tunica interna (intima)

folds forms ______________________ to prevent ________________ (similar to _________of the
heart)
tunica media

Thinner than __________________
tunica externa

________________layer in veins
Think about it:

List three differences between arteries and veins.

Think about this: Would arteries or veins be more effective for altering blood pressure?
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Circulation Physiology
- blood flow
- blood pressure
- nutrient and waste exchange
Blood Flow =
Note: total blood flow is volume of __________ flowing through a tissue in a given period of time (_______)
 Flow is _________________in ________________ leaving the heart, _________________ in the
capillaries (important for _________________)
 Continuous _________ flow is essential to provide cells with _____________ and remove their
____________________
Blood Flow is affected by:
1. Peripheral Resistance= ___________ to flow (drag of ____________on ______________)
Factors that affect resistance:
A. Viscosity: more _______________ = greater _____________________
(Causes include ___________________ or ____________________)
B. Number of vessels (or Total blood vessel length)

the ______________________ vessel = ___________________ resistance

(Note: these factors are usually fairly_______________)
C. Lumen diameter

___________________ diameter = ____________________ resistance

(this factor is easily_______________)
Blood pressure = _______________________ area exerted on vessel __________________
Pressure differences within __________ system provide the driving force that keeps blood
______________________.
Blood flow = Difference in ________________________
– When there are ________________ (______________ bp), there is _________ blood flow
– Increases in ____________________ result in _____________ blood flow
Unless otherwise stated, blood pressure refers to __________blood pressure in the
________________ arteries of the heart
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Pressure is ________________ in _________________and ______________ in
____________________
Systolic = ______________ mmHg when L ventricle ___________ blood is forced into _______
Diastolic = ______________ mm Hg semilunars close and ____________flows from
_____________into _________________ and out to body
Note: pulse pressure (Pulse) = difference between ___________________.
Venous Blood Pressure:
•
Much ________________ than ___________ bp
•
Venous return to the heart aided by
–
____________ pump
–
____________ pump
–
____________muscle around veins
Capillary pressure:
 is ______________ ; this pressure is a ________________ behind ____________ exchange
This is good because
1. Capillaries are ______________________
2. Even ________pressure is enough to force ________________ out of the bloodstream and into the
___________ space
Clinical applications of Blood Pressure
 ___________________ and pulse rate are excellent indicators of how well the
______________system is working

Vital signs: ____________________________________________
Taking Blood Pressure
• inflate the cuff to above systolic (cuts off brachial flow so no pulse)
• reduce pressure and listen for sound to resume = _________________________
• continue to reduce pressure until you hear no sound = ______________________
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Control of Blood Pressure
Pressure varies with:
1.
2.
3.
This means the ________________ for your regulatory systems (__________________ &
___________________) are: _________________________________
It is ESSENTIAL to Remember
 __________________ can be changed by adjusting _____________or __________
 _______________________ can be adjusted by changing vessel _____________________
 ________________________ can be adjusted by adjusting ______________output
A. Neural Control
Cardiovascular center in the ____________________ target ______________ and ________________
Fig. 19.8
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Stimulus is Increased Blood Pressure
Increased blood pressure triggers ______________
Messages to ________ center
_______ increase ___________________ innervations
___________ arteries
(this ________ peripheral resistance)
____ HR and ________ SV
(this ______ CO)
Results in ____________________
Stimulus is Decreased Blood Pressure
Decreased blood pressure triggers ________________
Messages to ___________________
CV increases _______________________ innervations
___________ arteries; this _______ peripheral resistance
______ HR and ____SV; this ___CO
Results in ___________________________
See figure 19.9 in text for review of this important concept
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B. Endocrine control
Epinephrine & Norepinephrine
Stimulus is Decreased Blood Pressure
____ center sends ______________ to adrenal cortex
Adrenal cortex releases ____________ and _______________
____________ arteries; this _______ peripheral resistance
____ HR and ___ SV; this ___ CO
______________ pressure
Angiotensin II
Stimulus is Decreased Blood Pressure
Kidneys secrete ______________
_____________ converts angiotensinogen to _____________________
______ (from lungs) converts ______________ to __________________
_______________ arteries
_________________ blood pressure
Note: ___________ also influences aldosterone and ________________ production which influences
blood volume and therefore ________________
Antidiuretic Hormone (ADH)
Stimulus is Decreased Blood Volume/ Blood Pressure
Hypothalamus detects __________ or ___________ blood volume
Impulses to posterior pituitary to release ___________
__________ arteries
_______________ blood pressure
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Note: ADH’s major action is conserving ______________ and therefore ________ blood pressure
Atrial Natriuretic Peptide (ANP)
Stimulus is Increased Blood Pressure
________ blood pressure stretches on ________ walls
____________ secretes _________
______________ vessels
______________ pressure
Note: ANP also promotes ___________________________ by kidney, which _________ blood volume and
therefore ___________ blood pressure

Increase in _______________ followed
by an increase in _____

______________ increases _____________ thus
____

Direct renal mechanism alters blood___________
independently of _____________

Indirect renal mechanism: involves
__________release by _________________.
Figs. 9.10 and 9.11
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Pressure disorders
Hypertension =______________________
•
Short term results from: ___________________________
•
Defined as sustained __________________ of _______________
•
Chronically warns of _____________peripheral resistance which stresses the ______________,
damages ____________________, etc.
•
_______________people over the _______________ are ________________
•
Major cause of _________________________________________________________________
•
Asymptomatic for __________________ years, slowly strains the __________ and damages
________________.
•
Preventatives:
Think about it:
 Where are the receptors for blood pressure located?
 Where is the control center for the nervous system response to changes in blood pressure?
 If blood pressure decreases, will more or less epinephrine be secreted? More or less ANP?
Nutrient/Waste Capillary Exchange
Mechanisms for exchange
1. Diffusion

molecules move with ______________gradient through the intercellular____________,
_________________, or through the _______________
2. Bulk Flow

movement of _____________and _____________due to pressure gradient (fluids move from area of
_______________ to areas of __________________). Involves opposing pressures:
Hydrostatic pressure = pressure of _____________against _____________________(capillary
____________________) due to heart pumping blood into ______________
HPc = pressure inside _____________________
•
Tends to push fluids _____________of capillary into _______________________
•
Higher at _____________end than ________________end of capillary
HPif = opposing pressure in ____________________, it is a constant and _____________
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____________________________________________________________
arterial BHP (or HPc) =
venous BHP (or (or HPc) =
____________________________________________________________
Osmotic pressure = pressure caused by ____________proteins (primarily _____________) within
the _______________________
OPc = pressure inside ______________
 Tends to draw ________________ into the ______________ from the interstitial space
 _________________ vary along the length of the capillary
OPif = ______________________________ in the interstitial fluid; it is a constant and ______________
__________________________________________________________
BCOP ( or OPc) =
___________________________________________________________
IMPORTANT:
At any point along the capillary when:
net _________ 
net _________ fluid _________capillary
net ____________ 
net ____________ fluid __________capillary
__________________________________________________________
arteriole end net HP =
venous end net HP =
net OP =
net OP =
__________________________________________________________
Fluids __________ at arteriole end
Fluids __________ at venule end
Circulatory Shock
• Results from __________filling of _________vessels, thus blood can’t ______________properly
•
If it persists, can cause ______________________
•
Hypovolemic shock – results from large scale ____________________
•
Vascular shock – ______________ is normal, but circulation is poor as extreme vasodilationi causes
abnormal ________________of the vascular bed. Could be due to __________________ or
___________________ (bacterial infection – bacterial toxins are noted ________________)
•
Cardiogenic shock – occurs due to __________________________.
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Atherosclerosis:
 Process in which deposits of ___________________, cholesterol, wastes, calcium, etc. build up in the
__________________ of an artery. This build up is known as plaque.
 Atherosclerosis is an _______________ of this process.
 How would a plaque affect resistance?
 How would it affect blood flow?
Differences between arteries and veins:
Arteries
Veins
Note that ____________ and _____________________ have unique venous drainage systems:
Brain – veins drain via dural venous___________________
Digestive system – veins drain via ____________________________
Circulation
(See list of arteries/veins in objectives)
Systemic Circulation

Delivers ________________________ to body tissues from heart and
__________________________ ______________________ from body tissues to heart
Circle of Willis
Hepatic Portal Circulation

Shunts _________________rich blood from __________________ to
___________________________ for filtering before going to general circulation
Pulmonary circulation

Delivers _______________blood from heart to lungs for _____________________ and oxygen
from lungs to heart
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