1. I. OVERVIEW OF BLOOD VESSEL STRUCTURE AND FUNCTION
OVERVIEW: Parts & Function
Arteries and arterioles:
Capillaries
Veins and Venules
TOPICS
Histology
Gross Anatomy
Physiology
Blood Flow
Blood Pressure
Disorders
How Capillary’s Function
Specific Blood Vessels & Identification
Arteries
Capillaries
Veins
ADDED

2. Ch. 19-b The Cardiovascular System: Blood Vessels

3. II. PHYSIOLOGY OF CIRCULATION
OVERVIEW
IMPORTANCE: All Organs/Tissues Need Adequate Blood– O2, Co2 & Nutrients & To Get Rid Of Wastes
Heart gets blood into Vessels, then
Vessels take over getting blood to cells
BLOOD VESSEL FUNCTIONS
Systemic Blood Pressure (Overall) must be maintained to keep blood moving to all the tissues as a whole
Blood Flow is Altered To Specific Organs/Tissues to supply what they need when they are active or not
Interrelated

4. II. PHYSIOLOGY OF CIRCULATION …
A. Definitions and Physics of Blood Flow, Blood Pressure, and Resistance
1. *Blood Flow (F) =
if the entire body: then blood flow = Cardiac Output
Amount to particular Organs varies with organ’s activity and needs
2. *Blood Pressure (BP) =
*For largest arteries near heart, BP =
*Pressure Gradient =
- *Purpose?
Blood flows from _______________ pressure to ________________pressure
Resistance NEXT SLIDE 

5. F = P/R 3. *Resistance = Factors Affecting Peripheral Resistance:
Definition of Terms …
3. *Resistance =
Factors Affecting Peripheral Resistance:
a) *Blood Viscosity =
- Mostly away from Heart
b) *Total Blood Vessel Length & Relationship =
c) * Blood Vessel Diameter
& Relationship to Resistance
- most important
- In small-diameter arteries
F = P/R
Volume
Velocity
Arteries Capillaries Veins

6. c) Blood Vessel Diameter ….
A change in diameter of the blood vessels or protruding portions of blood vessel wall create turbulence which increases resistance
Relationship between Flow, Pressure, and Resistace
 = Change in
P = Pressure Gradient = difference in pressure
between two points in the
vessels
If P increases-Flow ________
If R increases-Flow ________
Velocity volume
F = P/R
Arteries Capillaries Veins

7. B. Systemic Blood Pressure
*Arterial Blood Pressure: Due to what two factors?
a) GRAPH:
*Greatest Pressure in what Vessels? Why?
*Lowest Pressure is in what type of Vessels? Why?
What is the relationship?
b) *Pulse Pressure & Pulse =
93mm = MAP
Systolic Pressure:
Diastolic Pressure:

8. B. Systemic Blood Pressure …
c) Mean Arterial Pressure: is the actual pressure that propels blood throughout the vessels
- Because pressure varies and the blood remains longer in Diastole, then:
MAP = diastole + 1/3 pulse pressure
Both MAP and Pulse Pressure decline with increased distance from the hear
- Arterioles: many & small
Have the Steepest Pressure drop, actually loose pulse
93mm = MAP

9. e) Pressure Points in taking BP
1. Arterial Pressure …
d) Vital Signs
e) Pressure Points in taking BP
Capillary Blood Pressure =
35 – 15mm Hg
Venous Blood Pressure = 15mm to 0mm Hg (entering right atrium)
b) Muscular Pump
a) Respiratory Pump

10. C. Maintaining Blood Pressure OVERVIEW:
∆P = CO X R
Interaction between heart and Blood Vessels
1. SHORT-TERM
Autonomic N.S. (EXTRINSIC)
Via Baroreceptors  Vasomotor & Cardiac Centers
Via Chemoreceptors  “ “ “
HORMONAL (EXTRINSIC)
Sym.  Adrenal Medulla: Epinephrine and NE
Kidney: Renin  Angiotensin II
Heart: Atria Natriuretic Peptide
2. LONG-TERM-- KIDNEY
DIRECT: amount of urine produced (INTRINSIC)
INDIRECT (EXTRINSIC)
Renin  Angiotensin  Aldosterone
 ADH
 thirst
3. BLOOD VESSELS OF A PARTICULAR ORGAN

11. C. Maintaining Blood Pressure OVERVUEW– INTRODUCTION
Three Main Variables:
Cardiac Output (Blood volume)
Peripheral Resistance
Blood Volume
Organs Involved: Heart, Blood Vessels, Kidneys, Nervous System & Endocrine system
For Entire circulation: Blood Flow (F) = CO = ∆P/ R
and rearrange to ∆P = CO X R
Also from Heart: CO = SV x HR
Homeostasis: factors affecting Cardiac Output interact with those affecting Mean Arterial Pressure– if one variable changes blood pressure is compensated by changes in other variables
 Regulation of Heart functions and Blood Vessels interrelated

12. C. Maintaining Blood Pressure … Mechanisms
Mechanisms OVERVIEW:
Short-term: Normal Regulation via autonomic NS and Hormones
Long-term: via mostly kidneys in unhealthy people, emergency states.

13. Maintaining Blood Pressure …
∆P = CO X R
1. Short-term–Neural Controls
a. Purpose:
i) Maintain Mean Arterial Pressure (MAP) so as to maintain Systemic Blood Pressure
altering vessel diameter to change Resistance
ii) Specific organ demands
altering blood distribution via diameter
changes & vascular shunts
b. Mechanism–Cardiovascular Center in Medulla: Vasomotor (Sym), Cardioinhibitory (Para), Cardioacceleratory (Sym): Affects Resistance and CO
i) Baroreceptor-Initiated Reflexes most important
- Location: in Carotid Sinus
(Internal Carotid A) & Aortic Arch
- If BP increases ↑ stretch of Baroreceptors

14. *Vasomotor Center: inhibited  Results in what?
Short Term Neural Controls … Mechanism … b) Baroreceptors and Vasomotor Center …
∆P = CO X R
ii) If BP increases  increased stretch of Baroreceptors  sends messages to the Cardiovascular Center in Medulla:
*Vasomotor Center: inhibited  Results in what?
Cardioaceleratory: inhibited:  Results in what?
Cardioinhibitory stimulated  Results in what?
*If BP decreases  decrease in stretch of Baroreceptors  Then what?
iii) Baroreceptor Problems with Sustained increase in pressure: they adapt in Long-term especially in those with chronic high blood pressure
- Then Long-term mechanisms are used-- Renal

15. Maintaining Blood Pressure … Short-term Neural Controls
iv) Short-term Chemical Reflexes: for O2, CO2, & H+
Mainly in response to breathing changes
Via Chemoreceptors  Autonomic NS
Short-Term Mechanisms: Hormonal Controls
- Alters RESISTANCE by changing vessel diameter
Adrenal Medulla Hormones-- produced during stress
i) Norepinephrine (NE)  mostly
constriction of vessels
But, Vasodialation in skeletal &
cardiac muscle
ii) Epinephrine  affects mostly the Heart
Angiotensin II: produced in kidney using Renin
- Causes Intense Vasoconstriction
∆P = CO X R

16. Control of Blood Pressure … 3. Long-Term Mechanisms: Renal Regulation
Via changing: BLOOD VOLUME
a. Direct (intrinsic) independent of hormones
↑ BP in renal arteries  more urine  less blood volume  ↓ BP
b. Indirect (extrinsic) renin-angiotensin mechanism (Same as Short term mechanism)
 Angiotensin II: affects on blood volume (CO)
↑ Aldosterone: reabsorbs Na+, and water follows
↑ ADH: reabsorbs H2O
↑ Thirst via Hypothalamus
∆P = CO X R
Figure 19.10

17. REVIEW: Systemic BP Regulation
∆P = CO X R
Interaction between heart and Blood Vessels
1. SHORT-TERM– affects vessel diameter
Autonomic N.S. (EXTRINSIC)
Via Baroreceptors  Vasomotor & Cardiac Centers
HORMONAL (EXTRINSIC)
Sym.  Adrenal Medulla: Epinephrine and NE
Kidney: Renin  Angiotensin II
2. LONG-TERM– KIDNEY affects blood volume
DIRECT: amount of urine produced (INTRINSIC)
INDIRECT (EXTRINSIC)
Renin  Angiotensin  Aldosterone
 ADH
 thirst

18. III. Blood Flow To Specific Body Tissues
A. Blood Flow to particular tissues
Capillaries have greatest affect
Independent of MAP (systemic pressure)
Flow = ∆P X R
To specific Organs: Flow is right for proper function
B. Autoregulation INTRINSIC
Modifies via diameter of arterioles
Mechanisms next slide
Brain
Heart
Skeletal
muscles
Skin
Kidney
Abdomen
Other
Total blood
flow at rest
5800 ml/min
Total blood flow during strenuous
exercise 17,500 ml/min

19. Metabolic: INTRINSIC To ↑ Flow to Active Tissues
B. Autoregulation …
Metabolic: INTRINSIC To ↑ Flow to Active Tissues
Active Tissues: have increased CO2, H+, NO
trigger dilation
Precapillary Spincters open
Inflammatory chemicals (tissue damage)  dilation
2. Myogenic: INTRINSIC To protect against inadequate perfusion and high of pressure that would rupture vessels
↑ Pressure ↑stretch  damage to small vessels: so compensate by constricting to reduce flow to organ
↓ Pressure ↓stretch  tissue not adequately oxygenated: so compensate by dilating
Long-term Regulation
Angiogenesis: ↑ blood vessels

20. C. Blood Flow in Specia Areas
1. Blood Flow: Lungs
Pulmonary circuit is short and Arteries/arterioles structurally like veins/venules
Arterial resistance and pressure are low (24/8 mmHg)
Autoregulation opposite of most tissues at capillaries
Low O2 levels = blocked/damaged air sacs  bypass with vasoconstriction;
High O2 levels means that air sacs are functional, so send blood to them  dilation

21. D. Blood Flow Through Body/Tissue Capillaries and Capillary Dynamic
1. Capillary Exchange of Respiratory Gases and Nutrients– how they get from blood to tissues
Gases Diffusion of O2 and CO2
TO TISSUES:
FROM TISSUES:
a. Lipid-soluble molecules diffuse directly through membranes
b & c. Water-soluble solutes pass through clefts/fenestrations
d Larger molecules, such as proteins, actively transported
SEE NEXT SLIDE FOR DIAGRAM

22. IV Disorders of the Blood Vessels
Students Do Following:
Atherosclerosis
Types of Circulatory Shock
Hypo- and Hypertension

23. PART 3 CIRCULATORY PATHWAYS: BLOOD VESSELS OF THE BODY
Two Main Circulations
V. Systemic Arteries & Veins
Arteries: Left Ventricle  AORTA
Arch
Thoracic Aorta
Abdominal Aorta
Pelvic Cavity: Common Iliac Arteries
Figure 11.12

24. Veins: entering Right Atrium
V. Systemic … …
Veins: entering Right Atrium
Superior Vena Cava
- Circle of Willis (a.k.a. cerebral arterial circle) keeps blood flowing to brain
Figure 11.13

25. 2. Inferior Vena Cava
a) Digestive organ Veins do not directly take blood back to Inferior Vena Cava, but to Liver: food eaten may have toxins in it, so must be processed by Liver before toxins are spread to the rest of the body

26. b. Hepatic Portal System Digestive Organ Capillaries drain into
Veins: entering Right Atrium …
2. Inferior Vena Cava
b. Hepatic Portal System
Digestive Organ Capillaries drain into
 Digestive Organ Veins: Superior & Inferior Mesenteric and Splenic
Do not directly empty into the Inferior Vena Cava
Hepatic Portal Vein  drains into
 Liver Sinusoids for processing of digested food
Hepatic Veins then take processed blood
 Inferior Vena Cava
Figure 11.13

27. b. Hepatic Portal System …
Digestive Arteries  Digestive Capillaries  Digestive veins
 Hepatic Portal V.  Liver sinusoids  Hepatic Veins
 Inferior Vena Cava  Right Atrium

28. VI. Pulmonary Arteries & Veins
Arteries– Pulmonary Trunk from Right Ventricle
Left and Right Pulmonary Arteries
B. Veins– 4 Pulmonary Veins enter Left Atrium

29. END PPT
Review Questions
Extra Slides

30. precapillary sphincters
Review Questions
What type of capillaries are found in the liver and bone marrow?
What type of vessel maintains the lowest pressure and highest blood volume?
One mechanism of blood flow control through capillary beds is via __________ ___________ that can bypass beds by routing blood through vascular shunts.
Sinusoid
Veins
precapillary sphincters

31. Review Questions
Alternative routs for blood flow that develop from interconnecting vessels are known as _____________.
What type of vessel provides the major source of resistance to blood flow?
Blood pressure depends on what 3 major variables?
anastomoses
Arterioles
CO, R, and Blood Volume

32. Baroreceptors and Chemoreceptors
Review Questions
Short term neural control of BP is controlled by reflex arcs involving what types of receptors?
________ is the only hormone that reduces blood volume and is produced by the __________
Which short term hormonal control is initiated by renin release from the kidneys?
Baroreceptors and Chemoreceptors
ANP
heart
Angiotensin II

33. CO, Resistance, and Blood Volume Blood Volume – which is regulated by?
Review Questions …
Blood pressure depends on what 3 major variables?
Short term control of BP is regulated by which of the above?
Long term control is regulated by changing which variable?
CO, Resistance, and Blood Volume
Resistance (and CO)
Blood Volume – which is regulated by?

34. Via intercellular clefts or fenestrations
Participate
Localized adjustments made to ensure blood flow according to tissue needs = __________________
_________ autoregulation occurs when arterioles are stretched if systemic BP increases
How do water soluble solutes pass through capillary walls?
autoregulation
Myogenic
Via intercellular clefts or fenestrations

35. Net Filtration Pressure
Review Questions
What does NFP stand for?
When net hydrostatic pressure (HP) is less than net osmotic pressure (OP), which way do fluids flow?
What vein delivers blood TO the liver?
Net Filtration Pressure
Into capillaries
Hepatic portal vein