Bio 104 Lecture Outlinecourse Coordinator

1

Bio 104 Lecture OutlineCourse Coordinator:

Chapters 17, 18, 19, 20L. Falkow

Revised 1/05

The Cardiovascular System

1. Introduction & Overview of the CV System

Pulmonary circuit

Systemic circuit:

Coronary circulation

Arteries

Capillaries

Veins

1. Anatomy of the Heart
2. Location & Size

1. Mediastinum

2. Size

B. Pericardium

1. fibrous pericardium

2. serous pericardium

parietal pericardium

[pericardial cavity]

visceral pericardium

3. Disorders

pericarditis

cardiac tamponade

C. Superficial Anatomy

Auricle

Coronary sulcus

Interventricular sulcus

Base

Apex

D. Internal Anatomy

4 Chambers: 2 atria and 2 ventricles

1. Right Atrium

SVC

IVC

Coronary sinus

Foramen ovale

Right atrioventricular (AV) valve>

2. Right Ventricle

chordae tendinae

papillary muscles

Pulmonary Semilunar valve  ______

 LUNGS  ______

3. Left Atrium

<Left Atrioventricular (AV) valve>

4. Left Ventricle

<Aortic Semilunar valve>

 ascending aorta

 openings to coronary arteries

5. Structural differences between ventricles

RV wall –

LV-

6. Heart valves

AV valves:

Semilunar valves:

E. Heart Wall

1. Epicardium

2. Myocardium

3. Endocardium

cardiac muscle tissue characteristics

F. Coronary Circulation

1. Right coronary artery

└> marginal branch

└> posterior interventricular branch

(post. descending artery)

2. Left coronary artery

└> circumflex branch

└> anterior interventricular branch

(left anterior descending artery)

3. Coronary veins

great cardiac vein

└> coronary sinus  ______

G. Cardiac Muscle Cells

Contractile cells do the pumping (99%) of all cardiac cells.

Conducting system (specialized cells) regulate actions of contractile cells.

III. Conduction System and ECG

A. Conducting system includes:

Nodal tissue

SA (sinoatrial) node

AV (atrioventricular) node

AV bundle (of His)

Bundle branches

Purkinje fibers

ACh (PSN)

Ectopic pacemakers

B. Electrocardiogram (ECG)

- measure of electrical changes that accompany each cardiac cycle

(heartbeat)

1. Wave forms:

P wave

QRS complex

T wave

2. Intervals

P-R interval:

Q-T interval:

3. Conduction system problems

a. heart block

ex. SA node block

AV node block

b. arrhythmias

bradycardia < 60bpm

tachycardia >100bpm

C. Cardiac Cycle

1. Consists of:

systole – contraction phase

diastole – relaxation phase

2. Average heartrate: ~75 bpm (70-80bpm)

3. Heart sounds

auscultation

“lubb” =

“dupp”

[MVP]mitral valve prolapse -

murmur -

IV. Cardiodynamics

- movements & forces during contractions of the heart

A. Cardiac Output

CO = HR x SV

HR = heartrate (bpm)

SV = stroke vol. (ml/beat)

NormalCO:

CO = HR x SV

During exercise:

CO = HR x SV

B. Factors affecting stroke volume

[ EDV, ESV, ventricular stretching, contractility, hormones]

1. The EDV

EDV [end diastolic volume]

= amt. blood in ventricle at end of diastole(start of vent. systole)

2. The ESV

ESV [end systolic volume]

= amt. of blood in ventricle after contraction

(at start of vent. diastole)

3. Frank-Starling principle (Starling’s law of heart}

“more in = more out”

4. Contractility

5. Hormones

C. Factors affecting heart rate

[ ANS,Atrial reflex, Hormones, Venous return]

1. ANS Innervation

CAC (cardioacceleratory center)

CIC (cardioinhibitory center)

2. Atrial reflex (Bainbridge)

3. Hormones

4. Venous Return

D. Exercise and Cardiac Output

C.O. varies to needs of body; metabolic needs of the cell.

athletenonathlete

V. Blood Vessel Anatomy

Arteries

Arterioles

Capillaries

Venules

Veins

A. Structure of vessels

1. 3 basic layers (tunics)

a. tunica interna (intima)

<internal elastic lamina or membrane

b. tunica media (middle coat)

<external elastic lamina or membrane>

c. tunica externa (adventitia)

2. Arteries

- 3 layers:

tunica interna

tunica media

tunica externa

- highest pressure []

Elastic arteries (conducting)

Ex.

Muscular arteries (distribution arteries)

Ex.

3. Arterioles

- resistance vessels

- greatest change in pressure [ ]

As arteries ____in size  elastic tissue ____

 smooth muscle ____

Elastic arteries can withstand sudden _____ in BP as blood leaves the heart.

Arterioles can regulate distribution of blood to different capillary beds

by ______and _____ .

4. Capillaries

- one cell thick

- low pressure[]

a. Continuous capillaries

BBB

b. Fenestrated capillaries

c. Capillary beds

precapillary sphincter

anastomosis

5. Venules

- 2 layers thick (interna, externa)

6. Veins

- 3 layers

- low pressure [ ]

- reservoir

- valves:

- muscle pump:

- respiratory pump:

B. Structural differences between Arteries and Veins

Arteries Veins

Wall thickness:

X-section:

Tunica media:

Elastic fibers:

Valves:

VI. Cardiovascular Physiology

A. Pressure and Resistance

Hydrostatic pressure (HP)

Circulatory pressure

Blood pressure (BP)

Peripheral resistance (PR)

B. Overview of CV Pressures

1. Vessel diameter

2. Total cross-sectional area

3. BP

4. Velocity

C. Capillary Exchange

- movement of materials across capillary walls:

1. Diffusion - water, ions, small organic molecules, water-soluble, lipid soluble

2. Filtration - hydrostatic pressure forces water& small solutes

across capillary wall

Capillary hydrostatic press. (CHP) = BP in capillary

3. Reabsorption

Osmotic pressure (OP) = water drawing power

Blood colloid osmotic pressure (BCOP)

= blood proteins draw fluids into capillary

4. Interplay between Filtration and Reabsorption

Net hydrostatic pressure = [CHP-IHP]

[tends to move H2O & solutes out of cap.]

CHP (capillary hydrostatic pressure)

arterial end = 35 mmHg; venous end = 18 mmHg

IHP (hydrostatic press. of interstitial fluid)

[~ 0 mmHg]

Net colloid osmotic pressure:

[tends to pull H2O & solutes into cap.]

BCOP (blood colloid osmotic press.)

ICOP (interstitial fluid osmotic press.)

NET FILTRATION PRESSURE = Net hydrostatic pressure - Net colloid osmotic pressure

(NFP) = (CHP - IHP)- (BCOP – ICOP)

Arterial end:

NFP = (35-0) - (25-0) = 10 mmHg

{moves fluid out of cap.}

Venous end:

NFP = (18-0) - (25-0) = -7 mmHg

{moves fluid into cap.}

:. more Filtration occurs than Reabsorption and excess fluid flows into

lymphatic vessels

----> venous (blood) circulation

Edema: = excess fluid in interstitium (fills spaces between cells)

Causes:

1) damage to capillaries:

2) starvation:

3) increased BP:

4) blockage of lymphatic vessels:

5) kidney damage:

VII. Cardiovascular Regulation

A. Autoregulation

1. Local VD

2. Local VC:

B. Neural Control

CV center in brain =

1. Baroreceptors - monitor stretch in vessel walls

carotid sinus -

aortic sinus -

atrial baroreceptors

If BP increases… what happens ?

1.

2.

If BP decreases… what happens?

1.

2.

2. Chemoreceptors

- respond to changes in CO2, O2, pH in blood & CSF

carotid bodies

aortic bodies

If CO2 or pH or O2

C. Hormones

ADH (Antidiuretic Hormone)

- post. pituitary

- promotes water retention; released when decr. blood vol.

[conserves water]

Angiotensin II ACE

- Angiotensin I ------> Angiotensin II in lungs

- powerful VC; incr. BP

[Drugs called ACE-inhibitors]

- stim. thirst

EPO (Erythropoietin)

- from kidneys, released if BP decr. or [O2] decr.

- stim. RBC production

ANP (Atrial Natriuretic Peptide)

- from heart (RA);

- released when chamber wall stretches duringdiastole;

- reduces blood vol. & BP

D. CV Response to Hemorrhage

1. Short-term elevation of BP

2. Long-Term restoration of blood vol.

VIII. Selected Blood Vessels

A. Pulmonary circulation

Pulmonary arteries

Pulmonary veins

B. Systemic Circulation

1. Aorta

Ascending aorta:

 right & left coronary arteries

Aortic arch:

1)

2)

3)

Descending aorta

2. Hepatic portal circulation

-

- inferior mesenteric vein - splenic vein

- superior mesenteric vein

Splenic v. & superior mesenteric v. join to form

hepatic portal vein --> liver

3. Fetal circulation

umbilical arteries (2) - drain deoxygenated blood from fetus

umbilical vein (1) - carries oxygenated blood from placenta

Placenta --> umbilical v. --> ductus venosus to liver --> IVC -->

RA ---> foramen ovale --> LA ---> LV --> aorta (head &

upper extremities)

Blood from upper extremities --> SVC --> RA --> RV (mostly)

pulm. artery (lungs) but most flows through

ductus arteriosus to aorta --> rest of body---> return via umbil. arteries

to placenta

Tetralogy of Fallot:

“blue baby” -> 4 defects:

Pulmonary stenosis

Enlarged RV

Ventricular septal defect

Patent ductus arteriosus

IX. Blood

A. Functions

1. Transportation

nutrients

wastes

respiratory gases

heat

hormones

2. Regulation

pH

electrolytes

body temp. (VC, VD)

3. Restriction

4. Defense

B. Physical Characteristics

1. viscosity:

2. pH:

3. volume:

4. specific gravity:

5. Hct:

X. Components of Blood

A. Plasma [~55%]

1. Differences between plasma & interstitial fluid

Components of plasma:

92% - water

7% plasma proteins

1% other stuff (electrolytes, nutrients, and wastes)

2. Plasma proteins

- albumins [60%]

- globulins [35%]

- fibrinogen [4%]

B. Formed Elements [~45%]

1. Erythrocytes

RBCs

2. Leukocytes

WBCs

3. Thrombocytes

Platelets

C. Hemopoiesis

- production of formed elements

stem cells

hemocytoblasts

myeloid stem cellslymphoid stem cells

all formed elementslymphocytes

except lymphocytes

Hemopoiesis-

Sites of production:

D. Erythrocytes

1. Abundance

RBC count:

Hct:

2. Structure

3. Hemoglobin

Hb

globin: protein part

heme: Fe-containing pigmented part

Hb + O2 ----> HbO2

(reduced(oxyhemoglobin)

hemoglobin)

4. RBC Lifespan & Circulation

5. Erythropoiesis

- RBC production

6. Blood Types

Type AType BTypeABType O

RBCantigen Aantigen Bantigens A,Bnone

Plasmaanti-B antibodiesanti-A antibodiesnoneanti-A & anti-B

antibodies

agglutinogens = surface antigens

Rh factor:

Rh positive =

Rh negative =

cross-reaction - antibody meets its specific antigen =>clumping of RBCs

HDN (hemolytic disease of the newborn)

or erythroblastosis fetalis

- mother is Rh neg., baby is Rh pos.

-

-

1970’s: Rho-Gam

7. Clinical disorders

anemia

hematuria

hemophilia

E. Leukocytes

1. Characteristics

-

-

- nucleated

-

Lifespan: a few hours to a few days

WBC count:

2. Types

Granulocytes: / % / Description / Function
Neutrophils / 50-70% / multi-lobed nucleus / phagocytosis
Eosinophils / 2-4% / 2-lobed nucleus,
red granules / incr. during allergic rxn.
Basophils / <1% / dk.blue granules,
obscure nucleus / inflam. response
Agranulocytes:
Lymphocytes / 20-30% / round nucleus,
little cytoplasm / immune
response
Monocytes / 2-8% / Kidney bean -
shaped nucleus / macrophages

3. Formation

Red bone marrow:

Lymphoid tissue:

4. Clinical

leukopenia

leukocytosis

F. Thrombocytes

1. Characteristics

2-4 μm

cell fragment

150,000 - 500,000 /mm3 [avg. 350,000]

9-12 days

2. Functions

- blood clotting

3. Formation

megakaryocytes

4. Clinical

thrombocytopenia

thrombocytosis

XI. Hemostasis

- prevention of blood loss

A. Vascular phase

vascular spasm - VC of SMC

B. Platelet phase

platelet plug formation

platelets release:

C. Coagulation phase

clotting factors:

extrinsic & instrinsic pathways

XII. Lymphatic System

A. Functions

1. production of lymphocytes

2. return lymph (tissue fluid) to venous circulation

3. distribution of hormones, nutrients,and wastes to circulation

B. Lymph vessels

lymphatic capillaries --> vessels (lymphatics)

---> cisterna chyli --> thoracic duct ==>left subclavian vein

--> right lymphatic duct => rt. subclavian v.

C. Lymph tissues

Tonsils

Lymph nodes

Thymus

Spleen

Aggregate lymphoid nodules

Appendix