1. Isovolumetric ventricular contraction (isometric b/c no blood ejection); aortic valves remain closed until P vent>P aorta

2. Ventricular ejection (isotonic); P vent>P aorta

3. Atria fill from great veins (P atria rises)

1. Isovolumetric ventricular relaxation, no blood enters from atria b/c AV valves are closed (P vent> P atria)

2. Ventricular filling, occurs when AV valves opena b/c P vent < P atria)

3. Atria contract, at this point 80% of ventricular filling already occured before contraction 

R= (viscosity)(length)/(radius)^4

Therefore, if rad inc 2x, then flow increases 16x 

5 liters/min @ rest 

1. Striated (strong)

2. Branching

3. Gap junctions b/w fibers (intercalated disks)

4. Each fiber is not innervated, actions potentials spread electrically 

R atrium fibers contract after AP spreads via gap junctions

L atrium fibers also get AP via special conducting fibers

1. Need atria to empty before ventricles contract

2. Cells of AV node have less intercalated disks, so have slower transmission of AP (.03-.05m/s) 

1. SA node to atria (almost instant)

2. Purkinje fibers (5 m/s)

3. AV node (.03-.05 m/s) 

Parasympathetic (vagus nerve)

Acetylcholine (ACh) 

______ nerves slow HR (eg. ________)

example of hormone that inc. HR are ________ 

Sympathetic

Epinephrine and norepinephrine 

_______ nerves increase HR

example of hormones that inc. HR are ________ & ___________

1. Slow contraction of heart (300msec vs 20-100msec in skeletal muscles)

2. Long absolute refractory period (250-300 msec)

Due to slow inward flow of Ca++ before K+ eflux hyperpolarizes cell

rest= 5 liters/min (5.3 quarts/min)

max= 30 liters/min 

CO at rest=

during max exercise= 

1. Decrease parasympathetic innervation (vagus nerve) and increase sympathetic innervation

2. Increase stroke volume 

extrinsic control

contractility (strength of contraction) by allowing additional Ca++ to enter

(sympathetic also increases HR) 

increases, decreases

Increases; stays the same or decreases a little; decreases

During exercise, HR _____, so filling time ______.

SV _____, while EDV _____ and ESV _____

At end of systole, ventricles are much lower in pressure b/c they are so empty, so blood goes into ventricles faster.

(greater pressure diff b/w atria and ventricles) 

1. 2.5 cubic cm  (330 mm/s)

2. 20

3. 40

4. 2500

5. 250

6. 80

7. 8 

Total x-section are of 1.aorta (blood speed too)

2. small arteries

3. arterioles

4. capillaries (& blood spd)

5. Venules

6. Small veins

7. Vena cava 

1. Aorta

2. Vena cava

3. Arterioles; capillaries 

1. Highest BP is in ________

2. Lowest is in ______

3. Biggest BP drop is in ________ and then________ 

tissues use up O2 and give off CO2 and lactate

smooth muscles to dilate (increase flow) and relax precapillary sphincters (allows blood into capillary bed) 

Local control of arterioles is caused when _______

which causes _______ and ________ 

Metarterioles and thoroughfare channels

Arteriovenous anastomoses

Precapillary sphincters are composed of ___ and ____.

When closed, blood bypasses capillaries using _____ 

Sympathetic innervation

Gut and genitals, parasympathetically 

Reflex controls of most arterioles are with _____

A few arterioles in ______ and ______ are innervated _______ 

_____ sympathetic fibers give off _______

which increases alpha and beta receptor firing rates 

Vasoconstriction

Vasodilation 

Increase in alpha receptor firing = _____

Increase in beta firing = _____ 

Cholinergic, acetylcholine,

smooth muscles of arterioles in skeletal muscle, ACh, vasodilation

_______ sympathetic fibers give off ______,

and they innervate _________.  Increase in _____ results in _________

local control, reflex control

fuel can be diverted ot skeletal muscles 

capillary

muscles to change radius 

low, large, distensible

low (pressure falls very little in veins 

Accessory pumps

1. Skeletal muscle pumps

2. Pressure changes due to breathing 

_________ help propel low pressure venous blood against gravity.  Two examples of this are:

1.

2. 

1. Arteriole dilation by local control

2. Some reflex vasodilation by beta adrenergic fibers of sympathetic system 

Increased flow to cardiac muscle is b/c of:

1.

2. 

local control of arteriole diameter and relaxation of precapillary sphincters 

5-10%

85% 

_____% of capillaries open at rest

___% of total blood flow goes to skeletal muscle during max exercise 

increases to capillaries near surface (to get rid of heat)

is diverted from surface via arteriovenous anastomoses 

During exercise, skin blood flow ______

In cold weather skin blood flow ______ 

Autoregulation

dilate

constrict 

There is ____ of cerebral arteries:

when P falls, they _____

when P rises, they _____ 

84%

        64%

        15%

        5%

7%

9% 

__% of blood is in the systemic circuit

            ___ in systemic veins

                ___ in systemic arteries

                    ___ in systemic capillaries

___% in heart

___% in pulmonary circuit 

1. Temporary reservoir during systole (atria and arteries/veins)

2. Flexible pipes can accomodate inc flow and can bend when we move 

Why vessels are not rigid

1.

2. 

Under the same pressure, bigger blood vessels need ____ walls than a small pipe to resist expansion 

greater

weight of column of blood 

1. Elastic tissue (elastin) is stretchable

2. Collagen: 100x stiffer than elastin, and becomes unkinked when stretched, resisting more stretching

Aneurysms don't happen b/c:

1.

2. 

pulmonary capillary resistance is high;

resistance decreases 

Shunts are needed in fetuses b/c of ______;

during birth the shunts close b/c ____ 

O2 and nutrients from placent to fetus

Waste-laden blood from fetus to placenta 

Umbilical veins carry _____ from ___ to ____

Umbilical arteries carry ____ from ___ to ____

cells & large proteins can't

H20 and small solutes can 

Capillaries are leaky:

____ & ____ can't leave

____ & ____ can leave 

1. Returns excess interstitial fluid to the blood stream

2. Returns important small proteins lost at capillaries

3. Transports fats absorbed from the small intestine to the blood

4. Immunological defense against disease via lymphocytes 

Purposes of lympathic system:

1.

2.

3.

4. 

capillaries, overlapping endothelial cells that form one-way valves letting extracellular fluid in;

lymphatic ducts 

67%

33%

    80%

     20%

Total body fluid distribution:

Intracellular:

Extracellular:

        Interstitial:

                            In blood plasma (vessels):

Increased sympathetic input (eg. adrenal hormones)

vasoconstriction, BP 

Baroreceptors

aortic arch and carotid sinuses

medulla (vasomotor and cardiac control centers) 

_____ (stretch receptors in vessel walls) are located in ____ and ______

and send info to the ____ (_____ and ____ centers) 

Chemoreceptors

carotid arteries and cerebral vessels

Vasoconstriction

vasodilation 

____ in blood vessels respond to CO2 levels

Located in ____ and _____

Trigger ____ when CO2 is low in interstitial fluid

_____ when CO2 is high in interstitial fluid

1. Plasma

2. Formed elements:

erythrocytes (RBCs) and leukocytes (WBCs),  thromobocytes (platelets)

Blood is made of:

1.

2. 

1. large surface area for diffusion

2. Contain hemoglobin to transport O2

3. Lack nucleus and mitochondria, so no aerobic metabolism 

Life: 3-4 month

Heme broken down in liver into biliruben and excreted via bile (globin proteins are recycled)

Erythrocytes features:

1.

2.

3. 

Lifespan:

Broken down into 

do contain

amoeboid

capillaries 

Leukocytes (do/do not) contain nuclei, mitochondria

They move in ____ fashion

Can leave blood at ________ 

1. Basophils

2. Eosinophils

3. Neutrophils 

1. Detoxification

2. Help break down blood clots

pink 

Eosinophils 2 purposes

Are stained _____ w/ eosin 

heparin, an anticoagulant

blue in basic stain 

Basophils produce ____, which is ______

stains _____ in _____ stain 

1. Large lymphocytes

2. Small lymphoctyes

3. Monocytes 

The 3 agranulocyte types

Red bone marrow aka myeloid tissue

Flat bones of skull, head of humerus/femur, sternum, ribs, pelvis 

New red blood cells are made in _______  found in:

Lymphoid tissue

Lymph nodes, tonsils, spleen, thymus 

1. Albumins

2. Globulins

3. Fibrinogen 

1. plasma

2. buffy coat (WBCs)

3. Packed cells (RBCs) 

1. Vasoconstriction

2. Formation of platelet plug

3.Production of fibrin (protein) web solidifying the thrombus (clot)

Breaking of blood vessel leads to:

1.

2.

3.

1. Serotonin and some prostoglandins to stimulate vasoconstriction

2. Phospholipid activation of clotting factors in plasma

3. ADP helps other platelets stick to collagen and each other to make a platelet plug

Platelet release reaction causes

1.

2.

3. 

fibrin, thrombin,

prothrombin 

Heparin - prevents activation of factor IX

Aspirin- inhibits prostaglandin action 

delayed negative feedback loop

plasmin, bradykinin 

1. Peptide hormones

2. Catecholamines 

1. Have charges on surface

2. Soluble in water so can be transported in blood

3. Cell membranes are nonpolar so act as barriers to polar hormones

4. Thus, receptors for hormones are on surface of cell (second messenger is produced inside cell membrane)

Adrenal medulla, tyrosine

Epinephrine and norepinephrine 

1. Steroids made from cholesterol

2. Thyroid hormones 

Gonads: testosterone, estrogen

Adrenal cortex: cortisol, aldosterone, corticosterone 

1. Fat so can't dissolve in blood (need carriers for transport)

2. When bound to carrier they're inactive, active upon detachment

3. Can move thru cell membranes (nonpolar) so receptors are found inside cell so second messenger does not need to be made

4. Usually act on level of gene (turns on/off production)

Trophic: Gonadotrophins (LH and FSH), ACTH, TSH

Nontrophic: growth hormone, prolactin 

1. GnRH

2. CRH

3. TRH 

Releasing hormone for:

1. Gonadotrophins

2. ACTH

3. TSH