Blood/ Circulation

What is the purpose of cirulation? Which ones are slow and fast

Transport nutrients and wastes (energy, electrolytes). Often can be relatively slow.

Transport gasses (Oxygen to muscles, release Carbon Dioxide). Often must be fast.

Transport heat (from core to periphery). Often must be fast.

Control body functions by transporting hormones. Often can be relatively slow.

What can small organism use

use diffusion to exchange nutrients, gasses, and heat with the environment.

What is L and D

L = diffusion legnth

D= diffusion coefficient

What can larger organism not rely on?

cannot rely on diffusion

What must large organism move?

must move water, nutrients, and dissolved gasses through “circulation:” bulk movement of fluids.

Most animals (like insects, crustaceans, and mollusks)

use what kind of circulatory system

Open circulatory system

what pumps blood? what is blood not confined to

One or many hearts pump blood, but blood is not confined to blood vessels.

Where does blood flow

Blood flows freely around body tissue

What does open circulatory systems in insects transport? What does it not transport?

transport nutrients but NOT gasses

What do insects have for gas exchange

(insects have small tubes called “trachea” for gas exchange)

What do many Open circulatory systems not need

do NOT need fast fluid flow.

What do Animals like earthworms,fish,reptiles and mammals use?

Some animals (like earthworms, fish, reptiles and mammals) use a “closed” circulatory system.

What happens to closed cirulatory systems in order to move fluid

Closed circulatory systems are pressurized to move fluid

How many hearts do earthworms have? what does it help?

(Earthworms have five hearts to help pump blood).

What are the benefits of a closed ciruclatory system

• Fast transport of blood through vessels (arteries and veins).

• Blood can be directed to (or away from) specific tissues.

• Blood volumes for closed circulatory systems ≈ 10% of body weight (compared to 30-60% of body weight for open circulatory systems).

• Specialized carriers can travel in vessels and transport hormones or nutrients to specific sites

• Filtration of blood by kidneys

What do humans only have 1 of

Humans only have one heart

What must blood vessels be

must be small enough for diffusion to be able to exchange nutrients and gasses with tissues.

How to go from one big heart to many small capillaries?

Branching

What do arteries from the heart branch into? What do they convey?

Arteries from the heart branch into smaller “Arterioles”

that convey blood to tissues.

What do arterioles branch into? what does it connect to?

Arterioles branch several times into very small “Capillaries,” that connect the arterioles to “venules.”

Where do Venules Join and form? where/what does it return

Venules join to form “veins” to return blood to heart.

What does shear thinning help to reduce

helps to reduce the resistance in very small

capillaries.

What is there still even with shear thinning?

there is still substantial resistance in capillaries.

What causes blood pressure to drop

Resistance in small vessels and capillaries converts pressure energy to heat causing blood pressure to drop

Where must blood pressure start from? What could happen?

The blood pressure must start high in the larger vessels. Otherwise, there could be “ischemia”

What is Ischemia?

ischemia is low blood flow in capilarries

Where does blood flow down?

Blood flows down a pressure gradient

What happens as blood vessels branch?

As blood vessels branch, the cross-sectional area increases.

How does blood flow in capillaries?

Blood flows more slowly in capillaries.

What does slow blood flow facilitate?

facilitates nutrient and gas exchange with tissues.

What is blood? What is blood composed of?

A “connective tissue” composed of PLASMA & FORMED ELEMENTS

What is plasma? How much does it make up? What does it contain

the liquid component of blood, making up around 55% of its volume, and containing vital proteins

What is Albumins? What is it a major contributor to? What does it transport?

Albumins – 60% of plasma proteins

Major contributor to osmotic pressure of the blood. •

Transport compounds such as bilirubin, ions, fatty acids, and drugs.

What is Globulins? What does it transport?

Globulins – 35% of plasma proteins (Antibodies)

(transport lipids, hormones, vitamins, etc.)

What is another word for Antibodies

immunoglobulins

What is Fibrinogen? What do they form?

Fibrinogen – 4% of plasma proteins

• Join together to form fibrin in order to start clotting

process.

What are formed elements?

Platelets, white blood cells, & Red blood cells

What are platelets

membranes filled with proteins and growth factors

Why are platelets important

Important for blood clotting and repairing tissue damage.

Imagine that a blood vessel branches. Each branch (B) is a “bifurcation” into two equal parts with half the radius of the larger vessel (A). What will happen to the TOTAL resistance

The branches will have much MORE resistance than the main artery

What is cool propety of Blood?

the viscosity of blood (η) decreases with shear rate.

What is the main problem in viscosity and shear? Why is it a problem in smaller pipes?

“resistance”

because resistance increases SO MUCH with smaller pipes.

What needs to be brought in for Nutrient, gas , hormone exchange and waste removal

Blood must be brought into close proximity with tissues for

nutrient/gas/hormone exchange, waste removal,

What needs to happen for flow and capillary filtration

Blood pressure in small vessels must be enough for flow and

capillary filtration.

What do Big vessels at high pressure have? What equation would model this? And what could it lead to in walls?

BIG vessels at high pressures have lots of tension

(Laplace’s equation: T = P * r)

in walls (could lead to aneurisms)

What does blood exhibit? what is the result?

Although blood exhibits “shear thinning,” SMALL capillaries result in HIGH resistance to flow

What requires the heart/ large vessels to operate? At what pressure?

Maintaining blood pressure in small vessels requires the heart and large vessels to operate at relatively HIGH pressure.

What are Leukocytes

(White Blood Cells)

what do leukocytes respond to

Immune response to pathogens.

What are Erythrocytes

Erythrocytes (Red Blood Cells)

What do Erythrocytes transport?

Transport gases within the blood (especially oxygen)

Where are Formed Elements produced? what is the process called?

Formed elements are produced in the bone

marrow in a process called “hematopoesis.”

What can differentiate into all different types of formed elements.

A single “stem” cell, called the “Hematopoetic” stem cell, can differentiate into all different types of formed elements.

What does Heme mean?

“Heme” from “

What does Haima mean

blood

What does Poesis mean

“to make” as in “poetry.”)

What stimulates Hematopoesis

Cytokines, thrombopotein, Colony-stiumulating factors

What does Cyto mean

Cell

What does Kinos mean

movement

Where is Thrombopoietin found? what does it stimulate?

Thrombopoietin (TPO) found From liver. Stimulates production of platelets.

How are Colony-stimulating factors released? what is stimulated?

Released by lymphocytes and other cells during immune response to stimulate production of leukocytes.

What does Erythropoietin stimulate?

Stimulates production of erythrocytes.

What does Erythropoietin produce in response? Whats another name?

Produced by cells in kidney in response of low blood oxygen (hypoxia).

How much is Plasmas Viscosity compared to water

Plasma has a viscosity of ~1.8 times that of water.

How much is Whole bloods viscosity compared to water

Whole blood has a viscosity 3-4 times that of water.

What causes the Viscosity of Blood to increase?

Viscosity of blood increases with hematocrit

How much blood does the heart pump in one day?

In one day the heart pumps about 2,000 gallons of blood.

How far does blood circulate through and where?

Blood circulates through 60,000 miles of arteries, veins, and capillaries.

How many times does the heart beat on average? how many times per day?

The heart beats an average of 70 times in one minute or over 100,000 times a day.

What is heart rate related to

Heart rate is related to body size.

What is a canarys (birds) heart rate

A canary has a heart rate of 1000 beats per minute.

What is a new borns heart rate

The newborn human has a heart rate of 130 BPM

What is an adults heart rate

the adult human has a heart rate of 70 BPM.

What does a human heart consist of

The heart consists of 4 chambers

What are the 4 chambers of the heart? What is the atria superior to?

2 Atria & 2 Ventricles (Atria is superior to ventricles)

What are the 2 seperate chambers the heart pumps blood into? Where does the blood go?

Pulmonary Circuit (deoxygenated blood to lungs)

Systemic Circuit (Oxygenated blood to body)

What does the Atria receive

Blood

What does the Atria not need?

Doesnt need strong muscles

What do ventricles do?

Pump Blood

What are Ventricles described as

Very muscular

What does Auricles act as?

pressure relief and extra blood storage for atria.

What does the right side of the heart receive

Blood from the systemic body circuit and pumps blood to the pulmonary lung circuit

What does the left side of the heart receive

receives blood from the ”pulmonary” lung circuit, and pumps blood to the “systemic” body circuit.

What is heart rate (HR)?

The number of times your heart beats per minute

What is a normal resting heart rate

55-100bpm 75BPM

60 BPM is considered what?

60 bpm: “bradycardia”

What does bradycardia mean

“bradus” meaning “slow”) (slow heart rate)

100 BPM is considered what?

100 bpm: “tachycardia”

What does Tachycardia mean

“tachycardia” (Greek: “Tachy” meaning “swift”) (Fast heart rate)

What is blood pressure

The force of blood pushing against vessel walls when the heart beats

A persons blood pressure is 120/80 What do these numbers mean

120 = Systolic

80 = Diastolic

What does Systolic mean

To contract

What does Diastole mean

Seperation Expansion

During the cardiac cycle what is Late Disatole

Both sets of chambers are relaxed and ventricles fill passively from venous ”diastolic” pressure.

During the cardiac cycle what is Atrial systole

Atrial contraction forces additional blood into ventricles.

During the cardiac cycle what is Ventricular systole A. What is the first sound

Ventricles contract. Pressure closes valves between atria and ventricles. First sound: “Lub”

During the cardiac cycle what is Ventriclar systole B? what does it open? Where does blood flow?

Ventricular pressure exceeds pressure in arteries, opening “semilunar” valves. Blood flows from heart into arteries.

During the cardiac cycle what is Ventriclar diastole. What is the Second sound?

Ventricles relax. Some “backflow” of blood closes semilunar valves. Second sound:“Dub”

In heart valves what are Mechanical Valves made of

made up of cells, collagen, and elastin (proteins)

In Heart valves where is the atrioventricular located

Located between atrium and ventricle