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

Many open circulatory systems 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

(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

However the blood vessels 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?

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

“Shear thinning” helps to reduce the resistance in very small

capillaries.

What is there still even with shear thinning?

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

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 when 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?

Slow blood flow facilitates nutrient and gas exchange with

tissues.

What is blood

A “connective tissue” composed of PLASMA & FORMED ELEMENTS

What is plasma?

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

What is Albumins?

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?

Globulins – 35% of plasma proteins •

Antibodies (“immunoglobulins”) •

Transport globulins (transport lipids, hormones, vitamins, etc.)

What is Fibrinogen?

Fibrinogen – 4% of plasma proteins

• Join together to form fibrin in order to start clotting

process.

What are formed elements?

What are platelets

membranes filled with proteins, growth factors, and other things