Lesson 14 - Animal blood circulation

Exam 3

Types of circulatory system

No circulatory system

Open Circulation

Closed Circulation

Capillaries or no capillaries: open circulation

no capillaries

Capillaries or no capillaries: closed circulation

connected by capillaries 

Circulatory system overall function

maintain homeostasis

Circulatory functions

maintain homeostasis

transportation

regulation

protection

Transportation function

transport…

• O2

• nutrients

• metabolic rate

Regulation function

regulate…

• hormones

• temperature

Protection function

protects from…

• injury

• toxins

• clotting

• pathogens

Blood composition

plasmic fluid matrix

• H2O

Blood functions

maintain homeostasis

circulate formed elements

Formed elements in blood

Erythrocytes

Leukocytes

Platelets

Erythrocyte characteristics

Red blood cells

Lack nuclei

Hemoglobin transports O2

1 iron holds 4 oxygen

Leukocyte characteristics

white blood cells

defense/protect from infection

Platelets characteristics

Thermobocytes

Involved in blood clotting

Cells fragments

Direction of blood flow process

heart → blood through arteries → arterioles → capillaries → venules (make up veins) → heart

Cardiac Cycle

1. Atria contract and blood flows into ventricle 

2. Ventricles contract pushing atrioventricular valves closed 

3. Pressure rises in ventricles and semilunar valves open 

4. Blood flows back against closing semilunar valves

Vertebrate Circulatory System Characteristics: Fish

chamber-pump heart

• four structures

• form two pumping chambers

  • 1st chamber: sinus venosus and atrium

  • 2nd chamber: ventricle and conus arteriosus

Vertebrate Circulatory System Characteristics: Reptiles

septum partially or completely subdivided ventricle

reduce/eliminate de-O2 and O2 mixing

Small body size impact on circulatory system

blood mixing

incomplete

Large body size impact on circulatory system

no mixing

complete

Where does the electrical impulse for contraction occur?

Sinus venosus in vertebrate

Sinoatrial node in mammals

Vertebrate Circulatory System Cycle

Sinus venosus (“pace maker”) →

Atrium →

Ventricle →

Conus arteriosus →

Gills (O2 in, CO2 out) →

Circulate unloading and loading to sinus venosus

Is the vertebrate circulatory system an open or closed system?

closed system

Amphibian Circulatory System Characteristics

double circulation

3 chamber heart

Parts of the double circulation

pulmonary circulation

systematic circulation

Pulmonary circulation location

between heart and lungs

Systematic circulation location

blood rest of body

Parts of the amphibian circulatory system 3 chamber heart

2 atria

1 ventricle

Pulmonary and systematic circulation characteristics

ventricle incomplete seperation

de-O2 and O2 blood mixing

Heart contraction process

1. SAS node(pacemaker) in right atrium sends signal to surrounding atria tissue causing beat

2. Stimulates AV node connected to Purkinje fibers 

3. Conduct cardiac signal through ventricular septum 

4. Signal to ventricles to beat 

Describe the mammalian heart contraction

periodic action potential

no neural activation

involuntary

What are mammalian heart contractions initiated by?

auto rhythmic fibers

Where is the sinoatrial node located in mammals?

wall of right atrium

What does the sinoatrial node produce?

spontaneous action potential

Spontaneous action potential process

constant leakage or Na+ into cell

depolarize membrane

creates action potential

action potential ends

What direction does the arteries pump blood?

oxygenated blood away from the heart

What makes up blood vessels?

Arteries

Arterioles

Capillaries

O2, nutrients, waste

Veins

Heart

Pulmonary artery function

de-O2 blood from heart to lungs

Characteristics of arteries

thick smooth muscle

stretching

blood pumping away from heart

higher blood pressure

deoxygenated blood to lungs

Characteristics of veins

thin smooth muscle

lower blood pressure

blood back to heart

What makes up the venules?

venous pump

venous valve

Venous pump function

returns blood to heart

Venous valve characteristics

one way

Skeletal muscle contracts

Contracts: pressure opens valve

Relaxes: closes valve

During contraction, pressure

Opens venous valve

During relaxation…

Venous valve closes

Characteristics of capillaries

very narrow

larger than blood cells

Why is capillary size important?

slows blood flow

pulls nutrients

off loads unnecessary nutrients

What does the lymphatic system contain?

lymph/interstitial fluid made of H2O and solutes in blood plasma

Where does lymph filter through?

capillary walls

Where does lymph fluid leave?

through arteriole(end of capillaries)

Where does lymph fluid return?

to veins via osmosis

Lymph characteristics

flows in one direction

proteins do not pass through capillaries due to size

builds up osmotic pressure gradient (H2O moves into capillaries)

What does high capillary blood pressure cause?

increased interstitial fluid accumulation

fluid not returned to capillaries

compromises lymphatic system

Where does excessive tissue fluid drain?

into lymph capillaries → larger lymphatic vessels → subclavian veins → heart

Connection between lymphatic and circulatory system

fluid made of massive molecules do not enter veins → leak from blood capillaries → lymph capillaries collect

Label: Aorta, Right ventricle, Right atrium, Left ventricle, Left atrium, Superior vena cava, Inferior Vena Cava

A. Left ventricle

B. Right atrium 

C. Aorta

D. Right ventricle 

E. Left atrium 

F. Superior vena cava 

G. Inferior Vena Cava