Nutrients and gases can move by processes such...

Transport in Animals

• Gastrovascular cavities

– flatworms and cnidarians

• Nutrients and gases can move by processes

such as diffusion and active transport.

Figure 42.1 Internal transport in the cnidarian Aurelia

Earthworm

Closed Circulation

Water

Water

Water

Water Water

MouthWater

Incurrent

pore

Sponge Hydra Nematode

Gastrovas-

cular cavity

Gastrovas-

cular cavity

Gastrovascular cavity

Osculum

(excurrent

opening)

a.

b. c.

No Circulatory System

Grasshopper

Open Circulation

Anus

Hemolymph

Heart Heart

Lateral

hearts

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Open Circulatory systems

• Insects, other arthropods and most mollusks

• No distinction between blood and the

interstitial fluid


• Hemolymph

– name of general body fluid

– directly bathes the internal organs

• System of sinuses

• Heart and body movements cause

circulation


• Slower circulation

• sluggish animals BUT...

– Insects are very active

Figure 42.2 Open and closed circulatory systems

Closed Circulatory Systems

– Earthworms, squids, octopuses, and vertebrates

• Blood is confined to vessels and is distinct

from interstitial fluid

• Consists of the heart, blood vessels and

blood

Blood

• Plasma – about 55% of blood volume

– 90% water

– inorganic salts (electrolytes), metabolites

(vitamins, aa, glucose), wastes & hormones

– proteins

• osmotic balance, viscosity

• buffers, transport lipids, antibodies, clotting factors

(fibrinogen)

Plasma

(92% water, 55%

of whole blood)

Formed

elements

Platelets and

leukocytes (<1%)

Red blood cells

(erythrocytes)

(45% of whole

blood)

Other solutes (1.5%)

Electrolytes

Nutrients

Gases

Regulatory

substances

Waste products

Water (91.5%)

Plasma proteins (7%)

Albumin (54%)

Globulins (38%)

Fibrinogen (7%)

All others (1%)

Blood Plasma Red Blood Cells

PlasmaRed blood

cells

White blood cells

Platelets

Platelets

4 million–6 million/

mm3 blood

Neutrophils Eosinophils

Basophils LymphocytesMonocytes

3–8%


0.5–1% 20–25%

60–70% 2–4%

150,000–300,000

mm3 blood

Figure 42.14x Blood smear

Blood

Cellular Elements:

• Red Blood Cells (Erythrocytes)

– Most numerous (5-6 million in one cubic ml)

– Transport oxygen & carbon dioxide

Blood

Cellular Elements:

• White Blood Cells (Leukocytes)

– Function in body’s defense

– A cubic ml of blood has about 5,000 – 10,000

– in interstitial fluid or in the lymphatic system –

where your body fights pathogens

4. Threads of

fibrin trap

erythrocytes

and form

a clot.

1. Vessel is

damaged,

exposing

surrounding

tissue to blood.

5. Once tissue

damage

is healed,

the clot is

dissolved.

3. Cascade of

enzymatic

reactions is

triggered by

platelets,

plasma factors,

and damaged

tissue.

2. Platelets

adhere and

become

sticky, forming

a plug.

Prothrombin

Thrombin

Thrombin

Fibrinogen

Fibrin

Cellular Elements:

Platelets are cell fragments that pinch off from

larger cells in the bone marrow

-Function in the formation of blood clots

Blood

Figure 42.16x Blood clot

Heart

• one atrium or two atria

• one or two ventricles

Heart

• one atrium or two atria

– chambers that receive blood returning to the

heart

• one or two ventricles

– chambers that pump blood out of the heart.

Blood vessels

• Arteries

– branch into arterioles

• Capillaries

• Veins

– venules merge into veins

Blood vessels

• Arteries

– branch into arterioles

– carry blood away from heart

• Capillaries

– materials are exchanged

• Veins

– venules merge into veins

– carry blood back toward heart

Blood Vessel Structure

• Walls of arteries or veins have three layers:

– epithelium

– smooth muscle with elastic fibers

– connective tissue

– Arteries have thicker walls than veins

• Capillaries only have the inner epithelium

layer

Capillary Exchange

• Law of Continuity

– blood flows slowly in capillaries because larger

total cross-section

– allows materials to be exchanged

Figure 42.10 The interrelationship of blood flow velocity, cross-sectional area of

blood vessels, and blood pressure

Capillary Exchange

• About 85% of the fluid that exits capillaries

re-enters at the venule end.

Return of Blood to Heart

• Pressure too low in veins

• contraction of skeletal muscles move blood

• one-way valves in veins prevent backflow

Variation in Vertebrate

Circulation

FISH

• Two chambered heart and a single circuit of

blood flow

Systemic

capillaries

Respiratory

capillaries

Gills

Sinus

venosus VentricleConus

arteriosus

Atrium

Body


Vertebrate Circulatory Systems


Circulation

AMPHIBIAN

• Three chambered heart (two atria and one

ventricle) and double circulation (two

circuits of flow)

Lungs

Body

Pulmonary

capillaries

Systemic

capillaries

Ventricle

Conus

arteriosus

Right atrium Pulmonary vein

Pulmocutaneous

artery

Posterior vena cava

Truncus arteriosus

AortaCarotid artery

Systemic artery

Left atrium

Sinus venosus

Ventricle

Conus

arteriosus

Right atrium

Left atrium

a. b.


Amphibian Circulation


Circulation

AMPHIBIAN

• Pulmonary circuit

– blood is pumped to the lungs, where it is

oxygenated and carried back to the left atrium

• Systemic circuit

– blood is pumped to the rest of the body, where

it gives up oxygen and is carried back to the

right atrium


Circulation

AMPHIBIAN

• Double circulation assures a vigorous flow

of blood to the vital organs

• single ventricle --some mixing of oxygen-

rich and oxygen-poor blood.


Circulation

MAMMALS & BIRDS

• Have a four chambered heart and double

circulation

• The left side of the heart handles oxygen-

rich blood and the right side handles only

oxygen-poor blood.

Head

Body

Lungs

Systemic

capillaries

Pulmonary artery

Pulmonary

semilunar valve

Inferior

vena cava

Superior

vena cava

Aorta

Tricuspid

valve

Right ventricle

Left

ventricle

Right atrium

Pulmonary

veinsLeft atrium

Bicuspid

mitral

valve

Systemic

capillaries

Pulmonary

artery

Superior

vena cava

Inferior

vena cava

Artery

Pulmonary

vein

Aorta

Respiratory

capillaries

a. b.


Mammalian or Bird Heart

• Valves prevent backflow of blood when the

ventricles contract

– Between each ventricle and atrium is an

atrioventricular (AV) valve

• tricuspid and bicuspid (mitral)

– At the exits of the heart are the semilunar

valves

Head

Body

Lungs

Systemic

capillaries

Pulmonary artery

Pulmonary

semilunar valve

Inferior

vena cava

Superior

vena cava

Aorta

Tricuspid

valve

Right ventricle

Left

ventricle

Right atrium

Pulmonary

veinsLeft atrium

Bicuspid

mitral

valve

Systemic

capillaries

Pulmonary

artery

Superior

vena cava

Inferior

vena cava

Artery

Pulmonary

vein

Aorta

Respiratory

capillaries

a. b.



QS

Milliv

olt

s

Seconds

R

P wave

1 sec

+1

-1

0

1. The impulse begins at the SA node and travels to theAV node.

2. The impulse is delayed at the AV node. Itthen travels to the AV bundle.

SA node(pacemaker)

AV node

AV bundle

Left and rightbundle branches

Left and rightbundle branches

Purkinje fibers

Purkinje fibers

Left atriumRight atrium

Purkinje fibers

Interventri-cular septum

AV bundle

Interventricularseptum

AV

AV bundle

Internodalpathway

3. From the AV bundle, the impulse travels down the interventricular septum.

4. The impulse spreads to branches from the interven-tricular septum.

5. Finally reaching the Purkinje fibers,the impulse is distributed throughoutthe ventricles.

T waveThe control of heart rhythm

Cardiac Cycle

• a complete sequence of the heart

contracting to pump blood, relaxing to fill

with blood.

• total length is about 0.8 s

– The contraction phase is called systole

– The relaxation phase is called diastole

Figure 42.6 The cardiac cycle

Cuff

Blood pressure

gauge

Stethoscope

0

50

150100

200

250

1. Cuff pressure: 150 mm Hg

No sound:

Artery closed


Pulse sound:

Systolic pressure


Sound stops:

Diastolic pressure

0

50

150100

200

250 050

150100

200

250


Nutrients and gases can move by processes such...

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