Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic.

Chapter 42: Circulation and Gas Exchange

1. What is the function of the circulatory system?- Transport nutrients & O2 to all cells- Transport metabolic waste to kidneys & CO2 to lungs

2. What is the difference between a gastrovascular cavity and an open & closed circulatory system?- Gastrovascular cavity

- digestion & distribution of nutrients- 2 cell layered thick organisms – Cnidarians

Figure 42.2 Internal transport in the cnidarian Aurelia

Circularcanal

Radial canal

5 cmMouth





- Animals with more than 2 cell layers need more

Heart

Hemolymph in sinusessurrounding ograns

Interstitialfluid

Heart

Small branch vessels in each organ

Anterior vessel

Lateral vessels

Ostia

Tubular heart

Dorsal vessel(main heart)

Ventral vessels

Auxiliary hearts

(a) An open circulatory system (b) A closed circulatory system

Figure 42.3 Open and closed circulatory systems

-Heart pump hemolymph into large cavity-VERY inefficient due to mixing of good & bad substances

-Heart pump blood through vessels in a complete circuit-More efficient & consistent





- Animals with more than 2 cell layers need more 3. Let’s compare some vertebrate hearts

Figure 42.4 Vertebrate Circulatory Systems

FISHES AMPHIBIANS REPTILES (EXCEPT BIRDS) MAMMALS AND BIRDS

Systemic capillaries Systemic capillaries Systemic capillaries Systemic capillaries

Lung capillaries Lung capillariesLung and skin capillariesGill capillaries

Right Left Right Left Right Left Systemic

circuitSystemic

circuit

Pulmocutaneouscircuit

Pulmonarycircuit

Pulmonarycircuit

SystemiccirculationVein

Atrium (A)

Heart:ventricle (V)

Artery Gillcirculation

A

V VV VV

A A A AALeft Systemicaorta

Right systemicaorta

- 1atrium & 1 ventricle- single circuit- blood flows from gills directly to rest of the body

- BP is LOW after gill capillaries - Swimming helps blood complete the circuit

FISH






circuitSystemic

circuit


Pulmonarycircuit

Pulmonarycircuit


Atrium (A)

Heart:ventricle (V)


A

V VV VV


Right systemicaorta

- 2 atria & 1 ventricle - Double circulation- blood flows from ventricle to pulmocutaneous circuit, back to the heart & then from the same ventricle to the systemic capillaries

- Mixing of blood in ventricle is INEFFICIENT

AMPHIBIANS






circuitSystemic

circuit


Pulmonarycircuit

Pulmonarycircuit


Atrium (A)

Heart:ventricle (V)


A

V VV VV


Right systemicaorta

- 2 atria & 1 ventricle- pulmonary circuit since skin is dry- 90% ridge between right & left ventricles- ridge is complete in crocodilians

- Mixing of blood in ventricle is less

REPTILES






circuitSystemic

circuit


Pulmonarycircuit

Pulmonarycircuit


Atrium (A)

Heart:ventricle (V)


A

V VV VV


Right systemicaorta

- 2 atria & 2 ventricles- no mixing of O2-rich & O2 poor blood- 2 complete circuits – pulmonary & systemic

MAMMALS





- Animals with more than 2 cell layers need more 3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our circulatory system?

Right atrium

Right ventricle

Posteriorvena cava

Capillaries ofabdominal organsand hind limbs

Aorta

Left ventricle

Left atrium

Pulmonary vein

Pulmonaryartery

Capillariesof left lung

Capillaries ofhead and forelimbs

Anteriorvena cava

Pulmonaryartery

Capillariesof right lung

Pulmonary vein

Aorta

1

10

11

5

4

6

2

9

33

7

8

Figure 42.5 The mammalian cardiovascular system: an overview


1. What is the function of the circulatory system?2. What is the difference between a gastrovascular cavity and an open

& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?

1. Right ventricle2. Pulmonary artery 3. Pulmonary capillaries4. Left atrium5. Left ventricle6. Aorta7. Capillaries above heart – head & arms8. Capillaries below heart – abdominal organs & legs9. Anterior vena cava – from above heart10. Posterior vena cava – from below heart 11. Right atrium

5. How does structure fit function of the heart?

Figure 42.6 The mammalian heart: a closer look

Aorta

Pulmonaryartery

Leftatrium

Pulmonaryveins

Semilunarvalve

Atrioventricularvalve

Left ventricleRight ventricle

Anterior vena cava

Pulmonary artery

Semilunarvalve

Atrioventricularvalve

Posterior vena cava

Pulmonaryveins

Right atrium



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?

- Atria have thin walls – only pump to ventricles below- Ventricles have THICK walls – left is thickest- Valves prevent back flow

- Atrioventricular valves – between atria & ventricles - Semilunar valves - between ventricles & exit vessels

6. How is the heart beat controlled?

Figure 42.8 The control of heart rhythm

SA node(pacemaker)

AV node Bundlebranches

Heartapex

Purkinjefibers

1 2 Signals are delayedat AV node.

Pacemaker generates wave of signals to contract.

3 Signals passto heart apex.

4 Signals spreadthroughoutventricles.

ECG






6. How is the heart beat controlled?7. How does blood flow through our vessels?

Artery Vein

100 µm

Artery Vein

ArterioleVenule

Connectivetissue

Smoothmuscle

Endothelium

Connectivetissue

Smoothmuscle

EndotheliumValve

Endothelium

Basementmembrane

Capillary

Figure 42.9 The structure of blood vessels

Figure 42.10 Blood flow in veins

Direction of blood flowin vein (toward heart)

Valve (open)

Skeletal muscle

Valve (closed)



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?

Figure 42.11 The interrelationship of blood flow velocity, cross-sectional area of blood vessels, and blood pressure

5,0004,0003,0002,0001,000

0

5040302010

0

120100806040200

Aor

ta

Art

erie

s

Art

erio

les

Cap

illar

ies

Ven

ules

Vei

ns

Ven

ae c

avae

Pre

ssur

e (m

m H

g)V

eloc

ity (

cm/s

ec)

Are

a (c

m2 )

Systolicpressure

Diastolicpressure

- Capillaries increase surface area

- Cells flow through single file

- Slow flow means better ability for exchange

Figure 42.14 Fluid exchange between capillaries and the interstitial fluid

At the arterial end of acapillary, blood pressure is

greater than osmotic pressure,and fluid flows out of the

capillary into the interstitial fluid.

Capillary Redbloodcell

15 m

Tissue cell INTERSTITIAL FLUID

CapillaryNet fluidmovement out

Net fluidmovement in

Direction of blood flow

Blood pressureOsmotic pressure

Inward flow

Outward flow

Pre

ssu

re

Arterial end of capillary Venule end

At the venule end of a capillary, bloodpressure is less than osmotic pressure, and fluid flows from the interstitial fluid into the capillary.



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?9. What is blood made of?

Plasma 55%

Constituent Major functions

Water Solvent forcarrying othersubstances

SodiumPotassiumCalciumMagnesiumChlorideBicarbonate

Osmotic balancepH buffering, andregulation of membranepermeability

Albumin

Fibringen

Immunoglobulins(antibodies)

Plasma proteins

Icons (blood electrolytes

Osmotic balance,pH buffering

Clotting

Defense

Substances transported by bloodNutrients (such as glucose, fatty acids, vitamins)Waste products of metabolismRespiratory gases (O2 and CO2)Hormones

Cellular elements 45%

Cell type Numberper L (mm3) of blood

Separatedbloodelements

Functions

Erythrocytes(red blood cells) 5–6 million Transport oxygen

and help transportcarbon dioxide

Leukocytes(white blood cells)

5,000–10,000 Defense andimmunity

Eosinophil

Basophil

Platelets

Neutrophil Monocyte

Lymphocyte

250,000400,000

Blood clotting

Figure 42.15 The composition of mammalian blood






6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?9. What is blood made of?10. Where do blood cells originate?

Figure 42.16 Differentiation of blood cells

B cells T cells

Lymphoidstem cells

Pluripotent stem cells(in bone marrow)

Myeloidstem cells

Erythrocytes

Platelets Monocytes

Neutrophils

Eosinophils

Basophils

Lymphocytes

Ch 43

Erythropoeitin (EPO) – kidney hormone released in response to low O2 to stimulate production of erythrocytes



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?9. What is blood made of?10. Where do blood cells originate?11. How does blood clot?

Plateletplug

Collagen fibers

Platelet releases chemicalsthat make nearby platelets sticky

Clotting factors from:PlateletsDamaged cellsPlasma (factors include calcium, vitamin K)

Prothrombin Thrombin

Fibrinogen Fibrin5 µm

Fibrin clot Red blood cell

The clotting process begins when the endothelium of a vessel is damaged, exposing connective tissue in the vessel wall to blood. Plateletsadhere to collagen fibers in the connective tissue and release a substance thatmakes nearby platelets sticky.

1 The platelets form a plug that providesemergency protectionagainst blood loss.

2This seal is reinforced by a clot of fibrin when vessel damage is severe. Fibrin is formed via amultistep process: Clotting factors released fromthe clumped platelets or damaged cells mix withclotting factors in the plasma, forming an activation cascade that converts a plasma proteincalled prothrombin to its active form, thrombin.Thrombin itself is an enzyme that catalyzes the final step of the clotting process, the conversion of fibrinogen to fibrin. The threads of fibrin become interwoven into a patch (see colorized SEM).

3

Figure 42.17 Blood clotting



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?9. What is blood made of?10. Where do blood cells originate?11. How does blood clot?12. What are some CV diseases?

- >50% of deaths due to CV disease- LDLs – low-density lipoproteins - bad cholesterol

- Associated with arterial plaques- HDLs – high-density lipoproteins – good cholesterol

- Reduce deposition of cholesterol

Figure 42.18 Atherosclerosis

(a) Normal artery (b) Partly clogged artery50 µm 250 µm

Smooth muscleConnective tissue Endothelium Plaque

- Atherosclerosis – cholesterol plaques in arteries slows blood flow

- Arteriosclerosis – hardening of the arteries due to Ca+2 added to plaques



& closed circulatory system?3. Let’s compare some vertebrate hearts4. What is the route of blood flow through our CV system?5. How does structure fit function of the heart?6. How is the heart beat controlled?7. How does blood flow through our vessels?8. What is the relationship between vessel size, BP & velocity?9. What is blood made of?10. Where do blood cells originate?11. How does blood clot?12. What are some CV diseases?

- LDLs – low-density lipoproteins - bad cholesterol- HDLs – high-density lipoproteins – good cholesterol- Hypertension – high BP- Heart attack – death of heart muscle due to blocked coronary arteries- Stroke – death of nervous tissue in brain due to blocked brain arteries

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic.

Documents

open closed circulatory

vertebrate circulatory

cv system

transport nutrients

mixing of o2

cell layers

gas exchangewhat

vertebrate heartswhat