Types of circulatory systems Diffusion oxygen and carbon dioxide based on body shape and size Gastrovascular cavities distribution of substances throughout the body and in digestion Open circulatory system ID: 910936
Download Presentation The PPT/PDF document "Circulation and Gas exchange" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Circulation and Gas exchange
Slide2Types of circulatory systems
Diffusion – oxygen and carbon dioxide, based on body shape and size
Gastrovascular
cavities
– distribution of substances throughout the body and in digestion.
Open circulatory system
– arthropods, some
molluscs
Hemolymph
, interstitial fluid, clear fluid
Pumped through vessels into sinuses and back to heart
Closed circulatory system
–
Blood confined in
vessles
Slide3Figure 34.3
Branch vessels
in each organ
Tubular heart
Pores
Hemolymph in sinuses
(a) An open circulatory system
Heart
(b) A closed circulatory system
Heart
Blood
Dorsal vessel
(main heart)
Auxiliary
hearts
Ventral vessels
Interstitial
fluid
Slide4Cardiovascular system
Closed circulatory system of humans
Arteries – blood away from heart
Capillaries – gas exchange, simple squamous tissue
Veins – blood to the heart
Not all arteries carry oxygenated blood and not all veins carry deoxygenated blood2 main chambers of the heart Atrium – receiving chamberVentricle – pumping chamber
Slide5Figure 34.4
Lung
and skin
capillaries
Body capillaries
Vein
Gill capillaries
(a) Single circulation: fish
Heart:
(b) Double circulation:
amphibian
Key
Systemic
capillaries
Pulmocutaneous
circuit
Artery
Ventricle (V)
Atrium (A)
Oxygen-rich blood
Oxygen-poor blood
Right
Left
A
A
V
Systemic circuit
Lung
capillaries
(c) Double circulation:
mammal
Systemic
capillaries
Pulmonary
circuit
Right
Left
A
A
V
Systemic circuit
V
Slide6Figure 34.5
Capillaries of
abdominal organs
and hind limbs
Aorta
Capillaries
of right lung
Superior
vena cava
Pulmonary
artery
Pulmonary
vein
Right atrium
Right ventricle
Inferior vena cava
Capillariesof left lung
Pulmonary artery
Pulmonaryvein
Left atrium
Left ventricle
Capillaries of
head and
forelimbs
Aorta
9
7
6
4
2
11
3
5
8
10
1
3
Slide7Figure 34.6
Aorta
Atrioventricular
(AV) valve
Semilunar
valve
Pulmonary artery
Right
atrium
Right
ventricle
Pulmonary
artery
Left
atrium
Left ventricle
Atrioventricular(AV) valve
Semilunarvalve
Slide8The mammalian heart
Approximately the size of a fist
Made of mostly cardiac tissue
Cardiac cycle
– one complete sequence of pumping and filling of the heart.Systole – contraction phase of cardiac cycle
Diastole – relaxation phase of cardiac cycleCardiac output – volume of blood each ventricle pumps per minute
Slide9Valves
Atrioventricular
– separate the atrium from the ventricle
Bicuspid – mitral valve
tricuspidSemilunar valves – found at exits of the heart
Pulmonary – leaving heart for lungsAortic – leaving the heart to the aortaLub DupLub – blood against the closed AV valvesDup – closing of semilunar valvesMurmurs – abnormal sounds
Slide10Conduction system
sinoatrial
node
– pace maker – sets rate and timing of cardiac muscle contraction.
Atrioventricular node – conduct impulses through wall separating atrium and ventricle
ECG – electrocardiogram – graph depicting stages in the cardiac cycle
Slide11Figure 34.8-4
Signals (yellow)
from SA node
spread
through atria.
SA node
(pacemaker)
1
Signals are
delayed
at AV node.
Bundlebranchespass signalsto heart apex.
Signalsspreadthroughoutventricles.
AV node
Bundle
branchesHeart
apexPurkinje
fibers
ECG
2
3
4
Slide12Blood vessels
3 layers of tissue
Endothelium – think epithelial tissue
Smooth muscle
Durable connective tissueArtery – arterioles – capillaries –
venules - veinsArteries and veins differ slightly in structureArteries have thicker walls due to higher pressure Veins have valves to prevent backflow
Slide13Figure 34.9
Connective
tissue
Smooth
muscle
Connective
tissue
Smooth
muscle
Endothelium
Endothelium
Artery
Vein
Artery
Vein
Red blood
cells
Basal lamina
Capillary
Red blood cell
Capillary
Arteriole
Venule
Valve
100
m
15
m
LM
LM
Slide14Blood pressure
Arterial blood pressure is highest during systole (contraction)
Pulse – rhythmic bulging of the artery walls with each heart beat.
Diastole – relaxation phase, arteries go back to normal, lower pressure
Slide15Homeostasis
T
o
maintain blood pressure as best it can
...Arterioles will dilate or constrictEndocrine and nervous system will produce Nitric oxide that will induce vasodilation, regulating blood
pressureGravity – you will faint to get head level to heart, increasing blood flow to brainGiraffes have higher systolic pressure, 250mmHgLymphatic system – gains liters of fluid (lymph) a day begin lost from capillaries.Lymph nodes – contain cells that destroy bacteria and viruses.
Slide16Figure 34.12
Interstitial
fluid
Lymphatic
vessel
Lymphatic
vessel
Blood
capillary
Tissue cells
Lymph node
Masses of
defensive
cells
Lymphaticvessels
Lymph nodes
Peyer’s patches(small intestine)
Appendix(cecum)
Thymus(immunesystem)
Adenoid
Tonsils
Spleen
Slide17Blood
55% plasma – liquid made of water, proteins, wastes, gas
45% - formed elements
Erythrocytes – red blood cells
Red biconcave disksNo nucleusFormed in red bone marrow
Leukocytes – white blood cellsImmune system5 typesThrombocytes – plateletsBlood clotting
Slide18Figure 34.13
Separated
blood
elements
Solvent for
carrying other
substances
Plasma 55%
Cellular elements 45%
Constituent
Major functions
Osmotic balance,
pH buffering,
and regulationof membranepermeability
Water
Ions (bloodelectrolytes)
SodiumPotassiumCalciumMagnesiumChlorideBicarbonate
Osmotic balance,pH buffering
Clotting
Defense
Fibrinogen
Plasma proteins
Albumin
Immunoglobulins
(antibodies)
Substances transported by blood
Nutrients (such as glucose, fatty
acids, vitamins)
Waste products of metabolism
Respiratory gases (O
2
and CO
2
)
Hormones
Functions
Leukocytes (white blood cells)
Transport
of O
2
and
some CO
2
Cell type
Number
per
L (mm
3
)
of blood
Basophils
Lymphocytes
Eosinophils
Neutrophils
Monocytes
Platelets
Erythrocytes (red blood cells)
250,000–400,000
5,000,000–
6,000,000
Blood
clotting
5,000–10,000
Defense
and
immunity
Slide19Cardiovascular disease
Disorders of heart and blood vessels
Cholesterol
Atherosclerosis – hardening of the arteries by fatty deposits
heart attack – myocardial infarction – damage or death of cardiac muscle tissue resulting from a blockage of one or more coronary arteries
Stroke – death of nervous tissue in the brain due to lack of oxygen.Hypertension – high blood pressure – damages endothelium in arteries, promoting plaque build up
Slide20Gas Exchange
Uptake of oxygen from the environment and the discharge of carbon dioxide to the environment
Respiratory medium – conditions for gas exchange, water or air.
Easier to breath in air, air is less dense and less viscous so easier to move and to force through passageways.
In water, more demanding. Less dissolved oxygen in water compared to air
Warmer and saltier the water, the less oxygen content.Puts higher energy expenditure on lobsters and fish
Slide21Respiration surfaces
Cells that carry out gas exchange have a plasma membrane that must be in contact with an aqueous solution.
Exchange takes place by diffusion, proportional to the surface area on which it occurs
Hence why most respiratory organs are folded or branched
Slide22Respiratory organs
Sponges, cnidarians and flatworms – cells on surface
Marine worms –
parapodium
– flat appendagesAmphibians, earthworms – skinAquatic animals – gills
Insects – tracheal system – network of tubesAmphibians (limited), most reptiles, birds and mammals depend on lungs
Slide23Figure 34.20
Bronchiole
Bronchus
Right lung
Trachea
(Esophagus)
Larynx
Pharynx
(Heart)
Terminal
bronchiole
Left
lung
Nasal
cavity
Capillaries
Alveoli
Dense capillary bed
enveloping alveoli
(SEM)
Branch of
pulmonary vein
(oxygen-rich
blood)
Branch of pulmonary
artery (oxygen-poor
blood)
50
m
Diaphragm
Slide24Mammalian respiratory system
Nose – filtered , warmed, humidified,
and
sampled
for odorsLarynxTrachea – windpipeBronchi – 2 branches
Bronchioles – branchesAlveoli – simple squamous – diffusion of gas exchange
Slide25Breathing
Alternating inhalation and exhalation of air
Positive pressure breathing – fill lungs with forced air – amphibians
negative pressure breathing – pulling air into the lungs – mammals
Tidal volume – volume of air inhaled and exhaled with each breath
Slide26Figure 34.22
Inhalation:
Diaphragm contracts
(moves down).
Diaphragm
Exhalation:
Diaphragm relaxes
(moves up).
Lung
Air
inhaled.
Air
exhaled.
Rib cageexpands asrib musclescontract.
Rib cage getssmaller asrib musclesrelax.
1
2
Slide27Control of breathing
involuntary
Nervous system – medulla oblongata mainly responsible
Built in buffering system –
Water reacts with water and forms carbonic acid.Carbonic acid can then dissociate into a bicarbonate ion and a hydrogen ion.
Slide28Figure 34.23-4
Carotid
arteries
Response:
Signals from
medulla to rib
muscles and
diaphragm
increase rateand depth ofventilation.
Homeostasis:Blood pH of about 7.4
CO2 leveldecreases.
Stimulus:Rising level of CO2in tissues lowersblood pH.
Sensor/controlcenter:
Aorta
Cerebro-spinalfluid
Medullaoblongata
Slide29Respiratory adaptations of diving mammals
Ex. Weddell seal of Antarctica
Ability to store large amounts of oxygen
Myoglobin – oxygen storing protein found in muscles.
Swim with little muscle movementBlood supply to muscles can be constricted
Use fermentation rather than respiration