Circulatory System Transport systems in animals. Overview 1. Functions of a transport/circulatory...
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Transcript of Circulatory System Transport systems in animals. Overview 1. Functions of a transport/circulatory...
Circulatory System
Transport systems in animals
Overview1. Functions of a transp
ort/circulatory system
2. Cellular transport3. Invertebrate
circulationa. Gastrovascular cavityb. Water vascular systemc. Open circulatory syste
md. Closed circulatory syste
m
4. Vertebrate circulationa. Fishesb. Amphibians
c. Reptilesd. Birdse. Mammals
Functions of the circulatory system Transports materials
Nutrients from digested food Respiratory gases: CO2 and O2
Waste materials: toxins and nitrogenous wastes Antibodies Hormones Enzymes
Immune functions Maintains homeostasis
Blood pH Heat transport
Transport at the cellular level Cell membrane
Passive transport (diffusion, facilitated diffusion, osmosis) high concentration of solutes to low
concentration of solutes no need to expend energy
Active transport spending energy moving materials from low
concentration to high concentration of solutes
Transport of large molecules endocytosis vesicles
exocytosis Cyclosis (cytoplasmic
streaming) occurs in eukaryotes, e.g. Paramecium
facilitated by microfilaments requires energy
Transport at the cellular level (con’t) Endoplasmic reticulum
manufacturing and transport facility
proteins produced in rough ER are packaged in vesicles
Golgi apparatus modification and storage
facility receiving end and
shipping end Vacuole
large membrane bound sacs
usually stores undigested nutrients
Gastrovascular cavity in simple invertebrates No system is
required Single opening:
exchange of materials with the environment
Central cavity for digestion and distribution of substances throughout the body
Body walls are two cell layers thick materials undergo diffusion
Cnidarians (e.g. Hydra) and flatworms (e.g. planarians)
How are materials transported in multicellular organisms?
How are materials transported in multicellular organisms?Water vascular
system in echinoderms
multi-purpose: locomotion, food and waste transport, respiration
closed system of canals connecting tube feet
madreporite ring canal radial and lateral canal tube feet ampullae
How are materials transported in multicellular organisms?Open circulatory system Phylum Arthropoda,
Phylum Mollusca (with one exception)
hemolymph (colorless) heart(s) sinuses
ostia heart(s) diffusion from sinuses
to organs insects: well-
developed respiratory systems, O2 not transported through the blood
How are materials transported in multicellular organisms?Closed circulatory system or
cardiovascular system cephalopods, annelids,
vertebrates presence of blood vessels advantages
1. rapid flow2. may direct blood to
specific tissues3. blood cells and large
molecules remain within vessels
4. can support higher levels of metabolic activity
General plan of the cardiovascular system Heart
Atrium Ventricle
Blood vessels Arteries Arterioles Capillaries and
capillary beds Venules Veins
Blood
Different adaptations of the cardiovascular systems in vertebrates: fishes Single-circulation Fish heart
2 chambered hearts atrium and ventricle vessel
African lungfish heart 3-chambered
2 atria left side of atrium
receives oxygenated blood (to tissues)
right side receives deoxygenated blood (to lung or gills)
spiral fold partially divided
ventricle
Different adaptations of the cardiovascular systems in vertebrates: amphibians Pulmocutaneous and
systemic circulation are partly separated
Amphibian heart 1 ventricle pumps
blood to lungs, skin, and tissues
2 atria: rt. atrium receives
deoxygenated blood lt. atrium receives
oxygenated blood advantage: oxygen-
rich blood reaches the body’s organs faster
some mixing of O2-rich and poor blood occurs
Different adaptations of the cardiovascular systems in vertebrates: reptiles Reptilian heart
3-chambers (except for crocodilians with 4) 2 atria 1 ventricle (2 ventricles
in crocodiles and alligators) partially divided,
decreases mixing
may stop sending blood to lungs when not breathing
Different adaptations of the cardiovascular systems in vertebrates: birds and mammals 4 chambered heart:
2 atria 2 ventricles
full separation of pulmonary and systemic circuits
Advantages1. no mixing of oxygenated and
deoxygenated blood
2. gas exchange is maximized
3. separation allows for pulmonary and systemic circuits to operate at different pressures
Importance1. Endothermic high nutrient and
O2 demands in tissues
2. Numerous vessels great deal of resistance, so requires high pressure
Blood flow in mammals R side of heart:
pulmonary circuit L side of heart:
systemic circuit one way valves:
atrioventricular valves semilunar valves
Blood flow in mammals1. right atrium receives O2-poor
blood from superior and inferior venae cavae
2. from right atrium into the right ventricle through the tricuspid valve
3. pumped into the pulmonary artery through the pulmonary semilunar valve to lungs
4. O2-rich blood from lungs is returned to the left atrium via the pulmonary veins
5. enters the left ventricle via the mitral or bicuspid valve
6. exits the left ventricle into the aorta via the aortic semilunar valve
7. circulated to body tissues