Download Circulatory and Digestive System

Vertebrate Zoology
SCBI 305
• หน้าที่
Circulatory System
– ลําเลียง อาหาร O2, CO2, ฮอร์โมน เม็ดเลือด ไปสู่เซลล์ต่างๆใน
ร่างกาย
– รักษาสภาพอุณหภูมิร่างกาย pH
• Closed system
Circulatory and Digestive Systems
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.).
McGraw-Hill, Inc., New York.
Oxygenated blood
ที่มา: Helfman et al. 1997. The Diversity
of Fishes. Blackwell Science.
Blood passes once through heart
Blood passes through heart twice
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.).
McGraw-Hill, Inc., New York.
Why are fish hearts small?
1
Vessels of the circulatory system
Bidirectional circulation
• Aorta
• Vein
– Blood into heart
• Major veins
ที่มา: Kardong, KV. 2009. Vertebrates:
Comparative Anatomy, Function,
Evolution (5th ed.). McGraw-Hill, Inc.,
New York.
– Common cardinal (sinus)
in primitive vertebrates
– Portal system (hepatic
portal veins, renal portal
veins)
– Post-, pre- cava (vena
cava)
– Blood out of heart
• Dorsal, ventral aortae
• Arteries
• Aortic arches
Phylogenetic modification
• Correlated with functional changes
Water
Land
Gill respiration
Lung respiration
Pulmonary circulation
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
2
Aortic arches
• Primitive pattern of aortic arches: debatable
• 6 = # taken as the basic embryonic pattern
• Fishes
Gills
Ventral aorta
Aortic arches
Afferent artery
Capillaries
Gills
Capillaries
1st arch absent
in adult of
most fishes
Efferent artery
Aortic arches
Dorsal aorta
Body
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
• Sharks, chondricthyans + primitive ray finned fishes
Modified into small
spiracle (sensory organ)
Lobe finned fish (Sarcopterygii)
Fishes with supplementary air-breathing organ
Lung  highly vascularized
Little mixing between oxygenated & deoxygenated blood
(undivided heart)
3
• Amphibians
• Reptiles
Larva: arch I, II absent
III, IV, V external gills
VI lung
adult salamander: lost of
external gills
• Modification of arch IV—systemic arches (double arches)
unite behind the heart to form common dorsal aorta
• Subdivision of ventral aorta
• Arch IV (pulmonary arch) branching out to lung
Adult frog: arch III, IV, VI persist
• Birds
Wing vessels (subclavians)
• Mammals
Only 3 arches (III, IV, VI) present in adult mammals
Pre-dominate systemic
arch (left systemic arch not
fully developed)
Present in turtles & birds
serving as major anterior
vessels in many birds
Pulmonary arch
Carotid artery
Systemic arch (left predominates)
4
Double systemic arches in
amphibians & reptiles
Single systemic arch (right)
in birds (left) in mammals
Aortic arches
Systemic arches
Pulmonary arch
Arterial circuits
Venous vessels
• 2 systems in double circulation (Not in fishes)
– Pulmonary systems  lung (found in fishes with
lungs, air-breathing vertebrates)
– Systemic systems  hepatic portal veins, renal
portal veins, other veins (few differences among
vertebrates, tending to retain basic characters)
• Abdominal veins present in fishes, merged/
absent in tetrapods
Most similar to basic pattern
Hearts
• Primitive heart (hagfish)
• Original form  contractile vessel
– In amphioxus
• Fishes: 4 chamber heart
– Atrium
– Ventricle
– Conus arteriosus found in many fishes, absent in adult
tetrapod
– Bulbus arteriosus (lacking cardiac muscle & conal valves)
found in most teleosts
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
5
• Lamprey—4 chamber heart
Body
Collect deoxygenated blood containing
pacemaker
Sinus venosus
Thick wall
ที่มา: Helfman et al. 1997. The Diversity
of Fishes. Blackwell Science.
Chondrichthyes:
4 chambers
Atrium
Ventricle
Conus arteriosus
Ventral aorta
Gills
ที่มา: Kardong, KV. 2009. Vertebrates:
Comparative Anatomy, Function, Evolution (5th
ed.). McGraw-Hill, Inc., New York.
Body
Sinus venosus
Small—not chamber-like
Atrium
ที่มา: Helfman et al. 1997. The Diversity
of Fishes. Blackwell Science.
Teleosts:
2 chambers
Formation of spiral valve in
the conus arteriosus for
regulating blood flow into
left/ right pulmonary arches
Ventricle
Conus arteriosus—muscular
extension of ventricle
Bulbus arteriosus
Small—not chamber-like
Ventral aorta
Gills
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
6
• Frog heart: 3 chambers
Body
– 2 atria, 1 ventricle
Right atrium
Ventricle
Lungs/ skin
Close similarity
between lungfish &
amphibians
Left atrium
Ventricle
Body
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
• Mixed blood in amphibian heart
• Why do their hearts evolve in this direction?
• Reptiles (lizards)
– 5 chambered heart (2 atria, 3 compartments of ventricle)
Reduced sinus venosus but same functions
Completely divided atrium
• Amniote heart: 4 major chambers
– 2 atria
– 2 ventricles
Ventricle with 3 compartments
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
7
• Reptile (alligator)
Completely divided ventricle
• Cardiac shunt  permitting heart to produce
different pressures within systemic & pulmonary
circuits
• Useful
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy,
Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
• Bird
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy,
Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
4 chambered heart
Reduced sinus venosus
Conus arteriosus 
pulmonary & aortic trunks
• Mammal
4 chambered heart
Reduced sinus venosus
( Purkinje fiber =
pacemaker) in wall of
right atrium
Conus arteriosus 
pulmonary & aortic
trunks
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy,
Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
8
• Birds & mammals  4 chambered heart BUT
independent evolution
– Seen in embryonic development
• Adaptation to environment ≠ improvement of
design
• Incompletely divided heart ≠ imperfect
– Perfectly matching with environment
• Evolution ≠ progressive improvement
– Alternative way of adaptation to demands of
different lifestyles
Pulmonary circuit Systemic circuit
Heat transfer
• Another function of the circulatory system
• Reptiles basking in the sun absorb heat in their
peripheral blood vessels to warm tissues
• Body heat dissipates to surface of body via capillaries
• Endothermic vs. ectothermic
• Homeothermic vs. poikilothermic
Animals that maintain constant
body temperature
Animals that show a change in
body temperature
• Birds & mammals  body temperature
regulations using own metabolism
• Other vertebrates  body temperature
depending on environments
– Adaptation  behaviors (movements)
• Effects of climate change
• Tolerant ranges, limitations  geographic
distribution
• Adaptations to climate change?
9
Temperature
Lower end
Limiting factor for
distribution in cold
environments
135 species
26 species
Cold temperature
Species cannot survive
Hot temperature
กิน
• Phylogenetic similarity
• Higher temperature  narrower cold temperature
tolerance, NOT increasing hot temperature
tolerance
Limiting factor for
distribution in warm
environments
Natural selection  physiological responses to
lower temperature
ที่มา: Araujo et al. 2013. Ecology Letters 16: 1206-1219.
– Similar responses to temperatures in closely related
species
Upper end
•
•
•
•
Eat = put food in mouth, swallow & chew it
Consume =
Ingest = take food into body usually by swallowing
Digest = be changed after eating into a form that the
body can use
• Absorb = take in a substance from the surface
• Egest = discharge undigested food as forces
– ≠excretion
10
โครงสร้างระบบทางเดินอาหาร
•
•
•
•
•
•
Buccal cavity: palate, teeth, tongue, oral glands
Pharynx
Esophagus
Stomach
Intestines: small, large
Others
• Teeth in fishes
– Buccal cavity, pharynx
• Tetrapods
– Palate, vomer, palatine, pterygoid bones
• Crocodiles, birds, mammals
Buccal cavity
• Palate = roof of the buccal cavity
– Fusion of ventral skull bones
• Teeth = derivations of dermal armor
– Toothless vertebrates  agnathans, sturgeons, some
toads, turtles, birds, baleen whales
– Toothed vertebrates  fishes (highly variables), most
amphibians, some reptiles, some birds, mammals
• Reduction in numbers and distribution (evolution)
• Succession of teeth
• Tooth replacement in waves (back to front, every other
tooth)
• Mammals 2 sets of teeth
– Jaws
11
• Shape of teeth  similar in vertebrates except
mammals
• Mammalian teeth  incisors, canines, premolars,
molars (heterodont dentition)
• Tongue
• Primary tongue (crescent-shaped elevation in the floor
of the buccal cavity caused by the underlying hyoid
skeleton)
– Found in most fishes, primitive amphibians
• Primary tongue + glandular field
– Found in most amphibians
• Primary tongue + glandular field + lateral lingual
swelling
– Found in reptiles & mammals
• Tongue mobility
– Immobilized  turtles, crocs, some birds, whales
– Highly mobile  snakes, insectivorous lizards & amphibians
& birds
– Attached to floor of buccal cavity but some mobility 
mammals
• Oral gland
• Saliva
– Not found in fishes
• Venom (lizards, snakes, mammals)
• Anticoagulant (vampire bats)
• Functions: Capturing, gathering food (woodpeckers), Taste,
Swallowing, Grooming, Thermoregulation (dogs), Human
speech
12
Esophagus
Pharynx
• Fish  respiratory organ
• Tetrapods  foregut
Stomach
• Muscular chamber
• Storage & macerating & secreting digestive enzymes
• Weakly developed in cyclostomes
• Muscular tube connecting pharynx and stomach
• Crop (birds)
Diversity of digestive tracts in fishes
Straight tube
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
13
• Differentiated from the esophagus in amphibians,
reptiles
• Glandular stomach + muscular stomach (gizzard) in
birds
• Well-developed in mammals
– Multi-chambered stomach
• Amphibians  coiled small intestine, short & straight
large intestine
• Reptiles & birds  coiled small intestine, short large
intestine emptying to the cloaca
• Mammals  coiled, differentiated, long small intestine,
long large intestine
Intestine
• Variation in fishes
Spiral value—modification
of intestine in
chondrichthyans,
sturgeons, lungfishes,
bichirs, coelacanths,
bowfin, gars—increases
absorptive surface areas
ที่มา: Helfman et al. 1997. The Diversity of
Fishes. Blackwell Science.
Others
• Liver
• Gall bladder
– Cyclostomes, most birds, some mammals have no gall
bladder
• Pancreas
14
• Ceca
• Cloaca
– Pyloric & duodenal ceca common in teleosts (for digestion
& absorption)
ที่มา: Kardong, KV. 2009. Vertebrates: Comparative Anatomy, Function, Evolution (5th ed.). McGraw-Hill, Inc., New York.
– Herbivorous Tetrapods (cellulose digestion)
Remain
Cloaca
well-developed, subdivided,
incorporated into other structures
Lost
• Well-developed in sharks & lungfishes
• Remain in amphibians, reptiles, birds, monotremes
• Lost in chimaera, ray-finned fishes, coelacanth,
eutherian mammals
– End of digestive tract (collection of intestine, urinary,
genital ducts) open to outside
– Opening to outside through a cloacal opening/ vent
– Latin: cloaca = sewer
– Found in all vertebrates during embryonic development
– Shallow or none in lampreys, ray-finned fishes, mammals
(except monotremes)
– Anus (end of digestive tract if no cloaca present)
Diet change
• Seasonal variation
– Opportunistic feeders
– Generalists
– Specialists
• Ontogenetic niche shift
– Evolutionary adapatation
– Anus
15
Ontogenetic niche shift
• Irreversible, genetically determined
• Morphological changes, age
– Habitat change?
• Driving forces (Claessen & Dieckmann 2002—Evolutionary
Ecology Research vol. 4: 189-217)
– Predator avoidance
– Niche variation
16