TERMS YOU SHOULD KNOW
DEUTEROSTOMES (Chapter 34)
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water vascular system – a
network of hydraulic canals unique to echinoderms that branches into extensions
called tube feet which function in locomotion, feeding
and gas exchange.
• vertebrate – a chordate animal with a backbone: the fish,
amphibians, reptiles, birds and mammals.
•
chordates – members of a
diverse phylum of animals that, as embryos, possess a (1) notochord; (2) a dorsal, hollow nerve cord,
(3) pharyngeal gill slits; and (4) a post-anal tail. Adult forms usually do not possess all these features.
•
pharynx – an area in the
vertebrate throat where air and food passages cross.
•
notochord – a longitudinal,
flexible rod formed from dorsal mesoderm and located between the gut and the
dorsal nerve cord in all chordate embryos. Often absent in the adult form.
•
paedogenesis – the precocious
development of sexual maturity in an immature or larval animal.
•
ectotherm – an animal, such as
a fish or a reptile, that must use environmental energy (e.g., basking in the
sun) or behavioral adaptations to regulate its body temperature.
•
endotherm – an animal that uses
metabolic energy to maintain a constant body temperature, such as a bird or a
mammal.
•
neural crest – a special strip
of cells that develops just before the neural groove closes over to form the
neural tube in embryonic development.
•
neural tube – the dorsal tube
that differentiates into the brain and spinal cord
•
placoderm – a class of extinct,
fish-like vertebrates that had jaws and were enclosed in a tough, outer
armor. Flourished during the
Devonian.
•
Chondrichthyes – the verteb
rate class of cartilaginous fishes, represented by sharks, rays and skates
• Osteichthyes – the vertebrate class of bony fishes,
characterized by a skeleton reinforced by calcium phosphate, the most diverse
and abundant of all vertebrates.
•
operculum – a flat, external,
bony protective covering over the gill chamber in fish.
•
swim bladder – a hydrostatic
organ in bony fishes that permits the fish to hover at a given depth.
•
amniotic egg – a shelled,
water-retaining egg that enables reptiles, birds and egg-laying mammals (e.g.,
platypus) to complete their life cycles on dry land.
•
cloaca – in some animals, the
common exit chamber from the digestive, reproductive and urinary systems.
•
pulmonary circulation – The
part of the circulatory system present in higher vertebrates that delivers
blood to and from the lungs for oxygenation. (see: systemic circulation)
•
systemic circulation – that
part of the circulatory system that devers blood to and from the tissues and
organs of the body (see: pulmonary circulation)
•
oviparous – a type of
development in which young hatch from eggs laid outside of the mother’s
body (compare with oviviparous
& viviparous).
•
ovoviviparous – a type of
development in which the young hatch from eggs incubated inside the
mother’s body (compare with oviparous & viviparous)
•
viviparous – a type of
development in which the young are born alive after having been nourished in
the uterus by blood from the placenta (compare with oviviparous & oviparous.
•
monotremes – egg-laying mammals
represented by the platypus and echidna.
•
marsupials – a subclass of
mammals characterized by the presence of an abdominal pouch in which the young,
which are born in a very undeveloped condition, are carried for some time after
birth. Represented by kangaroos,
koalas or oppossums.
•
eutharian mammals – placental
mammals. Young complete embryonic
development within the mother, joined to the mother by the placenta.
•
placenta – an organ that
develops in the uterus of higher mammals during pregnancy. The placenta is made up of fetal and
maternal components and is the site where materials are exchanged between the
mother and developing fetus(es).