Patrones arquitectónicos Archivo

Metazoos
LE 32-3
Single cell
Stalk
LE 32-4
Somatic cells
Digestive
cavity
Reproductive cells
Colonial protist,
and aggregate of
identical cells
Hollow sphere
of unspecialized
cells (shown in
cross section)
Beginning of cell
specialization
Infolding
Gastrula-like
“protoanimal”
Filos animales s/estructura corporal
I. Parazoa: poríferos (esponjas) (sin verdaderos tejidos)
II.Eumetazoa (con auténticos tejidos)
A. Animales con simetría radial (diblásticos): cnidarios
B. Animales con simetría bilateral (triblásticos):
1. Acelomados: platelmintos
2. Blastocelomados:nemátodos
3. Celomados
a. Protostomados: moluscos, anélidos y
artrópodos
b. Deuterostomados: equinodermos y
cordados
Simetría Radial
Simetría Bilateral
LE 32-8
Coelom
Body covering
(from ectoderm)
Digestive tract
(from endoderm)
Tissue layer
lining coelom
and suspending
internal organs
(from mesoderm)
Coelomate. Coelomates such as annelids have a true coelom, a
body cavity completely lined by tissue derived from mesoderm.
Body covering
(from ectoderm)
Pseudocoelom
Muscle layer
(from
mesoderm)
Digestive tract
(from endoderm)
Pseudocoelomate. Pseudocoelomates such as nematodes have
a body cavity only partially lined by tissue derived from
mesoderm.
Body covering
(from ectoderm)
Tissuefilled region
(from
mesoderm)
Wall of digestive cavity
(from endoderm)
Acoelomate. Acoelomates such as flatworms lack a body cavity
between the digestive cavity and outer body wall.
LE 32-9a
Protostome development
(examples: molluscs,
annnelids, arthropods)
Eight-cell stage
Spiral and determinate
Deuterostome development
(examples: echinoderms,
chordates)
Eight-cell stage
Radial and indeterminate
Cleavage
LE 32-9b
Protostome development
(examples: molluscs,
annnelids, arthropods)
Deuterostome development
(examples: echinoderms,
chordates)
Coelom formation
Coelom
Archenteron
Coelom
Mesoderm
Blastopore
Schizocoelous: solid
masses of mesoderm
split and form coelom
Blastopore
Mesoderm
Enterocoelous:
folds of archenteron
form coelom
LE 32-9c
Protostome development
(examples: molluscs,
annnelids, arthropods)
Deuterostome development
(examples: echinoderms,
chordates)
Mouth
Anus
Digestive tube
Mouth
Mouth develops
from blastopore
Anus
Anus develops
from blastopore
Fate of the blastopore
Protostomos
Deuterostomos
Blastoporo origina la boca
Blastoporo origina el ano.
Segmentación
espiral
Segmentación
radial
Formación celoma:
esquizocelia
Formación celoma:
enterocelia
Cadena nerviosa ventral –
Gastroneuralia
Cadena nerviosa dorsal Notoneuralia
Desarrollo embrionario temprano
•Fertilización y formación del cigoto
• Segmentación y formación de la blástula
•Formación de la gástrula
Clivaje reductivo
Patrones de segmentación
De acuerdo al tipo de huevo:
Holoblástica o completa
(isolecitos, mesolecitos)
Meroblástica o parcial
(telolecitos, centrolecitos)
Gastrulación
fibras
Movimientos morfogenéticos
Células mesenquimáticas
Gastrulación
•se establecen los ejes corporales
•movimientos celulares
•aumenta el número de capas celulares
•se forma el arquenterón (tubo digestivo)
•aparecen signos visibles de diferenciación
•aparecen las tres capas de tejido embrionario:
a.
Endodermo: interna
b.
Mesodermo: media
c.
Ectodermo: externa
Larva pluteus
LE 32-10
“Radiata”
Deuterostomia
Protostomia
Bilateria
Eumetazoa
Metazoa
Ancestral colonial
flagellate
LE 32-11
“Radiata”
Deuterostomia
Lophotrochozoa
Bilateria
Eumetazoa
Metazoa
Ancestral colonial
flagellate
Ecdysozoa
Figure 32-12
LE 32-13
Apical tuft
of cilia
Mouth
Anus
An ectoproct, a lophophorate
Structure of trochophore larva