Lectures for Test 1 Flashcards Preview

Comparative Vertebrate Anatomy > Lectures for Test 1 > Flashcards

Flashcards in Lectures for Test 1 Deck (192):
1

sagittal

any line that divides body into right and left

2

transverse

any line that divides body into front and back parts

3

frontal

any line that divides body into top and bottom parts

4

vertebrates belong to this clade

chordata

5

largest clade of chordata

craniata

6

how are groups defined and characterized?

groups defined based on ancestry, traits used to characterize group

7

chordates + hemichordates =

pharyngotremata

8

informal name referring to early and non complex craniates

protochordates

9

5 characters important in vertebrate evolutionary history

pharyngeal slits, notochord, dorsal hollow nerve cord, endotyle, post-anal tail

10

urochordata means

chordates with tails

11

example of urochordate

tunicate

12

what chordate characters does the tunicate have?

pharyngeal slits, endostyle, postanal tail with notochord and nerve chord in larval stage

13

cephalochordata means

chordates with heads

14

example of cephalochordate

amphioxus or branchiostoma or lancelet

15

habitat of amphioxus

in sand, half buried with head poking out

16

chordate characters present in amphioxus

notochord, dorsal hollow nerve cord, post-anal tail, pharyngeal slits

17

amphioxus feeding method is called

filter or suspension feeding

18

difference between amphioxus pharyngeal slits and more derived versions

amphioxus slits are for getting rid of water ingested during feeding not gas exchanged

19

informal group characterized by lack of jaws

agnathans

20

groups/species considered agnathans

myxinoidea, petromyzontoidea/hagfish, lamprey

21

characteristics of agnathans

lack jaws and paired appendages, now represented only by cyclostomes

22

earlier, diverse group of agnathans (now extinct)

ostracoderms

23

types of ostracoderms

osteostracans, anapsids, heterostracans

24

characteristics of cyclostomes

parasitic, no bone, long thin bodies, single median nostril, rasping tongue

25

lamprey method of feeding

oral cup clings to prey, ingests and filters food from body fluids

26

hagfish method of feeding

scavenges dead flesh, not a filter feeder

27

gnathostomes

all vertebrates beyond agnathans, possess jaws, natural group

28

most basal gnathostomes

placoderms

29

characteristics of placoderms

external jaws from bony armour that are similar but not the same as later jawed animals, paired fins, extinct

30

eugnathostomata

natural group, have true jaws

31

two groups in eugnathostomata

chondricthyes, teleostomi

32

characteristics of chondricthyes

basal eugnathostomes, cartilaginous fishes, well developed paired fins, two nostrils, usually claspers

33

3 stages of becoming a vertebrate

prevertebrate, agnathan, gnathostome

34

characteristics of pre vertebrate stage

suspension feeder, small, poor swimmer, colliery action to produce water movement

35

characteristics of agnathan stage

muscular bands + cartilaginous bars in pharynx, muscular pump to move water, filter feeder on larger particles, poor swimmer

36

characteristics of gnathostome stage

efficient movement of water with muscular pump, larger prey, modify pharyngeal slits for gas exchange

37

two main clades of chondricthyes

elasmobranchii, holocephalia

38

characteristics of elasmobranchs

typical sharks and rays, movable upper jaw, gills open directly to outside, rapid tooth replacement

39

characteristics of holocephalians

slow tooth replacement, operculum covering pharyngeal slits, upper jaw fused to brain case, bottom dwelling mollusc eaters

40

teleostomi

acanthodi and osteichtyes

41

characteristics of acanthodii

spiny sharks (but not true sharks), heterocercal tail, more than 2 pairs of "odd" paired fins (supported by spine), extinct

42

natural groups in osteichtyes

actinopterygii, sarcopterygii

43

characteristics of actinopterygii

99% of all living fish, very diverse, ray finned with poor muscle development in fins, primitively one dorsal fin, ganoid scales, no internal nostrils

44

characteristics of sarcopterygii

only a few are still alive, ancestors of land vertebrates (tetrapods), fleshy finned with well developed skeletal support, strong fin muscles, cosmic scales, 2 dorsal fins, (some) nasal opening extends to oral cavity

45

examples of sarcopterygii

lungfishes, coelacanths

46

3 types of actinopterygians

chondrostei, holostei (not natural group), teleostei

47

characteristics of chondrostei

early actinopterygians, e.g. sturgeon

48

characteristics of holosteans

few still living, intermediate forms, freshwater, fast swimming, e.g. gar pikes

49

morphological trends discussed in chondrostei, holostei, teleostei

body shape and fin form/function, jaws, tail structure

50

trends from chondrostei to teleostei

elongated fusiform body, long jaws with immobile margin, heterocercal tail >>>> short deep body, shortened jaws with mobile margin, homocercal tail

51

limbed vertebrates

stegocephalians

52

early tetrapod examples

elpistostegid fish, stegocephalians

53

recently discovered elpistostegid closely related to stegocephalians

tiktaalik

54

examples of basal stegocephalians

ichthyostega, acanthostega

55

characteristics of basal stegocephalians

fully formed limbs, skull, and vertebrae that could support weight on land but not well, retained full set of gills

56

clades of tetrapoda

amphibia, amniota

57

characteristics of amphibians

intermediate between bony fish and derived tetrapods, distinct mode of reproduction, lay eggs in water and have aquatic larval stage

58

characteristics of amniotes

extra-embryonic membranes surround and protect embryo, has longer development, gas exchange

59

living amphibians

lissamphibia

60

characteristics of lissamphibia

not primitive tetrapods, gas exchange by cutaneous respiration, pedicellate teeth, can have ancient or specialized locomotion

61

3 groups of lissamphibia

caudata, anura, gymnophiona

62

example of caudata

salamanders

63

example of anura

frogs

64

2 major lineages of amniotes

reptilia, synapsida

65

4 major skull types in amniotes

anapsid, euryapsid, diapsid, synapsid

66

characteristics of anapsid skull

no temporal fenestra

67

characteristics of diapsid skull

two temporal fenestra

68

characteristics of euryapsid skull

one dorsally positioned fenestra

69

characteristics of synapsid skull

one ventrally positioned fenestra

70

2 main subdivisions of reptilia

parareptilia, diapsida

71

characteristics/examples of parareptilia

anapsid skulls, eg turtles

72

characteristics/examples of diapsida

diapsid skulls and extinct euryapsid skulls, very large and diverse group

73

2 main groups of diapsida

arcosauromorpha, lepidosauromorpha

74

examples of arcosauromorpha

crocodiles, pterosaurs, dinosaurs, birds

75

examples of euryapsid lepidosauromorpha

ichtyosaurs, plesiosaurs

76

examples of diapsid lepidosauromorpha

rhyncocephalians, lizards, snakes (lizards non natural group, lizards and snakes in same natural group

77

2 broad groups of synapsids

"pelycosaurs", therapsida

78

characteristics of mammals

mammary glands, hair, muscular diaphragm

79

useful skeletal elements that help identify specimens as mammals

each mandible formed by 2 dentary bones, 3 middle ear ossicles, jaw joint at squamosal-dentary, complex teeth, non-sprawling posture

80

reptile-like jaw condition

quadrate-articular

81

bone that became incus

quadrate

82

bone that became malleus

articular

83

bone that became mammalian ectotympanic membrane

angular

84

2 groups of living mammals

monotremata, theria

85

2 groups of theria

marsupiala, eutheria (placentals)

86

species of monotremata and characteristics

platypus, echidnas - have hair, suckle young, endothermic BUT retain cloaca, lack nipples, lay eggs w leathery shells

87

characteristics of marsupiala

mainly found in SA and australia, pouched mammals, have placenta, most have yolk sac placenta

88

characteristics of eutheria

all have chorioallantoic placenta

89

microlecithal

egg with little yolk

90

mesolecithal

egg with moderate amount of yolk

91

macrolecithal

egg with a lot of yolk

92

fertilization >>> blastula process in microlecithal egg

protoplasm in animal pole divides twice vertically then horizontally until 1-cell width blastula forms

93

fertilization >>> blastula process in mesolecithal egg

smaller animal pole, cellular divisions less equal, forming several cell width blastula with blastocoele displaced toward animal pole

94

fertilization >>> blastula process in macrolecithal egg

only small cap of protoplasm divides, blastula forms as a plate of cells at animal pole which is separated from yolk by blastocoele

95

fertilization >>> blastula process in mammals

IN UTERUS - continued division produces blastula with outer trophoblast, structure that will be part of placenta

96

structure of trophoblast

looks like microlecithal blastula but has its own animal pole, the inner cell mass that continues to divide

97

mammalian embryology post-blastula

gastrulization leading to structural arrangement of 3 basic germ layers

98

3 basic germ layers

ectoderm, mesoderm, endoderm

99

gasrulization of amphioxus

blastula vegetal pole folds inward into blastocoele, animal pole cells form ectoderm and vegetal pole cells form endoderm

100

dorsal middle of ectoderm

neurectoderm

101

2 kinds of mesoderm

chordamesoderm at dorsal midline, lateral mesoderm on either side

102

gastrulation results in

elongated gastrula with gastrocoele that opens into the blastopore

103

ultimately, ectoderm differentiates into

skin and nervous system

104

ultimately, mesoderm differentiates into

somatic skeleton, muscle, circulatory system

105

ultimately, endoderm differentiates into

digestive tract and visceral derivatives (muscles and skeleton)

106

step 1 after gastrula

ectoderm differentiates to also form neurectoderm, mesoderm differentiates into chordamesoderm dorsally and lateral mesoderm that expands laterodistally, endoderm expands dorsomedially

107

step 2 after gastrula

neurectoderm invaginate while ectoderm expands to cover it forming neural crest cells and neurogenic placodes, mesoderm continues laterodistal expansion while subdividing to form a column on either side, endoderm completely surrounds gastrocoele

108

step 3 after gastrula

ectoderm covers neural tube, lateral mesoderm subdivides dorsoventrally into epimere, mesomere, hypo mere with enlarging column, endoderm relatively smaller

109

step 4 after gastrula

neural crest cells begin to migrate, epimere subdivides lateromedially into dermatome, myotome, sclerotome

110

step 5 after gastrula

further expansion of all mesoderm subdivisions

111

step 6 after gastrula

dermatome loses segmentation and expands deep into ectoderm, myotome expands dorsally between ectoderm and sclerotome and ventrally between ectoderm and hypo mere, sclerotome surrounds notochord and neural tube

112

hypomere divides into and becomes

somatic and visceral layers become parietal and visceral serosa, heart and blood vessels, lymph vessels, gonads

113

mesomere becomes

kedneys, excretory, and reproductive ducts

114

mesoderm development beyond step 6

dermatome becomes dermis of integument, dermal muscles and dermal skeletal structures, myotome gets divided by horizontal septum into epaxial and hypaxial musculature, sclerotome becomes vertebral column

115

endoderm development beyond step 6

primitive gut becomes liver, pancreas, lining of lungs, digestive tract, urinary bladder

116

primary body tissues

epithelial, connective, muscular, nervous

117

characteristics of epithelial tissue

covers exposed surfaces (internal, no exit - serosa and external, exit - mucosa), forms glands, has apical and basal surfaces, avascular, few to no nervous structures

118

2 main layers of integument

epidermis and dermis

119

characteristics of epidermis

superficial, epithelial, derived from ectoderm, usually thin

120

characteristics of dermis

deep, connective, derived from dermatome, usually thicker than epidermis, sensory receptors

121

method used by vertebrates to avoid water loss through integument

most superficial layer of epidermis formed by dead hard cells, waterproofed using insoluble proteins like keratins

122

typical arrangement of integument layers and characteristics

epidermis, dermis, hypodermis - deep to dermis, loose connective tissue and adipose tissue

123

2 main layers of epidermis

stratum corneum - thin layer of dead cells, stratum basal - mostly keratinocytes, living cells; continually divides to replace lost cells

124

characteristics of primitive fish skin

epidermis almost all live cells (not keratinized), secrete mucus, in some forms denticles

125

characteristics of derived fish skin

scales formed of both epidermis and dermis including enamel, dentin, bone

126

shark skin and scales

placoid scales formed from dentin and capped with enamel

127

role of dermis in bony fish

forms bony plates of placoderms and ostracoderms, posterior dermal scales in above, forms cosmoid and ganoid scales

128

cosmoid scale

primitive sarcopterygians, has dentin covering bone

129

ganoid scale

primitive actinopterygians, has enamel covering bone instead of dentin

130

teleost scale

derived actinopterygians, divided into cycloid form and ctenoid form

131

characteristics of amphibian skin

thin stratum corneum, most cells living for cutaneous respiration, have mucous and poison glands

132

characteristics of reptile skin

extensive keratinization into epidermal scales, may be modified into crests, spines or horns, dermal bone mainly present in gastralia, few glands, mainly scent

133

keratinized epidermal derivatives in mammals

scales in pangolins, beaver tail, calluses, nails/claws/hooves, hair, horns/antlers, glands

134

structure of true horns

keratinized sheath supported by unbranched bony core or spike, not shed (cattle, antelope, goats, sheep)

135

structure of antlers

velvety shin, bone only when mature, tends to be branched, shed annually, usually only males

136

structure of rhino horn

keratinized epithelium in form of fused hairlike epidermal papillae

137

structure of giraffe horn

ossified cartilage core covered by skin

138

types of gland structures

alveolar, tubular/coiled, complex/compound

139

two important glands found in birds

uropygial - near base of tail, secretes oily substance used in preening
salt gland - on head of some birds, secretes excess salt

140

glands found in mammals

eccrine - watery secretion
apocrine - viscous secretion (mammary, scent)

141

monotreme mammary glands

complex glands

142

marsupial and eutherian mammary glands

teat - complex glands that secrete into a cistern and out the teat through the teat duct
nipple - complex glands that secrete through a concentrated opening

143

mesenchyme

mainly from epi- and hypo mere, network of cells between outer tube and developing organs, cells capable of amoeboid movement, functions as embryonic CT, differentiates into muscles, circ system, CT

144

characteristics of bone

mineralized matrix, metabolically active, osteocytes in chambers and stellate lacunae in matrix, vascularized, grows by surface expansion

145

characteristics of cartilage

more variable than bone, rigid matrix, spherical chondrocytes and isolated lacunae, avascular, not metabolically active, grows by internal and surface expansion

146

3 broad classes of bone

dermal skeleton, endoskeleton, heterotopic skeletal elements

147

characteristics of dermal skeleton

forms directly in CT in dermis, never preformed in cartilage superficial position, e.g. bony plates/scales in early fish, osteoderms, crocodilians, turtles, armadillo

148

characteristics of endoskeleton

endochondral, almost always preformed in cartilage, most bones of the body

149

subdivisions of endoskeleton

somatic - formed by somites of epaxial mesoderm, axial and appendicular
visceral - associated or derived from branchial arches formed by neurectoderm

150

characteristics of heterotopic skeletal elements

anything not included as dermal or endoskeleton, similar to dermal but usually not preformed in cartilage

151

examples of heterotopic skeletal elements

bones that grow in tendon of a muscle - sesamoid bones: patella, os cordis (in septum of cattle heart), baculum (os penis), os clitoridis

152

shaft of bone

diaphysis

153

end of bone

epiphysis

154

separates diaphysis and epiphysis

epiphyseal line

155

hyaline cartilage layer in young between diaphysis and epiphysis

epiphyseal plate

156

fibrous CT surrounding element

periosteum

157

cavity in diaphysis

medullary cavity

158

CT lining cavity and spaces within bone

medullary cavity

159

cartilage at joints

articular cartilage

160

process of endochondral ossification

1. formation of bone collar around hyaline cartilage
2. perichondral ossification where collar will meet inner oss. centre
3. invasion of internal cavities by periosteal bud, spongy bone formation
4. formation of medullary cavity, appearance of secondary oss centres in epiphyses
5. ossification of epiphyses, cartilage remains only in plates and at articulars

161

types of vertebrae in fish

trunk, caudal

162

types of vertebrae in primitive tetrabods

trunk, sacral, caudal

163

types of vertebrae in advanced tetrapods

cervical, dorsal sacral caudal

164

types of vertebrae in mammals

cervical, thoracic, lumbar, sacral, caudal

165

embryological precursor to vertebrae

sclerotome of epimere

166

arrangement of vertebrae in amniotes

intersegmentally with respect to musculature

167

development of vertebrae

groups of sclerotome cells form primary sclerotome, migrate medially toward notochord and rearrange, form secondary sclerotome blocks made of 2 adjacent primary sclerotomes

168

bony fish post cranial skeleton

lots of dermal bone in skin, pectoral girdle formed from dermal (anchor girdle to body) and endoskeletal bone (supports fin)

169

tetrapod/mammalian post cranial skeleton

endoskeleton expansion, scapula becomes main shoulder element, only clavicle remains of dermal elements and is sometimes reduced to allow more mobile scapula

170

skull is fusion of

dermal and endoskeletal (endochondral)

171

3 parts of bony skull

brain case - somatic endochondral, some dermal
palatal complex - dermal, some visceral endochondral
skull roof - dermal

172

5 groups of skull roof bones

tooth bearing marginal series (rim of roof), midline series (adjacently paired), circumorbital series (surround orbit), temporal series (bw otic notch and midline series), cheek series (behind orbit, below otic notch)

173

palatal complex

paired bones, mostly dermal some visceral endochondral

174

bones of palatal complex

dermal: vomer, palatine, ectopterygoid, pterygoid
visceral endochondral: palatoquadrate

175

2 ossifications along palatoquadrate in tetrapods

quadrate (smaller, posterior), epipterygoid (larger, anterior, art with braincase)

176

in tetrapods, palatal quadrate articulates with

lower jaw via quadrate, braincase between epipterygoid and basisphenoid

177

brain case

not all paired bones, mostly somatic endochondral but one dermal bone

178

dermal bone of braincase

parasphenoid - in skin on roof of oral cavity, ventral brain case, narrow anteriorly wide posteriorly

179

somaric endochondral bones of braincase

supraoccipital, basiooccipital, paired exooccipitals (surround foramen magnum), opisthotic, prootic (surround canal of inner ear), basisphenoid, sphenethmoid

180

basisphenoid

median, mostly ventral and anterior to otic region, floor of cranial cavity, covered ventrally by parasphenoid, basipterygoid on either side

181

sphenethmoid

median ossification in sphenoid and ethmoid regions, trough shaped, contains olfactory nerves

182

5 skull types (evolutionary progression)

early tetrapod, amniote, early synapsid, non-mammalian therapsid, mammalian

183

changes from early tetrapod to basal amniote skull

otic notch closed, intertemporals lost, posterior displacement and reduction in other temporal bones, post parietals and tabular fused into occipital, supra temporal lost

184

changes from early synapsid to non-mammalian therapsid skull

early synapsids developed temporal fenestra, which enlarged to become fossa in non-mammalian therapsid, quadratojugal reduced, squamosal differentiates into zygomatic arch and part of braincase, prefrontals/postfrontals/postorbitals lost

185

changes from non-mammalian therapsid skull to mammalian

muscles go from outside skull to inside, brain bigger and completely enclosed in bone, development of a secondary palate to differentiate food and air passages, complex fusions of temporal region

186

role of squamosal in mammalian skull

large flat dermal bone on side of brain

187

role of petrosal in mammalian skull

braincase, fusion of prootic and opisthotic

188

role of ectotympanic in mammalian skull

angular dermal bone, old lower jaw

189

role of entotympanic in mammalian skull

new development in mammals from braincase

190

precursor to malleus

articular, dermal bone of old lower jaw

191

precursor to incus

quadrate, endochondral, palatal complex

192

stapes

hyomandibular, visceral endochondral