Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Comparative Anatomy > Anatomy of Amphioxus > Flashcards

Anatomy of Amphioxus Flashcards

1
Q

Vertical longitudinal plane passing from head to tail through the center of the body from dorsal to ventral surfaces

A

Median Plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Any vertical longitudinal plane through the body- that is, the median plane or any plane parallel to it, sometimes designated as parasagittal

A

Sagittal Plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Any horizontal longitudinal section through the body- that is, all planes at right angles to the median plane and parallel to the dorsal and ventral surfaces

A

Horizontal or frontal Plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Section cuts vertically across the body at right angles to the sagittal and horizontal planes

A

Transverse or cross-plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Line in the median sagittal plane extending from head to tail

A

Longitudinal or anteroposterior axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Any line in the median and sagittal plane extending from dorsal to ventral surfaces

A

Sagittal or dorsoventral axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Any line in the transverse plane running from side to side

A

Transverse or mediolateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Three axes of bilateral symmetry

A

Longitudinal, transverse, and sagittal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Plane which passes through the longitudinal and Sagittal axes

A

Median Sagittal Plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Regular repetition of body parts along the anteroposterior axis

A

Metamerism or Segmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Each division is termed a (3 divisions)

A

Metamere, segment, somite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Animal is said to exhibit both external and internal segmentation;

A

Internal metamerism is present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The segmentation of the animal body into nearly- like segments is spoken of as

A

Homonomous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The majority of segmented animals in which the various segments differ from each other to a greater or less extent

A

Heteronous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is a primitive and generalized state in which the various segments are more or less independent and capable of performing all necessary functions

A

Homonomous segmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The segmented groups of animals are (3)

A

Annelids, anthropods, chordates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Metamerism in the chordate line began in the hemichordates , where gonads show evidence of serial repetition

A

Pseudometamerism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

An intrinsic similarity indicative of a common evolutionary origin

A

Homology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Animals closely related by descent may differ greatly in general appearance after a long sojourn in different environments, such as seals and cats

A

Divergence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

They have a notochord which is a dorsal nerve cord and gill slits

A

phylum Chordata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Phylum Chordata comprises of 4 subphyla

A
  • Hemichordata (acorn worms)
  • Urochordata (tunicates)
  • Cephalochordata (amphioxus)
  • Vertebrata
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cephachordates consists of 2 genera

A

Branchiostoma and Asymmetron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Means sharps both ends is a member of the genus

A

Branchiostoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Small animal, only about 2-3 inches in length, that can be found lying along sandy seashores in temparate zones

A

Amphioxus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What differs in amphioxus and other fishes

A

Lack of skull, vertebrae, brain, heart, and kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The epithelium covering is but a single cell in thickness covered in what tissue?

A

Connective tissue is gelatinous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The muscle masses, the myomeres are separated by?

A

Myosepta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Extends the entire length of the body

A

Median dorsal fin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

An expanded continuation of the median dorsal at the posterior end of the body

A

Caudal Fin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

An anterior continuation of the caudal fin extending to the atriopore

A

Ventral Fin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The opening of an internal cavity, the atrium, located just in front of the ventral fin

A

Atriopore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The snout like anterior end of the body that projects over the oral hood

A

Rostrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

22 still tentacle-like structures projecting from the free edge of the oral hood. They are thought to contain sensory elements that might be used for taste

A

Buccal Cirri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The longitudinal series of about sixty angularly shaped muscle segments, known also as myotomeres

A

Myomeres

35
Q

The connective tissue partitions separating the myomeres

A

Myosepta

36
Q

The row of rectangular bulging masses located beneath the ventral ends of the myomeres

A

Gonads

37
Q

A pair of integumentary folds that extend along the ventrolateral surfaces from the anterior pharyngeal region almost to the atriopore

A

Metapleural folds

38
Q

A funnel shaped membrane located at the ventral part of the anterior end of the body; it helps to direct the water vortex, created by the wheel organ , into the mouth

A

Oral hood

39
Q

Funnel shaped cavity enclosed by the oral hood

A

Vestibule

40
Q

The internal connective tissue rods that are present as supporting elements in both the dorsal and ventral dins. They are absent from the caudal fin

A

Fin rays

41
Q

The supporting rod that extends almost the entire length of the body

A

Notochord

42
Q

The elongated cylindrical mass of nervous tissue that lies above the notochord, it is almost as long as the notochors

A

Nerve cord

43
Q

A linear series of pigment cells lying along the ventral wall of the nerve cord. They may possibly serve as photoreceptors

A

Ocelli

44
Q

A mass of pigment cells located at the anterior end of the nerve cord. Its sensory function has not been established

A

Eyespot

45
Q

A series of finger-like projections, lined with cilia, that lies on the the inner lateral and dorsal walls of the oral hoods.

A

Wheel organ

46
Q

The cilia beat in such a way as to suggest a turning wheel, and they help to create a vortex of water that is directed towards the mouth by the oral hood

A

Wheel organ

47
Q

The vertical membrane located just behind the base of the wheel organ, it regulates the amount of water entering the pharynx

A

Velum

48
Q

The opening in the velum

A

Mouth

49
Q

Short tender projections extending from the margin of the velum that rings the mouth, by bending across the mouth, they may prevent sand or particles from passing into it

A

Velar tentacles

50
Q

The chambar, interrupted by gill slits that extends from the mouth to the intestine

A

Pharynx

51
Q

Slender parallel oblique bar supported by branchial rods

A

Gill Bars

52
Q

That make up the side wall of the pharynx, cross pieces (synapticulae) link the bars

A

Branchial rods

53
Q

The large cavity surrounding the pharynx, its ventral boundary is visible as a line extending below the pharynx to the atriopore

A

Atrium

54
Q

The digestive tube that extends from the pharynx to the anus

A

Intestine

55
Q

The pouch that projects forwards as an outpocketing of the intestine (midgut), it extends along the right side of the posterior part of the pharynx

A

Hepatic diverticulum

56
Q

The outer cellular layer of the body, consisting of a single layer of columnar cells, it is covered by an acellular cuticle and rests upon a thin layer of a connective tissue

A

Epidermis

57
Q

A short projection from the dorsal midline region that is supported by the gelatinous fin rays

A

Dorsal Fin

58
Q

Masses of muscle under the skin, separated by connective tissue partitions, the myosepta

A

Myomeres

59
Q

The somewhat triangular structure located on the midline, slightly ventral to the dorsal fin

A

Nerve cord

60
Q

A very narrow cavity

A

Neurocoel

61
Q

The larger rounded structure that lies beneath the nerve cord, it is surrounded by a connective tissue sheath

A

Notochord

62
Q

The central cavity of the oral hood, located under the front part of the notochord

A

Vestibule

63
Q

The thickened ciliated epithelial masses of the wheel organ are found on the

A

Inner hood wall

64
Q

A number of these, cut transversely, are present at the lower boundary of the vestibule

A

Buccal Cirri

65
Q

These project down from ventrolateral corners of the body

A

Metapleural fold

66
Q

This lies in the wrinkled body wall between the metapleural folds. It extends from the myomeres on one side to those on the other. When it contracts, it compresses the atrial cavity dorsal to it from the side, thus expelling its water

A

Transverse muscle

67
Q

The narrow cavity limited laterally by gill bars that extend between the notochord and transverse muscle

A

Pharynx

68
Q

2 types of gill bars

A

Primary and Secondary gill bars

69
Q

The gill bars are braced by small bridges

A

Synapticulae

70
Q

The deeply grooved structure in the floor of the pharynx

A

Endostyle

71
Q

The cells of endostyle are (2)

A

Ciliated and glandular cells (Inset B)

72
Q

Located on the roof of the pharynx opposite the endostyle

A

Epipharyngeal groove

73
Q

The cavity that surrounds the pharynx laterally and ventrally

A

Atrium

74
Q

These are located ventrolateral in most, they protrude into the atrium from the body wall, still bounded by the atrial lining

A

Gonads

75
Q

In sections near the posterior end of the pharynx, this hollow oval shaped structure is seen on the right side of the pharynx

A

Hepatic diverticulum

76
Q

It lies within the atrial cavity

A

Coelem

77
Q

Present in the cross section as three sac

A
  • Ventral coelemic cavity (lies beneath the endostyle)
  • Dorsolateral
78
Q

Are located on both sides of the epipharyngeal groove

A

Coelemic Cavities

79
Q

The paired dorsal aortae may be seen between the notochord and the dorsal end of each of the paired coelemic cavities

A

Blood Vessels

80
Q

Enclosed within the ventral coelemic

A

Ventral aorta

81
Q

Are present close to the midpoint of the medical border of the gonads

A

Cardinal Veins

82
Q

This is a large hollow oval structure lying ventral to the unpaired dorsal aorta

A

Intestine

83
Q

Beneath the intestine

A

Subintestinal Vein

84
Q

This fin is seen cross sections of the intestine at levels posterior to the atriopore, at levels anterior to the atriopore, metapleural folds will be seen in its place

A

This rather than dorsal or ventral fins, is present, it is narrower and higher than either

Comparative Anatomy (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions