Introduction to Comparative Vertebrate Anatomy Flashcards
Studies the descriptive and functional morphology of vertebrates
Descriptive - structure of vertebrates
Functional - significance of the structure
Comparative Anatomy
A study of evolution to phylogeny
It can be considered as vertebrate evolution
Comparative Anatomy
study of structural evolution
Morphology
study of description of structures
Anatomy
Tail appearing outwardly symmetrical but with the backbone passing into the upper lobe, as in all higher fish
homocercal
Tailhaving unequal upper and lower lobes, usually with the vertebral column passing into the upper.
heterocercal
Big Five in chordates
post anal tail
dorsal hollow nerve cord
pharynx
notchord
endostyle
No vertebrate will proceed without passing through these five characteristics in embryonic development
true
_______ have been grouped into a single taxon
Protochordates and chordates
is a rod of living cells ventral to the CNS and dorsal to the alimentary canal
provides skeletal support throughout most of the length of a chordate
Notochord
most vertebrates, a more complex, jointed skeleton develops, and the adult retains only remnants of the
embryonic notochord
Fate during development of Notochord and Vertebral Column in head region
incorporated into skull floor
Fate during development of Notochord and Vertebral Column in Trunk and tail
surrounded by cartilaginous or bony vertebrae
Fate in adulthood development of Notochord and Vertebral Column in Trunk and tail in Protochordates
chief axial skeleton surrounded by notochord sheath
Fate in adulthood development of Notochord and Vertebral Column in Trunk and tail in Agnathans
similar to protochordates with addition of lateral neural cartilages
Fate in adulthood development of Notochord and Vertebral Column in Trunk and tail in Fishes and amphibians
persist the length of the trunk and tail within the centrum
Fate in adulthood development of Notochord and Vertebral Column in Trunk and tail in Reptiles, birds and mammals
disappears and becomes pulpy nucleus in mammal vertebrae
Vertebrae parts
Centrum (deposited around notochord)
Neural arch (forms over spinal cord)
Various processes
develops from a plate of ectoderm that rolls into a tube dorsal to the notochord
Formed by the process of invagination
Dorsal Hollow Nerve Cord
The nerve cord develops into the central nervous system:
Brain
Spinal cord
Common to hemichordates and chordates
can be perforated by openings (slits) to either the exterior or an atrium (reflecting common ancestry)
Membranous digestive and respiratory organ located at the back of the mouth that serves as passageway of food and air
Pharynx
The ______ Vital part of craniate embryo that produces:
Gills of fishes (permanent slits)
Lungs of tetrapods (temporary slits)
Skeleton & musculature of jaws
Endocrine glands that regulate metabolic rates in all body cells & maintain appropriate calcium levels in bones, other tissues & circulating blood (parafollicular cells & parathyroid glands)
Gives rise to middle ear cavity of tetrapods (auditory and tympanic cavity)
Provides initial cells of immune system during fetal life & shortly after (thymus in humans)
Pharynx
A column of tissue which separates each embryonic pharyngeal pouch or slit from the next
Pharyngeal Arches
Pharyngeal Arch typically has 4 components or blastemas from which these components develop:
Skeleton
Muscles
Nerves
Blood vessels
Total of _________ of Pharyngeal arches develop in cranio-caudal sequence
6 pairs
is complex, and contributes to both upper and lower jaw
First arch
Arch _
Skeletal Elements
Meckel’s cartilage
Malleus
Incus
Muscles
Muscles of mastication
Anterior belly of digastricus
Tensor tympani
Tensor palati
1
Arch 1
Cranial Nerve
Trigeminal nerve (mandibular division)
Arch _
Skeletal Elements
Stapes
Styloid process
Upper part of hyoid
Muscles
Stapedius
Stylohyoid
Muscles of facial expression
Posterior belly of digastricus
2
Arch 2
Cranial Nerve
Facial nerve
Arch _
Skeletal Elements
Lower part of hyoid
Muscles
Stylopharyngeus
3
Arch 3
Cranial Nerve
Glossopharyngeal nerve
Arch _
Skeletal Elements
Laryngeal cartilages
Muscles
Cricotyhroideus
Pharyngeal constrictors
Instrinsic laryngeal muscles
4 - 6
Arch 4 - 6
Cranial Nerve
Vagus Nerve
Supportive skeletal elements (pharyngeal skeleton)
Pharyngeal Arches
Pharyngeal Arches have ___________ (branches 5, 7, 9 and 10) which innervate muscles and provide sensory input to the brain
Cranial nerves
Pharyngeal Arches have an __________ that connects the ventral and dorsal aortas
aortic arch
Striated muscles that operate the Pharyngeal Arches
branchiomeric muscles
Ectodermally-lined grooves on the outside of the embryonic pharynx
Pharyngeal Clefts
Supportive skeletal elements (pharyngeal skeleton)
Striated muscles that operate the arch (branchiomeric muscles)
Cranial nerves (branches 5, 7, 9 and 10) which innervate muscles and provide sensory input to the brain
An aortic arch that connects the ventral and dorsal aortas
Pharyngeal Arches Components
Ectodermally-lined grooves on the outside of the embryonic pharynx
are lost in development because of proliferation of the underlying mesoderm
Pharyngeal Clefts
an important cleft because this Pharyngeal Cleft it develops into the external auditory meatus of the ear and provides the outer epithelium of the tympanic membrane
first cleft
Arises as diverticula of endoderm or foregut
Grows toward the surface of the animal
Establish the limits of the pharynx
Contribute to the development of a surprising diversity of structures
Pharyngeal Pouches