Comparative Anatomy Review Sheet, Exam I

This review sheet contains most of the information covered in lecture prior to the first exam.  It is
meant to serve as a guide, and is not a comprehensive, all inclusive listing.

Anatomy is the study of the form of the body.
Comparative anatomy is the study of differences in form between the various vertebrate
    groups, as well as how and why those differences came about.
Evolution is the central, guiding principle in modern biology.
Charles Darwin wrote: "On the Origin of Species..."
This book demonstrate that evolution occurs and proposed a mechanism by which it must operate:
    natural selection.

Know how natural selection works.
Know the definition of adaptation.
Know the two species concepts: Biological Species Concept and
Evolutionary species concept.  Who was the author of each?

What are the differences between microevolution and macroevolution?

Know the following terms and be able to use them in a sentence:
taxon                           homology
systematics                analogy
extinct                         parallelism
extant                          convergence
adaptive radiation                    

Know what allows adaptive radiations to occur and be able to cite some examples.
Know some examples that demonstrate homology
What is a character?

 Know the following terms:

Vertebrate Classification

What are the differences between the traditional classification of vertebrates and the
     modern, phylogenetic scheme?

 Know the geological time scale and how the remains of an organism become fossilized.

 Know the main characteristics, and some examples of the following taxa:
“Agnatha”                               Tetrapoda                             Lepidosauria
Conodonta                             Temnospondyla                   Squamata
Myxini                                      Lissamphibia                       Aves
Pteraspidomorpha               Urodela                                  Monotremata
Cephalaspidomorpha          Salientia                                Metatheria
Gnathostomata                     Gymnophiona                        Eutheria
Placodermi                            Amniota                                 Pelycosauria
Acanthodii                              Reptilia                                  Therapsida
Chondrichthyes                     Anapsida                              
Actinopterygii                        Synapsida
Sarcopterygii                         Diapsida
“Osteichthyes”                       Archosauria
Dipnoi                                     Testudines         


What are the 4 defining features of the Phylum Chordata?
Dorsal, hollow, nerve cord
Pharyngeal gill slits
Postanal tail

 Know the major protochordate groups:
Which of these is not a chordate group?
Why are the Chordates united with the echinoderms and Hemichordata into the  
    Superphylum Deuterostomia?
What are the differences between these and the Protostomia?
What are the Enteropneusta?  The Pterobranchia? The Ascidiacea? 
    The Thaliacea? The Larvacea?

Know the following terms:
Proboscis                                          peripharyngeal bands
Collar                                                  dorsal lamina
Blastopore                                         tadpole larva
Cleavage                                           adhesive papilla
Auricularia (or tornaria)                    otolith
Schizocoele                                       paedomorphosis
Trochophore                                      myomeres
Cilia                                                    buccal chamber
Tunic                                                   oral cirri
Tunicin                                                Hatschek’s pit
House                                                 atrium
Endostyle                                           epibranchial groove
Solenocytes                                       atriopore
mid-gut caecum                                Anterior and posterior cardinal veins
sinus venosus                                   Common cardinal veins
Endostylar artery

 Know the various hypotheses on the evolution of the vertebrates from protochordates
    and especially, the significance of the larval forms of each group mentioned.


Egg types:                  Telolecithal
Microlecithal              Cleavage types:
Mesolecithal              holoblastic
Macrolecithal                         meroblastic

Know the following terms:
Blastodisc                  Endoderm                 sclerotome                           
Blastomeres              Mesoderm                 nephric ridge                                   
Morula                         neurula                       dermatome                          
Blastocoele                neural plate               cleidoic egg             
Blastula                       neural crest               amnion
Blastopore                 somites                      chorion
Gastrula                      lateral plate                allantois
Epiboly                       splanchnic layer         somatopleure
Archenteron               somatic layer             splanchnopleure
Ectoderm                   myotome 


Know the 11 functions of this system

Know the basic makeup of the epidermis and the dermis

Know how the stratum corneum of the epidermis forms.

Know the characteristics of the integument in each of the major vertebrate groups: fish,
    amphibian, reptile, bird, mammal.  How is each group different from the others?
Know the types of skin glands. 
Know the types of dermal bones and scales
Know the types of chromatophores
Know the types of epidermal derivatives
Know the structure of a hair
Know the structure of a feather
Know the following terms:
Keratin                                                            mucous cuticle
Keratinocyte                                                 Chromatophore
Plies                                                               Osteoderm
Warp & weft                                                   Scale
Basement membrane
Stratum basale (= s. germinativum)

The Skeletal System.

1. Support                              4. Mineral sink
2. Protection                          5. Hemopoiesis

3. Movement/locomotion            6. Energy storage: fat deposition

Tissue types.

Connective tissues: large amount of matrix, relatively few cells.

: chondrocytes found in lacunae.  Matrix includes chondroitan sulfate. 
Hyaline cartilage - glassy, few, parallel collagen fibers in matrix.
Fibrocartilage - dense, white, opaque collagen fibers in matrix.
Elastic cartilage - primarily elastic fibers in matrix.
Chondroid tissue - found only in larval lampreys and some sharks
Calcified cartilage: cartilage impregnated with calcium salts, found in large sharks.

Growth of cartilage:
            Interstitial - internal cells divide in lacunae. Matrix deposited internally.
            Appositional growth - chondroblasts deposit new cartilage at surface just beneath

Cells - osteocytes: found in lacunae within bony matrix.
Osteoblasts: found beneath perichondrium, where they can deposit new bone at
    the surface.
Osteoclasts: responsible for dissolving bone.

Matrix of bone contains crystaline calcium salts called hydroxyapatite.
Mineral involved is calcium phosphate.

Two classes of bony tissue: spongy bone and compact bone.
Compact bone is arranged into osteons or haversian systems:
Haversian canal is surrounded by lamellae of matrix.

Lacunae arranged along the boundaries of the lamellae.  Lacunae occupied by
    osteocytes, interconnected through canaliculi.

Spongy bone: arranged into trabeculae. Lamellae absent, although lacunae with
    canaliculi present.

Trabeculae arranged along lines of stress.
Spaces within spongy bone filled with red marrow, location of hemopoiesis.
Yellow marrow occurs in marrow cavity of diaphysis.

Structure of a long bone:

Diaphysis - shaft (derived from primary ossification center).
Epiphysis - cap-like ends of bone (derived from secondary ossification centers).
Metaphysis - epiphyseal plate (=growth plate).
Articular cartilage - hyaline cartilage covering articular surfaces.
Periostium - white, fibrous connective tissue covering on non-articular surfaces
    of bone. Anchored by Sharpey's fibers.
Medullary cavity - space within diaphysis, contains yellow marrow.
Endosteum - internal membranous layer covering inner surface of bone.

Osteogenesis: bone formation.

Dermal bone (=membrane bone) ossifies directly in connective tissue membrane
    by deposition of trabeculae.
Endochondral bone - bone that is preformed in cartilage, which is replaced by bone during

Sequence of osteogenesis in a longbone:
1) periostial collar ossifies
2) primary ossification center ossifies in diaphysis
3) secondary ossification center ossifies to form epiphyses

Growth of a long bone occurs at Metaphysis as cartilage growth at one end of plate is followed
    by ossification at the other end of plate.

Bone remodelling occurs when osteoclasts dissolve away bone at one location, while osteoblasts
    are laying down bone at another location. Results in shape change.

Distribution of bone types:
Dermal bone - Scales of fishes, osteoderms, turtle shell, external skull bones, clavicle and interclavicle.
Endochondral bone - chondrocranium and derivatives, vertebrae, ribs, appendicular skeleton
    (except clavicle and interclavicle).

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