Bisc 316 Flashcards
Characteristic of Cartilage
- Chondrocytes (Mesenchyme cells) secrete chondromucoprotein
- Have less salt than bones - less rigid than bone
- Cells lack canaliculi
- Commonly found in embryos and young vertebrates
What are the type of Bones?
Dermal Bones
Replacement Bones
What is a Dermal Bone?
Bones of the skull is an example
Forms directly from mesenchyme (called osteoblast)
Thin plates of collagen matrix; salts is deposited
As the bone grows, the plate expand outer margin and thickens by adding new layers on inner & outer surface
What is the replacement bone?
Bone that replaces cartilage
Osteoblasts (Mesenchyme) enter along the blood vessels.
This is typical of long bones in vertebrates
Bone can also be added to the margins & outer surface end of bone cartilage & notochord.
What are the three types of Mineralized Tissues?
Bone
Dentine
Enamel
Dentine and Enamel don’t support the body
What is Dentine Tissue?
A mineralized tissue that defines the boundary between ectoderm and mesoderm.
Secreted by odontoblasts
It is internal to enamel and external to bone
It is harder than bone
Has inorganic salts of hydroxyapatite
What is Enamel?
Hardest tissue in the vertebrate body
Produced by ectoderm on top of dentine
No internal cells - so its a dead tissue
What are the 4 layers of dermal scales?
Lamellar bone - forms the base and contains a few blood vessels
Vascular layer - where the blood vessels go through
Dentine - Above the vascular layer
Enamel - Cap
What is the Super Class of Jaw Mouths called?
Gnathostomata
The 4 clades of Gnathosomes
Placoderms
Acanthodians
Chondrichthyes
Osteichthyes
Characteristics of Placoderms
Jaws but no true teeth Paired appendages with girdles Have neural and hemal arches (vertebrae) Gas bladder Heavy armor There are gaps in bony plates that allow for head articulation - allowing jaws to open wider and for jaw protrusion Have protrusible jaws
Characteristic of Modern Radiation
Hyostylic Jaw Suspension Teeth single cusp or flat crown Notochords are reduced to discs Complete pectoral and pelvic girdle Fins are narrow based Have claspers Full functioning vertebrae
What did the Elasmobranchii split into during the Jurassic?
Selachii
Batoidea
Characteristic of Holocephali
Has a subclass called Chimaeriformes Autostylic No teeth, but with plate to manipulate food Single gill opening Fnalike pectoral fins Oviparous
3 Major Radiation of Elasmobranchii
Paleozoic
Early Mesozoic
Extant Radiation (Jurassic)
Define Paleozoic Radiation
Early Sharks Notochord is continous Beginnings of the early centrum No pectoral girdle Amphistylic Jaw Suspension Teeth had 3 cusps No claspers Broad attachment to paired fins
Structure of the vertebrate
Centrum - The main supporting part of the vertebrate
Hema Arch - Only found in the tail
Neural and Hemal Spine - the function is to increase surface area for muscle attachment
Apophyses - Projection off the neural arch that help lock the vertebrate together
Advantages of the vertebrate
Stronger and more flexible than the notochord
Greater lateral movement then compared with a notochord
Prevents collapse during movement
Solid surface for muscle attachment
2 Subclasses of Chondrichthyes
Elasmobranchii
Holocephali
How many orders are there in Elasmobranchii
2 Living and 2 Extant
Characteristics of Chondrichthyes
Placoid Scales Cartilagenous Skeleton Spiracle Gill Openings No lung or gas bladder; liver for buoyancy Claspers that faciliate internal fertilization Teeth in replacement family Claspers
3 Major Radiation of Elasmobranchii
Paleozoic
Early Mesozoic
Extant Radiation (Triassic)
Define Paleozoic Radiation
Early Sharks Notochord is continous Beginnings of the early centrum No pectoral girdle Amphistylic Jaw Suspension Teeth had 3 cusps No claspers Broad attachment to paired fins
Define Early Mesozoic
Hemal Arch added Amphistylic Predatory Type Teeth Claspers Still no pectoral girdle Narrow based paird fins
Define modern/extant radiation
Hyoidstylic Jaw Suspension
Protrusible Jaw
Notochord constricted to form discs
Two types of drag
Viscous Drag
Inertial Drag
What is Viscous drag?
A boundary layer is created as layers of water (lamina) moves pass each other
Creates a shearing force where the faster the fish is moving, the thicker the boundary layers will be
Eddies created in boundary layer, and when the amount of eddies increase, it increases the amount of drag
What is Inertial drag?
Vacuum created as water is dispalced
Water flows in to replace the displaced water and creates inertial drag
Characteristic of Osteichthyes (Bony Fish)
Bony Skeleton Dermal Bone where the teeth is attached to bones of jaws Possession of three types of scales: Cosmoid Scales, Dermal Scales, and Elasmoid Scale Hyostylic Jaw Suspension Internal Support for the fins Primitive forms have hypercercal tails Modern ones have homocercal tail Diverticulum
What is diverticulum?
Lung or gas bladder that control the amount of gas inside the body which help it control its natural buoyancy
What are the three types of fish scales?
Cosmoid Scales
Ganoid Scales
Elasmoid Scales
What is a cosmoid scale?
Bone, dentine, and enamel
What is a ganoid scale?
Bone and enamel