Test 2

Front 1

Epi dermis

Back 1

o outermost layer (not scales); epithelial cells; no direct blood supply; derived from ectoderm; glands
• Sub-divided/ two layers
o Stratum Germinativum deepest layer of epidermis; produces higher layers of epidermis
o 2nd layer is highly variable between vertebrates

Front 2

Dermis

Back 2

• Dermis
o Largely composed of connective tissue; contains blood supply, nerves

Front 3

Hyodermis

Back 3

o Layer of fat found beneath the dermis; thicker in mammals and birds; highly variable among groups

Front 4

Agnathansm Integument

Back 4

• Relatively thick integument
• Numerous glands (protection against predators/microbes)
o Club glands slime of fibrous protein
o Granular glands unknown function (7)
o No elastic fibers in dermis
o No keratin is produced

Front 5

Cartilaginous Fish Integument

Back 5

• Denticles scales made of bone formed in the dermis; each with blood supply; similar in construction to vertebrate teeth
• Integument is thin and glandular (little if any keratin production)

Front 6

Bony Fish Integument

Back 6

• Scales composed of dermal bone; thin layer of dermal and epidermal tissue covers scales.
• Scales are not shed; ever-growing (may allow determination of age)
• Skin is permeable and functions in gas exchange (particularly in smaller fish)
• Mucus glands protect against infection; reduces friction
• Poison glands (alkaloid) usually associated with fin spins

Front 7

Amphibians Integument

Back 7

• Extinct species covered in scales of dermal bone
• Extent species have no scales
• Thin skin
• Mucus production prevents desiccation (facilitates gas exchange)
• Large amounts of keratin produced
• Pigments cells (digestion/heat exchange)Digestive enzymes are more efficient at higher temperatures (some fish have similar capabilities)
• Poison glands (most are simply distasteful chemicals/ others are deadly)

Front 8

Reptile Integument

Back 8

• Thick skin
• Lack glands
• Keratinized scales and scutes
• Lacks elasticity must shed to accommodate growth

Front 9

Bird integument

Back 9

• Thin, soft skin (little keratin produced in integument)
• Lack glands (except preen gland in tip of tail)
• Keratinized feathers
• Extensive layers of smooth muscle within dermis for control of feather position controls flight and thermoregulation

Front 10

Mammal integument

Back 10

• Hair (modified scales)
• Thick skin
• Cornified epidermis (keratin) prevents desiccation
• Sudoriferous glands (sweat glands)
o Eccrine glands open onto skin surface (not associated with hair follicles)
o Apocrine glandsopen into hair follicles of groin/anus/armpits develop during sexual maturity/sexual attractant (only release sweat during times of excitement or stress)
• Mammary glands
• Sebaceous glands secrete sebum/lubricates hair/waterproofs skin/encourages growth of bacteria/associated with all hair follicles

Front 11

Splanchnocranium

Back 11

• Originally believed to have arisen from walls of the digestive tract (visceral cranium)
• Arises from neural crest cells
• Embryologically, it begins as branchial basket, composed of fibrous connective tissue. Never bone or cartilage
• Supports the gills and/or offers attachment sites for respiratory muscles (referred to as branchial arches, or gill arches)
• Elements of Spanchnocranium also contribute to formation of jaws (gill arches can also be involved in this)
• 1st functional arch of jawmandibular arch, composed of Platoquadrate and meckel’s cartilage
• hyoid arch composed of hyomandibula
• Branchial arches vary with species, roman numerals

Front 12

Chondrocranium

Back 12

• Composed of neural crest cells and mesenchyme of mesodermal origin
• Produces elongate cartilages adjacent to notochord
o Trabeculae anterior pair of cartilages
o Parachordals posterior pair of cartilages
o Polar cartilages may lie between parachordals in some vertebrates
o Occipital cartilages form behind parachordals
• Produces sensory capsules associated with: (figure in book)
o Nose- nasal capsule
o Ears- otic capsule
o Eyes- optic capsule

Front 13

Dermatocranium

Back 13

• Dermal bone produced by dermis and sinks inward during embryological development
• Become associated or fused with elements of spanchnocranium and chondrocranium
• Contribute to formation of pectoral girdle
• Dermal elements in fish and amphibians have been lost or fused during evolution so that skulls in these groups have become more simplified
• All other groups the dermatocranium forms braincase and lower jaw
• Facial series snout: maxilla, premaxilla, nasals
• Orbital series encircles the eye: lacrimal, prefrontal, postfrontal, postorbital, jugal
• Temporal series behind orbit, produces openings called fenestrae (jaw muscles): intertemporal, supratemporal, squamosal, and quadratojugal
• Palatal series roof of mouth: pterygoid, vomer, palatine, ectopterygoid. Any of these may include teeth
• Vault series roofing bones: frontal, postparietal, parietal
• Mandibular series Meckel’s cartilage is usually encased in dermal bones. Mandibles meet in the midline at the mandibular symphysis

Front 14

Jawless vertebrates

Back 14

• Chondrocranium
• Cartilaginous throughout life (poorly known in extinct forms)
• All arches are branchial in function
• Number is variable
• Dermal head skeleton is highly variable armored shields/bony scales/none

Front 15

Cartiaginous fish

Back 15

• Chondrocranium not protected by bony plates (unusually solid with side walls and roof)
• Jaw suspension is:
o Amphistylic mandibular arch slightly supported by hyomandibula
o Hyostylic mandibular arch supported entirely by hyomandibula
o Autostylic fused to chondrocranium
• 6-8 post-mandibular arches

Front 16

Bony Fish

Back 16

• Skulls extremely varied and complex (diet, body shape, habits)
• Chondrocranium well ossified
• Mandibular arch regressed (dermal bone form teeth and jaws)
• Quadrate bone forms upper part of jaw hinge (all vertebrate groups)
• Hyostilic or amphistylic jaw support
• Operculum bony cover of gills unique to bony fish

Front 17

Amphibians

Back 17

• Hyomandibula new function/ sound transmission/ stapes

Front 18

Root

Back 18

o Hidden below gum line blood supply and nerves and attached to jaw
o Contains blood vessels and nerves
o Roots are held in socket by non-vascular bone (cement)

Front 19

Crown

Back 19

o Protrudes above jaw line
o Exposed surface of tooth

Front 20

Enamel

Back 20

o Hard outer covering of tooth

Front 21

Dentine

Back 21

o Bony material, surrounds pulp cavity, hard but not as hard as enamel

Front 22

Parts of a tooth

Back 22

Root
crown
enamel
dentine

Front 23

Types of tooth attachment

Back 23

Collagenous fibers (sharpey's)
Pleurodant
acrodont
thecodont

Front 24

Collagenous fibers

Back 24

attach dentine to dermis in cartilaginous fishes such as sharks (not attached to jaw) teeth are continually replaced

Front 25

Pleurodont

Back 25

each tooth touches bone with outer surface of root but not completely surrounded by bone (may be attached with collagenous fibers or cement)

Front 26

Acrodont

Back 26

little or no root, attach to crest of jawbone

Front 27

Thecodont

Back 27

teeth with well developed roots held in sockets by cement

Front 28

Types of tooth replacement

Back 28

polyphyodont
diphyodont

Front 29

Polyphyodont

Back 29

teeth continuously replaced/ most vertebrates

Front 30

Diphyodont

Back 30

2 generations of teeth

Front 31

Types of teeth arrangement (dentition)

Back 31

homodont
heterodont

Front 32

Homodont

Back 32

teeth are relatively the same size and glade-like shape

Front 33

Heterodont

Back 33

teeth specialized for chewing (only mammals) incisors/ canines/ premolars/ molars
 Dentition in mammals indicates their diet

Front 34

Fish endoskeleton

Back 34

• Cartilaginous and/or ossified skeleton
• Primarily for protection (not support against gravity)
• Lack sternum
• If ossified, bone is present.It is usually less dense than in tetrapods
• Skull is extremely complex

Front 35

Amphibian endoskeleton

Back 35

• Skull is smaller and flattened compared to fishes; fewer bones (reduced weight)
• Jaw modifications allow for crushing pressure of mouth
• 1 cervical vertebrae and 1 sacral vertebrae
• Sternum is poorly developed (may be absent in most anurans)
• Ribs poorly developed
• Pelvic girdle ilium, ischium, pubis
• Legs are set wide from the body
• Limbs may have evolved from lobe finned fish
• Caudal vertebrae (tail) absent in most anurans

Front 36

Reptile endoskeleton

Back 36

• Similar to amphibian skeleton
• Highly ossified bones
• Skull is longer than amphibians (improves respiration with the lungs)
• Secondary palate completely separates oral and nasal cavities (fish and amphibians do not have a secondary palate)
• More cervical vertebrae (at least 2) more in some reptiles
• More sacral vertebrae (at least 2) more in some

Front 37

Testudines

Back 37

• Carapace formed mainly from fused vertebrae and expanded ribs (dermal bone also)
• Plastron formed from pelvic girdle and dermal bone

Front 38

squamata Serpentes endoskeleton

Back 38

o Increased number of vertebrae and ribs (200)
o Sternum absent (ribs connect to belly scales for locomotion)
o Joints between vertebrae are very flexible
o Upper jaw moveable on skull/ lower jaw is loosely connected in center (can separate)

Front 39

Sauria endoskeleton

Back 39

o Caudal vertebrae in some lizards may have vertical fracture plane (depending on species)
o When tail regenerates, it is always shorter

Front 40

Aves endoskeleton

Back 40

• Most modifications of skeleton are due to flight
• Reduced number of skull bones (no teeth)
• Bones are hollow (light weight)
• Cervical vertebrae modified for free range of movement (allow head to be used as an additional limb)
• Uncinate processes projections of ribs that overlap subsequent ribs (forces ribcage to act as a single unit)/ provides greater strength in ribcage (also found in reptiles)
• Furcula large clavicles for attachment of flight muscles (wishbone)
• Sternum highly developed and enlarged (flight muscles) (keel)
• Pygostyle last caudal vertebrae (bladelike) (tail feather attachment and involved in flight)
• Carpals and metacarpals of forelimbs fused (carpometacarpus) (reduces weight and feather attachment)
• Tarsometatarsus fusion of tarsals and metatarsals (reduces weight)

Front 41

Mammal endoskeleton

Back 41

• Greater support against gravity
• Increased speed
• Legs underneath body
• Specialized teeth
• Highly developed sternum
• Highly variable number of caudal vertebrae