Zool 325

-temporal region of skull = behind eye -openings accomodate muscles -lighten skull too

Temporal Fenestrae

-communication btw parts of the body -contains neurons which transmit impulses -all nervous tissue makes up nervous system

Nervous Tissue

-rare -mucous may be secreted

Oral glands: Fish

-hollow: fusion of edges of neural fold -central canal enlarges into interconnected fluid filled ventricles

CNS embryology

-strong, moderate -no fatigue (lots of )2, no need for anaerobic) -involuntary

Cardiac Muscle Cells: contractions

A: prosencephalon/forebrain B: telencephalon C: diencephalon D: Mesencephalon/midbrian E: Rombencephalon F: metencephalon G: myelencephalon

5 major subdivisions of brain (posterior to anterior)

-reps, birds, and mamms

Amniota: what groups?

-no openings in temporal region -turtles

Anapsid

-generally not feeding but do possess a mouth and an anus -when feeding apparatus becomes functional (as they settle on the bottom), pharyngeal slits (stigmata) become basket where food gets trapped as water flows -transformation occurs over ~48 hours

Ascidian larvae: feeding

-terrestrial amniotes -air is aspirated by low pressure -lungs within pump: rib cage (ribs + intercostals) and diaphragm -feeding and ventilation de-coupled

Aspiration Pump

-liver = piston to ventilate lungs -post hepatic diaphragm, posterior to liver (not homologous) -liver moves with diaphragm to increase/decrease space

Aspiration pump: Crocodiles

-muscularized diaphragm anterior to liver

Aspiration pump: mammals

-endochondral -articulate, may fuse with vertebrae

Axial Skeleton: Ribs (about)

-notochord/vertebral column -sternum -ribs -gastralia (dermal bone) -median fins (everything endochondral bone except gastralia and notochord, which doesnt become ossified)

Axial skeleton

-sites for muscles attachment -protect viscera -accessory breathing apparatus

Axial skeleton: Ribs (function)

-accessory sets -1 set of primary ribs = ventral or pleural -1-3 sets of intermuscular bones

Axial skeleton: Ribs in Atinoperygians

-only on set -bicipital: tuberculum = dorsal, capitulum = ventral

Axial skeleton: Ribs in Tetrapods

-endochondral -absent in fishes, early phibs and turtles -frogs do have them, so do lizards -snakes do not have limbs = no rigid midline for attachment needed -turtles have muscle attachment to shell/plastron, do not need sternum

Axial skeleton: Sternum

Dorsal -Pharyngobranchial: paired -Epibranchial: paired -ceratobranchial: paired -hyobranchial: paired -basibranchial: unpaired Ventral

Branchial Arches: Elements

-mandibular arch: adductor mandibulae --> masseter and temporalis -hyoid arch: suspension of jaws --> hyoid apparatus (facial muscles) -branchial arches

Branchiomeric Musculature

-air ventilation, ventilates lungs -mouth cavity expands and compresses to pump air into lungs -two types: two stroke, 4 stroke

Buccal pump

1. buccal expansion: old air into mouth from lungs 2. buccal compression: old gas out nares 3. thorax/buccal expansion: new air into mouth via nares 4. Buccal compression: air into lungs from mouth

Buccal pump: 4 stroke in aquatic salamanders

1. Nostril open/glottis closed, buccal floor depressed: outside air drawn in through nares to be held in buccal cavity 2. Nostrils oppen, glottis open, thorax compressed: old air exits from lungs, out the nares 3. Nostrils closed, glottis open, buccal floor depressed: held air from mouth enters lungs 4. Nostrils open, glottis closed, buccal floor ocsillated: flush out expired air from mouth, new air in through nostrils

Buccal pump: 4 stroke in frogs

1. expand 2. compress

Buccal pump: Two stroke

-two lateral ventricles in cerebral hemispheres -third ventricle connected by interventricular foramen -cerebral aqueduct: connects thirds and 4th ventricle -fourth ventricle -brain + spinal cord wrapped in membranes = meninges (partly from neural crest)

CNS Development: Ventricles

-myelencephalon -centres for auditory, visceral sensory reflexes (heart beat, intestine, respiration) , balance

CNS Hindbrain/Rhombencephalon: Medulla oblongata

Cardiac -lots of mitochondria and oxygen (coronary artery) -continuous aerobic production of energy Skeletal -fewer mitochondria, uses up oxygen supply -anaerobic production of energy (ATP) -lactic acid build up = fatigue

Cardiac vs skeletal muscles: Fatigue

-heart from splanchnic mesoderm -vessels and blood from mesenchyme + mesodermal cells -blood islands = mesodermal cells form pools, eventually differentiate into endothelium and blood = angiogenesis and haemopoiesis)

Cardiovascular system: Embryology

-cell type: chondrocytes vs osteocytes -Matrix composition -microarchitecture -perichondrium, periosteum

Cartilage and Bone: Differences

-mineralize connective tissues -derived from mesoderm, with some cranial bones and neural crest cells -schleroblast mesenchyme: shed of the schlerotome become chondroblasts and osteoblasts

Cartilage and bone: formation

1. Hyaline cartilage: skeletal elements eventually replaced by bone in embryo (tips of ribs, tracheal rings), not a lot of collagen 2. Fibrocartilage: lots of collagen, resists compression, tension. ex) intervertebral disks, 3. Elastic cartilage: lots of elastic fibres. springy, flexible. Epiglottis.

Cartilage: 3 types

-oligodendroglia: insulation of neuron axons, myelin sheath (CNS) -Schwann: neurilemmal cells, insulation, myelin sheath, neural crest (PNS) -same things but different name, cause of different area

Cell types

A-Amphicoelous B-Opisthocoelous C-Procoelous D-Acoelous E-Heterocoelous

Centra shapes

-nasal capsule: neural crest (olfactory) -trabeculae: neural crest, at least in part -optic capsule: mesoderm (eyes) -parachordal: mesoderm -otic capsule: mesoderm, some neural crest? (inner ear) -occipitals: mesoderm (articulation with vertebral column

Chondrocranium: neural crest and mesoderm

-from proctodeum -common chamber for products from intestines and urogenital tracts (marsupials, monotremes) -separate in some lizards (coprodeum, urodeum) -placental mammals: absent (anus separate from urogenital openings)

Cloaca

-third branchial arch, mixed nerve -visceral afferent (sensory): taste from post tongue -visceral/somatic afferent (sensory): from first gill arch -visceral efferent (motor) to parotid gland -visceral/somatic efferent (branchial motor) to muscles of 1st branchial arch + derivatives -synapses in medulla

Cranial nerve IX - glossopharyngeal

-from olfactory placodes -all gnathostomes except birds -visceral sensory, some motor -reproduction: detection of pheromones and such

Cranial nerve O - Terminal

III, IV, VI, XII

Cranial nerves: Ventral series

Homodont -similar tooth overall -many fish Heterodont -specialized tooth classes -port jackson shark -mammals (4 different kinds of teeth) Polyphydont -teeth replaced constantly Diphydont -only two sets of teeth

Dentition

Thecodont -deep sockets -mammals and crocs Acrodont -fish, some lizards -tooth sits on tip of jaw bone Pleurodont -tooth sits on edge of jaw -roots visible from inside -most lizards

Dentition: tooth types

-no shunting -brachycardy = slowing of the heart -anerobic metabolism -divert blood to organs that need it most (brain) and away from those that dont (digestive) -only 1 aorta

Diving birds and mamms

-Normally: deoxy from body enters right atrium to right ventricle to pulmonary trunk to lungs -Oxy blood enters left atrium to left ventricle to R/L aortic arches via foramen of panizza and both AA carrie oxy blood to body During diving (non-breathing): deoxy blood from right ventricle goes to the left aa and back out to body (instead of pulmonary arch = bypassing the lungs)

Diving crocs

-R to L cardiac shunt -Normally: systemic blood enters right atrium/ventricle to lungs to left Atrium/Ventricle to body -No breathing (during diving): systemic blood enters right Atrium/ventricle to left atrium/Ventricle to body = LUNGS ARE SKIPPED

Diving turtles: Shunting

-transmit nervous impulse down body -comes from ectoderm: formed by envagination (neuralation) -hollow with fluid in it -diagram lecture 3, pg 4.

Dorsal hollow nerve cord

-epithelium (thin sheet of cells) -covers external body surfaces -nervous tissue

Ectoderm: what does it form?

-easily distended (swall0wing large objects) -may have mucous or be keratinized (prevent scratching) -anterior striates muscles, posterior smooth muscles -no chemical or mechanical breakdown

Esophagus

-crop -food storage, crop milk

Esophagus specializations?

-through gills, skin -ammonia + large amounts of water -Ammonotelism

Excretion of N: Fish

-less water available, storage -non-toxic form (uric acid or urea) -Birds, most reptiles: uricotelism -Phibs, mammals: ureotelism

Excretion of N: Terrestrial

-alter excretory pattern -produce ammonia in water -urea when aestivating

Excretion: African Lungfish

-ammonia in water -urea after metamorphosis in phibs -urea/uric acid on land for turts -uric acid on land for gators

Excretion: Amphibians, turtles, gators

-inverts = exoskeleton -bone from integument = exoskeleton -forms within body = endoskeleton

Exoskeleton vs Endoskeleton

-larval phibs, some larval fish -extend uncovered into water -move them with muscles to pass more water over gills

External gills

-rotate eye in orbit -six muscles -origin = walls of orbit, insertion = outer surface of eyeball -preotic somitomeres (3 or 4) -3 cranial nerves (III, IV, VI) -conservative in vertebrates

Extrinsic Eye Musculature

-optic vesicles from telencephalon -optic placodes settles into optic cup = lens -neurectodermal placode induces optic cup --> iris and retina -mesenchyme --> choroid and sclera -brain stalk = optic nerve (cranial nerve tract II)

Eye embryology: Composite structure

-no cones: nocturnal -no extrinsic eye muscles: birds turn head, not eyes -absence of fovea -flattened vs convex fronea shape -adaptations of lens shape to water/air -visual accomodation mechanism

Eye variations

-contraction of cilliary muscle squeezes lens -or circular suspensory ligament stretches lens

Eye variations: Amniotes excluding snakes

-corneal muscle attached to spectacle over cornea -contractions: flatten cornea -visual accommodation by external deformation of eyeball -at rest: lambreys are near sighted (lens pulled in to see farther)

Eye variations: Lamprey

-may have scleral ring -lens nearly round, circular suspensory ligament -retractor muscle inserts on ligament base, pulls lens foreward

Eye variations: Phibs

-water: light blocking particles + depth -refractive index -in air: cornea bends light waves and lens refines images -in water: cornea and water have similar refractive index, lens refracts most of light

Eye variations: aquatic and terrestrial

post midterm 2

Final start study

-keratin sheath -non-vascular -non nervous

Feathers: Characteristics

-primary gill lamellae line pouches or attach to septa -secondary lamellae branch off primaries -blood runs in opposite flow to the water

Gill structure

-nuptial tubercles, teeth of lamprey

Keratinized Structures: Fish

-anti-infection

Leukocytes = WBC

-parabronchi: numerous one way passages -avascular air sacs (6-12, 9 normally) 1. interclavicular (single) 2. cervical (paired) 3. Anterior thoracic (paired) 4. Posterior thoracic (paired) 5. abdominal (paired)

Lungs: Birds

-respiratory tree (trachea --> bronchi --> bronchioles), dichotomous branching -alveoli: blind ended compartments (gas exchange), large SA -constant ventilation with low metabolic cost

Lungs: Mammals

-respiratory surface anteriorly developed -septal surface -faveoli (compartments) -ventral outpocketings of gut, but lie dorsal to is

Lungs: Phibs

-typically single air chamber -faveoli with smooth muscles, may have smaller internal septa -posterior region may be non-exchange region, gas exchange takes place anteriorly

Lungs: Reps

-archinephric duct = vas deferens -mesonephric tubules may contribute to epididymis -metanephric duct = ureter

Male genital ducts: Amniote

-to vas deferens -anterior = epididymis -distal may expand = ampulla = sperm storage

Male genital ducts: Archineprhic duct

-archinephric duct may receive sperm from testes -separate sperm duct = testicular duct -salmonids: no duct, sperm into coelom

Male genital ducts: Bony fishes

-single testis, no genital ducts -sperm into coelom, exit via genital pores

Male genital ducts: Cyclostomes

-3 ossicles to amplify vibrations and transmit to fenestra ovalis -extensive cochlea with 3 parallel channels -middle = cochlear duct with organ of corti -cochlea/lagena tightly spiralled

Mamms: Hearing

?? lecture 9, pg 4

Maximum force proportional to cross-sectional area of myofibrils

-respond to small changes in mechanical force -"hair" cell + support cells and nerve fibres = neuromast organ -lateral line, vestibular apparatus (equilibrium/balance), ear

Mechanoreceptors

-Sharks: V-X -Mammals: VII-XII (V, VI relocated to pons)

Medulla oblongata: Cranial nerves in sharks and humans

mostly from mesoderm -some if neural crest: ectomesenchyme, neurectoderm and mesectoderm

Mesenchyme: Origins

-vertebrae, muscles, connective tissue etc

Mesoderm: what does it form?

-archinephric duct, wolffian duct, pronephric duct, opisthonephric duct, ductus deferens

Mesodermal duct: Other names

-motor unit: one neuron + set of muscle cells -more motor neurons/units allows increase in force -few fibres/neuron = delicate movments -many fibres/neuron = strength

Motor Neurons

-active component = sliding of molecular filaments -elastic componenet (stored energy) -graded force: rate of nervous stimulation (increase rate of contract + release) or number of muscle cells, motor neuron

Muscles: Force

-provide force for movement -prevent movement -shape body -produce heat -produce electric fields

Muscles: Function

-gill-based ventilation powered by cranial muscles -lung based ventilation powered by axial musculature -ram ventilation: locomotion assisted -waving of external gills -active pumping

Muscular Aids to Ventilation

-smooth muscle sheets -stimuli = nervous and hormonal -vasoconstriction and vasodilation

Musculature of vessels

-protects and insulates axons -improves signal conduction -enables neuron regeneration and connection reestablishment with receptors/effectors

Myelin Sheath

-forms body musculature

Myotome

-hagfishes -marine burrowers, scavengers -rasp flesh -slime/mucous glands -one semicircular canal -notochord present in adults

Myxinoidea

-direction of fibres (external and internal obliques) -shapes -position/location (temporalis, epibranchial) -number of divisions (humans)

Naming of muscles

-fish and phibs -lack dorsal roots = only motor -supply hypobranchial musculature (lower jaw, cucullaris in sharks)

Occipitospinal nerves

-salivary (mandibular, sublingual, parotid) -saliva = mucous, salts, proteins, enzymes (amylase for starch) -lubrication, starch, digestion, evaporative cooling

Oral glands: mammals

-220 mya -anapsid, teeth, plastron, expanded ribs

Odontochelys

-even more localized: nasal passages -chemoreceptors in olfactory epithelium: cranial nerve I = sensory cells with axons to mitral cells (short nerve) -Olfactory bulb: mitral cells, synapse in cerebrym -Olfactory tract: mitral cell axons

Olfaction

-recessed in paired nasal sacs -passage solely for detecting chemicals

Olfaction evolution: Fish

-exocrine: digestive enzymes in ducts -endocrine: islets of langerhans

Pancreas

-most tetrapods: distributed evenly in clumps -most birds: distinct lobes of panceas

Pancreas: Terrestrial verts

-cyclostomes + teleosts: adjacent but not separate -Hagfish: islets at base of bile duct -Lampreys: islets in intestinal wall or liver -elasmobranchs: islets within exocrine pancreas -most bony fish: scattered masses of islets around liver, gall bladder, blood vessels and intestines

Pancreas: aq verts

-develops in association with liver -dorsal bud from gut, ventral bud from hepatic diverticulum

Pancreas: development (end lecture 10)

-epithalamus (roof of diencephalon) -single, median photoreceptor

Parietal organ

-seasonal activities (reproduction, hibernation) -length of day

Pineal gland: environmental influences

-aka hypophysis -all verts -pervasive effects over much of body -adenohypophysis and neurohypophysis

Pituitary

-lizards: tail regenration -birds: premigratory fattening, brood patch, crop milk -Mammals: mammary glands, milk production, lactation

Pituitary hormone: prolactin (in terrestrial verts)

-teleosts: osmoregulation, parental care -phibs: inhibits metamorphosis, promotes growth, dermal pigmentation

Pituitary hormone: prolactine (roles in aq verts)

-continuation of the body behind the anus -contains muscles, notochord, nerve chord etc -no coelom

Postanal tail

-blocks of segmented muscles: myomeres -myosepta -horizontal septum

Postcranial axial musculature

-no horizontal septum

Postcranial axial musculature: Cyclostomes

-not very specialized

Postcranial musculature: Fish

-dermal bones -food and air enter anterior portion of mouth -found in all tetrapods

Primary palate

-sturgeon: cartilaginous bone still

Primitive Actinopterygians

-hemichordata -Urochordata -Cephalochordata

Protochordates

-arches III (carotid) and IV (systemic) = no capillary bed (reduced gills, developed lungs) -lung: supplied by efferent potion of aa VI or aorta -ductus arteriosus: connection btw pulmonary artery and dorsal aorta

Protopterus (african lungfish): Circulation

-flow through -two lungs connected to a trachea, ventilated by aspiration pump -membranous air sacs = skeletal connections -parabronchial system -unidirectional, continuous flow -biphasic breathing

Respiration: Birds

-anamniotes: directly btw environment and skin (phibs, fish). limits egg size, needs moisture. -birds, reptiles: extraembryonic membranes and shell, chorioallantois acts as respiratory organ -Eutherian mammals: oxygen via placenta

Respiration: Embryos

-replenish cells with oxygen, take away by products accumulated during metabolism (CO2) -partly circulatory system (cellular level) -partly respiratory system

Respiration: Fuction

-endodermal outpocketings from pharynx -ventral to digestive tract -increased compartmentalization through evolution to increase SA

Respiratory Surfaces: Lungs

-gas exchange btw organism "surface" and environment -O2 in, CO2 out -passive diffusion

Respiratory System

-dense capillary beds in branchial region -from pharyngeal pouches -endoderm meets ectoderm -interbranchial septa: bits left btw pouches join to create slits

Respiratory surface: Gills

-rumen, reticulum omasum = elaborations of esophagus -abomasum = true stomach

Ruminants: Components of stomach

-reps including birds

Sauropsida

-rapid, long -fatigues: lactic acid, switching over to anaerobic muscle lacking in oxygen -voluntary -tonus: the continuous and passive partial contraction of the muscles

Skeletal Muscle Cells: contractions

-striated -multinucleate (peripheral or not), long, can attach end to end

Skeletal muscle cells: Morphology

-gives shape to the body -supports body -creates system of levers to work with muscles to produce movements -protection

Skeleton: Functions

-from mesenchyme (loosely associated mesodermal scales) : invade a membrane, lay down bone -not preformed in cartilage, wont find it in cartilaginous animals -ex) ostracoderms, armadillo plates

Skin Derivatives: Intramembranous bone

-most absorption of water and nutrients -microvilli on cells: infoldings, increase SA -intestinal glands in mucosa: digestive enzymes -peristalsis moves food -mucous secretions to protect epithelium -enzyme secretion (digest proteins, carbs, lipids)

Small and Large intestines

-villi: increase SA of mucosa -duodenum: secretions from liver and pancreas -jejanum: chemical breakdown -ileum: absorption -ileocoecal valve: btw large and small intestine

Small intestine

-sensory neuron from periphery of body enters spinal cord via dorsal root -motor neuron exiting through ventral root at same level -often intermediate neurons: impulses transmited to other spinal cord areas/brain via tracts

Somatic reflex arc

-vibrations in via footplate of stapes -fenetra ovalis = oval window -fluid filled chambers of inner ear, fluid pushed around cochlea -vibrations out via fenetra rotundis = round window

Sound Transmission

-cervicals are reduced, fused to vertebrae -first few thoracic = floating -ucinate processes for muscle attachment

Specialization of ribs: Birds

-dorsal ramus: supplies epaxial muscles and skin of back -ventral ramus: supplies hypaxial muscles and skin

Spinal nerve: Major Branches

-accompany embryonic myotome and dermatome -spinal nerve passes btw adjacent vertebrae through intervertebral foramen

Spinal nerves: Development

1. Sympathetic chain -paravertebral ganglia = paired, linked series -attach to each spinal nerve via ramus communicans 2. Collateral ganglia -paired vertebral ganlia: paired cervical, coeliac, mesenteric etc 3. Visceral -in walls of visceral effector organs

Spinal nerves: Ganglion

-thick musculature -keratinized -crocs, gators, birds, some dinosaurs -grinds up food, aided by stones and grit

Stomach Specializations: Gizzard

-in front of the gizzard -secretory -found in birds

Stomach Specializations: Proventriculus

-foregut fermenters -no vertebrate can digest cellulose, have bacteria in foregut -regurgitate food, chew it and swallow it again

Stomach Specializations: Ruminants

-storage of food -absorption of water, salts, vitamins -mechanical and chemical breakdown )hydrochloric acid

Stomach: Functions

-Hyoid: only bone in body that floats unconnected to another bone. -Thyroid: adams apple. V-shaped cartilage has notch in front. -Cricoid: ring shaped cartilage attached to trachea -Arytenoid: pyramid shaped. sits on top of widest part of cricoid cartilage. Vocal folds attache to these cartilages and it is their movement that opens and closes glottis.

Structure of Larynx

-nerve axons into bundles (fascicles) -fascicles surrounded by perineurium -btw individual nerve axons = endoneurium

Structure of nerves and spinal cord

-single opening -upper border: squamosal and postorbital

Synapsid

1. Synostosis -some are ankylosed -sutures in skull become all fused up, bones in the skull 2. Synchondrosis -some are symphyses -two things joining are cartilage -ex) left and right dentary in lower jaw, pubic sumphysis 3. Syndesmosis -most sutures -from fibrous connective tissue

Synarthrosis Joints: Types

-reduced (fused verterbae)

Tetrapod axial musculature: Birds

-slera, uvea, retina

The vertebrate eye: 3 layers

-Mesoderm, ectoderm and endoderm

Triploblastic: Germ Layers

-complexity of fibre organization -Extent of bone development

Variations: Dermis

-differentiation -number and complexity of glands -keratinization

Variations: Epidermis

-contain up to 70% circulating blood -low pressure -one way valves

Veins

-anterior and posterior cardinal veins empty into common cardinal vein -subclavian vein emties into common cardinal -lateral abdominal empties into common cardinal -common cardinal empties into sinus venosus

Veins: Primitive Verts

-embryonic cardinal veins regress -composite postcava (posterior vena cava) drains posterior body -precava (ant vena cava) drains ant body

Veins: some fishes, tetrapods

-increase volume of medium through respiratory surfaces -requires muscle action = active process Two types -unidirectional: gills -bidirectional: lungs

Ventilation

-south american catfish: swallows air bubble, gas exchanged in digestive tract -Electric eel: hold air bubble in mouth, gas exchange occurs via lining of mouth -Rock skipper: gulped air held against gills -mudskipper: gulped air held in buccopharynx

Ventilation: Air Gulpers

-dual pump, buccal pump and pulse pump

Ventilation: Types of active pumping

-spinal nerves -endoskeleton - bone or cartilage -vertebrae: bone or cartilage blocks firmly joined into a backbone

Vertebrate characters (in addition to chordate characters): Skeleton and nerves in body

-cranium: bone or cartilage, supports and protects brain and sensory organs of the head -brain = tripartite (fore-, mid-, hind-) -10-12 pairs cranial nerves

Vertebrate characters (in addition to chordate characters): head

-anurans, some lizards, most mammals -vocal folds (cords): fleshy folds, strong elastic ligaments (mammals) -vibrate under tension

Vocalization

-larynx: btw glottis (opening to pharynx) and trachea -supported by cartilaginous derivatives of pharyngeal arches IV, V, VI -arytenoids and circoids -+ thyroids and additional small cartilages in some mammals (supporting at start of trachea)

Vocalization in tetrapods

-accessory olfactory sytem: parallel but separate -present in phibs, squamates and most mamms -social/reproductive behaviour pheromones

Vomeronasal organ

-respiration, digestion, thermoregulation, endocrine system, immune system and water balance

What are the functions of the circulatory system?

1. Cardiovascular system: blood, vessels, heart 2. Lymphatic system: lymphatic vessels, tissue and fluid

What are the two major components of the circulatory system?

-connective tissue

What kind of tissue is blood?

-area of mylinated fibre tracts (axons)

White matter

-must begin functioning so early -therefore, must change over development into adult before reaches final form

Why are there so many stages of kidneys?

-barbs at end for harpooning insects -muscles and tongue originate on top of beak -incredibly projectile

Woodpecker: Tongue

-abdominal/trunk -caudal -not a lot of regionalization -aq forces acting equally over the body

Zonation of the vertebral column: Most fishes

-cervical (atlas + atlas) -thoracic -lumbar -sacral (in birds = synsacrum) -caudal

Zonation of vertebral column: Tetrapods

-smooth muscle sheets

alimentary canal organization: Muscularis externa

-somatic afferent: II (optic), V and VIII -visceral afferent: I, taste fibres of VII, IX, X

cranial nerves: sensory

-blood coming back from the lungs enters left atrium to c. arteriosum to interventricular canal to cavum venosum to aortic arches then oxy blood goes out to body -blood coming in from body (deoxy) enters right atrium to c. venosum to muscular bridge to cavum pulmonale then out to lungs to become oxygenatied

turt, snake and lizard heart: blood flow

-N in form of ammonia (toxic) -Ammonotelism: direct excretion -Uricotelism: in form of uric acid -Ureotelism: in form of urea

Kidney: Excretion of N

-lobular formation, metanephric -ureter with numerous long branches for collecting tubules

Kidney: Reptiles

-serial repetition of structures in longitudinal axis -clear in embryos, maintained in some adults -vertebrae, ribs, spinal nerves, embryonic, kidney tubules

Metamerism

-new duct forms = ureter -stimulates metenephric tubules -archinephric duct no longer associated with kidneys (ductus deferens) -adult kidney of amniotes

Metanephros

-two sets of wings -sprawling leg position, does same thing as flying squirrels -probably not good at running -supports trees down

Microraptor gui

-1-3 ossicles in tetrapods (malleus, incus, stapes) -first pharyngeal pouch = tubotympanic recess, forms middle ear cavity and eustacian tube -connection to pharynx

Middle ear: Middle auditory meatus

-phibs: collumella + extra collumella (cartilagenous cap), operculum (helps transmit sounds) -reptiles: columella, extra columella -mammals: stapes, incus, malleus

Middle ear: Ossicles

-starts here -in phibs, some reps = at body surface -in most reps, mamms, birds = recessed at bottom of external auditory meatus -numberous evolutionary origins

Middle ear: tympanum

-important vert feature -responsible for development of many things -pigment cells, nervous tissue, sensory organs in the head etc

Neural Crest

Connective tissue -endomysium (cells/fibres) -perimysium (fascicles/bundles) -epimysium (muscle organ)

Organization of muscle tissue

-3 germ layers positioned relative to each other by the end of neurolation -mutually interact during organogenesis (different organs from different tissues) -mesoderm and ectoderm form integument

Organogenesis

1. ground up 2. trees down 3. flapping while climbing

Origin of flight: Theories

-first seen in placoderms, acanthodians -made of neural crest = vert characteristic -Jaws are homologous to pharyngeal arch -developing embryo shows jaws developing similarily all come from neural crest etc -they do look alike = similarity of underlying structure -similar topology = where they are in organism

Origin of jaws

-splanchnocranial elements -modification of post dentary elements (cartilage --> post dentary --> middle earbone) Palatoquadrate --> quadrate --> incus Hyomandibula --> columella --> stapes Meckels cartilage --> articular --> malleus

Origin of middle ear bones

-multiple -turtles, living lepidosaurs, archosaurs, mammals

Origins of tympanic ear (end lecture 15)

-motor -from adjacent segments join to form plexus -tetrapods: used for lots of coordinated movement, innervate limbs

Spinal nerves: ventral rami

-eye: focus light onto photoreceptors -detect contrast: light intensity -Detect colour: differences in wavelength

Photoreceptors: basic function

-anlagen migrate elsewhere -fusion (from myotomes of different segments that fused) -splitting (pectoralis: 1 to 4) -new placements (axial co-opted for appendicular)

Phylogenetic differentiation of muscles

- pattern of descent (cladistics) -similarities caused by inheritance -major differences caused by evolutionary change

Phylogeny: General

-fleshy finned fishes -fin muscles external to body wall -cosmine scales -coelacanths, lungfishes, rhipidistians (led to tetrapods) -tetrapods

Sarcopterygii

-schlerotome starts moving, comes out on either side of somite and deposit on the notochord -grow up and go over notochord -one somite deposits schlerotome anteriorly, the other posteriorly. Becomes vertebral body. -bones now inbetween muscles

Schlerotome reogranization

-forms vertebrae and ribs -mesenchymal, settles segmentally along notochord

Sclerotome

-primary role non-endocrine -release hormones to aid own function -gastrointestinal mucosa and kidneys

Secondary endocrine organs

-mammals, but also turts and crocs -anterior hard palate, posterior soft palate -separation of food and air: allows for suckling, mastication

Secondary palate

-two muscle masses: dorsal and ventral (elevators and depressors) -muscle slips: rotation -innervated by spinal nerves

Appendicular musculature: Fishes

-muscles are large, divided and complex -dorsal and ventral masses -primary limb muscles + axial and branchiomeric muscles (pectoral girdle) -changes with limb position, locomotion

Appendicular musculature: Tetrapods

-intercalated discs: support synchronized contraction of cardiac tissue -control centre in heart, wave passes through orderly muscle contractions

Cardiac muscle cells: innervation

-small sinus venosus -consus arteriosus transient in embryo (forms bases of pulmonary trunk and single aortic trunk) -left aortic trunk lost, right retained (right systemic arch IV)

Bird heart

-capillaries perpendicular to air flow -each progressive capillary picks up more air as it goes through the system

Birds: Crosscurrent blood flow

-thin skinned compared to reps -stratum corneum thin -epidermal scales on legs, feet -feathers

Birds: Skin

-apparent similarity caused by constraints for similar function -opposite is homology -similarity among organisms that is not inherited from a common ancestor

Convergence

-progressive loss and fusion of elements -ostracoderm bony armour --> fusion in modern fish and phibs --> amniotes with dominance of dermal bones

Dermatocranial evolution

-intramembranous/dermal bone: laid down directly in membranes of the skin -lacking in cartilaginous verts -from mesenchyme -several series

Dermatocranium

-operculum covers gill arches -proliferation of facial dermal bones -jaws = dermal bone, articulation is remains of palatoquadrate and meckels cartilage -premaxilla and dentary with extreme mobility

Dermatocranium: Actinopterygians

-ostracoderms with bony head sheilds -lacking in living agnathans

Dermatocranium: Agnathans

-skull fenestration = holes in dermal bones -mammals = loss and fusion of dermal elements

Dermatocranium: Amniotes

-almost no bone, dermal denticles = skin derivatives -no dermatocranium

Dermatocranium: Chondricthyes

-heavy dermal plates = placoderms -many smaller plates = acanthodians -upper jaw attached to skull

Dermatocranium: Early gnathostomes

-reduction in anterior dermal bones -opercular series lost -pectoral girdle loses attachment to skull

Dermatocranium: Early tetrapods

-many dermal bones lost (salamanders) or fused (caecillians)

Dermatocranium: Modern amphibians

-braincase typically ossifies in two units: cranial kinesis -for better gape, better predation

Dermatocranium: Sarcopterygians

-Pink: facial series (premaxilla, maxilla = upper jaws, replaces palatoquadrate. nasal bone) may be associated with teeth -Blue: Orbital series (jugal, postorbital = temporal arches.) -Green: temporal series -Yellow: Vault series (frontal, parietal) -Orange: Palatal Series (vomer, sphenoid, pterigoid, ectopterygoid, palatine) may be associated with teeth -Purple: mandibular series (Dentary etc) -teeth only associated with dermal bones, not endochondral

Dermatocranium: Series

-forms the skin

Dermatome

-fibres in bundles, arranged in piles = stratum compactum -lateral bending: low wrinkling, low turbulance -dermal scales

Dermis: Aquatic Chordates

-single opening -squamosal/postorbital bar = lower border of opening -loss of jugal/quadratojugal -ex) ichthyosaurs

Euryapsid

-works with nervous system to control organ activities -hormones transported in blood, influence limited to target tissues

Endocrine system: functions

-epithelium -lining of gut cavity/tube and some organs (liver, pancreas)

Endoderm

-lampreys D and V do not unite (alternate) -hagfish: unite in trunk, not tail

Evolution of spinal nerves: Lampreys vs hagfish

-two semicircular canals in cyclostomes -rest with 3 semicircular canals -stationary otoliths -secreted calcium, sand -sound transmitted through body tissues -sound transmitted through swim bladder (weberian) -no stapes

Fishes: Hearing

-thin, little cornified -stratum basale and stratum corneum -various keratinized structures: like feathers -no mucous glands, few specialized glands

Epidermis: Archosaurs and Birds

-simple, single layer of columnar cells -ciliated in young -secretes non-cellular cuticle (mucous layer) in adults

Epidermis: Cephalochordates

-multiple cell layers -mostly non-keratinized: exceptions = lamprey teeth, claws on phibs -moucous -specialized unicellular glands

Epidermis: Fishes and aquatic amphibians

-Thick and layered -many glands -chromatophores -hair

Epidermis: Mammals

-3 regions: stratum basale (actively dividing), stratum granulosum, stratum corneum (top, gets keratinized) -epidermal scales: folds in epidermis -few glands -keratinization prevents dessication, limited cutaneous resp, few glands

Epidermis: Reps

-Scales = keratinized epidermal folds all connected with hinges in between -basal cells start dividing = doubling up outer layers -new layers form beneath old ones -once formed, two outermost layers shed (stratum corneum and stratum granulosum)

Epidermis: Reptiles Shedding of the Skin

-respiratory surface -larvae: leydig cells (produce antibacterial substance) -thin stratum corneum, non keratinized -capillary beds in lower epidermis: cutaneous resp -multicellular glands develop in epidermis -chromatophores: from neural crest

Epidermis: Terrestrial Amphibians

-derived from ectoderm, as is upper part of basement membrane -stratum basale = stratum germinativum (lower layer) -periderm - embryological single layer of outer cells

Epidermis: Where does it come from?

-interface with environment

Epidermis: what is it

-membranes: sheets, and glands (secretory) -Function: secretion, absorption, protection, transcellular transport, sensation detection, and selective permeability -specialized: endothelium (inner lining of blood vessels)

Epithelial tissue: What does it form? What are its functions? Specialized forms?

-nucleated except mamms -variable size -carry haemoglobin, O2 sticks to that

Erythrocytes

-single dorsal root = both visceral motor and sensory fibres -no ventral root: striated muscle fibres from myomere enter cord directly for innervation -no dorsal ganglion: sensory neuron cell bodies in cord or scattered within nerve

Evolution of spinal nerves: amphioxus (cephalochrodata)

-paired ovaries, some only one develops -mullerian duct in 4 regions -archinephric duct drains opisthonephric kidney

Female genital ducts: Elasmobranchs

-two uteri -reduced cloaca, urogenital sinus

Female genital ducts: Marsupials, some rodents, bats

-eggs shed into coelom -paired oviducts posteriorly, but degenerate -some others: ovarian ducts from peritoneal folds, attach to ovary -archinephric duct for kidneys

Female genital ducts: bony fish

-single median ovary -tons of eggs -no ducts, eggs into coelom -exit via genital pores to cloaca

Female genital ducts: cyclostomes (lamprey)

-egg laying -cloaca + urpgenital sinus

Female genital ducts: monotremes

-single median uterus -urethral opening, vagina -separate from urethra/urinary system

Female urogenital ducts: Placental mammals

-renal artery brings blood supply -Renal corpuscle = glomerulus + bowmans capsule (filtration occurs here) -Neprhon: blood supply wrapped around, water loss (5% not reclaimed in frog, 1% not reclaimed in a human. Depends on environment)

Kidney: Tubule Structure

-both deuterostomes (enterocoelic coelom formation, radial cleavage) -larval echinoderm similar to tornaria larva of hemichordates -heterochrony?

First Chordates: From Echinoderms?

-maybe -or may be related to chordates but not a direct ancestor

First chordates from echinoderms? Current thoughts

-caudal, anal, dorsal fins, tails

Fish Median fins

-snakeheads: breath air with lung-like organ -also posses gills, but often reduced -bad invasive species: can walk from pond to pond

Fish accessory breathing organs

-heterocercal: spinal column goes up -hypocercal: spinal column goes down ventrally (ostracoderms) -diphycercal: symmetrical (sarcopterygian lungfish) -homocercal: (teleosts)

Fish median fins: Tail types

-aortic arch in two sections: afferent (blood to gills) and efferent (blood away from gills) -ventral aorta to afferent artery to capillary bed encircling gill to collecting loop to efferent artery to dorsal aorta

Fishes: Gills

-further from heart = lower pressure (friction along vessels, increase in are as spreads out in body) -One-way valves prevent backflow on way back to heart

Haemodynamics

-branchial heart is true heart -3 chambers in series (sinus venosus, atrium, ventricle, no bulbus) -3 one-way valves -no major nerves, heart not under nervous control -Frank-Starling reflex (stretch response: more blood flow to the hear = more it stretches = strong elastic recoil contraction)

Hagfish: Heart

-supplementary circulatory pumps (accessory hearts) -autapomorphy = only ones that have them -cardinal hearts, caudal hearts in tail, portal heart in portal system in liver -venus system is open sinuses

Hagfish: Rest of the circulatory System

-in early cambrian -chordate features present -gill bars -myomeres -head

Haikouella and Mylokunmingia

-thick covering = fur -guard hairs and underfur -has a grain normally

Hair: Pelage

-two parts: -nephron forms urine by filtering blood -collecting tubule delivers urine to excretory duct (concentrates urine, water reabsorbed) -microscopic, functional unit of kidneys

Kidney: Uriniferous tubule

-relatively large, metanephric -cavities in dorsal abdomen, protected by synsacrum -3+ lobes, many lobules -small glomeruli, many tubules

Kidneys: Birds

-larve: pronephros -opisthonephros/mesonephros in adult

Kidneys: Cyclostomes (Hagfish) - stages

-anterior tubules: peritoneal funnels -posterior tubules: glomeruli -30-35 glomerular tubules -archinephric duct

Kidneys: Cyclostomes (Hagfish) - structure

-Early larval: pronephros (with peritoneal funnels + pronephric duct) -Late larval: mesonephros addition -Adult: opisthonephros (pronephric tubule degenerates)

Kidneys: Cyclostomes (Lampreys) - stages

-increases in tubule numbers with loss of segmental arrangement -ant end taken over by testes

Kidneys: Other Anamniotes - changes over development

-Embryo/Larva: pronephros, usually supplemented by mesonephros -adult: opisthonephros

Kidneys: Other anamniotes - stages

-blind ended tubes (no capillary systems) -bring fluid from tissues back to CV system -carry fluid (lymph = water and dissolved substances)

Lymphatic vessels: function

-Uropygial gland: for preening, putting oil on feathers -salt gland: marine birds, for excretion of salt from diet

Specialized glands: birds

-vibrissae/whiskers -porcupine quills -rino horn = compacted keratinized hair, no bone

Specialized hairs

-very localized, responses restricted to specific stimuli -Chemoreceptors, electroreceptors, radiation receptors (ex: visual), mechanoreceptors (hearing, balance)

Specialized sensory structures: types

-Brachyodont: short -Hypsodont: sitting up high -Bunodont: pillow like cusps -Lophodont: alternating denting and enamel, knife edges of enamel -selenodont: crescent shapes

Specialized teeth in mammals

-club cells: communication, release alarm substance -granular cells: poisons -goblet cells: function unkown -Sacciform cell: function unkown

Specialized unicellular glands

-Embryo: mesomeres (segmental nephric tubules, in ant 12 or less segments) from pronephros -pronephric tubules from archinephric duct

Mammalian Kidney: Embryo

-glomeruli and coiled tubules -one per segment: additions; loss of segmentation -mesonephric series + duct lost to genital system before birth -posterior mesodermal mass forms metanephros, ureter forms and expands into renal pelvis

Mammalian Kidney: Mesonephric stage

-intermediate section, elongate -from cortex to medulla -ascending + descending limbs -fxn: concentration of urine

Mammalian Kidney: Nephric Tubule w Loop of Henle

Two types 1. Not associated with hair -for regulation: thermoregulation, waste products -active early on -thin sweat 2. Associated with hair -produces viscous sweat -associated with communication -starts at puberty

Mammalian Specialized Glands: Sudoriferous

-sinus venosus = purkinje fibres in wall of right atrium (SA node, pacemaker = contraction start here) -conus arterious of embryo = bases of pulmonary and single aortic trunks -LEFT aortic trunk (aa IV) retained, right highly reduced

Mammalian heart

-drains collecting tubules -subdivided into major and minor calyces

Mammalian kidney: Renal Pelvis

1. Monotremes -secretions from surface of body -not associated with hair 2. Marsupials/placentals -see lecture 7 pg 8

Mammary glands: 3 major forms

-from mesoderm -circled in pic is the urogenital ridge: one ridge forms urinary, one forms genital -ridge of mesoderm = nephrotome (nephric ridge): forms renal capsule/glomerulus

Kidney: Development

-carries pain, temp, crude touch and pressure (consious) -info to thalamus (recieves all conscious sensations), then terminates in areas of sensation perception in cerebral cortex

Spinothalamic tract

-aka peudobranch -alternate route for water to come in, when mouth occupied (ex burried in mud) -no gas exchange occurs

Spiracle

-major component of fish skull -reduced in phibs, hyomandibula not involved in jaw support -mamms: malleus, incus, staped and styloid bones

Splanchnocranial evolution

-associated with primitive gill arches -from neural crest cells (unique to verts, not found in protochordates)

Splanchnocranium

-hormones stored intracellularly -inhibit metamorphosis in larvae -fxn unkown in adult

Thyroid: Cyclostomes

-clotting function

Thrombocytes/plateles

-morymromasts: fxn unkown -knollenorgans: detect wave form of the electrical discharge

Types of electric receptors

-sarcolemma -myofibrils -sarcomeres

Organization of muscle cells

Homoplasy/convergence

-similarity based on common function

Apomorphy

-A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms

Heterochrony: metamorphosis

-abrupt and radical change in structures from larval to adult form

Mesenchyme

-cells capable of amoeboid movement -travel to various points in the body -give rise to variety of structures

Heterochrony

-change in the timing of appearance or rate of development of a part of the embryo from the ancestral state

Symplesiomorphy

-character is an ancestral trait shared by two or more taxa

Synapomorphy

-character state is a trait that is shared by two or more taxa and inferred to have been present in their most recent common ancestor, whose own ancestor in turn is inferred to not possess the trait

Analogy

-common function

Plesiomorphy

-refers to the ancestral trait on its own, usually in reference to another, more derived trait

Homology

-similarity -caused by common ancestry -structures may serve very different functions

-mesenchyme from ventral tips migrate into limb bud

Appendicular Musculature (embryology): Teleosts

-paired limbs on girdles (pectoral and pelvic)

Appendicular Skeleton

-body of the embryo -ant: drain head, post: drain body -unite near heart = common cardinal opening into sinus venosus

3 major sets of embryonic paired veins: Cardinal

-from embryo pelvic region -present in fishes, merged/absent in tetrapods -adult fish: iliac vein joins brachial at shoulder = subclavian vein into common cardinal -adult tetrapods: subclavian separate return to heart, lateral abdominal to liver -adult crocs, birds, mamms: no abdominal vein

3 major sets of embryonic paired veins: Lateral abdominal

-enter sinus venosus -liver primordium grows into them -proliferation of liver cords breaks up vitelline veins into hepatic sinusoids -hepatic veins into sinus venousus

3 major sets of embryonic paired veins: Vitelline

-kidney -gills for respiration: can grow large -notochord in body only -anterior expansion of nerve cord = tripartite brain -heart, liver, gall bladder -muscular pump

Ammocoete Characteristics

-most loose external gills as adult -carotid duct closes at metamorphosis -ventral aorta btw III and IV = common carotid

Amphibian Circulation

1. Sauropsida: birds, dinosaurs, living reps, extinct lineages 2. Synapsida: extinct therapsids and mammals -based on skull structure

Amniota: Groups

-secretions added to seminal fluid -prostate gland (alkaline solution), seminal vesicle, coagulating gland (copulation plug), bulbourethral/cowpers gland (mucous)

Amniote associated reproductive glands

-single vertebral elements -single centrum: pleurocentrum predominates -intervertebral cartilage = intercentrum

Amniotes: Vertebral element

-increasing complexity from fishes to tetrapods -co-opting of cranial and postcranial musculature -locomotion

Appendicular Musculature

-extraembryonic membranes: amnion, chorion, allantois, sometimes also yolk sac -prevent drying of embryo in terrestrial environment -allow a larger egg size -sequester waste, transport nutrients, exchange respirator gas

Amniotic Egg

-mesenchyme from ventral tips migrate to limb bud

Appendicular Musculature (embryology): Amniotes, tetrapods

-cutaneous respiration = highly vascularized, rarely dermal scales -stratum corneum present: living cells

Amphibia: skin

-unrestricted notochord -radial fin rays supporting tail fin -intercranial joint = cranial kinesis -internal gills on branchial arches -lateral line system -tetrapod pattern of skull bones

Acanthostega

-I, II lost early in devo -Larva: III-V external gills supplied by accessory capillary loops Adult: III, IV, VI tubular -V lost in most -ventral aorta splits to separate off pulmonary trunk

Amphibian Arches

-reduced dermal armour -subterminal mouth (like chondrichthyans) -ossified gill cover (like osteichthyans)

Acanthodii: Characteristics

-notochord retained and extending into tail -ossified neural and haemal arches

Acanthodii: Vertebral column

-early silurian

Acanthodii: time period

-ventral tips of adjacent myotomes into fin bud directly

Appendicular Musculature (embryology): Primitive Fish

A-Proboscis B-Stomocord C-Collar D-Pharyngeal slits with pharynx

Acorn Worm

-ray finned fishes -fins internally supported by lepidotrichia; internal muscle attachment

Actinopterygii

-best way to accomplish a task because of physical constraints -convergent and homologous

Adaptation

-rathkes pouch -grows up dorsally from roof of mouth towards brain -stomatodeum, ectoderm -not connected to brain

Adenohypophysis

-located near nephric system -composite organ: adrenocortical tissue (steroids) and chromaffin tissue (adrenalin)

Adrenal gland

-two tissue mingle or adjacent -blood supply from kidneys

Adrenal gland: Phibs

-adrenaline and noradrenaline -short term -neural crest

Adrenal gland: chromaffin tissue

-adrenocortical and chromaffin tissue separate -variable placement near kidneys -blood supply from kidneys

Adrenal gland: cyclostomes/teleosts

-adrenocortical tissue in distinct glands -chromaffin tissue clusters

Adrenal gland: elasmobranchs

-adrenal glands become distinct structures -reps: first time adrenocortical tissue recieves own blood supply -reps + birds: two tissues mingle -mammals: cortex of adrenocortical tissue around medulla of chromaffin tissue =

Adrenal glands: Amniotes

-water reabsorption, sodium transport -metabolism of carbs -reproduction: estrogens, androgens, progesterone -long term -splanchnic mesoderm

Adrenal glands: adrenocortical tissue

-Fish: retain basic 4 chambers -Tetrapods: varying degrees of internal subdivision, some original chambers reduced/lost

Adult heart

-Paraphyletic -no jaws, have mouth -early cambrian

Agnatha

-pouch like -all aortic similarily developed -afferent vessels supply front of one pouch and back of another

Agnathans: gills

Inside -Mucosa -submucosa -muscular externa -adventitia Oustide

Alimentary Canal Organization

-fibrous connective tissue, mesentaries (serosa)

Alimentary Canal Organization: Adventitia

-epithelium -loose, connective tissue (lamina propria) -smooth muscle fibres (muscularis mucosa)

Alimentary Canal Organization: Mucosa

-loose connective tissue, nerves, glands from mucosa

Alimentary Canal Organization: Submucosa

-esophagus, stomach, small intestine, large intestine -differentiated by difference in luminal glands, size and shape

Alimentary canal

-Chambers: sinus venosus, R + L atria w complete interatrial septum), single ventricle, conus arteriosus -Valves: semilunar, spiral valve = control of systemic vs pulmonary directions/separate oxy and deoxy -truncus arteriosus = base of systemic and pulmocutaneous arches

Amphibian heart: Chambers and valves

-variable (cutaneous, lung, gill respiration)

Amphibian heart: variability

-anterior end of ventral aorta (arch III) = external carotid -anterior end of paired dorsal aorta = internal coratid -stem of ventral aorta and IV arches = paired systemic -part of ventral aorta, part of arch VI and pulmonary artery from arch to lung = pulmonary system

Amphibians: Carotid system, Systemic and Pulmonary

-solenocytes: cells fxn in getting rid of waste but not organized into organs -cutaneous respiration: cannot grow large -Notochord extends into head -no brain -no heart, liver, gall bladder -passive filter feeding

Amphioxus: Particular Characteristics that are primitive compared to ammocoete

-chordata -lecture 2 slide 2?? -chordate but not a vertebrate -deuterostome condition of coelom formation (enterocoelic)

Amphioxus: group? coelom formation?

-ampullae of Lorenzini -receptors in narrow channels/pits with gel -passive picking up of electrical current

Ampullary receptor

-no fossae in temporal region of skull -primitive condition of basal reptiles -also in chelonia (turts) -paraphyletic grouping? -turtles redeveloped a fossa-less skull

Anapsida

-tongue passes back through neck, into thoracic cavity -surrounded by sleeve of tissue = glossal tube -follows ventral surface of the trachea back and positions base of tongue btw heart and sternum

Anora Fistulata

-right systemic arch gone -III = carotid arteries, VI = pulmonary, IV = left systemic -subclavian arteries (more asymmetry): left from left systemic, right includes right aa IV, part of right dorsal aorta and artetries from these into right limb

Aortic Arches: Mammals

1st. -mandiubular -upper: palatoquadrate -lower: meckels cartilage 2nd -hyoid -upper: hyomandibula -lower: ceratohyal -for jaw support

Anterior arches form jaws

-specialized skeleton: reduced vertebral column with urostyle -tadpole larvae, metamorphosis

Anura (Salientia)

-6 arches -asssociated with 5 gills and spiracle -pouch 1 = mouth, puch 2 = hyoid arch, pouch 3-7 are gill openings A- 1 mandibular arch B- 2 hyoid arch C- 3 First branchial arch D- 4 2nd branchial arch E- 5 3rd branchial arch F- 6 4th branchial arch G- Ventral aorta H- dorsal aorta

Aortic Arch Evolution: Ancestral condition

-blood supply to lungs -before lungs funtion = into the dorsal aorta (ductus arteriosus = dorsal part, closes when lungs begin to function)

Aortic Arch VI in tetrapods

-right systemic dominates (IV) -eliminated left systemic (not fully developed in embryo) -single trunk leaving heart = blood to carotids and head, pectoral girdles, body

Aortic Arches: Birds

-branch from ventral? aorta -service gills -cyclostomes = all similarly developed in embryo -gnathostomes = first arch (mandibular) is lost when they get jaws, second (hyoid) retained in some but associated with spiracle (elasmobranchs)

Aortic Arches: Fishes

-ureter develops -archinephric duct for sperm = ductus deferens -or degenerates

Archinephric duct in amniotes

-in some: carries sperm and urine -in most: post. kidney collecting ducts join accessory urinary duct in both sexes

Archinephric duct: Phibs

-arise from proneprhic tubules -for urine transport -invaded by male genital system in gnathostomes for sperm transport

Archinephric ducts

-bony fish: retained for urinary system -lungfish: sperm at post end -teleosts: new tube for sperm -sharks: sperm duct, new tube for urine in males, most females with accesory duct for urine

Archinephric ducts: fish

-all descendents from common ancestor of birds and crocs -pterosaurs, dinosaurs too -living = birds + crocs

Archosaurs

-4 main chambers (L and right atria + ventricles) -interventricular and interatrial septa -double pump (right = to lungs, left = to body)

Bird and mammal hearts

Inhalation -negative pressure -rib cage expands, diaphragm contracts back, air rushes into lungs Exhalation -rib cage contracts, diaphragm relaxes forwards, air forced out of lungs

Aspiration pump: Mechanics

-limbs aid in pumping -ribs fused to shell, cannot move

Aspiration pump: turtles

-structure varies with size: larger with more elastic fibres -elasticity to smooth out pulses of blood from heart, elastic walls expand to receive blood from contraction -elastic recoil upon relaxation

Ateries: Elasticity

-furcula: bends laterally during downstroke, recoils during upstroke. Inflates + deflates interclavicular air sac -sternal movements coupled with wingbeat: ascending and retracting on downstroke, descending + protracting on upstroke

Bird Biphasic Breathing: Aids

-blood twice through heart -heart to lungs to heart to systemic tissues

Basic Circulation Pattern: Amniotes

-tubular, autonomous -folds up into different configurations -from splanchic mesoderm -chambers: sinus venosus (blood in), atrium, ventricle, bulbus cordis (blood out)

Basic Vertebrate Heart: Embryology

Single circulation -blood once through heart during a complete circut -heart to gills to systemic tissues to heart

Basic circulation pattern: Fish

1. Inhalation: air into trachea, along primary bronchi and divides. Some into lungs, some to posterior air sacs 2. Exhalation: air from posterior sacs to lungs, lung air out to trachea 3. Inhalation: air divides, some refills posterior sacs, some to lungs pushing rest of spent air into anterior air sacs 4. Exhalation: air from anterior sacs exits along with lung air. air from posterior sacs flows to lungs.

Bird Biphasic breathing: steps

-resonating chamber located where trachea bifurcates into bronchi -walls strengthened by last several tracheal rings and first bronchial half rings -mucosal folds project into chamber -bony pessulus may form in a membranous fold -trachea vibrates

Bird Syrinx (end lecture 11)

-Fish, primitive tetrapods: direct gas exchange btw myocardium and blood in lumen -elasmobranchs, crocs, birds, mamms: coronary vessels (derived from efferent arches of the gills, to sunus venosus and myocardium)

Blood supply to the heart in different vertebrates

-Head: sense organs, brain, food, acquisition, breathing (fish) -Body: coelom houses the viscera, paired appendages, neck -Tail: postanal, muscles, skeleton, nerves, blood vessels, no body cavity -appendages: pectoral and pelvic

Body Regions

-osteocytes -normally vascularized -normally innervated -periosteon: fibrous connective tissue around bone -highly organized: osteons (common in primates) -storage for calcium and phosphate

Bone

-all come from schleroblasts 1. Osteoblasts -secreting bone, building of bone 2. Osteoclasts -cells that resorb bone: take it away so that new bone can be laid down 3. Osteocytes

Bone Cells

-forces acting on bones constrain shape -Columnar: Resistance proportional to Diameter = Get rid of weight and metabolic investment by making it hollow. -blade-like: R proportional to width*height^2 = neural spines, make it really tall, resist force better if it is higher rather than wider. -spherical: forces from 360 degrees = head of the femur, fibres running from inside out -adequate support with minimum weight and minimum metabolic investment -bones are genetically determined but external forces also play a part

Bone Shapes

1. Visual: cancellous (spongy) vs compact 2. Position: cortical: outside vs medullary: inside 3. Cellular: osteocytes in bone vs acellular: osteocytes retreat from bone matrix 4. Vascular vs avascular 5. Non-lamellar: fibres not organized, faster growing bone vs lamellar: fibres laying in same direction, organized can form in plies

Bone classification

-coordination of limb oscillation/placement -increased somatosensory info

Brain evolution: Forebrain

-advanced fish, optic tectum -visual info -sensory info from lateral line -3D space

Brain evolution: Midbrain (END LECTURE 14 YAYYY)

-3 layers -dura mater = outermost/mesoderm -secondary meninx (ectomesoderm) divides: arachnoid (middle, weblike) and pia mater (inner, blood vessels) -multiple layers allow fluid to circulate more effectively

CNS Morphology: Mamms

-anterior cephalic flexure (fore/midbrain -isthmus separates mid/hindbrain -localized thickenings of lateral walls and floor -median or paired dorsal, lateral and ventral envaginations

CNS development

-single ventricle of cerebellum -brain wrapped in single menix (singular meninge)

CNS development: Bony fish ventricles

-infundibulum grows down from dorsal forebrain -hypophyseal pouch grows up from mouth roof

CNS development: Pituitary

-Posencephalon = forebrain -Mesencephalon = midbrain -rhombencephalon = hindbrain

CNS embryology: 3 regions of anterior neural tube (brain)

-DVR expands, grows up over diencephalon, forms most of forebrain -stereocopic vision

CNS forebrain: Birds

-pair of cerebral hemispheres + olfactory lobes -amniotes: 50-20x enlargement (relative size, in comparison to fish and phibs) -outer walls of hemispheres = cerebral cortex

CNS forebrain: Cerebrum/telencephalon (general)

-roof -medial: olfactory, auditory, lateral line, somatosensory, visual -dorsal and lateral: visual

CNS forebrain: cerebrum --> pallium

-striatum (lateroventral): motor control -septum (medial): connects hypothalamus to midbrain

CNS forebrain: cerebrum --> subpallium

-corpus callosum: connects left and right halves in eutherian mammals -cingulated gyrum: subcortical tissue surrounding corpus callosum -gyri: founded folds -sulci: intervening grooves

CNS forebrain: cerebrum/telencephalon (anatomy)

-dorsal pallium expands = isocortex -70% neurons of CNS in primates here -auditory, visualm somatosensory, control of brain stem and spinal cord

CNS forebrain: mammals

-source of thalamus -epithalamus -hypothalamus

CNS forebrain: prosencephalon --> diencephalon

-expanded dorsal ventricular ridge (lateral pallium) -increase control needed for locomotion

CNS forebrain: reptiles

-modifies and monitors = no motor output -involuntary -maintain equilibrium: integrates infor to maintain muscle tone + balance -refinement of motor action = coordination

CNS hindbrain: Cerebellum (function

-highly convoluted -auricle: lateral, paired --> dorsal half = flocculus, ventral half lateral = line input (fish) -coordinating movement + position

CNS hindbrain: Cerebellum/metencephalon in fish (Anatomy)

-highly convoluted -corpus: medial body --> cerebellar hemispheres (birds +mamms) -auricle: , dorsal half = equilibrium, inner ear (tetrapods) -for complex locomotion

CNS hindbrain: Cerebellum/metencephalon in tetrapods (Anatomy)

-taste buds all over body (chemoreception) -vagal lobe receives many sensory fibres = huge -project second order fibres to other regions of brain

CNS hindbrain: Fish

=pyramids contain corticospinal tracts -carrying voluntary motor impulses from cerebral cortex to spinal cord -info coming in and being transmitted to other parts of body too

CNS hindbrain: mamms

-floor of hind brain expanded -info passing through pontine nuclei: info from cerebral to cerebellar cortex -metencephalon -nerves V-VII

CNS hindbrain: the pons! in mamms

-most prominent region -tectum recieves input from eye, acousticolateralis, cerebellum and cutaneous sensors -termentum learning centre

CNS midbrain: Anamniotes

Tectum (dorsal roof): sensory -optic tectum: mammals with superior and inferior coclliculi -torus semicularis: auditory, lateral line input Tegmentum (ventral floor): motor -trochlear IV and occulomotor III = associated with eye/extrinsic eye muscles

CNS midbrain: Mesencephalon

-less important -tectum visual and auditory, but info can also bypass (from thalamus to forebrain)

CNS midbrain: amniotes

-two layers -dura mater (mesoderm) = outer -secondary meninx (ectomesoderm) = inner

CNS morphology: Reps and phibs and birds

-diverging and converging information -nerves with similar info travel together = nerve tract -ascending: to higher levels of CNS -descending: responses from brain back down

CNS spinal cord functions: spinal tracts

Grey matter -nerve cell bodies, dorsal (afferent/sensory) and ventral (efferent/motor) horns White matter -nerve fibres: dendrites, axons -link levels of cord to each other and brain -myelinated

CNS spinal cord: Two regions

-circumvent brain -sensory fibres synapse with interneurons in dorsal horn of grey matter -impulse transferred to ventral horn, which sends impulse to effector

CNS spinal cord: functions (reflexes)

-hindbrain excluding cerebellum -midbrain excluding colliculi -in mammals = part of optic tectum

CNS: Brainstem

-slightly viscous -ventricles of brain, subarachnoid space, central canal -from blood, but no large formed elements -cushion around brain + spinal cord -source: choroid plexus (ependymal cells) -resorbed into venous sinuses

CNS: Cerebrospinal fluid

-somatic afferent: exeroreceptors, proprioreceptors (reception from skin, pressure, orientation etc) -visceral afferent: interoreceptors -memory

CNS: Information from?

-embryologically develops from anterior neural tube -3 regions, with subregions, formed based on flexures -increased complexity with increased body size -increase functional complexity with increased number of nuclei

CNS: overview of the brain

-single cell thick of tunica intima (endothelial) -forms beds serving an area of tissue -beds overlap, open or close to regulate blood supply via sphincters that restrict access of blood to capillary bed

Capillaries

-striated (repeating sarcomeres) -branched, mononucleate

Cardiac Muscle Cells: Morphology

-firm but flexible -cells: chondrocytes -matrix composition: avascular -microarchitecture: disorganized microfibres -not innervated -perichondrium: fibrous connective tissue around cartilage where blood supply is found

Cartilage: Structure

-Aspondyly: no centra (lamprey and hagfish) -monospondyly: one centrum per segment (mamms, reps, modern phibs) -diplospondyly: two centra per segment (modern bowfin fish) -polyspondyly: 5-6 centra per segment (some lungfish)

Centra: types

-has "sinus venosus" -circulatory system: no blood vessels or heart, get oxygen cutaneously -one way flow

Cephalochordata: Blood flow

-adult suspension feeder, larval planktonic and sessile -wheel organ: cilia beat to bring water in -food enters pharynx, gets stuck in mucous and cilia then goes through gut -endostyle under pharyngeal region provides mucous

Cephalochordata: Feeding

-muscular system = striated muscle blocks -muscles pick up direct stimulation from nerve cord, no spinal nerves, innervation done by muscles -metameric blocks of muscle down the body

Cephalochordata: Muscles

-gained bone, brain, specialized sensory structure -protochordate muscle fibres become vertebrate muscle hypomere (lateral plate 1) -muscularization of the mouth, pharynx, gut, vascular system, heart etc -3 tissues responsible for many vertebrate characteristics

Changes from cephalochordates to vertebrates

-convert chemical information to nerve impulses -taste and smell -taste = sour, bitter, sweet, salty, savoury

Chemoreceptors

-hadrosaurs, mammals -combination of cheeks, tongue and teeth -keep food in mouth, move it around

Chewing

-muscular limb with well-defined joints and digits

Chiridium

Muscular appendage with well defined joints bearing digits

Chiridium

-dermal scales present, bony -mutlicellular and unicellular glands -no stratum corneum -keratinized structures: nuptial tubercles

Chondrichthyes and Osteichthyes

-cartilage, may be calcified (secondary loss of bone) -placoid scales -oil filled liver for buoyancy -notochord or cartilage in vertebral column -first gill arch modified into spiracle

Chondrichthyes: Characteristics

-Elasmobranchii: sharks and rays -Holocephali: chimeras and ratfish

Chondrichthyes: What groups?

-supports brain -preformed in cartilage -bone or cartilage in adult -neural crest and mesodermal mesenchyme (schlerotome)

Chondrocranium

-cartilage, expands around brain dorsally

Chondrocranium: Elasmobranchs

-mainly in embryonic structure -endochondral ossification

Chondrocranium: Other vertebrates

-nasal and otic capsules, optic area -Bars of cartilage in embryo: trabeculae, parachordals, occipitals (articulate with first vertebrae)

Chondrocranium: Parts

-ethmoid plate, basal plate and occipital plate -ossify: ethmoid, sphenoid and occipital bones

Chondrocranium: bars of cartilage in embryo fuse to form?

-somatic efferent (motor) -innervates lateral recuts extrinsic eye muscle -abducens nucleus in medulla

Cranial nerve VI: abducens

-somatic: skeletal muscle -visceral: smooth and cardiac muscle and glands

Components of spinal nerves: Motor (ventral, efferent)

-somatic: general cutaneous, receptors in striated muscles and tendons -visceral: general receptors of digestive and respiratory systems

Components of spinal nerves: sensory (dorsal, afferent)

-plasma = ground substance -formed elements = cellular components = erythrocytes, leukocytes and thrombocytes

Components of the blood

-category of exclusion mostly -most involved in structure and support -most derived from mesoderm, with exceptions -skeleton, blood, fat, collagen, cartilage

Connective Tissue

-from mesoderm -distinctive cell type surrounded by extracellular matrix -matrix: protein fibres, surround substance = ground substance -bone, cartilage, ligaments, fibrous connective tissue, tendons, adipose and blood tissues

Connective tissue

-Calcification: addition of calcium carbonate (inverts) or calcium phosphate (verts) -Ossification: specialized form of calcification = calcium phosphate in the form of hydroxyapatite

Connective tissues: Mineralization

-tooth-like microfossiles -late cambrian to early triassic -body fossils from scotland, africa -verts?

Conodontia

-originates in cerebral cortex (voluntary motor control localized) -some fibres cross in medulla -fibres: upper motor neurons synapse with lower motor neurons in spinal cord, lead to skeletal muscles

Corticospinal tract

-movement in skull -rapidly changes size and shape of mouth -aquatic verts use for suction feeding: movement of upper jaw allows for rapid expansion of buccal cavity

Cranial Kinesis: aquatic verts

-transcranial joint = hinge across skull (in notes actually) -change in orientation of teeth (vipers) -increased mobility in quadrate = bigger gape

Cranial kinesis: Reptiles

-jaw and pharyngeal muscles (pharyngeal arches and derivatives 1. branchiomeric: somitomeres + cranial nerves 2. Hypobranchial: somites (myotomes) from cervical region, spinal nerves. below gills, extend from pectoral girdle to lower jaw. 3. epibranchial: above gills, originate from epaxial and hypaxial myotomes

Cranial musculature

-visceral afferent (sensory) -chemosensory for smell -very short: axons of receptor cells -cells of olfactory sac to olfactory bulb

Cranial nerve I (olfactory)

-vision -outpocketing of vein = nerve tract -from retina, thru optic chiasma, continues to brain -somatic afferent (sensory)

Cranial nerve II - optic

-somatic efferent (motor) -innervates dorsal rectus, medial rectus, inferior rectus, inferior oblique -also ciliary and iris muscles -nucleus in midbrain

Cranial nerve III - oculomotor

-somatic efferent (motor) -innervates dorsal oblique -trochlear nucleus in midbrain

Cranial nerve IV - Trochlear

-large, mixed nerve -nerve of mandibular (1st) branchial arch -3 branchs: opthalamic, maxillary, mandibular

Cranial nerve V - Trigeminal

-mixed nerve -visceral afferent (sensory): taste of ant tongue -visceral/somatic efferent (branchial motor): muscles of hyoid arch, derivatives (middle ear bone) -visceral efferent (motor): lacrimal + sublingual + mandibular salivary glands

Cranial nerve VII - Facial

-somatic afferent (sensory) -sensory fibres from inner ear -balance, hearing -synapses in several regions of medulla

Cranial nerve VIII - auditory/vestibulocochlear

-mixed nerve -visceral/somatic efferent: last 4 branchial arches -visceral/somatic afferent: from last 4 branchial archs, thoracic, abdominal viscera -visceral efferent: smooth muscle and glands of last 4 branchial arches and thoracic and abdominal viscera

Cranial nerve X - Vagus

-amniotes: small, distinct motor nerve -supplies derivatives of cucularis (cleidomastoid, sternomastoid and trapezius)

Cranial nerve XI - Accessory

-spinal accessory -visceral/somatic efferent (branchial motor) -branch of vagus and several occipital nerves

Cranial nerve XI - Accessory

-only in amniotes -somatic efferent (motor) -innervates muscles of tonue, hyoid -derived from hypobranchial nerve that innervates hypobranchial musclulature -hypoglossal nucleus in medulla

Cranial nerve XII - hypoglossal

-III -IV: dorsal oblique -VI: lateral rectus DO4LR6

Cranial nerves innervating eye

-preotic: anterodorsal, anteroventral, otic -postotic: middle, supratemporal, posterior -rooted in medulla -dorsolateral placodes -sensory: mechanoreceptors and electroreceptors -jawed fishes, some phibs

Cranial nerves: Lateral line =acousticolateralis

-somatic efferent: III, IV, V, VII, IX and X -visceral efferent: III, VII, IX, X

Cranial nerves: Motor

-V, VII, IX, X

Cranial nerves: dorsal series

-from dorsal and ventral nerves of a few anterior spinal nerves -"trapped" within the braincase -D and V do not fuse -some carry only sensory/motor, some mixed

Cranial nerves: evolution

-Complete interventricular septum (separate L and R ventricles) -Pulmonary trunk and left aa off right ventricle -right aortic arch off left ventricle -foramen of Panizza connects left and right aortic arches

Crocodile heart: differences

-arose in middle triassic -modern alligators, crocs, caimans, and gavial

Crocodilians

-blood calcium levels -release antagonistic hormones -ultimobranchial: decrease calcium -Parathyroid: increases calcium (rapid mobilization of calcium = eggshells and antlers)

Derivatives of pharyngeal pouches: ultimobranchial and parathyroid (functions)

1. placoid 2. cosmine 3. ganoid 4. Teleost

Dermal Derivatives: Dermal scales

-dermal bones forms part of the sjull and appendicular girdles

Dermal Derivatives: Skeleton

-lost most enamel, some have dentine and both types of bone: vascular bone and lamellar bone

Dermal Scales: Cosmine

-sharks -increase hydrodynamics of skin -bone sticks through epidermis -enamel cap comes from interactions with dermis -dermal bone sticking through epidermis

Dermal Scales: Placoid

-Turtles: plastron part is composite with endochondral bone and dermal bone -bone under scutes = keratinized epidermis

Dermal derivatives: dermal plates

-double layered -Outer papillary layer - dermal pappilae -lower reticular layer -Pappilary dermis: thin bundles of collagen arrayed haphazardly -Reticular dermisL deeper, made up of thick bundles of collagen

Dermis: Mammals

-fibrous but lacks layering, not highly organized -stratum compactum less developed

Dermis: Terrestrial verts

-maintenance functions

Dermis: What does it do?

-induction of epidermal derivatives -stratum spongiosum = stratum laxum: upper layer, vascularized -Stratum compactum = lower layer, dense and ordered

Dermis: What is it made of?

-mesoderm (dermatome) and mesodermal mesenchyme

Dermis: where does it come from?

-indeterminate, radial cleavage -blastopore becomes anus -coelom is enterocoelic (primitive in vertebrates)

Deuterostome Characteristics

-Phylum Echinodermata -Phylum hemichordata: Class Enteropneusta, Class Pterobranchia -Phylum Chordata: Subphylum Urochordata, class ascidiacea, class larvacea, class thaliacea

Deuterostomes: Taxa

-coelome of hypomere (lateral plate) becomes partitioned -pericardial (around heart) and pleuroperitoneal (around everything else) -separated by transverse septum: posterior wall = serosa of liver, coronary ligmant

Development of coelom

-pulmonary fold (extra membrane growing btw lungs, oblique septum), suspends liver and sequesters each lung

Development of coelom: crocs, turts, birds, some lizards pleural cavities

-coelomic fold (pleuroperitoneal membrane) meets transverse septum, becomes diaphragm after muscle invasion -mesothelium (epithelium from lateral plate, mesoderm): mesentary

Development of coelom: mammals pleural cavities (end lecture 9)

-two openings on each (L + R) side of the skull -upper bar = squamosal/postorbital -lower bar = jugal/quadratojugal

Diapsid

-living reps except turts -extinct mesozoic reps -archosauria, + lepidosauria = living -lepidosauromorpha: lepidosaurs + fossil members

Diapsida: Groups

-floor -collection of nuclei: regulate homeostasis (temp, osmolarity, apetite, bp, alerteness, sexual and emotional behaviour) -mammillary bodies: reproduction, short term memory -envagination forming infudibular stalk and posterior lobe of pituitary

Diencephalon: Hypothalamus

-pineal gland (roof) -modifies skin pigmentation -regulates photoperiod in anamniotes, biological rhythms -photoreceptor in lampreys -gnathosomes: endocrine organ, stimulated in part by light via retina -primates: large -aq mamms and croc: vestigial

Diencephalon: epithalamus (function in various verts)

Dorsal=thalamus -major coordinating and relay

Diencephalon: ventral and dorsal thalamus

-lips, cheeks (suckling) -teeth -tongue -oral glands -liver -pancreas

Digestion: Accessory Organs

-from archenteron (= gastrocoel) -endoderm: envaginations = stomodaeum and proctodaeum -Buccal cavity = stomodeaum + archenteron -Cloaca = archenteron + proctodaeum

Digestive System: Development

- L and R -usually unite before heart -oxy blood from lungs to heart

Double Circulation (Veins): Pulmonary system

-drain body tissues -hepatic portal system -renal portal system (not found in mammals)

Double circulation (Veins): Systemic system

-buccal and opercular pumps -continuous unidirectional flow across gills 1. suction: buccal cavity expands, water flows in 2. Force: buccal cavity compressed and gills open, water flows out

Dual pump

-modified mechanical receptors -neurmast organs in pits, generally on head -responsive to electrical fields

Electroreceptors: what are they?

Aspondylous: all elements separate hologspondyly: all vertebral elements in a segment fused to a single unit -pretty much all living vertebrates!

Early tetrapod taxonomy (do not need to know real well)

-sensory structures -eyes -inner ear -lateral line -taste buds -pituitary

Ectodermal placodes (embryonic, not found in adults)

-2nd pharyngeal slit = spiracle (supplied by aa II or dorsal aorta): false gill -collecting loops: pretrematic and posttrematic branches

Elasmobranchs (sharks and rays): gills

-Funnel: collects eggs from ovary -shell gland: secretes albumen, egg case -isthmus: connects shell gland to uterus -uterus: nutrition for embryos if held in female

Elasmobranchs: 4 regions of mullerian duct

A-Sinus venosus B-Sinoatrial valves C-atrium D-Atrioventricular valve E-Ventricle F-conus arteriosus -innervated by vagus nerve

Elasmobranchs: heart

-radiation: infrared, photoreceptors -visual light -ultraviolate: many fish, reps, birds -infrared detected with specialized receptors

Electromagnetic receptors

1. vitelline 2. Cardinal 3. Lateral abdominal

Embryo: 3 majore sets of paired veins

-single layer of external cells = ectoderm gives rise to epiderms -dermis from dermatome -periderm: starts to split and lower part of the epidermis is where proliferation of cells come from (stratum basale/germavitum) -Basement membrane: basal lamina from epidermis, reticular lamina from the dermis -dermis: stratum compactum and stratum spongiosum)..

Embryological Origin of Skin

1. Paraxial mesoderm -Skeletal muscles: somites, somitomeres 2. Hypomere (lateral plate) -cardiac muscles (also embryonic mesenchyme) Hypomere (splanchnic) -smooth muscles of gut and organ derivatives 3. Mesenchyme -smooth muscle -blood vessels

Embryology: 3 sources of cells for muscles

-paraxial mesoderm (epimere) becomes segmentally arranged into somites -somite split into 3 mesodermal populations: dermatome, myotome and sclerotome

Embryology: Somites

- Epiphysis (what is this made of?) -diaphysis: middle part, made of bone -metaphysis = epiphyseal plate: zone of replacement. Cartilage taken away and replaced by bone -continous remodelling. Once cartilage is gone, bone doesnt grow anymore.

Endochondral bone: Parts

-mesenchyme (schleroblasts) --> cartilage --> bone

Endochondral bone: development

-both begin with aggregations of mesenchyme -intramembranous = direct development -endochondral = preformed in cartilage, replaces cartilage

Endochondral vs Intramembranous bone: development

-folds of archenteron form coelom

Enterocoely

-opens the jaws

Epibranchial Musculature: Fishes

-cervical somites/muscles -epaxial myotomes, insert on neurocranium -above pharyngeal arches, grade into trunk muscles -axial musculature

Epibranchial musculature

-trunk muscles

Epibranchial musculature: tetrapods

-neural crest -melanophores: melanin (protect from sunlight) -iridophores: guanine (refracts light) -xanthophores: yellow pigments -erythrophores: red pigments

Epidermal Derivatives: Chromatophores

-often sink down into dermis -mucous -poison/granular: exocrine release products via duct to external surface -photophores: contain bioluminescent bacteria -two kinds of multicellular glands: exocrine and endocrine (release products into bloodstream)

Epidermal Derivatives: Multicellular glands

-seen in fishes and amphibians A-Epidermal cell B-Granular cells C-Club cells

Epidermal Derivatives: Unicellular glands

-mandibular (1) and hyoid (2) lost in early development -larvae: development of gills leads to interruption of arches; restored @ metamorphosis -Adults: 3, 4 and 6 persist, 5 lost -VI: associated with lungs + cutaneous resp -IV: dominant systemic arch bringing blood to body -III: dominant cranial arch, all blood goes to head = coratid

Evolution of Aortic Arches: Frog

-In most fishes: 3 to 6 normal, fully developed -exception: african lungfish (arches 3 and 4 with no or reduced gills, arch 6 becomes associated with lung

Evolution of Aortic Arches: Lungfish Exception

-asymmetry appears -ventral aorta splits: pulmonary arch to lungs (VI), left systemic arch (IV, part of left dorsal aorta), right systemic arch (associated with both carotids and pectoral limb vessels IV) -two systemic arches unite (dorsal aorta) but right more prominent

Evolution of Aortic Arches: Reptiles

-mandibular (1) and hyoid (2) lost in early development -3-6 may persist as continuous loops (no gills) in adult -3-6 associated with external gills -6 becomes associated with lungs (no gill developed @ pharyngeal pouch 7) -loss of dorsal aorta btw 3 and 4. all blood from arch 3 pushed towards head

Evolution of Aortic Arches: Salamanders

-begin to see asymmetry -I, II are gone -III = cranial blood supply (arch + associated dorsal aorta = internal carotid artery), (ventral aortic stem becomes common carotid artery) -IV: systemic arch = main channel for body blood -V: lost (small, transient in embryo) -VI: pulmonary arch = blood supply to lungs

Evolution of Aortic Arches: Tetrapods

-reduced: supplies for arches III, IV, VI -in tetrapods: only persists as portion at base of vessels leaving heart = truncus arteriosus

Evolution of Aortic Arches: Ventral aorta

-ancestral vert: 8-9 head segments -each innervated by dorsal mixed nerve and ventral motor nerve -losses and merges as segmentation was modified = complex

Evolution of cranial nerves

-I, II and VIII and lateral line nerves -derived separately (ectodermal placodes) in conjunction with special sense organs -nothing to do with head segments

Evolution of cranial nerves: missing

-insulation -tactile devices: protohairs btw scales

Evolution of hair

-gill breathers -heart to ventral aorta to external carotid arteries (paired) -ventral aorta (floor of the throat) gives off aortic arches -ventral aorta to capillaries (gills) to dorsal aorta -anterior extensions of dorsal aorta = internal carotid arteries -both dorsal aorta (oxy blood) and ventral aorta (deoxy blood) run away from head so they are both arteries

Evolution of hearts: Primitive condition

-aq to terrestrial locomotion -sprawling to parasagittal stance: acetabulum and glenoid fossa shifted ventrally -tetrapodal to bipedal: forlimbs to be used for other purposes -Limblessness: secondary loss

Evolution of limbs (end lecture 8)

-dorsal + ventral roots present, not united -dorsal roots also contained visceral motor fibres -some sensory cell bodies in ganglia, some scattered

Evolution of spinal nerves: Early verts

-D and V unite = spinal nerve -some bony fishes: D contains sensory fibres and visceral motor fibres -Sharks + tetrapods: dorsal root contains only sensory fibres -dorsal root ganglia

Evolution of spinal nerves: Gnathostomes

-loss of dermal elements -endochondral elements take over -amphibians -lost entirely or much reduced - primitive amniotes - cleithrum usually lost - turtles - clavicle incorporated into plastron - birds - furcula -synapsids with new endochondral ossification

Evolution of the pectoral girdle

-scleral bones/cartilages -round lens, held by suspensory ligament -retractor on lens pulls lens (elasmobranchs: forward, teleosts: backward) -sharks are farsighted at rest!

Eye variations: gnathostome fish

-Contour feathers -Flight feathers, a subset of contour feathers -down feather -filoplume

Feathers: Types

-pterylae: arranged in tracts

Feathers: What is this called

-develop from feather follicles -invaginations of the epidermis into the underlying dermis

Feathers: development

-ovaries paired, oviducts/mullerian ducts -birds, platypus: only left matures -rudimentary archinephric duct, metanephric kidney drained by ureters -shell gland prominent in oviparous -uterus distinct in viviparous

Female genital ducts: Amniotes

-paired ovaries -oviducts = mullerian ducts -archinephric duct for opisthonephric kidney

Female genital ducts: Amphibians

-cloaca to cloaca -fundulus fish: interlock fins -salamander with spermatophore

Fertilization: sperm transfer

-parallel: fibres parallel to line of tension (light load, long distance) -Pinnate: Fibres oblique to line of tension (heavy load, short distance) -many are a combo

Fibre orientation: Tissue level

-"flipped over" arthropod -arthropods with solid nerve cord, schizocoelic coelom formation, spiral cleavage -but chordates with hollow nerve cord, enterocoelic coelom (primitive) fromation, radial cleavage -not really a viable idea!!

First Chordates: Arthropod origins?

-4 limbs with digits -tracks 18 my older than earliest tetrapod fossils -10 my older than earliest elpistostagalian fishes

Fossil Footprints

-epithelium: from ectoderm and endoderm -connective tissue: from mesoderm -muscle tissue: from mesoderm -nervous tissue: from ectoderm

Four types of true tissues

-Embryo = bulbis cordis, contractile -Chondrichthyans, lungfish = conus arteriosus, contractile -Teleosts = bulbus arteriosus = thin walled, smooth muscle, no valves -Tetrapods = truncus arteriosus = small portion at base of departing arteries

Fourth Heart Chamber: different vertebrates

-tympanum: sound from extracollumella and stapes -muscles to pectoral girdle

Frogs: Hearing

-prevent air from escaping lungs -prevent foreign substances from entering lungs (epiglottis covers opening to larynx) -forcefully expel foreign substances which threaten the trachea (coughing) -vocalization

Function of Larynx

-Somatic: voluntary, willful control of effectors (skeletal muscle) -Autonomic division: control of autonomic effectors (smooth muscles, cardiac muscle, glands, not voluntary

Functional divisions of the nervous system

-lost of enamel retained -diamond/rhomboid shape -living: lost vascular bone, only acellular -scales do not pierce epidermis

Ganoid Scale

-4 gill arches in adult

Ganthostome Fishes: Gill arches

-neumatic duct -can be a respiratory organ -vascularized, attached to digestive tract

Gas Bladder: Physostomous

-gas from blood -noramally a buoyancy organ -gas gland (rete mirable)

Gas bladder: Physoclistous

-dermal bone (laid down in skin) -posterior to sternum, anterior to pelvis -muscle attachment, support for abdomen -crocs, turts, tuatara

Gastralia

-wall of digestive tract -stimulate/inhibit target = digestive system -production of gastric juices, inhibit secretion of gastric juices, release bile and pancreatic juices

Gastrointestinal mucosa

-wide distribution -3 basic kinds: free sensory receptors, encapsulated sensory receptors and associated sensory receptors

General sensory organs

-unspecialized nerve endings -detect pain and temperature

General sensory organs: Free sensory receptors

-nerve terminus wraps around organ -ex) hair

General sensory organs: associated sensory receptors

-becoming incapsulated in a structure increases sensitivity of the nerve -nerve ending enclosed in specialized structure -tough, pressure, cold

General sensory organs: encapsulated sensory receptors

-paired gonads from genital ridge (of urogenital ridge) -swelling of dorsal wall of coelom, thick cortex around medulla -indifferent stage early on -arises late in development

Genital system: Embryology

Holobranch -anterior and posterior surfaces -resp unit: half of anterior and half of posterior gill slits because water flows btw these things. Hemibranch -only one side of septum/arch -ex) spiracle

Gill types

-efficient, improve gas exchange -opposite flows of water and blood -rete: network of capillaries -point is: medium picking up oxygen (blood) is always lower pressure in oxygen than the other medium. So oxygen always flows down its gradient.

Gills: Countercurrent system

-jaws -derived from first pharyngeal arch (or thats the best way to explain things)

Gnathostoma: Major evolutionary event

-4 chambersL sinus venosus, atrium, ventricle, conus arteriosus/bulbus arteriousus -one way valves -heart twists into S shape: atrial contraction assists in ventricular filling -aspiration effect to move blood into sinus venosus and atrium

Gnathostome Fishes: Heart

-jaws with teeth -complex endoskeleton -paired fins -3 semicircular canals

Gnathostomes: Characteristics

-unmylinated neurons -call bodies + synapse occur here

Grey matter

-poorly known -damp tropical habitat -aquatic or burrowing

Gymnophiona

-specialized type of lamellar bone -acunae: cells sitting there maintaining the bone, laid down in concentric rings -down centre is hollow: blood supply -whole structure is called an osteon

Haversion

-impedance matching (air to fluid) -fluid more viscous -middle ear ossicles: transmit to fenestra ovalis, transfrom sound waves from air to fluid and amplify sound

Hearing in tetrapods

-lagena lengthened: hair cells in long strip (organ of corti) -owls: asymmetrical facial feathers direct sound to auditory meatus, feather tufts like pinnae

Hearing: Birds

-tympanum to extracollumella to stapes to inner ear -lagena and auditory papilla (organ of corti) -snakes: lack tympanum, stapes attached to quadrate (jaw), restricted sensitivity = pick up seismic vibrations

Hearing: Reps

-intrinsic property of cardiac muscle -synchronized in sinoatrial node = pacemaker (all tetrapods) -mammals: additional atrioventricular node with purkinje fibres (back-up synchronizing of contractions)

Heart contraction

-SA sinoatrial btw sinus venosus and atrium -AV atrioventricular btw atrium and ventrical -Normal flow: valves pushed open but pressure of blood in next chamber pushes them closed again = prevent retrograde flow

Heart valves

-Pericardial cavity semi-rigid = cannot increase area around heart -ventral contraction reduces volume/lowers pressure in cavity = expandion of sinus venosus and atrium = internal negative pressure thus aspiration of venus blood

Heart: Aspiration Effect

-subintestinal vein collects blood from intestines , thru liver, joins vitelline veins -when vitelline veins broken up into hepatic sinusoids, post. subintestinal becomes hepatic portal vein

Hepatic Portal System: Embryo

-btw capillaries of digestive tract and liver capillary bed -nutrients from digestive tract to liver

Hepatic Portal system

Retention of larval features in the adult 1. Neotony -nonreproductive organs delayed in development compared to reproductive organs 2. Progenesis: accelerated development of reproductive organs

Heterochrony: Paedomorphosis

-extended development, producing overdeveloped structures

Heterochrony: Peramorphosis

-idealized primitive type = no losses occur -each nephron associated with 1 glomerulus -anterior to posterior succession -mesodermal duct -early development in hagfish, elasmobranchs, caecilians

Holonephros

see recording lecture 15, near the end

Homologies of middle ear?

-attachement site similarity -functional similarity -nervous innervation -embryonic origin

Homologous Muscle criteria

-similarity of topology (found on the same place on the body) -similarity of detailed underlying structure -similarity of embryological development

Homology: 3 necessary features

-elongation of body -increased musculature -tail formed -BUT if metamorphosed, it will lose chordate characters, therefore adult stage eliminated = paedomorphosis -notochord + pharyngeal slits a de novo structure?

How could a larval echinoderm become a chordate?

-embryology: development of individual -phylogenesis: ancestral history -organ systems and evolution

How do we study comparative anatomy?

-strong or weak -briefly or extended periods of time -number of fibres/cells -tetanus: max and continuous contraction or tension

How muscle organ works

-runs btw ventral elements of (under) gill arches -btw gill arches and pectoral girdles -tongue -trunk axial muscles (not head muscles)

Hypobranchial musculature

-associated with shoulder girdle, ventilation (expansion of buccal cavity)

Hypobranchial musculature: Fishes

-associated with throat, hyoid, larynx and tongue -sternohyoideus

Hypobranchial musculature: tetrapods

-lateral plate mesoderm -mesoderm splits and forms coelom, growing down and sides of gut -responsible for muscularization of anterior end of organism: :will muscularize the pharynx -muscle associated with the gut, heart

Hypomere

-adenohypophysis to neurohypopysis -hormones carried directly

Hypophyseal portal system

-unrestricted notochord -radian fin rays supporting tail fin -lateral line system -no internal gills, breathes oxygen

Ichthyostega

-more active lifestyle, greater metabolic scope -larger body size -greater feeding capacity -Muscular anterior allows for modifications, such as jaws Stronger support system from pharynx pumping, respiration and such better.

Improvements of vertebrates

-combines all types of censory info -allows organism to respond to environment -initiates voluntary motor activity through primary motor cortex -forms and stores memories from sensory info

Isocortex/neocortex

-nocturnal vertss -detect "warming" effect of infrared on bodies that absorb it -vampire bats: "thermoreceptors" on face -primitive boas: within epidermal scales along lips -pythons: recessed labial pits along lips -pit vipers: facial/loeral pits, highly sensitive (mice at 30cm)

Infrared receptors

-scala vestibuli -scala typmani -scala media = coclear duct

Inner ear: Perilymphatic spaces

-vistubular apparatus + perilymphatic spaces -lagena = auditory -organ of corti = sensory organ in the lagena

Inner ear: internal auditory meatus

-Composite: epidermis, dermis, nerves, blood vessels -contains cells of neural crest origin: form chromatophores, aid in production of teeth -epidermis + dermis mutually necessary

Integument: Basic structure

-protection -regulation -material exchange -nutrition -support -locomotion -sensory -communication

Integumentary system: Functions

-feeding structures (specialized tissues: beaks, teeth) -food for young (Glands: mucous, milk) -food storage: as fats

Integumentary system: Nutrition

-color: patterns, blushing -display structures: dispay feathers on birds -scent glands: pheromones

Integumentary: Communication

-respiration -metabolic wastes -heat, moisture, gasses -fish excrete salt through gills

Integumentary: Exchange of materials

-aq: fin webbing etc -Terrestrial: hooves, claws, suction disks, snake scales -aerial: feathers, wing skin

Integumentary: Locomotion

-marsupium -frogs embed eggs in skin

Integumentary: Other functions?

-concealment -advertisement (aposematic) -radiation: UV, melanosomes for protection -moisture loss: mucous production

Integumentary: Protection against elements

-first line of defense -pathogens/microbes -abrasions = mechanical injury -predators (structural elements, quills) -active defense (horns, claws, toxins)

Integumentary: Protection against penetration

-barrier btw body and environment -water balance -thermal balance -gasses, ions, moisture loss

Integumentary: Regulation

-tactile: whiskers, barbels -pressure -temperature -chemical

Integumentary: Sensory

-dermal fabric: aq forms (no wrinkling and such) -source of skeletal elements: dermal bone from skin -sites for muscle attachment

Integumentary: Support

-D2 not produced by verts -D3 made in skin: reaction of 7 dehydrocholesterol with UVB light in epidermis -feathers/fur: vit d generated from oily skin secretions deposited onto fur/feathers, obtained orally during grooming

Integumentary: Vit D manufacture

-agnathans: medial to branchial arch -gnathostomes: gills lateral to branchial arch (homologous = magic of neural crest) -elasmobranchs: spiracle -bony fishes: gill lamellae open in to common opercular chamber

Internal gills

-nasal capsules (chondrocranium): olfactory epithelium in paired nasal sac, initially for smell -actinopterygians: external nares only, for olfaction, not open to mouth -rhipidistians/tetrapods: internal nares, open to mouth via hole in palate (fish bring water in for breathing, tetrapods bring air into mouth for breathing)

Internal nares and secondary palate

-connect one neuron with another -reflexes: interneurons connect sensory neurons with motor neurons

Interneurons

-Mesenchyme --> bone matrix cells -lay down bone directly in membrane -direct development

Intramembranous bone: Formation

1. Dermal -forms in integument 2. Sesamoid -Forms in tendons -most often formed in areas of wear, to protect joints -ex) patella

Intramembranous bone: Two types

-hagfish: tissues = water, nephron reduced to short duct -Elasmobranchs: osmoconformers = rectal gland secretes salt, retains urea in blood, concentration increased without salts -Living coelacanth: retains urea in blood

Isosmotic Verts

-heart to dorsal aorta to renal artery to be filtered in glomerulus (arterial blood) -renal portal system: wrapped around connecting tubules (venus blood) -mammals with no renal portal, so arterial blood wrapped around collecting tubules -some birds also have arterial blood around tubules

Kidney: Blood supply (in different vertebrates)

-palaeostyly: no jaws, regular gill arches -autostyly/euautostyly: upper jaw from paletoquadrate, lower jaw from meckels cartilage. Paletoquadrate supporte meckels cartilage = jaw supports itself. Hyomandibula not for support. Acanthodians, placoderms. -amphistyly: palatoquadrate with two connections = hyomandibula braces lower jaw, ligament holds palatoquadrate to anterior of snout. -hyostyly: upper and lower jaws only supported by hyomandibula, jaws not attached to braincase at all. -autostyly/metautostyly: tetrapods, jawbones becomes reduced. Dentary comes in to form lower jaw. Meckels cartilage pushed to back of lower jaw = articular. upper jaw: palatoquadrate ossifies becomes quadrate. Articulation = articular + quadrate. stapes = remnant of second pharyngeal arch, no longer acts in jaw support. -craniostyly. Lower jaw = dentary, part of dermatocranium. Articulates off braincase directly. Meckels cartilage becomes middle ear. Mammals!

Jaw suspension

1. Diarthrosis/Synovial -allows a lot of movement -associated with synovial fluid -ex) knee joint 2. Synarthrosis -not very mobile

Joints: Types

-epidermal hair follicle rooted in dermis -arrector pilli muscle -dermal papilla

Keratinized Structures: hair structure

-claws -nails -hooves

Keratinized Structures: mammals

-baleen -rattlesnake rattle -beak sheath

Keratinized structures: Misc stuff

-epidermal scales

Keratinized structures: Reptiles

-feathers

Keratinized structures: birds

-horn sheath -antlers are not keratinized

Keratinized structures: head ornaments

-secondary endocrine -renin: increase blood pressure -erythropoietin (mamms) increase oxygen levels via red blood cell production

Kidney (end lecture 16)

-paired per segment, nephric tubules -open to coelom (peritoneal funnel) = associated with developing nephrotome -open to nephric duct (growing down body)

Kidney Development: Primitive Form

-variations in structure -begin operation early in development -gonads take over ducts later in development

Kidney Evolution: Overview

-new duct = ureter -archinephric duct lost to genital system -trending towards more complex stucture, not remotely segmental anymore (short, stout, compact structure)

Kidney: Amniotes - Changes over development

-Embryo: mesonephric -Adults: metanephros

Kidney: Amniotes - stages

-big, fang like -grooves to aid penetration of prey and removing them -lots of infolding = labyrinth

Labyrinthodont Teeth

-retain bony scales: abdominal -large -metamorphosis btw juvenile and adult -labyrinthodont teeth -acanthostega, ichthyostega, tulerpeton: earliest paleozoic amphibians

Labyrithodonts

-lengthens in terrestrial verts -mammals: coiled in cochlea, associated with organ of corti (specialized neuromasts) -auditory nerve = cranial nerve VIII

Lagena: In various verts

-4 chambers (conus arteriosus) -one way valves: sinoatrial (SA) and Atrioventricular (AV) -semilunar valves in lumen of conus arteriosis -no accessory hearts A-Ventral aorta B-conus arteriosus C-Semilunar Valve D-Ventricle E-Atrioventricular valve F-Atrium G-Sinoatrial valve H-Sinus venosus

Lamprey Heart

-radial cleavage -blastopore becomes anus -enterocoelic (primitive)

Lamprey: Development

-no villi in mucosa: most absorption already done -straight tube to cloaca/anus -many mammals: colon (loop), rectum -absorbs food molecules, reclaims water and salts (shark rectal gland) -ends with smooth muscle sphincter

Large Intestine

-suspension feeder, cilia lined channels -muscular pump, not passive filter: active suction for feeding + respiration -pharyngeal slits act as valves, one way flow of water -adults are parasitic or non-feeding

Larval lamprey: Ammocoete

-recessed grooves (lat line canals), may be covered (skin with pores) -ectodermal placodes = ectodermal derivatives -detect water currents, feeding and navigation

Lateral line system

Outside -epidermis -basement membrane: two layers, from epidermis and dermis -dermis -hypodermis -neural crest cells: bony armour, pigments -nerves and blood vessels Inside

Layers of the Skin

-a bunch of stuff you don't need to memorize yet.. -come back to it at the end?

Lecture 6, pg 6

Rhynochocephalians -tuatara -primitive -different from lizards: scales, teeth, internal morphology (diapsid skull complete) Squamates -snakes, lizards, amphisbaenians

Lepidosaurs: Extant Groups

-smaller than labyrinthodonts -spool shaped centra -lack labyrinthodont teeth

Lepospondyls

-membranous/webbed with internal support -certatorichia, lepidotrichia, actinotricia, radial/pterygiophores

Limbs: Fish

-show up mostly in ectoderms -shows change in growth rate -fast growth in summer/rainy season

Lines of arrested bone growth

-anterior border of mouth -pliable, or rigid beaks -fleshy in mamms for suckling -follow tooth rows to angle of jaws -end before jaws: cheeks (for food storage, really pronounced in rodents)

Lips and cheeks

-frogs, salamanders, caecilians -essentially terrestrial, but ties to water -spool0shaped centra -pedicellate teeth: unite group

Lissamphibia

-Ruta: from temnospondyls -Carroll: from dissorophod temnospondyls and leposondyl microsaurs -Laurin and Reisz: lepospondyls

Lissamphibia: Monophyly?

has its own blood supply = arterial also gets blood supply straight from intestine = portal (venous blood). Passes btw these two organs without going through heart. Picks up nutrients and such. -liver and blood supply grow together

Liver: Blood supply

-reduces food chemically with bile (emulsifier), stored in gall bladder -production of RBCs in foetus -destruction of old red blood cells -detox of blood -storage/metabolism of carbs, proteins and fats

Liver: Function

-highly vascularized (detox blood), including venus blood -forms from hepatic diverticulum (ventral envagination of gut floor; endoderm) -exocrine function = bile, stored in gall bladder -gall bladder absent in some groups -grows to fit available space

Liver: Structure

-hagfishes and lampreys? Cyclostomata -single median nostril -lack bone: might be a reversal tho

Living Agnathans

-thin and soft, not scaled -single-celled glands -no stratum corneum -dermis thinner than epidermis -keratinized structures: rasping teeth

Living Agnathans: Skin

-phibs: btw nares -Squamates: separate pit, tongue delivers chemicals -mammals: nasopalatine duct, grimace behaviour

Location of vomeronasal organ

-african + south african: obligate air breathers -African with reduced number of gills -australian lungfish can survive with gills alone: breathes air in poor quality water

Lungfish

-now have lungs = double circulation

Lungfish: Circulation

-separate pulmonary circut (aa VI going to lungs) -AV valve replaced by atrioventricular plug = prevents retrograde flow -partial division of ventricle (interventricular septum) -4 chambers, two partial chambers, one way valves

Lungfish: Heart anatamy

-single atrium partially divided = intratrial septum/pulmonalis fold (larger right, smaller left) -pulmonary veins enter sinus venousus or directly into left atrial chamber (carring oxy blood) -sinus venosus carries systemic venous blood to right atrial chamber

Lungfish: Heart/blood flow

-accessory venous system -absorbs and returns fluid to circulation -absorbs liquids from digestive tract -made of lymphatic vessels and tissues

Lymphatic System

1. Free cells = part of the immune system 2. Lymph nodes: collection of lymphatic tissue wrapped in fibrous connective tissue

Lymphatic tissue

1. Leucocytes: destroy bacteria 2. Plasma cells: antibodies 3. Macrophages: cling to leucocytes

Lymphatic tissue: Free cells (end lecture 12)

-anastomosing channels -Major vessels: jugular lymphatics, subclavian lymphatics, lumbar lymphatics, thoracic lymphatics -lymph hearts = striated muscle (fish, reps, some birds)

Lymphatic vessels: Anatomy

-degerate mullerian ducts -ant reproductive kidney with short tubules (epidimus), join testes to archinephric duct/vas deferens -accessory urinary ducts for posterior kidney

Male genital ducts: Elasmobranchs

-various forms 1. neotenic: archinephric = sperm + urine 2. New accessory urinary duct, archinephric = vas deferens (some salamanders) 3. Accessory urinary ducts, vas deferens (frogs, some salamanders)

Male genital ducts: Phibs

-elasmobranchs: modified pelvic fins -some teleosts: gonopodium (anal fin modification) -ascaphus: extension of cloaca -lizards/snakes: hemipenes -birds, turts, crocs, mamms: single median penis -most mamms: baculum (bony penis structure)

Male intomittent organs (end lecture 13)

-mesochorium -in most verts: in upper part of ceolomic cavity -descend in most mammals (scrotal sacs, inguinal canal)

Male vertebrates: Testis

Inside -stratum basale: growing actively -stratum spinosum -stratum granulosum -stratum lucidum -stratum corneum Outside diagram lecture 7 pg. 5

Mammal epidermis: layers

-thick, tough dermis -epidermal scales mostly lost: tails of rodents -specialized glands -hair

Mammalia

3 sources: -thoracic myotomes (1) -mesenchyme (foregut) (2) --> dorsomedial diaphragm -muscle anlangen (muscle primordia that can migrate): cervical myotomes (3)--> body septum anterior to liver --> muscles of diaphram -innervated by phrenic nerve: cervical spinal nerves

Mammalian Diaphragm

-maintenance of homeostasis -excretion -osmoregulation

Mammalian Kidney Function

-anterior tubules degenerate before posterior form -segmental growth continues --> mesonephros

Mammalian Kidney: Development

-middle of nephric ridge -use archinephric duct -functional in embryo -replaced in amniote embryos -multiple nephrons associated with multiple glomeruli

Mesonephros

-mesenchyme vs somites/somatomeres (muscle blocks going down embryo, each segment with own somite)

Muscle Classification: Embryonic Origin

-somatic -visceral (associated with guts/organs)

Muscle Classification: Location

-smooth vs striated

Muscle Classification: Microscopic appearance

-voluntary vs involuntary

Muscle Classification: Nervous Control

-striated, skeletal, voluntary -primitively segmented -myotomal (group of muscles that a single spinal nerve root innervates) -mostly body wall and appendages -primarily for orientation in external environment -spinal and some cranial nerves

Muscle Classification: Somatic

-slow contraction -postural muscles in reps and phibs -extraocular and ear muscles of mammals -mutliple axons -graded contraction -maintain tension efficiently

Muscle Classification: Tonic

-smooth, nonskeletal, involuntary -unsegmented -mostly from splanchnic mesoderm -mostly visceral (except hair erectors and blood vessels) -regulate internal environment -autonomic nervous system (involuntary)

Muscle Classification: Visceral

-fast to slow contraction -slow: mammalian postural muscles -fast: most locomotor muscles -single axon innervation -all or none contraction -variably fatigues

Muscle Classification: twitch fibres

-more than one action (primary/secondary) -only in one direction: work in pairs (peristaltic action of gut)

Muscle Performance

-reduce axial -increase appendicular -pelvic and pectoral musculature bunched proximally

Muscle Specializations: Birds

-saltatorial -prominent hindlimb extensors -stout pectoral limbs

Muscle Specializations: Locomotion in Anurans

-appendicular muscles bunch proximally -long tendons

Muscle Specializations: Locomotion in cursorial tetrapods

-resting -active: tensile force, load = bone to be moved

Muscle activity states

-motor end plates -all or none contractions in cells

Muscle cell contractions

-decrease/increase joint angle: flexor, extensor -motion relative to body: abductor (away), adductor (towards) -jaw action: levator, depressor

Muscle naming: Mechanical action (antagonists)

-movement away from base: protractor, retractor -rotation of a part: supinator, pronator -increase/decrease openings: dilator, sphinctor/constrictor

Muscle naming: mechanical action

-synergists: doing things together -anatgonists: muscles that open jaw -fixators: prevent movement

Muscle perfomance: Basic muscle actions

-position of insertion proximal = speed -position of insertion distal = strength

Muscle performance: Position of insertion (if you have trouble with these cards, see casey lecture 9 notes)

-produce force, cause motion -locomotion or movement in internal organs

Muscle tissue

Red -slower -strong, sustained activity -myoglobin White -sudden, quick bursts -not sustained

Muscles Classification: Color

-thinner scales, originate from skin -homocercal tail -ossified vertebrae -complex jaw mobility

Neopterygii

PNS -all nervous tissues except CNS -cranial and spinal nerves CNS -brain and spinal cord -enclosed in bone for protection

Nervous System

-receive and interpret stimuli -transmit stimuli -translates past and present info into action

Nervous System: Basic Function

-neurulation: formation of dorsal hollow nerve cord -anterior = brain -posterior = spinal cord -central cavity filled with spinal fluid = neurocoel

Nervous system: development of CNS

-germinative layer = zone of cell proliferation -two lineages: (neuronal to neuroblasts to neurons) or ( neuroglia to neuroglial cells) -when division ceases = ependymal cells

Nervous system: innermost layer of neurocoel

-develop in head region, migrate ventrally and posteriorly through head and body -dermal skeleton, cartilage, bone, jaw muscles, visceral arch skeleton -sensory ganglia of some cranial nerves -visceral motor neurons innervating heart -aortic arch -incorportated into blood vessels -pigment cells

Neural crest (embryonic, not found in adults)

-placed btw neuron cell bodies and blood vessels -transport of nutrients/wastes

Neuroglial cells: Astrocytes

-line fluid-filled cavities of brain and spinal cord -production and circulation of cerebrospinal fluid -phylogenetically oldest (only neuroglial cells present in aphioxus and agnathans)

Neuroglial cells: Ependymal cells

-phagocytic, digest bacteria -mesodermal (appear only after blood supply established)

Neuroglial cells: Microglia

-nerve glue -no transmission -support, nourish and insulate cells

Neuroglial cells: function

-infundibulum -grows down, stays connected to the brain

Neurohypophysis

-two processes, one at either end -rare -ear and eye

Neuron cell types: Bipolar

-single stem axon, dendrite, body offset laterally -sensory neurons

Neuron cell types: Unipolar

-many processes -motor neurons and interneurons

Neuron cell types: multipolar

-carry message to effector (muscle, gland etc) -efferent: carry message away from CNS -originate in ventral horn of CNS, axonal processes grow out

Neuron types based on function: Motor neurons

-transmit nerve impulses -perikaryon -processes: axon (transmission from perikaryon), dendrites (transmission to perikaryon)

Neurons

-specialized neurons in CNS -secretions from ends of axons -delivered to blood capillary to reach target tissue (endocrine)

Neurosecretory cells

-hydrostatic organ -rough fibrous sheath with fluid filled cavity -not compressible: exerted muscle action bends it, good for locomotion! -often replaced with backbone/vertebrae -made out of mesoderm

Notochord

-long continuous rod (hydrostatic organ) -prominent in agnathans -reduced in later verts

Notochord

-compact cluster of neurons in the brain -act as hub or transit point

Nuclei

-external nares + internal nares -get connection between nose and mouth -for chemical detection but also breathing -new opening first found in rhipidistian fish

Olfaction evolution: Tetrapods

-olfactory placodes (ectoderm) invaginate towards neural tube -forms epithelium (sensory cells), induce telencephalon to produce olfactory bulb

Olfaction: Embryology

-Reptiles: turbinals (increase of bones with folding = increase SA) -Birds: turbinals may develop into scrolls (sense of smell is secondary, not as important) -Mammals: extensive turbinals (warm/moisten air), smell is a very important sense

Olfactory structures: Reptiles, birds and mammals

-nasolabial groove -tap nose on ground, moisture goes up via capillary action

Olfactory structures: plethodontids

-modified mesonephros, additional posterior tubules -fully fxning in adult fishes, phibs -replaced in amniote embryo -multiple nephrons per segment

Opisthonephros

-decussation: crossing over of fibres -complete in most craniates -incomplete in some primates = stereovision

Optic Chiasma

-venom: gila monster, venomous snakes, mammals, north american short tailed shrew -anticoagulant = vampire bats

Oral glands: Specializations

-more prevalent -drier environment -keeping food moist is a problem

Oral glands: Tetrapods

-lips to palatoglossal arch (fold in the cavity that separates oral from pharyngeal) -teeth, tongue, palate and glands

Oral/Buccal Cavity: Components

-receives and sorts food -stores food temporarily -physical and chemical reduction of food

Oral/Buccal cavity: Function

-btw two sets of capillary beds w/o passing through heart -hepatic portal system and renal portal system (absent in mamms)

Organ Drainage systems: Portal systems

-water balance -terrestrial: dehydration -aq: water fluxes -isosmosis: internal and external same

Osmoregulation

-Fish: gills pump salt out or in -Elasmobranchs: rectal gland -Aq phibs: skin -Reps: salt glands (nasal, orbital, sublingual, tongue)

Osmoregulators: Salt balance in Aq verts

-birds: nasal salt glands -mammas: no specialized glands, most eliminated through kidneys

Osmoregulators: Salt balance in marine birds + mamms

-hyperosmotic = excess water -large wuantities of fluid from glomerulus into renal capsule = filtration kidneys -large, well developed glomeruli -large amounts of dilute urine

Osmoregulators: Water elimination (freshwater)

-hyposmotic = remove salts and retain water -aglomerular kidneys: loss of glomeruli, renal capsule, distal capsule -lose glomerulus = not filtering liquid out of the blood

Osmoregulators: water conservation (marine)

-dehydration -mammals, birds: loop of henle - reabsorption of water from collecting ducts via huperosmotic surrounding environment

Osmoregulators: water conservation (terrestrail)

-Actinopterygians + Sarcopterygians -endoskeleton of bone -dermal scales -lepidotrichia: support fins -ossified gill cover: operculum -swim bladder

Osteichthyes

-bone shards from late cambrian -radiation in silurian, devonian -eye muscles -paired appendages -lateral line system -two semicircular canals

Ostracoderms

-vomeronasal - vomeronasal organ -epiphyseal - pineal gland

Other cranial nerves

-enlarged bony scutes in some fishes -gastralia fused into plastron in turts

Other dermal bones

-outer capsule (tunica albuginea) around cortex and medulla

Ovary: structure in mammals

-transport eggs from ovary to ostium -fibria and infundibulum are ciliated = pass eggs along -oviduct expands perteriorly into uterus, may contain shell gland -internal fert occurs before shell is formed

Oviducts (mullerian ducts)

-17 pairs -0, I-X, 6 lateral line -first few spinal housed in skull in derived groups = occipital -occipital nerves and anterior cervical spinal nerves unite = hypobranchial nerve

PNS Cranial nerves: Anamniotes

-cranial autonomic = cranial nerves -spinal autonomic = spinal nerves (thoracic, lumbar, sacral) -enteric autonomic: sensory and motor neurone in wall of digestive tract

PNS autonomic nervous system: Non-mamms

-sympathetic and parasympathetic

PNS autonomic nervous system: Two things in Mammals

-roots enclosed in braincase -TTOOOTTAVGVAH

PNS cranial nerves

-no lateral line -occipitospinal into brain (XI, XII)

PNS cranial nerves: amniotes

-shift from aq to terrestrial life = lose lat line system -spinal accessory XI separates from vagus (X) -branchiomeric muscles more prominent in holding and rotating head -hypoglossal XII becomes more prominent: tonrue and hyoid role in terrestrial feeding

PNS cranial nerves: evolution

-each head segment with separate D and V roots -losses or mergers -mixed up somatic and visceral, sensory and motor

PNS evolution of cranial nerves

-involuntary -visceral activity: sensory (afferent) and motor (efferent)

PNS function: Autonomic nervous system

-association neurons connecting sensory and motor -two types: somatic reflex arcs (3 neurons, posture) and visceral reflex arc (one or more sypathetic chain ganglia and ramus communicans = way more connection)

PNS functions: Spinal reflexes

-neural crest in metameric series along spinal cord -ectodermal placodes into brain

PNS nerve development: Dorsal roots (sensory)

-two may form single composite spinal nerve (gnathostomes) -processes accompany embryonic myotome and dermotome (segmental)

PNS nerve development: Dorsal/ventral combo

-neurons from CNS neuroblasts -cell bodies in spinal cord or brain -axonal processes grow to ganglia or to effectors

PNS nerve development: ventral roots (motor)

-fight or flight -increase visceral activity, decrease digestion -controlled by thoracolumbar spinal nerves -adrenaline: increase HR, shut down unnecessary things -only thing controlling adrenal system, turns off when sympathetic stimulation ceases

PNS: Mammalian Sympathetic nervous system

-restores body to resting state -decrease visceral activity, increase digestion

PNS: Mammalian parasympathetic

-Somatic nerves vs Visceral nerves -Afferent/sensory vs efferent/motor

PNS: Nerve types

-associated with vertebral region: cervical, thoracic, lumbar, sacral -named/numbered -ex) C-1

PNS: spinal nerves

-reduces food chemically: pancreatic enzymes via ducts (exocrine; trypsin, amylases, lipases) -regulates carbohydrate metabolism: endocrine function (no ducts); islets of langerhans. Insulin and glucagon.

Pancreas: function

-pharyngeal pouches 3 and 4 -fish: absent (regulate calcium with pituitary) -phibs, reps, birds: nea thyroid, dispersed along veins in neck -mamms: near or embedded in thyroid

Parathyroid

-branchiomeric contribution -axial contribution -muscular sling -dorsal and ventral muscles

Pectoral Girdle and Forelimb (recording?)

-loss of connection to skull -strengthening of girdle and limb -loss/reduction of dermal elements

Pectoral Girdle: Changes to tetrapods

Dermal elements -cleithrum, clavicle, supracleithrum, posttemporal, postcleithrum, interclavicle Endochondral: scapula, coracoid

Pectoral Girdle: Parts

-brachiomeric: mastoid and trapezius -axial (levator scaulae, serratus, rhomboideus) -dorsal (shoulder and upper arm) -ventral (chest and upper arm)

Pectoral girdle/limb

Dorsal musculature -shoulder and upper arm (latissimus dorsi, part becomes teres major) -digit extensors Vental musculature -chest and upper arm (pectoralis --> pectoantebrachialis, pectoralis major, pectoralis minor, xiphihumeralis) -digit flexors

Pectoral: dorsal and ventral contibution (see Appendicular musculature: Tetrapods for dorsal contribution pic)

-only endochondral elements -triradiate, single element (left and right) in some verts (ilium, pubis, ishium) -first appearance in placoderms

Pelvic Girdle

-no muscular sling: fixed to vertebral column, few extrinsic muscles -axial: psoas minor (extrinsic) -dorsal: pubioisciofemoralis internus→ psoas, iliacus, pectineus; iliotibialis → ambiens → sartorius -ventral: pubioisciofemoralis externus → obturator externus and quadratus femoris); gastrocnemius

Pelvic Girdle and Hindlimb

-around acetabulum -attached to vertebral column : sacrum (innominate bone/synsacrum in birds)

Pelvic Girdle: Tetrapod

-papilla amphibiorum (unique): low frequency -papilla basilaris (organ of corti): high frequency -both use neuromasts in sacculus -operculum with opercularis muscle (from levator scapulae) to suprascalupa of pectoral girdle

Phibs: Hearing

-lampreys

Petromyzontida

-spawn in fresh water - ammocoete larva -notochord in adult with vertebral blocks of cartilage (no bone) -two semicircular canals

Petromyzontida: Characteristics

-oval mouths grasp substrate/prey -keratinized teeth to rasp prey -parasitic or non feeding adults

Petromyzontida: Feeding

-fish, phibs, reps, birds: thymus (and parathyroid in reps)

Pharyngeal Pouches: 2nd pouch

-ultimobranchial bodies (blood calcium) -becomes thyroid in mammals

Pharyngeal Pouches: 5th

-become gills or -auditory tube and ear cavity of middle ear (connection btw ear and mouth) -parathyroid gland -thyroid gland -thymus gland -tonsils (lymph system)

Pharyngeal Pouches: Development

-sharks --> spiracle -Others --> tubotympanic recess (auditory tube, ear cavities of middle ear) like mammals

Pharyngeal Pouches: First pouch

-parathyroid, thymus

Pharyngeal pouches: 3rd and 4th

-originally evolved for feeding -later modified for breathing in other aq organisms -only exist briefly in the beginning of development in terrestrial animals

Pharyngeal slits

-striated muscles -from anterior gut (endoderm)

Pharynx: Components

-roof = pharyngeal tonsil -floor = thyroid, part of tongue, lingual tonsil -secondary palate (allows respiration and feeding simultaneously: oral pharyngeal and nasal pharyngeal)

Pharynx: Mammals

-opening to respiratory system -glottis, epiglottis

Pharynx: Tetrapods

-receive and sort food, respiration

Pharynx: function

-chemical specialization for intraspecific communication

Pheromones

-pulmonary artery lost or supplies skin of back and neck

Phib circulation: Lungless phibs

-ascidian larva as vertebrate precursor: paedogenesis -laval stage = motile, has all 3 chordate characters -Adult stage = sessile, some chordate characters lost

Phylum Chordata, Subphylum Urochordata

-Subphylum Urochordata -Subphylum Cephalachordata (lancelet/amphioxus) -Subphylum Vertebrata (Craniata): superclass Agnatha, superclass Gnathostoma

Phylum Chordata: Taxa

-pharyngeal slits -envaginated nerve cord, not hollow or dorsal: solid, found ventrally -stomochord (not solid/tubular): rigid support structure found at anterior end, formed by outpocketing of gut (endoderm) therefore not homologous with nerve cord -larval stage is echinoderm like

Phylum Hemichordata

-dorsal envagination of midbrain -photoradiation -endocrine function: melatonin, modulates activities in progress, melanophores in lower verts, circadian rhythms in mamms/birds

Pineal gland (epiphysis)

-hagfish: endoderm, not homologous? -ammocoete larva: adenohypophysis retains connection to olfactory organ -elasmobranchs: unique pars ventralis (ventral lobe) -teleosts: direct stimulation of adenohypophysis by hypothalamus

Pituitary: in aq verts

-snakes: no pars tuberalis -birds, crocs: no pars intermedia -mammals: some with no pars intermedia

Pituitary: terrestrial verts

-very successful group for a while -hole in armour for nostrils and eyes

Placodermi

-marine reps -euryapsid skull: dorsally-directed single temporal fossa -modified diapsid skull? or not closely related to diapsids?

Plesiosaurs and Ichthyosaurs

-an excess of digits

Polydactyly

-frontal: plane is horizontal -transverse: cross section / vertical -saggital: vertical, down the middle (along the spine)

Positional Terminology: Planes

-axial: head, ribs -appendicular: arms/legs/paired fins -distal: away from body -medial: towards the midline

Positional Terminology: Regional differentiation

Horizontal septum -divides myomeres into hypaxial and epaxial -bifurcating spinal nerves (dorsal, ventral) -dorsal ribs at horizontal septum/myosepta

Postcranial axial musculature: Gnathostomes

-paraxial mesoderm (somites, myotome)

Postcranial axial musculature: embryology

-reduced and specialized for locomotion

Postcranial axial musculature: tetrapods

-increased splitting and reductions

Postcranial musculature: birds, mammals

-more splitting

Postcranial musculature: lizards

-slightly specialized

Postcranial musculature: salamanders

axial and appendicular

Postcranial skeleton (begin studying for midterm 2)

-anterior, posterior, dorsal, ventral

Postitional terminology: directions

-anterior tubules -all verts: transient embryonic form, usually regresses -tubules join = archinephric duct to cloaca -ciliated peritoneal funnels -found in cyclostome larvae, anamniote embryos

Pronephros

-extinct flying archosaurs -pneumatic bones: lightening of skeleton for flight -wings supported by elongated 4th finger

Pterosaurs

-modification in air breathing fishes, uses water to help -exhalation under water, inhalation at surface -4 stroke buccal pump

Pulse Pump

Under water 1. expansion of buccal cavity: air from lungs to buccal cavity 2. compression of buccal cavity: air out buccal cavity Above water 1. expansion via branchial muscles: air flows in 2. Compression of branchial muscles: air from mouth to lungs

Pulse pump: steps

benefits: quicker, can be voided for quick escape if necessary and something else.. rabbits: corprophagy voids cecum first thing in the morning to get nurtrients out of it koalas are nasty: eat feces

Pros and cons of hindgut fermenting mammals

A-notochord B-dorsal hollow nerve cord/spinal cors C-pharyngeal slits D-postanal tail E-subpharyngeal gland; endostyle

Protochordates: Diagnostic characters

-when airbreathing: O2 blood through aa III and IV to systemic tissue -live in poor water conditions: may have higher PO2 in gills than surrounding water = good chance of losing O2 to water through diffusion -shunt blood through aa III and IV, where there are no gills

Protopterus: Shunt

-determinate, spiral cleavage -schizocoelous: cells split apart to become coelom (solid masses of mesoderm split to become coelom) -blastopore becomes mouth

Protostome characteristics

-loss of connection btw posterior cardinal and subcardinal/kidney -blood from tail through kidneys (caudal - renal portal vein) -capillaries of hindlimbs/tail to renal protal veins to capillary bed of kidneys

Renal Portal system

-blood from tail, flows into posterior cardinals dorsal to kidneys -subcardinal veins arise ventral to kidneys to drain them, empty into posterior cardinals

Renal Portal system: Embryo

-mesenchymal sclerotome stream to either side of somite -secondary schlerotome forms between somites (muscle blocks) -vertebral central btw muscle blocks

Reorganization of sclerotome

Epaxial -transversospinalis, longissimus, iliocostalis Hypaxial -dorsomedial, medial, lateral, ventral musculature

Reptile axial musculature

-more terretrial = more active = higher metabolic rate and more O2 required -need efficient separation of oxy and deoxy -two basic patterns of hearts (turts/squams and crocs)

Reptiles: Circulation consequences of being more terrestrial

-well developed stratum corneum -epidermal scales present -reduction in number of glands -thick dermis

Reptiles: Skin

-respiration = gas exchange -ventilation = moving respiratory medium across respiratory surface. Passive diffusion into organism replaced by respiratory pumps.

Respiration vs ventilation

-SA: increase A for diffusion by increased folding, subdivisions -Distance: greater distance = longer time to diffuse, decrease thickness! -Moist: facilitates gas exchange (thin, moist, convoluted surfaces best!)

Respiratory System: Features

-dorsal to digestive tract -physostomous and physoclistous

Respiratory surfaces: Gas Bladder

-cutaneous respiration -done by aq and terrestrial verts

Respiratory surfaces: Integument

-hinge like transverse joint in skull -anterior braincase raises relative to posterior part -also found in primitive labyrinthodonts -lift up front part of head as well as lowering the jaw = larger gape

Rhipidistian Cranial Kinesis

-Notochord persists -ossified neural and haemal arches and centra -cranial kinesis -labrynthodont teeth -predatory adaptations -cartilage replaced by bone, does not become bone

Rhipidistian Fishes

-no tympanum -squamosal bone to stapes -pectoral girdle to operculum

Salamanders: Hearing

-carry message to CNS -afferent: towards brain or spinal cord -neural crest origin: neural crest cells go out, help make sensory structures and then grow back

Sensory neurons

-monitor internal/external environment -translate environmental energies into nerve impulses

Sensory organs: Function

-adds membranes/shell -post fert -birds/reps: albumen + shell membrane + calcareous outer coat

Shell gland

-mononucleate, short, fusiform -form sheets, electrically-coupled -contractions may be passed down as a wave

Smooth muscle cells: Morphology

-visceral functions: peristaltic action of gut -involuntary -slow, sustained contractions -hormone control

Smooth muscle: function

-cervical and lumbar remnants only -thoracic region defined by ribs -most meet the sternum

Specialization of ribs: Mammals

-typhlosole -prolong passage of food for max absorption

Specializations of the intestines: Ammocoete

-bacterial fermation -bony fishes: pyloric, up to 100s -tetrapods: none to tow -birds: one or several -hindgut fermenting mammals

Specializations of the intestines: Intestinal caeca

-scroll valve -coiled muscle flap -increase SA

Specializations of the intestines: Ostracoderms

-rectal clands: aid in salt regulation -spiral valve: coils around and pushes food around. prolongs passage of food

Specializations of the intestines: Sharks

-Sebaceous: oily substance, genitalia for lubrication, waterproof fur -Sweat/sudoriferous: unique to mammals -Scent: probably arose from scent glands, produce pheromones for social communication -mammary: from sebaceous or sweat glands, produce nutritive liquid, 3 major forms

Specialized Glands: Mammals

-for mating, maybe defense -femoral gland: pelvic region by the femur -scent glands: jaws or cloaca

Specialized glands: Reps

-rugae (folds in relaxed stomach, can expand when more space is needed) -glandular epithelium -3 sections: cardia, fundus (largest part, lots of glands), pyloris (lots of mucous = neutralize acid) (front to back) -cardiac and pyloric sphincters (smooth muscle, for control)

Stomach: Components

-rare in protochordates, agnathans -poorly developed in some fishes

Stomachs: in things other than mammals

-outer covering forms sheath around nerve -often nerve, artery and vein run together = connective covering merges

Structure of nerves and spinal cord: epineurium

-endostyle homologous with thyroid gland -Thought to be fixing iodine

Subpharyngeal Gland

-notochord -dorsal hollow nerve cord, but no brain -pharyngeal region

Subphylum Cephalochordata: Amphioxus

-synsacrum = fused vertebrae -innominate bone = fused girdle bones (not part of vertebral column)

Synsacrum + Innominate bone

-Fish: taste all over body surface -tetrapods: taste receptors, mouth and pharynx

Taste: in fish and tetrapods

-mechanical digestion -help proteolases get into food -enamel (hard), dentin, cementum (connection btw tooth and bone) -placoid scales also have these tissues. teeth come from the same place.

Teeth

-carnassial (premolar, molar) -tusks (incisors) -pedicelate (phibs: the crowns of the teeth are separated from the roots by a zone of fibrous tissue) -labyrinthodont (Strongly folded tooth surface, involving infolding of the dentin and enamel of the teeth, so that a cross section resembles a classical labyrinth (or maze), hence the name of the group)

Teeth: Other variations

-lost enamel, dentine and vascular bone -scales only formed by avascular lamellar bone -cycloid and ctenoid (ctene or projections off the back) -scales do not pierce epidermis

Teleost Scale

A-Sinus venosus B-SA valve C-Atrium D-AV valve E-Ventricle F-Bulbous valve G-Bulbous arteriosus (non-contractile) -vagus nerve innervation

Teleosts: Heart

-4 pr aa arches service gills (III - VI, I and II lost) -afferent and efferent arteries for each gill -blood in aa III tends to pass to the head rather than going with main aortic flow

Teleosts: gills

1. Upper: squamosal and postorbital 2. Lower: jugal and quadratojugal

Temporal arches

-connective tissue -epimysium (around the tissue) to periosteum (around the bone) -aponeuroses (bundled, thick) and fascia (sheets) -delicacy of control -low energy

Tendons

CNS -axon bundle = nerve tract -perikaryon bodies = nucleus PNS -axon bundle = nerve -perikaryon bodies = ganglion

Terminology

-chiridium -pectoral: humerus, radius, ulna -pelvic: femur fibula, tibia -manus, pes: carpals/wrist, tarsals/ankle, metapodials (metacarples/metatarsals), phalanges (digits)

Tetrapod Limb

-true: do meet the sternum. go all the way around the body -false: do not meet sternum. meet rib in front -Floating: doesnt meet sternum or rib in front

Tetrapod Rib Classification

-two elements: Vertebral/coastal = dorsal and bony Sternal = ventral/cartilaginous -create hinge for expansion of cavity

Tetrapod Ribs: True Ribs

-reptilian divisions -numerous splits to give rise to new muscles

Tetrapod axial musculature: Mammals

-horizontal septum lost/indistinct -limbs provide propulsion -hypaxial associated with rib cage for breathing

Tetrapod axial musculature: Reptiles

-epaxial = dorsalis trunci -hypaxial = a few muscles but still simple -locomotion similar to fish

Tetrapod axial musculature: salamanders

-reduction of phalanges: number of digits stabilized at 5 -hyperphalangy: number of phalanges (elongation) per digit increases

Tetrapod limb evolutionary trends

-four feet, with modifications -chiridium -earliest primarily aquatic -earliest retain cranial kinesis

Tetrapods

-cranial supply -dorsal aorta btw III and IV reduced/lost = separation of cranial and body segments of dorsal aorta -if it persists = carotid duct -AA III = ass w anterior part of dorsal aorta = internal carotid artery -Ventral aorta stem leading to aa III = common carotid artery

Tetrapods: AA III

-large, bilaterally developed in lower tetrapods = systemic arch (main channel from heart to body) -in later tetrapods = asymmetrical

Tetrapods: AA IV

-V lost, may not even develop in embryo -VI = blood to lung (pulmonary artery), dorsal part = ductus arterisus in embryo

Tetrapods: AA V and VI

-pump: forcing, aspiration = moves blood through vessels -channels oxy and deoxy blood to appropriate places -prevents mizing of deoxy and oxy blood

The Heart: Summary

-anterior: iris to cornea = aqueous humor -posterior: iris to lens = aqueous humor -vitral: behind lens = vitreous humor

The vertebrate eye: Chambers

1. photosensitive cells in deepest cell layer -rods: black and white, cones: color (some fish, phibs, reps, birds, primates) 2. Middle cell layer -area of synapse of photoreceptors 3. Surface cell layer -inverted retina a space saving solution? keep eyes as large as possible in small organisms (space btw lens and photosensitive cells to focus)

The vertebrate eye: Retina (3 layers)

1. choroid -large, pigmented region, highly vascularized -tapetum lucidum in some: re-stimulates light sensitive cells 2. Cilliary body -vision accomodation/focus: change lens shape -smooth muscle attaches to lens via suspensory ligament 3. Iris -thin continuation of uvea around lens -smooth musceles act as diaphragm in mamms: regulate light (pupil)

The vertebrate eye: Uvea (3 parts)

-indentation of retina -cones -area of sharpest focus -some hawks with 2!

The vertebrate eye: fovea

-clear at front: cornea -capsule of connective tissue -muscle attachment -scleral ossicles in birds, reps, bony fish: aid in keeping eyeball round

The vertebrate eye: sclera

Endotherm -associated with metabolic rate -elevate oxygen consumption and heat production Ectotherm -dont produce heat though -lizard: at high temps, increases oxygen consumption

Thyroid: Fxn in endotherms and ectotherms

-hormones stored in follicles -teleosts: dispersed masses of follicles -others: single or doble lobed organ in throat

Thyroid: Gnathostomes

-birds and mamms need normal levels of thyroid hormone for normal growth -underproduction = stunted growth -overproduction = heightened activity, bulging eyes, weight loss

Thyroid: Growth (birds + mamms_

-hair or feathers -shedding of the skin

Thyroid: Molt

-gonad maturation in all except phibs

Thyroid: Reproduction

Fish and reps -growth -in salmon parr: thyroid enlarges prior to transformation to smolt Phibs -arrest growth of larvae, promote metamorphosis

Thyroid: fish, reps and phibs

-endostyle (chordate character) -thyroid is a vertebrate character

Thyroid: homolog?

-bidirectional -new and old air mix (never 100% fresh) -air into trachea, then to lungs, then back out trachea -30% lung volume = dead space

Tidal ventilation

-elpistostegalian fish -scales and fins -shallow water habitat: eyes on top of head, flattened body) -functional neck (separation of pectoral girdle from skull) -tetrapod ribs (breathing, support) -modified inner ear -functional wrist

Tiktaalik roseae

-fleshy and mobile, firm and fixed -lacking in most fish -lingual feeding: sticky tongue protruded -jacobsens organ (snakes, lizards) -mammalian carnivores: keratinous roughening for rasping flesh

Tongue

-from hyobranchial musculature -attached to hyoid apparatus (from gill arches, was once supporting the gills)

Tongue: Tetrapods

-firmly in socket -cementum helps form crown in some other mammals

Tooth anatomy: Thecodont

-enamel organ in epidermis secretes enamel -mesenchyme (neural crest) supply cells (osteoblasts) to secrete dentin -dermal papilla with odontoblasts in dermis

Tooth development

-group of axons in CNS -carry info up and down spinal cord -part of white matter

Tracts

-somatic afferent (sensory): from skin of lower jaw region, teeth of mandible, lower lip, tongue and ear region -visceral/somatic efferent (branchial motor) to the muscles of the mandibular arch -from neural crest

Trigeminal: Mandibular branch

-somatic afferent (sensory) -from skin of upper jaw regions, maxillary teeth, upper lip and palate -from neural crest

Trigeminal: Maxillary branch

-somatic afferent (sensory) -from doral and lateral head, eye and nasal region -from ectodermal placode

Trigeminal: Opthalmic branch

-formation of nephric tubules: anterior, middle, posterios of nephric ridge (develop in sequence) -results: loss, merge, replacement in adults -connected to coelom anteriorly only via peritoneal funnel

Tripartite Kidney Organization: development

-high frequency -electric fishes: generate electricity from muscles and project around the body -receives individuals own electric discharge

Tuberous receptor

-single, but with 3 interconnected compartments: cavum venosum, c. pulmonale, c. arteriosum -interventricular canal

Turt, snake and lizard heart: Ventricle

-sinus venosus reduced -atrium completely divided -L and right AV valves -conus arteriosus of embryo = adult forms base of trunks of pulmonary, L and R aortae (arch IV)

Turt, snake, lizard: heart

-Arteries/arterioles: carry blood from heart, not all oxy (pulmonary artery) -veins/venules: carry blood to heart (not all deoxy = pulmonary vein) -capillaries: btw veins and arteries, site of gas exchange

Types of vessels

-pharyngeal pouch 5 -throat region in birds, fish, phibs, reps -absent in cyclostomes -mamms: incorporated into thyroid -from neural crest (embryonic source)

Ultimobranchial body

-water enters through buccal cavity -flows through pharyngeal curtain -exits pharyngeal slit

Unidirectional Ventilation

-ureters directly into bladder -urethra from bladder to exit body

Urinary Bladder: mamms

-chondrichthyes: mesodermal, non-cloacal, small, from urinary ducts -teleosts: pocket of embryonic cloaca

Urinary bladder: development in aq verts

-outpocketing of cloaca -new structure in phibs -lost in snakes, birds -highly distensible, smooth muscle

Urinary bladder: in tetrapods

-least specialized amphibian -larvae similar to adult, but with gills -axial musculature for locomotion -small limbs

Urodela/Caudata

-mesonephric duct drains mesonephric kidney, later regresses => metaneprhic kidney w ureter -mullerian duct forms oviduct

Urogenital ducts: Female amniote embryos

-mesonephric duct becomes vas deferens + epididymis

Urogenital ducts: Male amniote embryos

-smooth muscle walls, expansion -shelled eggs or embryos -placenta

Uterus

-transverse process: all the things that stick out from the arches and the centra -parapophyses: ventral attachment of the rib -basapophyses: remnant of haemal arch, rib may attachment -diapophyses: upper head of the rib attachment -zygapophyses: pre and post, overlap each other. Stability of vertebral column.

Vertebrae: Processes

-central linked into column -shapes of surfaces affect properties

Vertebral column

-increased regionalization -loss of ribs: more efficient running

Vertebral column: Changes from aq to terrestrial environment

-discrete, repeating units -protect spinal cord, dorsal aorta -site for muscle attachment -suspension of body, terrestrial locomotion

Vertebral column: functions

Primitive -unpaired neural spine -paired neural arch -paired interneural arch -paired intercentra: forms vertebral body -paired pleurocentra: forms verterbral body -paired haemal arch -paired interhaemal arch

Vertebral elements

-bilaterally symmetrical -coelomates -triploblastic (3 germ layers) -deuterostomes

Vertebrate Characteristics based on embryonic development

-composite -3 parts: splanchnocranium, chondrocranium and dermatocranium

Vertebrate Skull

-paired appendages -neural crest and ectodermal placodes -closed circulatory system with chambered heart -integument with epidermal and dermal layers

Vertebrate characters (in addition to chordate characters): Body

-excretory system with nephrons -supharyngeal gland developed into thyroid

Vertebrate characters (in addition to chordate characters): Organs

-absent in fish and phibs -external auditory meatus -opens to exterior via external orifice -elongated in birds, mamms -mamms have pinnae

Vertebrate ear: External ear

-first vert (presence of bone) = ~ 500 mya -probably active -no paired appendages yet but possessed jawless mouth

Vertebrate origins

-filtration kidneys with large volumes of glomerular filtrate -marine vertebrates mostly hyposmotic (dehydration) -modifications for marine environment via urea in blood, salt glands, loss of glomeruli

Vertebrate origins = freshwater? Kidneys?

-Reptiles: turtles, tuatara, crocs, snakes, lizards -Birds: ratites, neornithines -Mammals: monotremes, marsupials, eutherians

Vertebrates: Groups

-sound reception -part of sacculus -specialized: becomes separate organ to detect sound instead of motion

Vesibular apparatus: Lagena

-central laeyer -tunica intima: innermost layer, epithelial cells lining lumen -tunica media: middle layer, differs in veins and arteries, elastic fibres + smooth muscle (elastic recoil, smoothly pushing blood along) -tunica adventitia: outermost layer, fibrous connective tissue

Vessel structure

-balance/equilibrium -part of inner ear = inside skull -filled with endolymph, surrounded by perilymph (cerebrospinal fluid essentially) -arises from otic placode -external connection in elasmobranchs = endolymphatic duct

Vestibular apparatus

-sacculus and utriculus -maculae: ex) sacculus -concretions: otoliths!! -gravity -linear acceleration

Vestibular apparatus: chambers

-endolymph inside canals -respond to angular acceleration, rotation -oriented in 3 planes (or 2) -contain cristae = modified neuromast

Vestibular apparatus: semicircular canals

-nerve fibres travel through 1+ sympathetic chain ganglia and through ramus communicans -regulates HR: baroreceptor pathway

Visceral reflex arc (autonomic)