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)