Lectures After Test 1 Flashcards
components of shark skull
brain case and palatoquadrate cartilage
shark skull - occipital region
posterior; surrounds foramen magnum and includes occipital condyles
shark skull orbital region
otic capsules, orbital, sphenoidal
brain case containing nasal capsules
ethmoid region
brain case ventral articulation
with palatoquadrate
3 parts of basic bony vert skull
one element dermal, 2 elements dermal/endochondral combination
skull roof
dorsal cover of skull, nearly solid with openings for mouth/eyes/pineal, primitively nitched posteriorly, paired bones
5 groups of skull roof bones
tooth bearing marginal, midian, circumorbital, temporal, cheek
bones of tooth bearing marginal series
premaxillary, maxillary
bones of median series
nasal, frontal, parietal
bones of circumorbital series
jugular, lacrimal, prefrontal, postorbital, postfrontal
bones of temporal series
tabular, supratemporal, intertemporal
bones of cheek series
squamosal, quadratojugal
composition of bones of palatal complex
in roof of oral cavity; paired, mostly dermal, some visceral endochondral
early tetrapod dermal palatal bones
pterygoid, vomer, palatine, ectopterygoid
early tetrapod visceral endochondral palatal bones
palatoquadrate, quadrate, epipterygoid
early tetrapod lower jaw articulation
palatal complex with lower jaw via quadrate, basal brain case articulation between basisphenoid and epipterygoid
composition of bones of early tetrapod brain case
not all paired, mostly somatic endochondral, one dermal
dermal bone of early tetrapod brain case
parasphenoid; forms in skin on roof of oral cavity, ventral brain case
4 bones surrounding foramen magnum
supraoccipital, basioccipital, paired occipitals
2 paired bones associated with otic capsules - inner ear
opisthotic, prootic
basisphenoid
median, ventral, anterior to otic region, covered ventrally by parasphenoid, basal articulation with palatal complex via basipteygoid
sphenethmoid
median ossification of sphenoid/ethmoid regions, trough shaped, contains olfactory nerves
progression of skull types
early tetrapod, basal reptile, early synapsid, non mammalian therapsid, mammalian
characteristics of somatic muscles
derived from myotomes somites, always striated, mostly voluntary, innervated by somatic motor fibres, in appendages
characteristics of visceral muscles
derived largely from hypomere, smooth or striated, innervated by visceral motor fibres, in gut
characteristics of fish axial musculature
series of myomeres developed into zig zag important for locomotion, derived from myotome
epaxial muscle of fish
dorsalis trunci
reptile epaxial musculature
(closest to spinal column to farthest) iliocostalis, longissimus dorsi, transversospinalis
tetrapod hypaxial musculature
subvertebral, lateral, ventral series, insertion at aponeurosis
tetrapod subvertebral musculature series
underneath transverse processes of vertebrae
tetrapod ventral musculature series
rectus abdominus
tetrapod lateral musculature series
external oblique, internal oblique, transversus abdominus
function of connective tissue
produce same contractile strength and protect against breakage and torsion, decreases relative length of contraction
embryologic derivation of cranial muscles
somatic axial from epimere, visceral branchiomeric from neural crest
embryologic derivation of extrinsic eye muscles
3 preotic somites
resulting eye muscles of 1st myotome and innervation
ventral oblique, medial, dorsal, and ventral rectus; innervated by oculomotor nerve
resulting eye muscles of 2nd myotome and innervation
dorsal oblique innervated by trochlear nerve
resulting eye muscles of 3rd myotome and innervation
posterior rectus innervated by abducens nerve
coracoarcual muscles
in fish opens jaw, in tetrapods modified as throat musculature including tongue
branchiomeric musculature
striated, visceral, associated with visceral arches and later face/shoulder/jaw, derived from mesenchyme
evolutionary progression of gill/branchial arch musculature
levators fuse into cucullaris and attach to pectoral girdle, loss of superficial constrictors and interbranchials after operculum develops, loss of levators; then trapezius replaces cucullaris and all other muscles lost or reduced to muscles of larynx
evolutionary progression of muscles of hyoid arch
most muscles lost as hyoid turns into jaw support, most fish retain superficial constrictor and levator, tetrapods modify superficial constrictor into sphincter colli and depressor mandibulae, mammals lose depressor mandibulae while sphincter colli modified into facial muscles and digastric m
evolutionary progression of muscles of mandibular arch
levators lost as upper jaw fuses with braincase, intermandibularis name changed to mylohyoid in mammals
changes in mammalian jaw
mammals moved dermal skull bones inside musculature so lower jaw shortens, old jaw joints become ossicles, new jaw process
3 main muscles closing mammalian mouth
temporalis, masseter, pterygoideus
mammalian depressor mandibulae
function replaced by digastric derived from sphincter colli and mylohyoid
development of pharyngeal slits
in pocketing of endoderm and ectoderm until they make a passage
pharyngeal slit condition of cyclostomes
spherical pouches with small circular openings to external environment either separate for each pouch or joining in a common opening
flap like valve separating lamprey esophagus from respiratory tract
velum
lamprey gas exchange condition
when not eating lamprey ingests water through mouth like normal fish condition, when eating velum closes so blood doesn’t go near gills
hagfish gas exchange condition
eats solid food so no need for isolated respiratory tube, gas exchange continues when attached to prey, nasal opening pumps water past gills
comparison between shark and teleost pharyngeal slits
both are vertical but teleosts have operculum so one opening, while sharks have separate openings for each slit all with own musculature
why are teleost pharyngeal slits more efficient at gas exchange than sharks
operculum stops need for interbranchial septa which allows for different arrangement of gills allowing as much water as possible to pass over gill lamellae
development of tetrapod lungs
analogous to gills, pharynx reduced, entrance to lungs through glottis i.e. ventral floor of pharynx, lungs develop from from pharynx embryologically
characteristics of the teleost swim bladder
dorsal, functions in buoyancy not gas exchange, not always connection between pharynx and swim bladder, most likely a specialization of ancestral lungs rather than ancestral to lungs themselves
characteristics of lungs
trachea > bronchi > bronchioles > alveoli where gas exchange happens, more derived = more surface area
bird respiratory system
lungs + air sacs distributed throughout trunk and some bones, air first enters more posterior air sacs and then moves forward to lungs then anterior sacs and out so that there is constant air distribution - more efficient than amphibians/mammals
characteristics of bird lungs
no alveoli, parabronchi instead which are tiny tubes, allows for one way, constant, flow of air wasting less air
cutaneous respiration
gas exchange through skin, usually secondary ability so mostly still have lungs
functions of digestive system
transport, mechanical digestion, chemical digestion, absorption
divisions of foregut
pharynx, esophagus, stomach - distinct internal epithelia, divided by cardioesophageal sphincter
divisions of small intestine
duodenum following pyloric sphincter, jejunem, ileum, ends at iliocecal valve
characteristics of large intestine
may be divided into ascending, descending, transverse, sigmoid and end in rectum which only exits digestive tract or cloaca which also exits other systems
functions of foregut
pipe taking food to where its treated, little chemical digestion, little specialization before derived animals
functions of stomach
only develops in jawed vertebrates as a storage area to feed food into intestine at rate at which it absorbs chemicals, size reduced by peristaltic contractions, jaws/stomach allow for large meals and then periods without food, in derived animals also chemical digestion
2 part stomach of birds
proventriculus - thin walled and glandular (chemical digestion); gizzard - thick walled and muscular, contains grit (intentionally ingested pebbles) to grind food (bc no teeth)
4 chambered system of ruminant animals
esophagus - rumen, reticulum, omasum; stomach - abomasum
why is a complex stomach necessary?
plant matter hard to digest but very easily obtained, one or more chambers carry microorganisms that digest plant matter
process of ruminant digestion
rumen and reticulum = fermentation chambers for breakdown of cellulose and production of useful material, food regurgitated as cud, further broken down in mouth, then swallowed into omasum and abomasum (mouth > rumen > mouth > reticulum > omasum > abomasum)
functions of hindgut
usually most of chemical digestion/absorption, large intestine = storage, water resorption
4 methods of increasing intestinal surface area as animals get bigger
lengthen (teleosts/tetrapods), spiral valve (primitive jawed fish), cecum (tetrapods), roughen internal surface
glandular organs of the gut
liver, spleen, pancreas
characteristics of liver
largest gland, typically divided into lobes, attached to cardiovascular system by hepatic system, develops as ventral outgrowth of anterior intestine (endoderm), connects to gut via bile duct (with gall bladder)
functions of liver
storage and manufacture of materials used by the body (from intestine), production of RBCs in fetus, disposal of old blood cells, detox of blood, production of bile and bile salts for lipid emulsification
characteristics of pancreas
develops from one ventral and one dorsal outgrowth of intestine, has one or more ducts leading to duodenum
functions of pancreas
produces pancreatic juice (alkaline enzymes), exocrine activity, islets of langerhans produce insulin and glucagon for endocrine activity
characteristics of spleen
not a gland, not part of digestive system but happens to be embryologically derived from endoderm, major embryonic blood producing organ (taken over by bone marrow in mammals), storage and destruction of blood corpuscles
development of mouth
in pocketing of ectoderm then boundary between endoderm and ectoderm breaks down, becomes opening to oral cavity
characteristics of tongue
true tongue essentially in terrestrial verts (different from rasping/primary tongues - once gills are lost), formed from hypobranchial musculature based at hyoid apparatus
functions of tongue
manipulate/obtain food, swallowing, may develop taste buds, vomeronasal function
types of oral glands
fish: few mucus glands; lamprey: pair of anticoagulant glands; terrestrial: salivary glands, sometimes poison
characteristics/functions of thyroid
begins as mid ventral outgrowth of pharynx and loses connection with it, can be scattered follicles or discrete glands, can migrate posteriorly in some animals; produces hormones and metabolizes iodine
characteristics/functions of thymus
develops from some pharyngeal pouches in all verts, located at base of neck, stem cells that differentiate into lymphocytes - involved in immune response (prominent in young reduced in adults)
teeth of cyclostomes
not true teeth, denticles protruding from disk, keratinized cones used to cling to flesh
teeth of gnathostomes
true teeth, mainly marginal series, may be secondarily lost, can also be palatine, vomerine, pharyngeal teeth; epidermal and dermal origin
homodont
reptiles, fishes - teeth all the same usually conical and simple
heterodont
mammals - differentiated teeth in different regions of oral cavity
patterns of tooth attachment to jaw bones
acrodont, pleurodont, thecodont
parts and materials making up true teeth
crown, root, pulp cavity; enamel, dentine, cementum
polyphyodonty
teeth continuously replaced in organized waves ensuring no one area becomes toothless, most lower verts
diphyodonty
two sets of teeth - most mammals
monophyodonty
one set of teeth that grow continuously as they are worn down throughout life - whales, sloths
types of mammalian teeth
incisors, canines, premolars (have juvenile precursors), molars (not replacement teeth)
functions of cardiovascular system
transportation of material to and from cells, circulation of hormones, immune system, repair of injured tissue
basic cardiovascular condition in fish
blood with low O2 goes heart to gills, blood filled with O2 goes to gut and back to heart via liver
basic cardiovascular condition in tetrapods
low O2 blood goes to heart to lungs, back to heart and out to body
4 systems of veins
subintestinal/hepatic, dorsal cardinal veins/vena cavae, abdominal veins, pulmonary veins
subintestinal veins
first system to arise in embryo, paired initially extending along gut surface and coalescing into single vein, initially: anteriorly heart to ventral aorta and posteriorly gut to heart; after liver develops: divides anterior part into hepatic vein, divides posterior part into hepatic portal vein
hepatic vein conditions
in most fishes hepatic vein - heart-liver, lungfish and tetrapods - part of hepatic vein incorporated into posterior vena cava so hepatic vein only defined as part that goes liver-post vena cava
cardinal veins in chondricthyeans and actinpterygians
replaced by vena cavae in higher forms, largely posterior/anterior paired veins in embryos, collect into common cardinal and into sinus venosus
cardinal veins in lungfish and tetrapods
posterior cardinal becomes less important so common cardinal becomes continuous with anterior cardinal, subclavian feeds into common cardinal so that dorsal veins begin to look like anterior vena cava
veins from head to heart in tetrapods
leaves head posteriorly through internal/external jugulars and subclavian more posteriorly, then through left/right anterior vena cavae or sometimes just right since left disappears (mammals forms brachiocephalic and AVC)
posterior cardinals in agnathans and sharks
in agnathans posterior cardinal drains blood from caudal, kidney, dorsal parts of body; in sharks renal portal vein develops
posterior cardinals in lungfish and urodeles
changes toward posterior vena cava by hepatic vein connecting to right posterior cardinal through a vein called posterior vena cava so that posterodorsal body parts have multiple return paths to heart
cardinal veins in lower tetrapods
loss of posterior cardinals, anterior cardinals reduced to azygous veins as anterior vena cava develops
cardinal veins/vena cavae in mammals
renal portal system lost, some mammals lose left anterior vena cava so azygous remains as hemiazygous
abdominal veins
in adult primitive verts and embryos of all verts, extend along anteroventral body wall
abdominal veins in chondricthyeans
abdominal vein receives subclavian and iliac veins
abdominal veins in actinopterygians and adult birds
NONE but iliac connects to renal portal and a vein goes from renal portal to liver, probably derived from abdominal
abdominal veins in lungfish, amphibians, reptiles
single median vessel, part of hepatic portal system, connects with iliac, renal portal
abdominal veins in mammals
NONE (also no renal portal) iliac goes into posterior vena cava
pulmonary vein
absent in most fish bc no lungs, but in lungfish pulmonary bypasses sinus venosus and enters heart through atrium, the condition existing in all higher verts
heart
formed from sub intestinal vein, posteriorly hepatic and hepatic portal veins, anteriorly becomes aorta/very muscular to pump blood
primitive heart condition and development
a tube with 4 chambers (same as shark) arranged in sequential order with valves to prevent back flow; chambers fold in on themselves in an S shape
tetrapod heart
sinus venosus and conus arteriosus become parts of large vessels, and atrium/ventricles get subdivided so that the heart can be a double pump
steps to building a double barrelled heart
separate entrances to heart for body and lungs, separation of atrium/ventricle into 2 chambers - lungfish incomplete separations, amphibians 2 atria 1 ventricle
heart chamber condition in turtles, snakes, lizards
partial septa in ventricle
heart chamber condition in reptiles
ventricle partially subdivided into dorsal and ventral, dorsal further incompletely subdivided
heart chamber condition in crocodiles
ventricles divided, gap at base of arterial trunks at foramen of panniza shunts blood from left ventricle to left systemic artery - foramen can be closed and is useful for diving
heart condition in birds and mammals
completely separated chambers, completely separate flow of ox and deox blood
lymphatic system
secondary system supplementing veins returning excess interstitial fluids from tissues to heart that has left capillaries due to osmotic pressure
arise from heart in pairs and pass through gill bars as efferent or afferent
aortic arches
extends downwards and forwards from efferent branchial artery, supplies oxygenated blood to lower jaw
external carotid artery
aortic arch 1, between mouth and spiracle
mandibular artery
aortic arch 2, between spiracle and first normal slit
hyoid artery
role of kidney
major excretory organ in vertebrates, rids body of nitrogenous waste, major role in water balance
early kidney embryology
mesomere develops into nephrotome which develops from front to back - 1 nephric unit/body segment
holonephros
idealized primitive kidney formed from longitudinal series of nephric units draining into archinephric duct which at that point = wolffian duct
what exists instead of holonephros
sometimes almost approach holonephros condition but in hagfishes and higher verts anterior tubules degenerate,
pronephros
anteriormost holonephros that develops into archinephric duct
opisthonephros
posterior to pronephros in idealized primitive and later develops an increased # of tubules, a loss of segmentation, and a concentration to posterior of body into kidneys, and anterior part to associate with testis by archinaephric
amniote primitive kidney condition
nephrotome develops into segmentally arranged tubules at anterior end, 1st 3 join into pronephros > archinephric, leads to developing cloaca
mesonephros
posterior to pronephros, develops to join existing archinephric, but acts as a functional kidney for embryonic development
metanephros
develops from tubules posterior to mesonephros, unsegmented mostly spherical mass that develops large # of tubules in late embryo and adult, tubules do not empty into archinephric but into newly developed ureter
anamniote kidney condition
no metanephros > ureter, drained by archinephric and accessory ducts
cyclostome urogenital duct condition
no gonadal ducts, sperm and ova shed directly into body cavity, archinephric used for urine by kidney
gnathostome/teleost urogenital duct condition
sperm and ova pass to outside via closed tubes but ova shed into coelum and funnelled into duct lying close by, archinephric used for urine by kidney
female gonadal ducts
ovarian or mullein that eventually develop uterine tube and uterus in various forms by infolding or splitting epithelium near archinephric
male gonadal ducts
testes usually taps into archinephric, develops anteriorly in coelom (near part of kidney that loses urinary function) along with seminiferous tubules, which may connect with anterior kidney
anamniote urogenital duct condition
archinephric used for sperm conduction, ova through mullerian duct, urine passes through accessory ducts to caudal archinephric or cloaca
amniote urogenital duct condition
archinephric develops into ductus deferens for sperm conduction, oviduct conducts ova (female archinephric degenerates), ureter used for urine
motor neurons
efferent; develops from CNS
sensory neurons
afferent; develops from neural crest
4 nerve fibres of the PNS
somatic sensory, somatic motor, visceral sensory, visceral motor
function of somatic sensory nerves
from skin and sense organs of muscles, tendons
function of somatic motor nerves
to somatic musculature
function of visceral sensory nerves
from gut
function of visceral motor nerves
to gut muscles, blood vessels, glands
visceral efferent system
efferent > autonomic / special branchial > parasympathetic / sympathetic
characteristics of spinal nerves
usually paired and in every segment, formed from dorsal and ventral roots at spinal cord (primitively unfused), divides into rami upon leaving vertebral canal (mostly somatic fibres)
mammalian arrangement of fibres by root
dorsal - somatic and visceral sensory, ventral - somatic and visceral motor
lower amniote, fish, amphibian arrangement of fibres by root
dorsal - somatic, visceral sensory and visceral motor, ventral - somatic and visceral motor
amphioxus arrangement of fibres by root
dorsal - somatic motor, ventral - somatic and visceral sensory, visceral motor
central nervous systems
brain and spinal cord, formed from rolling neurectoderm i.e. early chordomesoderm along mid dorsal line into neural tube and then front enlarges becoming brain
primitive tripartite brain sections
prosencephalon, mesencephalon, rhombencephalon
functions of primitive tripartite brain sections
smell, sight (later switches to cerebrum), lateral line (and later hearing)
basal vertebrate 5 part brain sections as they develop from tripartite sections
prosencephalon - telencephalon, diencephalon; mesencephalon; rhombencephalon - metencephalon and myencephalon
telencephalon
olfactory bulbs; cerebrum
diencephalon
thalamus, epithalamus, hypothalamus
mesencephalon
optic lobes
metencephalon
cerebellum and pons in mammals
myencephalon
medulla oblongata
ventricles associated with brain sections
telencephalon - 2 lateral; diencephalon - 3rd, mesencephalon - optic (until location changed), metencephalon - cerebellar; myencephalon - 4th ventricle
3 types of cranial nerve fibres
special branchial motor, special visceral sensory (taste), special somatic sensory (nose, eyes, ears/lateral line)
3 types of nerves (cranial and spinal fibres combined)
special sensory, dorsal root, ventral root
the 13 cranial nerves
0 terminalis I olfactory II optic III oculomotor IV trochlear V1 profundus V2,3 trigeminal proper VI abducens VII facial VIII acoustic IX glossopharyngeal X/XI vagus/accessory XII hypoglossal
ventral root cranial nerves
i.e. somatic motor; oculomotor, trochlear, abducens, hypoglossal
special somatic sensory cranial nerves
olfactory, optics, auditory and bonus lateral line nerves
muscles innervated by oculomotor
ventral oblique, dorsal, ventral, medial rectus
muscles innervated by trochlear
dorsal oblique
muscles innervated by abducens
lateral rectus
dorsal root cranial nerves
trigeminal, facial, glossopharyngeal, vagus/accessory
nerve of mandibular arch
trigeminal
nerve of hyoid arch (and spiracle when present)
facial
nerve of first branchial arch
glossopharyngeal
nerves of last 4 branchial arches
vagus and accessory
