Comparative Anatomy Sensory and Endocrine Organs Note Set 14 Chapter 15 & 17

Comparative Comparative AnatomyAnatomy

Sensory and Endocrine Sensory and Endocrine OrgansOrgans

Note Set 14Note Set 14

Chapter 15 & 17 Chapter 15 & 17

Sense OrgansSense Organs

Monitor external & internal Monitor external & internal environmentenvironment

Somatic or visceral receptorsSomatic or visceral receptors Specific or generalSpecific or general

Special Somatic ReceptorsSpecial Somatic ReceptorsNeuromastsNeuromasts

In skin of fish and amphibiansIn skin of fish and amphibians Monitors mech, elect, and Monitors mech, elect, and

chem stimulichem stimuli Ampullae of Lorenzini in Ampullae of Lorenzini in

shark snoutshark snout

Figure 16.1: Ampullae of Lorenzini in shark.

Special Somatic Receptors Special Somatic Receptors (cont.)(cont.)

NeuromastsNeuromasts Pit organs along Pit organs along

shark gill regionshark gill region Lateral line canalLateral line canal

Linear seriesLinear series Derived from Derived from

ectodermal placodes ectodermal placodes Figure 16.2: External openings of neuromast organs in Squalus.

Figure 16.3: Neuromast organ and lateral line canal in a fish.

Special Somatic ReceptorsSpecial Somatic ReceptorsMembranous Labyrinth Membranous Labyrinth

Vertebrates have pair of Vertebrates have pair of fluid filled membranous fluid filled membranous labyrinthslabyrinths

Filled with endolymphFilled with endolymph Surrounded by Surrounded by

perilymphperilymphFigure 16.5: Membranous labyrinths of human.

Figure 16.4: Left membranous labyrinth of craniates; semicircular canals (1, 2, & 3), sacculus (s) and utriculus (u).


Membranous Labyrinth Membranous Labyrinth

Semicircular canals, Semicircular canals, utriculus, and utriculus, and sacculussacculus

Inside canals:Inside canals: OtolithsOtoliths Sensory hairs- perceive Sensory hairs- perceive

motionmotion Angular motion Angular motion

detected by detected by semicircular canalssemicircular canals

Linear motion Linear motion detected by utriculus detected by utriculus and sacculusand sacculus

Figure 16.6: Vestibular apparatus.

Figure 16.7: Human anatomy of the ear.

Figure 16.8: Anlagen of amniote inner ear (otocyst). Embryonic head (a) and cross section of head (b).



LagenaLagena Out pocketing of Out pocketing of

sacculus wallsacculus wall Gives rise to Gives rise to

cochlea in cochlea in mammalsmammals Organ of CortiOrgan of Corti

Figure 16.9: Cochlea and organ of corti in mammal.

Special Somatic Special Somatic Receptors Receptors (cont.)(cont.)


Weberian ossiclesWeberian ossicles Fish transmit sound Fish transmit sound

waveswaves Modified transverse Modified transverse

processprocess Sinus impar (some Sinus impar (some

fish)fish) Assists in transport Assists in transport

of soundof soundFigure 16.10: (a) weberian ossicles (b) weberian apparatus for transmitting swim bladder vibrations to ear.

(a)

(b)



Middle Ear of Middle Ear of TetrapodsTetrapods

Canal from evagination Canal from evagination of 1of 1stst pharyngeal pouch pharyngeal pouch

Eustachian tubeEustachian tube Communication btwn Communication btwn

pharynx and middle earpharynx and middle ear

Figure 16.11: Position of eustachian tube.


Membranous Labyrinth Membranous Labyrinth Middle Ear of Middle Ear of

TetrapodsTetrapods Bones:Bones:

Malleus, incus, and Malleus, incus, and stapesstapes

Derived from 1Derived from 1stst and 2and 2ndnd visceral visceral archesarches

Stapes is columella Stapes is columella in reptiles and birdsin reptiles and birds

Figure 16.12: Middle ear bones.


Membranous Labyrinth Membranous Labyrinth Middle Ear of TetrapodsMiddle Ear of Tetrapods

Figure 16.13: Development of the middle ear bones.

Outer Ear of TetrapodsOuter Ear of Tetrapods PinnaePinnae Ear drum set back into skullEar drum set back into skull

Crocs, birds, and mammalsCrocs, birds, and mammals Tympanic membrane on outsideTympanic membrane on outside

Frogs Frogs External auditory meatusExternal auditory meatus

Canal leading to tympanic membraneCanal leading to tympanic membrane



Pits that open to surfacePits that open to surface Btwn epidermal scalesBtwn epidermal scales

Loreal pitsLoreal pits Pit vipersPit vipers Btwn nostril and eyeBtwn nostril and eye thermosensitivethermosensitive

Labial pitsLabial pits PythonsPythons Other thermosensitive pitsOther thermosensitive pits Appear similar to neuromastsAppear similar to neuromasts

Special Somatic ReceptorsSpecial Somatic ReceptorsInfrared ReceptorsInfrared Receptors

Special Somatic ReceptorsSpecial Somatic ReceptorsLight ReceptorsLight Receptors

PhotoreceptorsPhotoreceptors Lateral eyesLateral eyes Median eye (3Median eye (3rdrd or pineal or pineal

eye)eye) On top of headOn top of head Has lens and corneaHas lens and cornea Do not form retinal Do not form retinal

imagesimages Ex: lamprey, ganoid fish, Ex: lamprey, ganoid fish,

larval anurans, lizardslarval anurans, lizards Figure 16.15: Parapineal organ of iguana.

Figure 16.14: Parietal eye.

Special Somatic Receptors Special Somatic Receptors (cont.) (cont.) Light ReceptorsLight Receptors

Median eye (3Median eye (3rdrd or or pineal eye) (cont.)pineal eye) (cont.) Part of epiphyseal Part of epiphyseal

complexcomplex Anterior parapineal is Anterior parapineal is

often photosensitive often photosensitive Lamprey- both pineal Lamprey- both pineal

and parapineal are and parapineal are photosensitivephotosensitive

Lizard- parapineal Lizard- parapineal becomes 3becomes 3rdrd eye eye

Frontal organsFrontal organs 33rdrd eye in larval frogs eye in larval frogs PhotosensitivePhotosensitive

Figure 16.16: Epiphyseal complex of lamprey and embryonic and adult lizard.

Special ChemoreceptorsSpecial ChemoreceptorsOlfactory OrgansOlfactory Organs

Ectodermal placodesEctodermal placodes Sink into headSink into head Internal naris- Internal naris-

opening insideopening inside Lungfish and tetrapodsLungfish and tetrapods

External naris- External naris- opening outsideopening outside Fish Fish

Higher vertebrates Higher vertebrates possess both typespossess both types

Figure 16.17: Internal and external naris shown and vomeronasal organ.

Special ChemoreceptorsSpecial Chemoreceptors (con’t)(con’t)

Olfactory OrgansOlfactory Organs

Vomeronasal organ Vomeronasal organ (Jacobson’s Organ)(Jacobson’s Organ) Olfactory mechanisms Olfactory mechanisms

isolated form nasalisolated form nasal Snakes and lizardsSnakes and lizards Insert forked tongue Insert forked tongue

into organinto organ

(a)

(b)

Figure 16.18: Snake collecting scent molecules (a) that are then delivered to the vomeronasal organ by the tongue (b).

Special ChemoreceptorsSpecial ChemoreceptorsOrgans of TasteOrgans of Taste

Taste budsTaste buds Similar to Similar to

neuromastsneuromasts In oral cavity In oral cavity

and pharynxand pharynx

Figure 16.19: Anatomy of the taste bud.

Endocrine OrgansEndocrine Organs

Ductless organsDuctless organs Secrete hormonesSecrete hormones Derived from the 3 Derived from the 3

germ layersgerm layers

Figure 16.20: Embryonic germ layers.

Pituitary GlandPituitary Gland

Figure 16.21: Phylogeny of the vertebrate pituitary.

Pituitary Gland Pituitary Gland (Hypophysis)(Hypophysis)

Derived from Derived from ectodermectoderm

Two divisionsTwo divisions Neurohypophysis Neurohypophysis

(post. pit.)(post. pit.) Adenohypophysis (ant. Adenohypophysis (ant.

pit.)pit.)

Figure 16.22: Anterior and posterior pituitary.

Pituitary Gland Pituitary Gland (cont.)(cont.)

NeurohypophysisNeurohypophysis Infundibulum of Infundibulum of

diencephalondiencephalon Stores hormonesStores hormones

Adenohypophysis Adenohypophysis Cells evaginate Cells evaginate

away from away from stomadeum stomadeum

Secretes hormonesSecretes hormones Rathke’s pouchRathke’s pouch

Figure 16.23: Embryogenesis of the amniote pituitary.

Caudal Neurohemal Caudal Neurohemal OrganOrgan

Endocrine gland unique to some fish Endocrine gland unique to some fish UrophysisUrophysis Neurosensory organNeurosensory organ Occurs at tip of tail off of spinal cordOccurs at tip of tail off of spinal cord

PinealPineal

Derived from Derived from ectodermectoderm

Produces melatoninProduces melatonin Gonadal regulatorGonadal regulator PhotoperiodismPhotoperiodism

Figure 16.24: Location of the pineal gland in the human brain.

Adrenal GlandAdrenal Gland

Adrenal MedullaAdrenal Medulla Derived form Derived form

ectodermectoderm From neurocrest From neurocrest

cells cells Adrenal CortexAdrenal Cortex

Derived from Derived from mesodermmesoderm

Figure 16.25: Cross section of Rt adrenal gland (top) and anatomical position of the adrenal glands.

GonadsGonads

Derived from mesodermDerived from mesoderm Within kidney tissue in some rayfin Within kidney tissue in some rayfin

fishfish Corpuscles of StanniusCorpuscles of Stannius

Endodermal OriginEndodermal Origin

Pancreatic Islets of Pancreatic Islets of LangerhansLangerhans

Thyroid glandThyroid gland Foramen Cecum- Foramen Cecum-

reminant of thyroid reminant of thyroid evaginationevagination

Bursa of FabriciusBursa of Fabricius Outpocket of cloacaOutpocket of cloaca Thymus in natureThymus in nature

Figure 16.27: Mammalian thyroid development.

Pharyngeal PouchesPharyngeal Pouches

Derived from endodermDerived from endoderm FishFish

Pouches 2, 3, 4, 5 (dorsal)- Pouches 2, 3, 4, 5 (dorsal)- thymusthymus

Pouch 5 (ventral)- Pouch 5 (ventral)- ultimobranchial bodiesultimobranchial bodies

AmphibiansAmphibians Pouches 3, 4, 5 (dorsal)- Pouches 3, 4, 5 (dorsal)-

thymusthymus Pouch 5 (ventral)- Pouch 5 (ventral)-

ultimobranchial bodiesultimobranchial bodies

Figure 16.28: Contributions of the embryonic pharyngeal pouches to development of endocrine glands.

Pharyngeal Pouches Pharyngeal Pouches (cont.)(cont.)

MammalsMammals Pouches 3 & 4 (dorsal)- Pouches 3 & 4 (dorsal)-

thymusthymus Pouches 3 & 4 (ventral)- Pouches 3 & 4 (ventral)-

parathyroidsparathyroids No ultimobranchial No ultimobranchial

bodiesbodies

Figure 16.29: Contributions of the embryonic pharyngeal pouches to development of endocrine glands.

Literature CitedLiterature CitedFigure 16.1- http://people.eku.edu/ritchisong/342notes11.htmlFigure 16.2, 16.4, 16.8, 16.10 (b), 16.15, 16.16 & 16.17- Kent, George C.

and Robert K. Carr. Comparative Anatomy of the Vertebrates. 9th ed. McGraw-Hill, 2001.

Figure 16.3- http://fig.cox.miami.edu/~cmallery/150/neuro/senses.htm#illusions

Figure 16.5- http://anatomy.iupui.edu/courses/histo_D502/D502f04/lecture.f04/Earf04/Ear.f04.html

Figure 16.6- http://faculty.etsu.edu/currie/study/hearing.htmFigure 16.7-

http://anatomy.iupui.edu/courses/histo_D502/D502f04/lecture.f04/Earf04/Ear.f04.html

Figure 16.9- http://faculty.etsu.edu/currie/study/hearing.htmFigure 16.10 (a) http://www.voiceproblem.org/anatomy/learning.asp

Figure 16.11- http://www.familydoctor.co.uk/htdocs/deafness/deafness_specimen.html

Figure 16.12- http://137.222.110.150/calnet/Aud/page2.htmFigure 16.13-

http://anatomy.iupui.edu/courses/histo_D502/D502f04/lecture.f04/Earf04/Ear.f04.html

Figure 16.14- http://www.anapsid.org/parietal.html

Figure 16.18- http://www.massasauga.ca/stewardship_guide/section_2/pg16.htm

Figure 16.19- http://www.csus.edu/indiv/l/loom/oct19%20f05.htmFigure 16.20-

http://www.bme.gatech.edu/vcl/Tissue_Engineering/Background/2_cell_types.htm

Figure 16.21, 16.23, 16.27, 16.28 & 16.29- Kardong, K. Vertebrates: Comparative Anatomy, Function, Evolution. McGraw Hill, 2002.

Figure 16.22- http://www.abcbodybuilding.com/magazine03/endocrineinsanity1.htm

Figure 16.24- http://webs.uvigo.es/endocrinologia/marco_izquierda.html

Figure 16.25- http://www.bartleby.com/61/imagepages/A4adregl.html

Literature CitedLiterature Cited

Documents

Comparative Anatomy Sensory and Endocrine Organs Note Set 14 Chapter 15 & 17