COMPANA LE1

Long Exam 1 Intro to Tetrapods

The study of the descriptive and functional morphology of vertebrates

Comparative anatomy

What do you call the study of evolution which shows the changes in structures of different animals across time?

Phylogeny

morphology:____________

anatomy:_______________

structural evolution; describing the structure as it is

Species are grouped together with how they are similar to each other

Cladogram

not all species of chordates would develop the structures as they get more mature. these are called what?

prochordata

Animal species with distinct head part with tripartite brain

Craniata

Jawless animals

Agnathan

Why are prochordates and chordates grouped in a single taxon?

because they possess these FIVE ELEMENTS in at least 1 point in their lifetime

Rod of living cells ventral to the CNS and dorsal to the alimentary canal

notochord

what will the notochord develop into in adulthood?

vertebral column

more complex, jointed skeleton that develops in most vertebrates

vertebral column

do adults retain the notochord?

no, this develops into the vertebral column since adults retain only remnants of the embryonic notochord

the part of the notochord near the head region will be incorporated into the ____________ while those in the rest of the body will eventually _____________

skull floor

surround the cartilaginous or bony vertebrae structures

what are the different fates of the notochord during adulthood?

protochordates: chief axial skeleton surrounded by notochord sheath

agnathans: chief axial skeleton + lateral neural cartilages

fishes and amphibians: Persists the length of the trunk and tail within the centrum of the vertebral column

reptiles, birds, and mammals (amniote): Disappears and becomes pulpy nucleus in mammal vertebrae

an animal whose embryo develops in an amnion and chorion and has an allantois; a mammal, bird, or reptile.

amniotes

What do you call the study of evolution which shows the changes in structures of different animals across time?

phylogeny

does the notochord develop into the CNS?

No

the dorsal hollow nerve cord of a chordate embryo develops from what?

a plate of ectoderm that rolls into a tube dorsal to the notochord through invagination

the action or process of being turned inside out or folded back on itself to form a cavity or pouch during gastrulation

invagination

this develops into the CNS— the brain and spinal cord

dorsal hollow nerve cord

the pharynx is common to what two phylum?

hemichordata and chordata

these are species that do not possess all 5 criteria to classify them as chordates

hemichordates

the pharynx can be perforated by what?

openings (stilts) to either the exterior or an atrium (reflecting common ancestry)

define the pharynx

Membranous digestive and respiratory organ located at the back of the mouth that serves as passageway of food and air

what does the pharynx develop into?

gills of fishes (permanent slits)

lungs for tetrapods (temporary slits)

skeleton and musculature of jaws

endocrine glands (Parafollicular cells and parathyroid glands)

middle ear cavity of tetrapods (Auditory and tympanic cavity )

initial cells of immune system during fetal life and shortly after (thymus)

what are the embryonic components of the pharynx?

pharyngeal arches

pharyngeal clefts

pharyngeal pouches

pharyngeal slits

pharyngeal arches are separated by grooves. of the groove is OUTSIDE the embryo, what is it called? what if it is INSIDE the embryo? what if it makes an OPENING?

cleft; pouch; slit

what do the arches develop into?

skeleton

muscles

nerves

blood vessels

how many pairs of arches develop in the cranio-caudal sequence?

6 pairs where development starts from the pharyngeal arch closest to the head (cranial) and proceed caudally to the tail

Indentations are present in both external and internal arches. describe each

external: clefts lined with ectoderm

internal: pouches lined with endoderm

what are the skeletal elements in the first pharyngeal arch?

meckel’s cartilage

malleus

incus

what are the muscles in the first pharyngeal arch?

muscles of mastication

anterior belly of digastricus

tensor tympani

tensor palati

what cranial nerve in the first pharyngeal arch?

trigeminal nerve (mandibular division)

what are the skeletal elements in the second pharyngeal arch?

stapes

styloid process

upper part of hyoid

what are the muscles in the second pharyngeal arch?

stapedius

stylohyoid

muscles of facial expression

posterior belly of digastricus

what is the cranial nerve in the second pharyngeal arch?

facial nerve

what is the skeletal elements in the third pharyngeal arch?

lower part of hyoid

what is the muscle in the third pharyngeal arch?

stylopharyngeus

what is the cranial nerve in the third pharyngeal arch?

glassopharyngeal nerve

what are the skeletal elements in the 4th-6th pharyngeal arches?

laryngeal cartilages

what are the muscles in the 4th-6th pharyngeal arches?

cricothroideus

pharyngeal constrictors

instrinsic laryngeal muscles

what is the cranial nerve in the 4th-6th pharyngeal arches?

vagus nerve

what are examples of laryngeal cartilages?

epiglottis, thyroid, cricoid, arytenoid

examples of muscles of mastication are

Masseter. Temporalis. Lateral pterygoid. Medial pterygoid

what is digastricus

the digastric muscle - important muscle in the neck, which pulls the mandible downward to open the jaw and elevates the hyoid bone for stabilization during swallowing, and it is also involved in chewing and speech

what are the components of pharyngeal arches?

• Supportive skeletal elements of the pharyngeal skeleton

• Striated muscles that operate the arch

  • Branchiomeric muscles

• Cranial nerves (5, 7, 9, 10) which innervate muscles and provide sensory input to the brain

• Aortic arch that connects the ventral and dorsal aortas

  • The blood vessel dorsal to the arches (dorsal aorta) and the ventral aorta are connected by the aortic arches

what are the components of pharyngeal clefts

• Ectodermally-lined grooves on the outside of the embryonic pharynx

• Only the first cleft is important

  • Develops into the external auditory meatus of the ear

  • Provides the outer epithelium of the tympanic membrane

  • Clefts are lost in development because of proliferation o f the underlying mesoderm

T/F: The dorsal nerve cord develops from the process of invagination

true

Enumerate the four types of adult structures that arise from the pharyngeal arches

Skeleton

Muscles

Nerves

Blood vessels

where do pharyngeal pouches arise from?

Arises as diverticula/invagination of endoderm of foregut

pharyngeal poches _________ toward the surface of the animal

grow/deepen

these establish the limits of the pharynx

pharyngeal pouch

max. number of pharyngeal pouches in basal shark

8

max. number of pharyngeal pouches in living agnathans

15

Pharyngeal clefts grow toward each pouch and is separated from each other via the _________

pharyngeal plate

Pharyngeal clefts grow toward each pouch and is separated from each other via the pharyngeal plate. If you lose the plate, it will now become the

pharyngeal slit

first pharyngeal pouch derivatives

middle ear cavity

endodermal aspect of tympanic membrane

pharyngotympanic tube

second pharyngeal pouch derivatives

palatine tonsil

third pharyngeal pouch derivatives

inferior parathyroid gland

thymus

fourth and fifth pharyngeal pouches derivatives

superior parathyroid gland

parafollicular cells of the thyroid gland

Formed between the pharynx and the exterior when the pharyngeal plate ruptures

pharyngeal slits

What do you call vertebrates with absent jaw?

agnathans

Which cranial nerve arises from the second pharyngeal arch?

facial nerve

glandular groove in the floor of the pharynx and is involved in filter feeding

endostyle

endostyle gives rise to

thryoid gland

an endocrine that produces hormones

thyroid gland

where does the endostyle/thyroid gland arise from

floor of pharynx

involved in iodine metabolism

significance of muscular postanal tail to many aquatic species

propelling force

Special sense organ to monitor external environment through senses

head

centralization/localization of nervous structures and functions in the head with accompanying dominance of the head

cephalization

what houses most of the visceral organs?

coelom

what surrounds the coelom?

Body wall surrounds the coelom and consists chiefly of muscle, vertebral column, and the ribs

Present in ALL EMBRYOS though adult form may lose this along development

postanal tail

type of Chordates with a NEUROCRANIUM or BRAINCASE

craniates

Animals that have a NOTOCHORD in the embryo stage at least

chordates

T/F: craniates have a three-part brain

true

Chordates with vertebrae

vertebrates

when does the vertebrae appear?

during embryonic development after the notochord has formed

Which group of animals are considered as chordates but NOT as craniates?

protochordates

Enumerate the five fundamental structures in the architecture of vertebrates

Notochord

Dorsal hollow nerve cord

Pharynx

Endostyle or Thyroid Gland

Postanal tail

The science that studies the inheritance of traits from parents to offspring.

genetics

Which of the following is NOT characteristic among agnathans?

• presence of a notochord

• absence of a jaw

• presence of swimbladder

• presence of a postanal tail

presence of swimbladder

Which of the following is an important reason for studying comparative vertebrate anatomy?

• To understand man's place in the vertebrate world without emphasis on man himself

• To comprehend the functional basis of biology

• To appreciate the superiority of vertebrates in comparison to lower forms of organisms

• To understand the organism-environment interactions of man and the biosphere

To understand man's place in the vertebrate world without emphasis on man himself

Which of the following groups of organisms are classified as deuterostomes?

• Cnidaria

• Nematoda

• Hemichordata

• Arthropoda

hemichordata

Which structure separates the pharyngeal cleft/groove from the pharyngeal pouch

pharyngeal plate

Which of the following adult structures are derived from the 3rd pharyngeal pouch?

• thymus

• incus

• palatine tonsil

• facial nerve

thymus

which of the following descriptions are TRUE regarding the different pharyngeal components?

• Pharyngeal slits are temporary structures for adult animals that breath through gills.

• Pharyngeal clefts are lined by ectodermal cells.

• Pharyngeal arches give rise to all the cranial nerves.

• Gnathostomes have a maximum of 6 pharyngeal pouches during embryonic development.

Pharyngeal clefts are lined by ectodermal cells.

Which of the following is FALSE regarding the regional components of a vertebrate?

• The trunk has a coelom which houses most of the organs derived from ectodermal cells.

• All craniates posses a three part brain.

• Postanal tail may be lost during adulthood among some vertebrates.

• Cephalization pertains to the localization of nervous structures in the head.

The trunk has a coelom which houses most of the organs derived from ectodermal cells

Why are protochordates grouped separately from chordates?

• Lack of cephalization of sense organs.

• Some of the fundamental architectures of chordates are lost during adulthood.

• Some of the fundamental architecture of chordates are absent even during embryonic stage.

• Failure to develop bony vertebrae during adulthood.

Some of the fundamental architectures of chordates are lost during adulthood.

who proposed a taxonomic classification of deuterostomes

Ernst Haeckel (1874)

deuterostomes are also known as

• Also known as ENTEROCOELOMATES

  • Coelom develops through enterocoely

Four extant phyla (still seen today, present time)

• Xenoturbellida

  • Invertebrate

• Echinodermata

  • Invertebrate

• Hemichordata

• Chordata

difference of cleavage formation

difference of coelom formation

difference of fate of blastophore

• Blastophore forms during gastrulation and connects the archenteron to the exterior of the gastrula

  • The three-germ layer already formed

    • Ectoderm outside, endoderm within lining the primitive gut, mesoderm lying between the ectoderm and endoderm

  • Now develop into two different structures:

    • Protostome

      • Blastophore will become the mouth

    • Deuterostome

      • Blastophore will become the anus

What is the fate of the blastophore during deuterostome development?

anus

TRUE or FALSE: the indeterminate cleavage of deuterostomes makes it possible for one embryo to give rise to identical twins

true

what are closest relatives of vertebrates along with the hagfish

protochordates

protochordates are composed of

hemichordata

urochordata

describe hemichordates

• Acorn worms

• Vermiform bottom dwellers found in shallow mud water

• Very small but can reach up to 5 feet in length

• Very fragile