Vertebrate Anatomy - Chapter One (Introduction)

Comparative Vertebrate Anatomy

The study of vertebrate structure (or morphology) & the functional aspects.

Phylum Chordata

Made of a group of animals all processing four common features

Four Common Features of Phylum Chordata

• Notochord

• Dorsal Hollow Nerve Cord

• Postanal Tail

• Endostyle

Notochord

A rigid cartilaginous rod defining the longitudinal axis of the embryo.

Dorsal Hollow Nerve Cord

Spinal cord on the brain

Endostyle

Glandular groove in the floor of the pharynx

The phylum can be divided into what?

Three subphyla(s)

What are the three subphylas?

• Urochordata

• Cephalochordata

• Vertebrata / Craniata

Urochordata

The tunicates and sea squirts

Cephalochordata

Amphioxus

Vertebrate / Craniata

Chordates having a vertebral column of bone or cartilage.

Regional Differentiation

The typical vertebrate body has three regions

What are the three body regions?

• Head

• Trunk

• Tail

Cranialization

The development of the head

Coelom

Body cavity that houses the visceral organs

What Is the coelom surrounded by?

Body wall

The body wall consists of what?

• Muscles

• Vertebrate

• Ribs

Neck

a narrow structure connecting the head to the trunk.

Postanal

It originates posterior to the anus.

Bilateral Symmetry

The vertebrate body can be divided into two equal right and left hand portions.

How many major planes are of the body?

Three

Transverse Plane (aka Horizontal Plane, Cross Section)

Separates cranial and caudal structures along the trunk, and proximal from distal structures on the limb in most vertebrates.

Midsagittal Plane (aka Media Sagittal)

Runs along the midline of the body.

Parasagittal Plane

Runs other than the midline of the body.

Dorsal Plane

Divides the body into ventral and dorsal portions.

Metamerism

Serial repetition of structures along the long axis of the body.

Notochord

Cartilaginous rod the defines the long axis of the embryo.

Centrum

The weight bearing portion of the vertebra.

Nucleus Pulposus

Portions of the intervertebral discs.

Lateral Neural

The extensions of the notochord.

Hemal Arch

A second arch that extends from the centrum ventrally in caudal vertebrae.

What is the purpose the the Hemal Arch?

Surrounds and protects the caudal artery.

Dorsal Hollow Nerve Cord

The vertebrate nerve cord is dorsally oriented and hollow.

What does the Dorsal Hollow Nerve Cord consist of?

• Brain

• Spinal Cord

Neurocoel

The hollow center of the vertebrate nerve cord.

Neuralation

Occurs along the longitudinal axis of the embryo dorsal to the notochord.

Neural Groove

Forms dorsal to the notochord.

Neural Tube

The neural groove sinks into the embryonic body and close off.

Neural Keel

Wedge-shaped ectodermal structure dorsal to the notochord.

Pharynx

Shows the relationship between vertebrates and other chordates.

The structures that are produced from the Pharynx

• Gills in fish

• Lungs in tetrapods

• Jaw skeleton and musculature

• Some endocrine glands

• Middle ear in teteapods

• Serves as a stem immune cells source

Pharyngeal Pouches

Outpocketings of gut endoderm.

Ectodermal Grooves

Grooves in the above lying ectoderm.

Branchial Plate

Thin tissue of membrane.

Pharyngeal Slit

A passageway that develops if he branchial plate ruptures.

Pharyngeal Arches

Columns of tissues between adjacent pharyngeal pouches.

Visceral Skeleton

Supportive skeletal component.

Branchiomeric Musculature

Muscular component

Aortic Arch

Connects the Dorsal and Ventral aorta.

Mandibular Arch

First pharyngeal arch that contains the upper and lower jaw structures.

Hyoid Arch

Second arch.

Branchial Arch(es)

the remaining arches due to resembling unmodified gill arches.

Outer Tube

Body wall

Inner Tube

Digestive tract

Coelom

The space between the outer and inner tubes, between the body wall.

Pericardial Cavity

Houses the heart.

Pleuroperitoneal Cavity

Houses the remaining viscera.

Transverse Septum

Fibrous c.t. partition.

Integument

Composed of the skin and the hypodermis.

What is the skin composed of?

• Dermis

• Epidermis

Epidermis

Superficial layer composed of many layered lepithelium.

Dermis

Deep to the epidermis and is a connective tissue/

Respiratory Structures

Most vertebrates conduct external respiration by means of extremely well vascularized membranes.

Digestive System

Consists of a digestive tube and a number of

accessory organs.

The Digestive Tube/Alimentary Canal/Gastroinestinal Tract.

A long tube running from the mouth to the cloaca

Accessory Organs

Located outside of the digestive tube

and release their products into the tube by means of ducts.

What are the accessory organs?

• Liver

• Pancreas

• Gall Bladder

Urogential System

The urinary and reproductive systems.

Circulatory System

Vertebrates have a closed circulatory system whereby blood is pumped by a muscular heart through a series of blood vessels.

Skeleton

Internal (an endoskeleton) and composed of

cartilage/bone.

Axial Skeleton

• Skull

• Vertebrate

• Rib cage

Appendicular Skeleton

Composed of the bones of the limbs and their associated girdles.