Comparative Anatomy in Vertebrate Morphology Lab

Chondrichthyes

A class of vertebrates that includes sharks and rays, characterized by a cartilaginous skeleton.

Actinopterygii

A class of vertebrates that includes bony fish, characterized by a bony skeleton and ray-finned fins.

Amphibia

A class of vertebrates that includes frogs, toads, and salamanders, characterized by a life cycle that includes both aquatic and terrestrial stages.

Mammalia

A class of vertebrates characterized by the presence of mammary glands, hair, and three middle ear bones.

Dermal Denticles (placoid scales)

Tough protective covering on skin that resemble tiny teeth. They have hydrodynamic properties that allow sharks to move with minimal water resistance.

Nares

Incurrents and excurrents apertures in sharks used for odor detection.

Ampullae of Lorenzini

Specialized sensory cells that are capable of detecting weak electric fields at short ranges, enabling sharks to locate prey without visual or olfactory clues.

Spiracle

A rudimentary first gill slit that may be highly reduced or absent in most fast moving sharks. It provides for oxygenated blood directly to the eye and brain via a separate blood vessel.

Gill Slits

Exits for water that has passed through the gills after entering through the mouth.

Claspers

Male copulatory organs found in sharks.

Lateral Line

A system of small fluid-filled canals in sharks that detects underwater sound and mechanical disturbances.

Stomach

The organ in sharks with three parts: cranial, fundic, and pyloric, responsible for food storage and digestion.

Pancreas

A flattened white gland that secretes digestive juices and insulin.

Gall Bladder

A green sac that holds bile for enzymatic digestion.

Intestine

Contains the spiral valve, which is an internally twisted or coiled organ that serves to increase the absorptive surface of the intestine.

Liver

Bile secretion, glycogen and Vitamin D storage. A large, soft, oily organ, which occupies as much as 25% of the body cavity. It also produces and holds a large amount of oil to aid in buoyancy.

Spleen

Maintenance of blood (destroys old RBCs and makes new RBCs).

Heart

Muscular S-shaped tube with 'two' chambers for pumping blood throughout the body. (shark)

Ventricle

Pumping chamber of the heart.

Atrium

Collecting point of blood for all veins.

Gill Lamellae

Feather-like portion of the gills responsible for gas exchange.

Kidneys

Elimination of waste and regulation of internal environment.

Rectal Gland

Acts as a salt gland for osmoregulation by removing excess sodium chloride from the blood and excreting it through a duct in the rectum.

Ovaries/Testes

Female: egg and hormone production/ Male: gonads for sperm production.

Cloaca

A common chamber receiving the openings of the urinary tract, oviduct (females) and the intestine.

Unpaired fins (fish)

Two dorsal fins, caudal fin and one anal fin: Spiny dorsal is primarily for maneuvering, stabilization and defense. The soft dorsal is primarily for low speed maneuvering and swimming. Caudal fin is used for propulsion. Anal fin is primarily for stabilization.

Paired fins (fish)

Pectoral fins and pelvic fins: Pectoral fins are for swimming, maneuvering and stabilization. Pelvic fins are for stabilization.

Operculum

Gill cover. Protects gills and serves as 'bellows' to help pump water over gills.

Branchiostegal Membrane

Seals operculum and prevents backflow of water into the gill chamber.

Nares

Consist of both incurrent and excurrent apertures, used in odor detection, not breathing.

Lateral Line

A series of small fluid-filled canals lying just beneath the skin on the head and along the sides of the body. This complex system of receptors transforms underwater sound or mechanical disturbance into nerve impulses.

Caudal Peduncle

Generates power to the caudal fin for swimming.

Stomach

Food storage and digestion. Note the pyloric caeca which aid in both digestion and absorption.

Gall Bladder

A sac, usually green, that holds bile for enzymatic digestion.

Intestine

Simple intestines for digestion.

Pancreas

Secretion of digestive juices and insulin. Note: The pancreas is a diffuse organ in fish, extending over the surface of the intestine, along the portal vessels, and is interspersed with the adipose and other connective tissue and blood vessels. It can only be differentiated through microscopic examination of tissues.

Liver

Bile secretion, glycogen and Vitamin D storage.

Heart-fish

Two chambers, atrium and ventricle.

Gill Rakers

Strains water and retains food.

Gill Arches

Supports the gills.

Gonads

Female, ovaries: egg and hormone production. Male, testes: sperm production.

Cloaca

A common chamber receiving the openings of the urinary tract, oviduct (females) or vas deferens (male) and the intestine.

Swim Bladder

Hydrostatic balancing and sound production.

Myomeres

Blocks or bundles of skeletal muscle. Note the shape of each bundle. The space between each myomere is called the myosepta.

Tympanic membrane-frog

senses vibrations, hearing

Nictitating membrane-frog

covers and protects eye

Vomerine teeth-frog

grasping

Maxillary teeth-frog

chewing

Tongue-frog

attached to anterior of floor of the mouth, catching prey

Stomach-frog

mechanical and chemical digestion of food, contains rugae

Rugae-frog

(stomach interior) folds that increase the surface area of stomach for increased absorption efficiency

Small intestine-frog

chemical digestion and nutrient absorption

Large intestine-frog

water absorption and fecal packing

Pancreas-frog

secretion of digestive juices, insulin

Gall bladder-frog

greenish sac, holds bile for enzymatic digestion

Liver-frog

makes bile, stores carbs, metabolizes fats and other compounds (3 lobes)

Fat bodies-frog

energy storage

Heart-frog

THREE chambers, circulation of blood

Ventricle-frog

receives blood from atria, pumping chamber of the heart

Right atrium-frog

collecting point of blood from sinus venous

Left atrium-frog

collecting point of blood from lungs

Lungs-frog

site of gas exchange

Ovaries-frog

(♀) egg and hormone production

Testis-frog

(♂) sperm and hormone production

Urinary bladder-frog

urine storage

Cloaca-frog

common chamber receiving the openings of the urinary tract, the oviducts (♀) or vas deferens (♂), and the intestine

Teats-pig

mammary papillae

Umbilical cord-pig

connects placenta with fetus

Urogenital orifice-pig

combined urine and reproductive system opening

Genital papilla-pig

female only; small fleshy protuberance anterior to the urogenital orifice

Scrotum-pig

male only; contains testes

Palate-pig

forms the roof of the mouth, hard palate is anterior portion and soft palate posterior

Epiglottis-pig

prevents food and liquid from entering the trachea

Glottis-pig

opening to trachea

Trachea-pig

air passage to lungs, cartilaginous rings

Esophagus-pig

food passage to stomach, muscular wall

Rectum-pig

passage between intestine and anus

Muscular diaphragm-pig

separates thoracic from abdominal cavities, lung expansion

Uterine horns-pig

provides space for multiple embryos to develop (litter)

Testes-pig

male gonads

Spermatic cord-pig

includes vas deferens