A Glossary of Terms from Lab 13:

abdomen
The part of the body of vertebrates containing the viscera, that is the kidneys, liver, stomach, and intestines. In arthropods the abdomen is the part of the body directly behind the thorax, and in many other invertebrates it is divided into segments.

aboral, or dorsal
Toward the back, or upper surface.

ampulla
Any small vesicle or sac-like offshoot. Some examples include the dilation at the end of the semicircular canal of the ear, or the internal expansion of the echinoderm tube foot.

anus
The terminal opening of the gut; the solid residues of digestion are eliminated through the anus.

bilateral symmetry
An animal body structure in which the right and left halves of an organism are approximately mirror images of each other. Most higher invertebrates and all vertebrates have members which are bilaterally symmetrical.

blastopore
The opening of the gastrula that develops into the mouth in protostomes and the anus in deuterostomes.

bone cell
Osteoblast

cardiac portion
Of or relating to the heart.

cardiac stomach
Front portion of the stomach.

coelom
The main body cavity, which is lined with mesoderm, and found in annelids, molluscs, arthropods, echinoderms, and chordates.

cephalization
The evolution of a head (anterior) end with sensory structures and a highly specialized brain to process sensory input; a feature of bilaterally symmetric animals, especially the vertebrates.

cervical
Referring to the neck.

conaliculi
Fine passages that radiate from the lacunae of the lamellae.

cranium
The skull of vertebrates.

deuterostome
An evolutionary line of coelomates (ex. echinoderms and chordates) that are characterized by radial, indeterminate cleavage and development of the anus from the blastopore.

digit
Any part of the pentadactyl limb of vertebrates that contains a linear group of phalanges. A primate finger or toe.

digitigrade
Walking on the toes or fingers, as in most fast-running animals, such as dogs and cats.

distal
Farthest from the body in any structure, or farthest from the center of the system concerned. For example, the finger is at the distal end of the human arm.

esophagus
The part of the alimentary canal of vertebrates that lies between the pharynx and the stomach.

external nares
An external opening of the nose leading into the nasal cavity.

exoskeleton
A skeleton present on the outside of an organism, as in Arthropods or Mollusks.

femur
The thigh bone of tetrapods.

fibula
A bone present in the posterior limb of tetrapods lying slightly posterior to and parallel with the tibia.

ganglion (plural, ganglia)
A cluster (functional group) of nerve cell bodies in a centralized nervous system.

gill
The respiratory organ of aquatic animals.

gonads
The male and female sex organs; the gamete-producing organs in most animals.

haversian canal
One of many channels formed within bone by the development of osteoblasts in concentric rings around them, and whose function is to facilitate linking of the living parts.

hepatic caeca
A blind-ending sac in the digestive system, which occurs in mammals at the junction of the small and large intestines. In herbivores the cecum contains bacteria that produce cellulase, enabling breakdown of cellulose cell walls.

humerus
The bone of the vertebrate forelimb, or arm, nearest to the body, to which it is attached at the shoulder. It is attached distally to the radius and ulna at the elbow.

indeterminate cleavage
Characteristic of deuterostomes, each cell produced by early cleavages retains the ability to develop into a complete embryo.

integument
The outermost layer or layers of tissue that serve in protection.

limb
An articulated (jointed) projection from the body of an animal that is used for locomotion, such as a leg or wing.

lacunae
One of many small cavities uniformly spaced along the lamellae of bones. In living bone, each lacuna contains one bone cell known as an osteocyte. Small canals (canaliculi) radiate from the lacunae and in these are small protoplasmic processes that connect with the osteoblast in other lacunae.

lamellae
(a) the sheet-like membrane that occurs within the chloroplast, each of which consists of a pair of membranes with a narrow space between. (b) the gills of a basidiomycete fungus that radiate out from the stalk beneath the cap of the fruit and bear the spores.

lumbar
Vertebrae present between the thoracic vertebrae and the sacral vertebrae, in the region of the waist in mammals.

madreporite
The porous opening to the hydrocele in echinoderms.

mammary gland
A gland present in female mammals that produces milk used to suckle the young. It probably evolved from a modified sweat gland and at least two are normally present, although in many mammals more than two are developed, usually concentrated on the underbelly beneath the pelvic girdle. In most mammals the size of the gland is determined by the state of the estrous cycle.

mesoderm
The middle primary germ layer of an early embryo that develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system.

mouth
The anterior opening of the alimentary canal of animals through which food is taken into the body. It is often surrounded by mouthparts or tentacles that facilitate feeding.

notochord
A longitudinal, flexible rod formed from dorsal mesoderm and located between the gut and the nerve cord in all chordate embryos.

osteocyte
A cell located in lacunae of vertebrate bone, that deposits a matrix of collagen and calcium phosphate that forms a mineralized connective tissue.

pectoral girdle
The skeletal support for the anterior limbs of vertebrates that transmits power from limbs to the body and also serves to protect and support the organs in the thorax.

pelvic girdle
The skeletal support for posterior limbs of vertebrates that transmits power in locomotion from the hind limbs to the body.

pentadactyl
Bearing five digits (fingers or toes), which is present in amphibia, reptiles, birds, and mammals.

pharynx
An area in the vertebrate throat where air and food passages cross; in flatworms, the muscular tube that protrudes from the ventral side of the worm and ends in the mouth.

plantigrade
Walking on the entire sole of the foot, as in humans and bears.

proboscis
The elongated mouthparts of some insects.

pyloric portion
Of or relating to the end of the vertebrate stomach that opens into the intestine.

radial canal
Part of the water vascular system, it extends into each arm of the starfish and ends in a small external tentacale at the tip of each arm.

radial symmetry
Characterizing a body shaped like a pie or barrel, with many equal parts radiating outward like the spokes of a wheel; present in cnidarians and echinoderms.

radius
The anterior bone in the lower part of the forelimb of vertebrates.

rectum
The terminal part of the intestine of an animal, opening into the anus or cloaca.

scale
Any plate-like outgrowth of the integument, each in the form of a flat calcified or horny structure on the surface of the skin.

teat
Of female mammals, the nipple of a breast or udder, from which the young suck milk.

thorax
1. in vertebrates it is the part of the body that contains the lungs and heart, and in mammals is divided from the abdomen by the diaphragm. 2. in arthropods it is the part of the body directly behind the head and in front of the abdomen. 3. in insects it is the three segments bearing the legs and wings.

tibia
The anterior of the two long bones articulating in the hind limb. In humans, the tibia is the shinbone.

tripartite
Having three parts.

tube feet
The locomotory organs of Echinoderms, which are protruded from the body by, and are retracted by, fluid pressure from the water vascular system.

tunica
Any layer of tissue or membrane that encloses a structure or organ in either an animal or plant.

ulna
The posterior of two bones of the forearm of tetrapods. The ulna articulates proximally with the humerus and distally with the carpals.

urethra
A tube that releases urine from the body near the vagina in females or through the penis in males; also serves in males as the exit tube for the reproductive system.

vagina
A thin-walled chamber that forms the birth canal and is the repository for sperm during copulation.

ventral
Of or relating to the underside of an organism, or the side normally directed downward in the usual stance or resting position.

vertebral column
Spinal cord or backbone; the series of vertebrae surrounding the spinal cord.

vibrissa (plural, vibrissae)
Any of the stiff sensitive hairs found around the mouths of mammals; whiskers.