General Zoology Lab Definitions

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Chapter 1


Metric system- standard measurement system used internationally based on a conversion factor of 10.


English unit system- system of measurements based on practical American needs.  No easy conversion factor.


Microscopy- use of a microscope


Objective lens- lenses of different magnifications (ours exist on a nosepiece that can be turned to increase magnification between objective lenses) that work in conjunction with ocular lenses to magnify an image


Body on microscope- housing that keeps parts of the microscope aligned


Arm- supports body stage and adjustment knobs


Course focus adjustment- large knob that moves the stage to focus image


Fine focus adjustment- small knob to the outside of the course adjustment knob which moves the stage in small increments to control fine focus needs


Stage- supports slide


Stage adjustment knobs- move stage to center image under objective lens


Condenser- lens used to focus light beam; located under stage


Illuminator- source of light


Base- supports microscope unit


Light intensity adjustment dial- changes amount of light reaching slide


Magnification- ocular lens power X objective lens power


Field of view- portion of slide visible when looking through microscope.   Decreases as magnification increases


Depth of field- thickness of an image visible under magnification.  Increases as magnification increases


Wet mount- Combination of a concave slide, a drop of water with image to view under microscope, and a cover slip. 


Asymmetry- lack of symmetry; irregular arrangement of body parts with no plane of symmetry


Radial symmetry- body parts arranged around a central axis; any plane passing through body causes division of the body into two similar halves


Bilateral symmetry- body parts are divided into mirror images by only one plane


Transverse Plane- separates body into cranial and caudal halves


Saggital plane- separates body into right and left halves


Median plane- a saggital plane running down the midline of the body


Frontal plane- plane separating body into ventral and dorsal halves


Medial- closer to midline of body


Lateral- farther from midline of the body


Dorsal- back half of body


Ventral- front half of body


Proximal- closer to median plane or point of attachment


Distal- farther from median plane or point of attachment


Rostral- closer to nose region

Chapter 2


Nucleus- “brain” of the cell; organelle that contains genetic material


Plasma membrane- barrier enclosing cell from the outer environment and regulating movement of particles, chemicals into and out of  the cell.


Nuclear membrane- barrier regulating passage of substances into and out of the nucleus


Cytoplasm- fluid substrate through which organelles in the cell move


Tissue- group of similar cells working together to perform a function in an animal


Epithelial tissues- cover external surfaces or line internal surfaces; tightly packed


Simple Epithelium- tissues that consist of a single layer of cells and are classified based on shape.


Simple squamous epithelium- single layer of flattened cells looking like shingles on a roof (lungs, and artery walls)


Simple cuboidal epithelium- single layer of cube-shaped cells found in kidneys


Simple columnar epithelium- single layer of rectangular cells found in intestinal walls


Stratified epithelium- layered epithelial cells comprised of more than one cell type (skin)


Connective tissues- tissues that bind organs together, hold them in place, support body structures or store food


Cartilage- group of cells in a gelatinous matrix that provide firm and flexible support.  Composed of lacunae, chondrocytes.Found between bones, in ears, nose and voice box of humans


Hyaline cartilage- type of cartilage made of chondrin and collagen; found between bones


Elastic cartilage- type of cartilage made of collagen and elastic fibers found in ears, nose and voice box of humans


Bone- structural connective tissue composed of osteocytes, lamellae, lacunae, Haversian canals, canaliculi.  Stores calcium, and produces red blood cells.


Adipose tissue- tissue that stores food for the body in fat droplets.  Finite number in adult human.


Loose connective tissue- loosely scattered cells surrounded by clear gelatinous matrix; composed of collagen, elastic fibers which hold organs and tissues together in the body.


Blood- connective tissue composed of fluid plasma and cells which are responsible for transporting oxygen, carbon dioxide, nutrients, electrolytes, hormones, metabolic wastes and other substances through the body.


Muscle Tissue- tissue that has the ability to contract and cause movement by actin and myosin filaments.  


Smooth muscle tissue- autonomically controlled, long and spindle-shaped muscle tissue containing a single nuclei.  Found in bladder, uterus, stomach. 


Skeleton muscle tissue- muscle tissue under reflex and voluntary control comprised of myofibrils making the tissue look striated. 


Cardiac Muscle- autonomically controlled muscle tissue that is branched and embedded in the ganglia of the heart.  Contain intercalated discs.


Nervous tissue- tissue controlling and transporting electrical impulses; composed of neurons (cell body, axon, and dendrites) and glial cells.

Chapter 3


Cell cycle: events that encompass the entire life cycle of a cell from one division to the next


Mitosis:  Cell division of somatic cells producing exact diploid copies of the original cell.


Chromosome: complex body, spherical or rodlike, that arises from the nuclear network during mitosis, splits longitudinally, and carries a part of the organism's genetic information s genes composed of DNA.


Centriole: paired cylindrical structures containing a ring of microtubules which align chromosomes during Prophase and Metaphase as well as contract to pull the separated chromosomes apart in Anaphase.


Asters: Microtubule filaments projecting from centrioles and attaching to the cell pole that serve to anchor centrioles.


Centromere: clear portion of a chromosome where the two sister chromatids are joined.


Chromatid: Genetic information in condensed form typically found in identical pairs after replication during Interphase; linked at the centromere- make up a chromosome.


Interphase: Longest stage of mitosis.  Distinct nuclear membrane enclosing lightly stained chromatin and prominent nucleolus.  DNA and centriole replication occurs late in stage.


Prophase: Stage at which chromosomes form from DNA coiling. Nuclear membrane disintegrates and centrioles move to opposite poles with spindle fibers between.  Centrioles anchor to poles using asters


Metaphase: Stage at which spindle fibers position chromosome pairs on the metaphase plate. Spindle fibers and asters surrounding the centriole pairs are visible at this stage.


Anaphase: Stage at which microtubules of a spindle apparatus (centriole) separate sister chromatids and centromeres of each chromosome and move them to opposite spindle poles.


Telophase: Final stage in which chromosomes decondense into threadlike structures and a distinct cleavage furrow is established. The cell completes cytoplasm division in late Telophase.


Spindle fibers: microtubules anchored at centrioles that position chromosomes in cell and pull separated chromosomes apart.


Gametogenesis: gamete development. Result is haploid gametes (sperm, ova) by the process of meiosis.


Meiosis: Cell division restricted to sex-cell production involving two successive nuclear divisions that result in daughter cells with the haploid number of chromosomes.


Spermatogenesis: meiotic production of sperm cells


Oogenesis: meiotic production of egg cells


Chapter 4 Protista


-Microscopic protists: unicellular forms


-Macroscopic protists: multicellular algae and slime molds


-Eukaryotic: All protists are eukaryotic, meaning their cells contain membrane-bound nuclei and other membrane-bound organelles.


-Autotrophic: characteristic of an organism that produces its own organic food molecules, usually through photosynthesis.


-Heterotrophic: characteristic of an organism that obtains nutrients by ingesting or absorbing organic material from external sources.


-Plasma membrane: the membrane at the boundary of a cell that acts as a selective barrier regulating the cell's chemical composition.


-Cell wall: protective, rigid outer layer of the cells of plants, fungi, bacteria and many protists; may consist of cellulose, calcium carbonate, silica or other materials.


-Starch: storage polysaccharide consisting of long polymers of glucose molecules; found in plants and some protists.


-Lipids: family of compounds including fats, phospholipids, and steroids, that are insoluble in water.


-Asexual reproduction: type of reproduction that occurs without genetic recombination and results in the production of offspring that are genetically identical to the parent; may occur by simple fission of a single cell, budding or fragmentation.


-Sexual reproduction: type of reproduction in which offspring with unique genetic combinations are created by the union of sets of genetic material, usually, but not necessarily, from two separate parents.


-Cysts: dormant, resistant stage of cells that allows them to survive prolonged periods during which environmental conditions are unfavorable for growth and survival.


-Monophyletic: pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa.  Protists are not monophyletic.


-Polyphyletic: pertaining to a taxon whose members were derived from two or more ancestral forms not common to all members.


-Taxonomy: the study of classification, identification, and nomenclature (naming) of organisms.

-Classification: ordering of organisms into a hierarchy of classes; ordering of organisms into groups based on similarities and/or differences.  Serves as a filing system.


-Taxon: a taxonomic group of any rank.










-5 Kingdom System: Monera, Protista, Plantae, Fungi, Animalia


-3 Domain System: Domain Bacteria, Domain Archaea, Domain Eukarya (Eukaryotes)


-Under Protists:


            Subdomain Eugelozoa: Euglenoids and Kinetoplastids


            Subdomain Alveolata: Dinoflagellates, sporozoans, and ciliates


            Subdomain Stramenopila: Diatoms


            Recurrent Body Forms: Amoebas and slime molds


-Flagellum (pl.=flagella): long cellular appendage specialized for locomotion 


-Eyespot of euglenoid: rudimentary photoreceptors capable of detecting shadows and extremes in light.


-Chloroplasts: organelle found in autotrophic protists and plants that absorbs sunlight and drives photosynthetic reactions to produce sugars.


-Kinetoplast: characteristic organelle of kinetoplastids consisting of a single, large mitochondrion that contains extra-nuclear DNA.


-Trypanosoma brucei: African sleeping sickness


-Alveoli: small cavities found beneath the surface of protists in the candidate kingdom Alveolata


-Cellulose plates: structural element of dinoflagellates found beneath the outer plasma membrane providing support and shape to their cells.


-"Red tides": ecological phenomenon caused by massive population explosions of dinoflagellates.


-Plasmodium: a blood parasite carried by the female Anopheles mosquito which transmits malaria


-Vector: an organism that acts as a secondary host to a parasite and transmits the parasite to its primary host, usually without suffering any ill effects itself.


-Cilia (of ciliates): hair-like projections used for locomotion and feeding


-Micronucleus of ciliates: typical eukaryotic nucleus containing entire genome; essential for genetic recombination


-Macronucleus of ciliates: organelle containing many copies of a few genes; primarily controls metabolic processes of the cell.


-Oral groove of ciliates: lateral depression into which food is swept by ciliary currents.


-Food vacuole: small, spherical organelle containing enzymes to digest food.


-Contractile vacuole: one or more spherical organelles which pump out water to maintain the internal osmotic balance of the cell.


-Binary fission (or ciliates): type of cell division by which many unicellular protists and bacteria reproduce asexually; generally involves a simple mitotic division of the parent cell producing two genetically identical daughter cells.


-Conjugation (of ciliates): process that occurs in some protists and bacteria in which genetic material from one cell is transferred to another cell, or genetic material from two cells is simultaneously transferred.


-Diatomaceous earth: type of soil formed by the accumulation of siliceous diatom cell walls over hundreds of millions of years.


-Plankton: mostly microscopic organisms that drift passively or swim weakly near the surface of ponds, lakes, and oceans.


-Pseudopodia of amoebas: cytoplasm-filled extensions of the plasma membrane employed by amoeboid species for locomotion and feeding.


-Cytoplasmic streaming: phenomenon in which cytoplasm of a cell flows from one region of the cell body to another, often as a means of distributing food, gases, or other substances.


-Phagocytosis: a type of endocytosis in which large food particles are engulfed


-Motile: having or pertaining to the ability to move


-Plasmodial slime molds:


Chapter 5 (Porifera)


Ostia: pores on the body surface of the sponge where water enters.


Incurrent Canals: ostia channel water down these canals to a larger number of tiny pores scattered along the folds of these canals.


Prosopyles: the tiny pores scattered along the folds of the incurrent canals.


Radial Canals: flagellated chambers that the prosopyles channel water into.


Choanocytes: specialized cells that line the interior surface of the radial canals; these cells trap small food particles with their flagella and engulf them through phagocytosis.


Apopyle: opening through which water passes out of the radial canals into the spongocoel in sponges.


Spongocoel: large central cavity that passes through the center of sponges


Osculum: large opening located at the top of sponges through which water which has collected in the spongocoel is pushed out.


Spicules: hard, crystalline calcium carbonate or silicon structures which form the skeleton in many sponges.


Spongin: proteinaceous, flexible material secreted by some sponges to form the skeleton


Amoebocytes: mobile cells specialized for distributing food throughout the sponge and for producing its skeleton.

Chapter 6 (Cnidaria)


Radially symmetrical: Body parts are arranged around a central axis such that any plane passing through the central axis divides the body into two similar halves.  All Cnidarians are radially symmetrical.


Metamorphic: A characteristic of having different body forms during the lifecycle.  Most Cnidarians are metamorphic.

Medusa: stage in the Cnidarian lifecycle represented by a circular, free-swimming form resembling the familiar jellyfish in its morphology.


Polyp: stage in the Cnidarian lifecycle represented by a cylindrical organism which remains attached to the substrate by a short stalk.


Cnidocytes: stinging cells in Cnidarian tentacles used for defense and for capturing food.


Bud of the Hydra: asexual outgrowth of the parent that pinches off when mature and lives independently.


Medusa buds: young, immature medusae produced within the reproductive polyps of some Cnidarians.


Basal disc of the Hydra: specialized region for attachment to the substrate.


Hydranth of Obelia: feeding polyp in some colonial Cnidarians.


Marginal tentacles of jellyfish: Cnidarian tentacles that provide sensory information and are used for defense and locomotion.


Oral arms of jellyfish: Cnidarian tentacles used for defense and prey capture.


Tentacles of sea anemone: long, extensible, prehensile found in Cnidarians and some mollusks which aid in defense, prey capture, and locomotion.


Ostia of sea anemone: pores or openings that allow circulation of fluids between adjacent body or organ sections.


Chapter 7 Platyhelminthes


-Platyhelminthes: flatworms


-Triploblastic: referring to an animal whose body develops from three embryonic tissue layers.


-Acoelomate: animals whose central space is filled with tissue (mesoderm).  No true body cavity exists.  Example: flatworms.


-Pseudocoelomate: animals with a central body cavity that lies between gastrodermis and mesoderm.  Example: roundworms (nematodes).


-Eucoelomate: animals with a central body cavity that lies within mesoderm.  Examples: earthworms, molluscs, insects, chordates.


-Epidermis: outer tissue covering in animals; derived from ectoderm.


-Gastrodermis: inner tissue lining of the digestive system in many animals; derived from the endoderm.


-Mesoderm: middle primary embryonic germ layer which lines the coelom and gives rise to muscle tissue, skeletal tissue, reproductive tissue and most circulatory tissue.


-Bilateral symmetry: all flatworms have bilateral symmetry (body parts are divided into similar halves (mirror images) by a single plane of symmetry.


-Cephalization: concentration of nervous tissue and sensory structures at the cranial end of the body.


-Class Turbellaria: free-living flatworms.  Example: planaria


-Eyespots of a planaria: sense light (only shadows and direct light, not images).


-Auricles of a planaria: chemoreceptors that detect dissolved chemicals in the water.


-Gastrovascular cavity: (syn.= coelenteron) Central digestive compartment in some invertebrates; characterized by a single opening which functions as both mouth and anus.


-Pharynx: muscularized portion of digestive  tract usually responsible for pulling food into the digestive system.


-Class Trematoda: parasitic flatworms commonly referred to as flukes.  Example: common liver fluke.


-Oral sucker of a liver fluke: specialized  for attachment to host; used in feeding.


-Ventral sucker of a liver fluke: secondary point of attachment to host.


-Gastrovascular cavity of a liver fluke: forked tube of digestion (minimal in flukes) and distribution of nutrients throughout the body.


-Monoecious: referring to an organism that contains both male and female reproductive structures.


-Endoparasite: parasite that lives within the body of its host.


-Class Cestode: tapeworms


-Scolex: cranial end of tapeworm; lacks sensory structures but possesses modifications for attachment to intestinal wall of host.


-Hooks and suckers: Hooks - sharp, pointy attachments characteristic of many cestodes; modified for attachment of the parasite to its host.  Suckers - specialized structures common in trematodes and cestodes for attachment of the parasite to its host.


-Proglottids: serially repeated "segments" of a tapeworm's body containing primarily reproductive organs; each can live for a limited time after it detaches from the main body.


-Gravid proglottid: tapeworm segment containing ripe fertilized eggs; this segment is ready to drop off the tapeworm body and be eliminated from the host in feces.


Chapter 8 Nematoda


-Pseudocoelom: a body cavity that lies between a layer of mesoderm and a layer of gastrodermis


-Complete digestive tract: containing both a mouth and anus.


-Cuticle: a thin covering on nematodes secreted by the epidermis, permeable only to water, gases and some ions and thus serves as a protective coating, especially in parasitic forms.


-Dioecious: the sexes are separate


-Onchocerca spp.: a parasitic nematode which migrates to the victims' eyes causing blindness.


-Elephantiasis: results from a blockage of the lymphatic system brought about by one of several nematode species.


-Ascaris: large parasitic roundworm that infects humans and pigs.


-Spicules of the Ascaris: on the males, two small spiny projections; on the ventral surface near the anus; used during copulation.


-Seminal vesicle (male): enlarged tube representing terminal portion of male reproductive tract which transports mature sperm out of the nematode.


-Ductus deferens (male): stores mature sperm and transports them to seminal vesicle


-Branched uterus (female): site where developing eggs mature before being released.


-Oviduct (female): repository for eggs produced in ovary until fertilization


-Ovary (female): produces eggs


Chapter 9 Mollusca


-Class Bivalvia:  clams and mussels


-Class Cephalopoda:  octopus, squid, nautilus


-Adaptive radiation:  the evolution of numerous species from a common ancestor following migration into a new environment (mussels and squid being in the same phylum).


-Dioecious: the sexes are separate


-Open circulatory system: bivalves; a system in which the blood in not confined within a network of vessels; no veins are present.


-Closed circulatory system: blood in permanently contained within a network of arteries and veins.


-"Cephelopoda" = head foot, as in the squid


-Convergent evolution:  the independent development of similarity between species as a result of similar selection pressures typically generated by comparable ecological roles.  (Eyes of squid and humans).


Anatomy of a Cephalopod (squid):


Siphon: hollow tube through which water is expelled from the mantle cavity at high velocity to propel the squid through the water.


Mantle: body tube encircling visceral mass forming a hollow chamber in which water is collected and used for propulsion.


Arms: shorter appendages (8) used to manipulate captured prey and act as a rudder for navigating while swimming.


Tentacles: long, extensible, prehensile appendages (2) for capturing prey


Fins: triangular-shaped extensions of the caudal end of the body tube that are used for leisurely swimming and for maneuvering during locomotion.


Gills: feathery organs used for respiration


Ink sac: large sac that opens into the anus and secretes a dark brown or black fluid when the animal is alarmed.



Anatomy of a Bivalve:


Incurrent and excurrent canals: extendable, fleshy tubes that transport water into and out of the body.


Gills: used primarily for respiration and filter feeding; female freshwater mussels brood eggs in special gill pouches.


Mantle: thin membrane that secretes the shell.


Shell: hard outer covering that protects soft internal organs; composed of a mixture of calcium carbonate and protein.


Foot: muscularized region adjacent to visceral mass for burrowing and locomotion.


Visceral mass: pouch that contains several major internal organs.


Adductor muscle: large, tubular muscles located at the cranial and caudal ends of the animal; close shell and hold it tightly together.


Labial palps: fleshy folds of skin located near the mouth that collect food particles from the gills and transport them to the mouth.


Nephridia (kidney): excretory organs of bivalve which concentrate nitrogenous wastes and eliminate them from the body.


Digestive gland: greenish, granular tissue that secretes digestive enzymes into stomach and intestine to assist in the breakdown of food.


Chapter 10 Annelida


-Class Polychaeta: lugworms, clamworms, sandworms


-Class Oligochaeta: earthworms and blackworms


-Class Hirudinea: leeches


-ectoparasites: (leeches); attach to the outside of the host organism to obtain their nourishment.


-cranial sucker: sucker on the leech near the mouth (to attach to host).


-caudal sucker: sucker on the leech near the anus (to attach to host).


-true coelom: body cavity lined on both sides by mesoderm


-segmentation: the repetition of body regions containing similar organs


-closed circulatory system: consisting of pumping vessels (hearts, arteries and veins.


-complete digestive system: with specialized subregions.  Passes food through in one direction from the mouth to the anus.


-setae: small, hairline bristles used for locomotion


-hermaphroditic: referring to an animal which possesses both male and female sex organs, but is not capable of self-fertilization.


-clitellum: unsegmented band of tissue found in some groups of annelids; used in reproduction.


-parapodia: paired, feathery extensions along the lateral margins of polychaetes used primarily for respiration and, to some degree, for locomotion.


-polychaeta: "many bristles."


Anatomy of an earthworm (Lumbricus terrestris):


-Mouth: ingests soil


-Pharynx: muscularized region of digestive system specialized for pumping in soil.


-Esophagus: passageway between pharynx and crop.


-Crop: thin-walled chamber where food in stored.


-Gizzard: thick-walled, muscularized chamber where soil is ground and usable organic materials are separated from indigestible materials.


-Intestine: long tube occupying nearly two-thirds the length of the body in which nutrients are absorbed into the bloodstream.


-Hearts: specialized, muscularized branches of the dorsal blood vessel that rhythmically contract to pump blood throughout the body.


-Dorsal blood vessel: longitudinal blood vessel that distributes blood to the dorsal aspect of the body.


-Seminal vesicles: cream-colored, lobed organs fastened ventrally, but extending dorsally around each side of the esophagus that store maturing sperm.


-Septa: thin, fleshy partitions between segments.


Chapter 11


Arthropoda- phylum for classes Arachnida, Insecta and Malacostraca.  10 million species identified.  Evolved at least 410 million years ago.  Characters uniting group:  jointed appendages and segmented body and exoskeleton.  Arthropods contain a hemocoel and an open circulatory system. 


Hemocoel- main body cavity of arthropods


Malacostraca- Class containing lobsters, shrimp, and crabs as well as crayfish ( we dissected Cambarus).  Biramous appendages and two sets of antennae are defining characteristics.


Cephalothorax- head and thorax combined into one region.


Swimmerets or pleopods- caudal appendages used for swimming. 


Copulatory swimmerets- clubshaped swimmerets used to stimulate female crayfish during mating


Maxillipeds- 3 sets of appendages located on ventral surface used to manipulate food.


Uropod/telson- combined to form the tail of the crayfish used in locomotion.


Chelipeds- large pincers used for grasping food and for defense


Mandibles- hard mouthparts used for chewing


Walking legs or periopods- used for terrestrial movement


Insecta- class containing organisms with six uniramous walking appendages, single set of antennae and three distinct body regions- head, thorax and abdomen (we dissected Romalea


Cuticle- waxy covering around insects which protect from dessication. 


Spiracles- external openings in the abdomen that allow air movement into the tracheae of insects


Ocellus- photoreceptor in insect eye; cannot detect images


Gastric ceca- additional digestive areas between crop and stomach that assist in chemical digestion


Ovipositor- external opening bordered by chitinous teeth that allow female to bury eggs in soil


Malphigian tubules- stringy, fibrous excretory organs along the stomach and intestine that excrete waste allowing water to be conserved and reabsorbed by the intestine and the rectum

Chapter 12

Species dissected- Asterias

Radial symmetry- body parts arranged around a central axis such that any plane passing though the central axis divides the body into 2 similar halves


Pentamerous- having 5 limbs (arms in the case of the sea star)


True coelom- body cavity lined on both sides by mesoderm


Water vascular system- hydraulic system composed of a network of canals and small pumps that move water through the bodies of echinoderms to affect locomotor movements


Endoskeleton- animal support system enclosed beneath the outer body surface


Deuterostome- animal whose mouth develops from the 2nd embryonic opening (or anus develops first)


Oral surface- surface containing the mouth


Aboral surface- surface containing the madreporite- the “top” of the sea star


Pedicellariae- pincers on the aboral surface used to clean the sea star’s skin as well as its dermal branchiae


Dermal branchiae- structures on surface of skin that function in gas exchange and excretion


Spine- calcareous projections for protection and support


Madreporite- porous entrance to the water vascular system that regulates pressure and acts as a filter


Tube foot- powerfully strong structure on the oral surface of sea stars (sea urchins and sea cucumbers also have them) that capture food, and are responsible for locomotion of the animal


Radial canal- central structure of the water vascular system of Asterias and all organisms in the class Asteriodea that regulates water flow into the radial canals


Ambulacral groove- concave area on outer oral surface where tube feet are located


Pyloric stomach-digests food

Cardiac stomach- can be inverted to envelope prey

Aristotle’s lantern- structure on sea urchin (class Echinoidea) that control the teeth


Tentacles of sea cucumber- modified tube feet used to capture food particles floating in the water


Chapter 13

Species examined- Amphioxus



Homologous structures- structures in different species that are similar due to common ancestry


Myomeres- segmented muscles for movement


*Notochord- provides rigid support for myomeres


*Dorsal nerve cord- handles majority of nervous coordination without intervention of the brain


Wheel organ- lined with cilia that provides current of water to bring food into the mouth


Oral cirri- filters on outside of mouth


Oral hood- surrounds mouth


*Gill slits- allow for outflow of water from pharynx


Closed circulatory system- system in which blood is transported through arteries by a heart structure


*Postanal tail- extension of body past anus


* structures all chordates have at some point in their development


Chapter 14

Agnatha- superclass of jawless fish

Condrichthyes- class of cartilaginous fish


Fusiform- body shape adapted for efficient swimming; tapered at both ends of body


Scale- epidermally derived flattened plates


Opercula- paired bony plated covering gills; open to allow water release


Mandible- lower jaw having teeth, not fused to skull


Maxilla- upper jaw fused to skull, having teeth


Fins: Function

Pectoral- steering and braking, dorsal-ventral orientation

Pelvic- steering

Anal- steering

Caudal- thrust and steering

Adipose- pretty much just sits there

Dorsal- steering and dorsal-ventral orientation


Lateral lines- sensory organs that detect vibrations in water


Gills and gill filaments- highly vascularized (contain capillaries) for gas exchange and respiration


Heart- 2- chambered in fish; pumps deoxygenated blood to gills then to organs


Liver- white organ that detoxifies digested compounds and stores lipids and glycogen


Stomach- food storage and start of digestion


Intestine- site of final digestion


Hypaxial muscle- ventral part of muscle tissue


Epaxial muscle- dorsal part of muscle tissue


Swim bladder- hollow gas-filled sac used for buoyancy


Chapter 15

Genus names to know- Nectarus – the mudpuppy

Larval form- compressed tails, fusiform body shape, gills


Adult form- lungs, jointed limbs, lightweight skull


Ectotherm- animal that derives the majority of its heat from external sources


3-chambered heart- amphibian and reptile heart in which deoxygenated and oxygenated blood are not completely separated


urostyle- 10th vertebrae that extends to tail, forming the support for leaping (frog)


Chapter 16

Direct development- method of development in which embryo develops without need for water or a larval stage.  Young look like mini adults when born


Internal fertilization- direct implantation of sperm inside body, and fusing of sperm and egg in body. 


Keratinized scales- protein-based overlapping plates; does not allow for growth, and must be replaced often by ecdysis; turtles have modified keratinized scales called scutes of the shell


Ecdysis- shedding of reptile skin


Amniotic egg- reptile egg having leathery texture; allows for gas exchange but is waterproof


Ectotherm- animal that derives the majority of its heat from external sources


Carapace- turtle top (dorsal) shell fused to vertebrae; extension of rib cage


Plastron- turtles bottom (ventral) shell


Hinges- point of transverse flexion of the plastron in some turtle species


Hemipenes- paired penises of snake


Chapter 17

Homeothermic- maintaining a nearly constant body temperature


Feathers- modified scales used for flight (there are exceptions…some avians are flightless but still have wings -kiwi)


Beak- structure at end of jaws that has horned texture.  Lacks teeth; used for food mastication.


Four-chambered heart- pulmonary and systemic circuits are separated in this system; 2 ventricles and 2 atria


Hollow bones- modified bones to minimize weight in flying animals; muscles weigh more than bones in birds


Sternum- bone connecting ribs ventrally


Keel of sternum- large bone extending posterior from the sternum; attachment point for large pectoralis muscles used for flight


Clavicle- homologous to human collar bone, but positioned into a U-shape directing downward from the last cervical vertebrae


Pectoralis- largest muscle in the avian body, it’s “breast”, used to power the wings for flight.


Chapter 18

Species dissected : Rattus rattus

Endotherm- an animal that derives the majority of its body heat from internal metabolic sources.


Viviparous- referring to an animal that produces live young instead of eggs. ( all mammals are viviparous except the platypus and spiny anteater which produce eggs)


Internal fertilization- reproductive strategy in which sperm aare deposited within the female reproductive tract and fusion of sperm and egg occurs inside the body.


Mammary glands- modified tissues on the ventral surface of mammals that secrete milk           to nourish young.


Fetal membranes- embryonic tissues involved in pregnancy; chorion, amnion, and allantois


Placental attachment- method of mammalian development in which the fetus is connected           to the mother by the placenta, and derives nutrients from it.


Heterodont dentition- teeth that differ structurally to accommodate various food items


Dentary bone- bone of the lower jaw.  In mammals, this is characteristic in that it is the   only bone of the lower jaw.


*Identifying structures of male rats- preputial orifice (location of penis), scrotum.


*Identifying structures of female rats- vulva, mammary papillae (some male mammals have these-ex: humans!?- but are not as prominent as in females)


Structures of the rat


(Bold terms to know for practical)


Nares- openings in nose for breathing

Vibrissae- whiskers

Incisors- anterior teeth used to cut and gnaw

Auricles- disk shaped external ears for collection of sound waves

Preputial orifice- external opening to prepuce (sheath) through which penis extends

Scrotum- pouch extending from the caudal region that houses the testes

Mammary papillae- small protuberances on the ventral body surface through which that                      mammary glands secrete milk

Clitoris- homologous structure to the penis which plays a role in sexual stimulation

Vulva- most caudal region of the female urogenital tract

Anus- regulates egestion of undigested food from the body


Internal structures


Circulatory system- Specific vessels to know


Aortic arch- carries oxygenated blood to cranial regions of the body – find it!

Vena-cavas- main veins that carry deoxygenated blood back to the heart- find them!

Descending aorta- large main artery that carries oxygenated blood to the structures posterior to the heart- find it!

Subclavian arteries- branching off of the aortic arch, the artery carrying blood to the forelimbs

Subclavian vein- the vein bringing deoxygenated blood back to the heart from the forelimbs

Iliac artery- vessel branching from descending aorta to carry blood to the legs


Muscles- identify a muscle vs an organ in texture and location, but not names


Sternomasoideus- turns head

Sternohyoideus- pulls tongue back

Acromiodeltoideus- pulls humerus forward

Biceps brachii- flexes forelimb

Triceps- extends forearm

Pectoralis major- adducts forelimb

Pectoralis minor- same

Latissimus dorsi- pulls humerus backward

Rectus abdominis- compresses abdomen

External oblique- compresses abdomen and flexes trunk


Some organs/structures of the rat/mammal


Esophagus- transports food to the stomach

Trachea- conducts air to and from the lungs during respiration

Aortic arch- transports oxygenated blood from the left ventricle of the heart to the dorsal aorta for distribution to the regions of the body

Diaphragm- flat, muscular sheet separating thoracic and abdominal cavities used to ventilate lungs through negative pressure.

Liver- produces bile , converts glucose to glycogen for storage detoxifies many constituents of the absorbed digested compounds

Duodenum- part of the small intestine; receives chyme from the stomach and along with secretory enzymes from the gallbladder and pancreas

Spleen- regulates blood volume by releasing stored red blood cells into the bloodstream                       when necessary

Respiratory system- system used to bring oxygenated air into the body and release carbon         dioxide from the body.  Mammals must also warm and humidify the incoming air            and cool and dehydrate exiting air.

 Heart – 4-chambered muscle (in birds and mammals) with 2 atria and 2 ventricles that pumps blood to lungs and to body tissues

Lung- paired multi-lobed highly vascularized organs for respiration

Pancreas- produces digestive enzymes to be secreted into the small intestine

Cecum- beginning of the large intestine, responsible for breaking up vegetation  

Stomach- produces HCl and pepsinogen that aid in the chemical breakdown of food

Small intestine- breaks down food and absorbs nutrients to be sent to body

Large intestine- comprised of cecum, decending colon and rectum, responsible for transport of fecal matter and reabsorption of water