Zoology Lab Notes PDF

ACT 01 IRIS DIAPHRAGM The Microscope -​ Controls the amount of light. CONDENSER -​ Gather light from the microscope'...

ACT 01 IRIS DIAPHRAGM The Microscope -​ Controls the amount of light. CONDENSER -​ Gather light from the microscope's light source and concentrate it into a cone of light that illuminates the specimen. LIGHT SOURCE/ILLUMINATOR -​ Reflects light through the specimen. COARSE ADJUSTMENT KNOB -​ Appropriate for focusing on Scanner or LPO. FINE ADJUSTMENT KNOB -​ For final focusing. BASE -​ Serves as a support for microscopes. Parts of the Microscope and their Calculating Calibration Functions -​ STAGE MICROMETER OCULAR/EYEPIECE -​ OCULAR MICROMETER -​ Contains a lens normally with a 10 x magnification with pointer to aid in locating objects within the field of view. ARM HANDLE -​ Attachment for other mechanical -​ 4x (SCANNER) = 25 parts. -​ 10x (LPO) = 10 REVOLVING NOSEPIECE -​ 40x (HPO) = 2.5 -​ Holds and shifts the objectives. -​ 100x (OIO) = 1 OBJECTIVES -​ Contain lenses for magnification. Comparison of Microscopes -​ SCANNER: 4x Microscop Compound Dissecting -​ LOW POWER OBJECTIVE: 10x e Aspect Microscop Microscop -​ HIGH POWER OBJECTIVE: 40x e e -​ OIL IMMERSION OBJECTIVE: 100x STAGE Magnificati 4x, 10x, 5x, 50x on 40x, 100x (Higher) -​ Platform on which slide is positioned. (Lower) STAGE CLIPS -​ Hold the slide in place. Dimensions 2D 3D -​ Move the slide on the stage.  SHAPE: Fusiform/spindle Inversion of Inverted Upright FROG OVARY Image Direction of Opposite Aligned Movement of with movement movement being being done done Animal Cell Structure SHAPE: Spherical-shaped -​ Under the light microscope, three -​ Frog egg cells provide a lot of room parts can be seen in the animal cell: for storing nutrients and helping the the cell membrane, nucleus, and growth of early embryos. cytoplasm. FROG BLOOD SMEAR (BONE MARROW) -​ CELL MEMBRANE: The structure that surrounds the cell and regulates the flow of substances between the cell and its surroundings. -​ NUCLEUS: Usually spherical or ovoid structure that contains the genetic material. -​ CYTOPLASM: The substance outside RBC SHAPE: Oval the nucleus where the other WBC SHAPE: Amorphous structures such as organelles are -​ RBC has distinct nucleus that are located. more evident with frogs because Human Cheek Cells Activity they don't need a lot of oxygen as -​ Utilize methylene blue to get a more amphibians. in-depth or clearer view of the -​ WBC has no distinct nucleus that are cellular structures present in our more evident with humans because cheek cells. we need it for our immune system. Animal Cells Activity FROG SPERM (TESTIS) FROG STOMACH SHAPE: Thread-like -​ The chromatin fibers start to appear -​ The sperm cell can move toward the as coiled, thickened, condensed egg and fertilize it due to the structures forming chromosomes. flagellum. By whirling back and forth, it moves the sperm forward and through the female reproductive tract. ACT 02 Cell Division/Mitosis INTERPHASE METAPHASE -​ The chromosomes are aligned at the equatorial region/metaphase plate of the nucleus. -​ The replicated chromosomes, which are much shorter and more condensed, are known as sister G0 - The resting phase. The cell is neither chromatids. dividing nor preparing to divide. -​ Centromeres are kinetochores, G1 - The preparation phase. This is where protein complexes to which the cell growth and the number of cytoplasmic spindle fibers are attached to. structures increase. Also where doubling in ANAPHASE number of centromeres occurs. -​ Sister chromatids are pulled apart S - DNA synthesis. toward the opposite poles. This stage G2 - Biochemical preparation for the onset is differentiated into early and late of mitosis stages depending on the distance -​ Genetic material is called chromatin travelled by the chromatids. here. TELOPHASE PROPHASE -​ A constriction of the plasma membrane at the region of the equatorial plate starts to appear. -​ EARLY TELOPHASE - the nuclear membrane and the nucleolus start to reappear. The chromosomes begin to uncoil and assume a threadlike appearance. The asters and mitotic spindles disappear.  -​ LATE TELOPHASE - the cleavage furrow becomes more constricted leading to the formation of 2 daughter cells. Animal Development CLEAVAGE EARLY CLEAVAGE -​ Consists of ectoderm, mesoderm, and endoderm, blastopore, yolk plug, and archenteron. BASTRULA -​ Cleavage cells are called blastomeres that make up the embryo. LATE CLEAVAGE -​ Cavity = blastocoel. NEURULA -​ Small blastomere = micromere at animal pole. -​ Large blastomere = macromere at vegetal pole (yolk). GASTRULA  TISSUES -​ Once the germ layers are established, the different organs start to form = organogenesis. -​ The stage of development = neurulation. Epithelial Tissue -​ The embryo at this stage = neurula. -​ Consists of neural fold, neural -​ Forms the covering of external groove, neural fold, notochord, surfaces. ectoderm, lateral plate mesoderm, -​ Lines the internal surfaces. and endoderm. -​ Forms secretory units of the exocrine and endocrine glands. Germ Layer Structures Derived from Functions of Epithelial Tissue Layer -​ Protection of the skin. Ectoderm CNS, sense -​ Excretion of waste products in the organs, epidermis kidney. -​ Special functions for the sensory Mesoderm Heart, muscles, organs thru the neuroepithelial cells. urogenital system, vertebral column, Characteristics of Epithelial Tissue dermis of the skin 1.​ Highly cellular -​ Composed of cells closely packed Endoderm Lining of the together. intestinal tract, 2.​ Avascular lungs -​ Lacks blood vessels, but it's innervated by nerves. ACT 03 3.​ Presence of basement membrane  -​ Provides structural support for the -​ Makes up the superficial surface of epithelium. the conjunctiva and cornea of the eye. Simple Epithelium ​ Nonkeratinized Epithelium -​ Lacks keratin. -​ MESOTHELIUM: Covers external -​ Has a wet and porous surfaces of digestive organs, lungs, surface. and heart. -​ Moisturized by mucus from -​ ENDOTHELIUM: Covers the lumina of salivary or mucus glands. the heart chambers, blood vessels, -​ Covers moist cavities. and lymphatic vessels ​ Keratinized Epithelium 1.​ Simple Squamous Epithelium -​ Lines external surface of the body. -​ Alveoli of lungs. -​ Made up of nonliving (dead layer), -​ Parietal layer of Bowman's capsule. keratinized cells filled with keratin -​ Inner lining of blood vessels. protein. 2.​ Simple Cuboidal Epithelium -​ Acts as a waterproof barrier. -​ Certain ducts of pancreas and 1.​ Transitional Epithelium salivary glands. -​ Lines the lumen of renal calyces, -​ Collecting tubules of kidney. pelvis, ureters, and urinary bladder. -​ Follicles of thyroid gland. -​ Designed to withstand stretching. -​ Surface of ovary. 2.​ Pseudostratified Columnar 3.​ Simple Columnar Epithelium -​ Lines the membranous and spongy -​ Lines the stomach, intestine, and parts of the male urethra. large ducts of some exocrine glands. -​ Ciliated pseudostratified columnar > -​ Typically lines the uterus, oviducts, Respiratory epithelium. and pulmonary bronchi. ​ Cilia Stratified Epithelium -​ Present in the apical surfaces of the cell. -​ Found in skin, oral epithelia, -​ Specialized for transport of stomach, and some glands. fluid or mucous over the 1.​ Stratified Squamous Epithelium surface of the epithelium. -​ New cells are formed in deep layers -​ Motile, fingerlike extensions of only. the plasma membrane. -​ Forms the epidermis. -​ Lines the digestive tract from oral Connective Tissues cavity to esophagus. -​ Envelops the muscles. -​ Lines the vagina and part of urethra. -​ Binds body parts together while allowing some degree of movement.  -​ Forms supporting framework of -​ Colorless but if present in abundant various organs. amounts, they show white color to -​ Place for exchange of gases and fresh tissue. substances. -​ Composed of cells and extracellular Elastic Fibers substances (matrix). -​ Yellow fibers. ​ Matrix -​ Not as widely distributed as the -​ Made up of ground collagen fibers. substance and tissue fluid. -​ Abundant in structures that are -​ GROUND SUBSTANCE: subjected to frequent stretching. Homogenous, transparent, -​ Usually found in auricle and external and hydrated gel, consists acoustic meatus, external nose, mainly of water that is auditory tube, epiglottis, and some stabilized by proteoglycans, parts of the larynx. mineral salts, and glycoproteins. Reticular Fibers -​ FIBERS: Provides tensile strength and flexibility. Elastic -​ Very fine fibers that tend to branch fibers provide resiliency and anastomose. -​ Form extensive networks in some Loose Connective Tissue organs. -​ Main extracellular fibers in the stroma -​ Hypodermis of the skin. of the bone marrow, liver, lymph -​ Tunica adventitia of blood vessels. nodes, and spleen. -​ Lamina propria and submucosa of digestive, respiratory, and urogenital Dense Connective Tissue tracts. -​ Characterized by high vascularity -​ Contains an abundance of closely and abundance of extracellular packed collagen fibers in the substances. extracellular matrix. -​ Collagen fibers run in various Collagen Fibers directions. -​ Dermis of the skin. -​ White fibers -​ Dura mater of the brain. -​ Present in all connective tissues but -​ Capsule of the liver, lymph nodes, in varying amount. spleen, and testis. -​ In most connective tissues, they are the main extracellular fibers. Adipose Tissue  White blood cells ​ Granulocytes -​ NEUTROPHILS: Most numerous among leukocytes, defend the body against pathogenic bacteria, mediate inflammatory response. -​ EOSINOPHILS: Bilobed nucleus, defend body against parasites. -​ Fat cells, adipocytes. -​ BASOPHILS: U- or J-shaped, -​ Specialized to store lipids in its known to release histamine, cytoplasm. least known among the -​ SIGNET RING CELLS: Large empty granulocytes. space and flattened nucleus ​ Agranulocytes located on one side of the cell. -​ LYMPHOCYTES: Principal agent of the body's immune White Adipose Tissue response, nucleus occupies -​ Serves as energy source. almost the entire cell, -​ Provides insulation under the skin. kidney-shaped or round with -​ Forms cushioning fat pads around coarse, clumpy chromatin organs. granules. -​ MONOCYTES: Bean- or Brown Adipose Tissue U-shaped nucleus, 2 or more nucleoli can be seen, serve -​ Supply body with heat. as precursor to macrophages, originate from Blood bone marrow. Red blood cell Cartilage -​ Unstained RBC is pale yellow or -​ Form the bulk of the fetal skeleton. greenish yellow. -​ CHONDROCYTES: Cells of the -​ Routinely stained RBCs are pink. cartilage vary in shape and size, -​ ROULEAUX FORMATION: young chondrocytes are elliptical in Phenomenon where the RBCs tend shape, mature chondrocytes to adhere to each other on their flat become larger and rounded, and surfaces like a stack of coins, the nucleus is ovoid. common in horses.  Hyaline Cartilage -​ Can withstand greater stress than hyaline or elastic cartilage. -​ Glistening, smooth, and pearly white -​ Composes the intervertebral and in fresh specimen. articular discs and surface layers of -​ Most abundant type of cartilage. tendons and ligament. -​ Serves as temporary skeleton for the fetus. Bone ​ Articular cartilage -​ Hyaline cartilage in joints. ​ Costal cartilage -​ Trachea, bronchi, parts of larynx, nose, ears, and sternal end of ribs. Elastic Cartilage -​ Special form of connective tissue. -​ Becomes calcified due to mineral deposition in the matrix. -​ Functions > Protects brain (skull), heart and lungs (thorax), and urinary and reproductive organs (pelvic -​ More flexible than hyaline. bones), hemopoiesis, reservoir for -​ Present in auricle and external calcium, phosphate, and other acoustic meatus of the ear, auditory minerals tube, and epiglottis and some parts Muscle Tissue of the larynx. Fibro Cartilage Cardiac Muscle  Nervous Tissue ORGANOLOGY Smooth Muscle Frog’s skin Epidermis -​ Outer layer. -​ Made up of stratified epithelium. Skeletal Muscle -​ STRATUM CORNEUM: Layers of dead, flattened cells. -​ STRATUM GERMINATIVUM: > Several layers of cuboidal to columnar cells. Dermis -​ STRATUM SPONGIOSUM: Loosely arranged connective tissue fibers and blood vessels. -​ STRATUM COMPACTUM: Inner layer, made up of white fibrous connective  tissue running parallel to the surface -​ MUSCULARIS MUCOSA: A thin layer of of the skin smooth muscle. -​ MELANOPHORES: Black pigment cells Submucosa between stratum germinativum and stratum spongiosum. -​ This layer beneath the mucosa is made of connective tissues Frog's Stomach and Small Intestine containing glands, blood vessels and nerves. Rugae Tunica muscularis -​ Folds in the inner wall of the stomach that projects into the cavity of the -​ This is a thick layer of circular and organ. longitudinal smooth muscles. Villi Serosa -​ The outermost layer of loose -​ Folds found in the small intestine. connective tissue covered by a layer Tunica mucosa of mesothelium. Blood vessels -​ TUNICA INTIMA: This internal layer -​ This layer is thrown into folds into the which includes the lining epithelium lumen. of the vessel and a layer of elastic -​ SIMPLE COLUMNAR EPITHELIUM: In the tissue in wavy appearance. small intestine, goblet cells may be -​ TUNICA MEDIA: This is the seen among the columnar cells. intermediate layer made of smooth Goblet cells are absent in the muscle, collagenous and elastic stomach. fibers, and connective tissue cells. -​ LAMINA PROPIA: A connective tissue -​ TUNICA EXTERNA: This external layer layer containing glands and blood in which the elements include vessels. external elastic membrane,  collagenous and elastic fibers, blood vessels, and loose connective tissue. Spinal Cord -​ Inner = central canal > grey matter > white matter > dura mater (skin)