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Zoology/nv, , NAVAS CHEEMADAN, ii) Cuboidal epithelium, , Chapter 7, Structural Organization In Animals, Animal Tissue, •, •, , Tissues are group of similar cells along with intercellular, substances perform a specific function., Tissues are broadly classified into four types:, , The cuboidal epithelium is composed of a single layer of, cube-like cells., • This is commonly found in ducts of glands and tubular, parts of nephrons in kidneys, • its main functions are secretion and absorption., • The epithelium of proximal convoluted tubule (PCT) of, nephron in the kidney has microvilli, iii) Columnar epithelium, •, , A) Epithelial tissue, B) Connective tissue, C) Muscular tissue, D) Neural tissue, , A) Epithelial tissue, This tissue has a free surface, which faces either a body, fluid or the outside environment.., • Epithelial tissues provide a covering or a lining for some, part of the body., • The cells are compactly packed with little intercellular, matrix., • Based on the number of layers tissues are of two types, namely, a)simple epithelium, b) Compound epithelium., i)Simple epithelium, • it is composed of a single layer of cells, • it functions as a lining for body cavities, ducts, and, tubes., • On the basis of structural modification of the cells,, simple epithelium is further divided into three types., These are, i) Squamous epithelium, ii) Cuboidal epithelium, iii) Columnar epithelium, i) Squamous epithelium, , •, , •, •, •, , •, •, •, •, , The columnar epithelium is composed of a single layer, of tall and slender cells., Their nuclei are located at the base., Free surface may have microvilli., They are found in the lining of stomach and intestine, and help in secretion and absorption., , Ciliated Epithelium, •, , •, •, , The squamous epithelium is made of a single thin layer, of flattened cells with irregular boundaries., They are found in the walls of blood vessels and air, sacs of lungs, They are involved in functions like forming a diffusion, boundary., , If the columnar or cuboidal cells bear cilia on, their free surface they are called ciliated, epithelium ., Their function is to move particles or mucus in a, specific direction over the epithelium., They are mainly present in the inner surface of, hollow organs like bronchioles and fallopian, tubes, , ., , Functional modification of epithelium, Some of the columnar or cuboidal cells get, specialized for secretion and are called glandular, epithelium, They are mainly of two types:, 1, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, individual cells. Three types of cell junctions are found in the, epithelium and other tissues. These are called as, i) Tight junction,, ii) Adhering junction, iii) Gap junctions., i) Tight junctions:, Tight junctions help to stop substances from, leaking across a tissue., ii) Adhering junctions, it perform cementing to keep neighboring cells, together., iii) Gap junctions, it facilitate the cells to communicate with each, other by connecting the cytoplasm of adjoining cells, for, rapid transfer of ions, small molecules and sometimes, big molecules., , i) Unicellular glandular epithelium:, it consist of isolated glandular cells, eg: goblet cells of the alimentary canal, ii) Multicellular glandular epithelium,, it consist of cluster of cells, eg: salivary gland, , Types of glands, On the basis of the mode of pouring of their, secretions, glands are divided into two categories namely, i) Exocrine gland, ii) Endocrine glands., i) Exocrine glands:, These glands secrete mucus, saliva, ear wax, oil,, milk, digestive enzymes and other cell products. These, products are released through ducts or tubes, ii) Endocrine glands, The secretion of these glands are called Hormones., they do not have ducts. The Hormones are secreted directly, into the fluid (Blood). Hence this gland is called ductless, gland., ii)Compound Epithelium, , B) Connective tissue, •, •, , •, •, , Connective tissues are most abundant and widely, distributed in the body of complex animals., They are named connective tissues because of, their special function of linking and supporting, other tissues/organs of the body., In all connective tissues except blood, the cells secrete, fibres of structural proteins called collagen or elastin., The fibres provide strength, elasticity and flexibility to, the tissue. These cells also secrete modified, polysaccharides, which accumulate between cells and, fibres and act as matrix (ground substance)., , Connective tissues are classified into three types:, (i) Loose connective tissue,, (ii) Dense connective tissue, (iii) Specialised connective tissue., , (i) Loose connective tissue, Loose connective tissue has cells and fibres, loosely arranged in a semi-fluid ground substance,, Examples:, 1. Areolar tissue:, It is present beneath the skin. Often it serves as a, support framework for epithelium. It contains fibroblasts, (cells that produce and secrete fibres), macrophages and, mast cells., , •, , •, •, , Compound epithelium is made of more than one layer, (multi-layered) of cells and thus has a limited role in, secretion and absorption., Their main function is to provide protection against, chemical and mechanical stresses., They cover the dry surface of the skin, the moist, surface of buccal cavity, pharynx, inner lining of ducts of, salivary glands and of pancreatic ducts., , Junctional Complex, . In nearly all animal tissues, specialised junctions, provide both structural and functional links between its, 2, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , b)Dense irregular connective tissue, In dense irregular connective tissues, fibroblasts, and many fibres (mostly collagen) that are oriented, differently (irregularly). This tissue is present in the skin., , 2. Adipose tissue:, It located mainly beneath the skin. The cells of this, tissue are specialised to store fats., • The excess of nutrients which are not used, immediately are converted into fats and are stored, in this tissue, , (iii) Specialised connective tissue., Cartilages, Bones and blood are various types of specialised, connective tissues., a)Cartilage:, Cells of this tissue (chondrocytes) are enclosed in, small cavities within the matrix secreted by them. Most of the, cartilages in vertebrate embryos are replaced by bones in, adults. Cartilage is present in the tip of nose, outer ear, joints, between adjacent bones of the vertebral column,, limbs and hands in adults., , (ii) Dense connective tissue, In this type of connective tissue Fibres and, fibroblasts are compactly packed. Based on the orientation, of fibres (regular / irregular) dense connective tissues are of, 3 types, , a) Dense regular connective tissue, In the dense regular connective tissues, the, collagen fibres are present in rows between many parallel, bundles of fibres., , b)Bones, Bones have a hard and non-pliable ground, substance rich in calcium salts and collagen fibres which, give bone its strength The bone cells (osteocytes) are, present in the spaces called lacunae, , Examples:, 1.Tendons:, It attach skeletal muscles to bones, 2.ligaments, It attach one bone to another bone, , 3, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , The main functions of the bones are, 1. It is the main tissue that provides structural frame to, the body., 2. Bones support and protect softer tissues and, organs. Limb bones, such as the long bones of the, legs, serve weight-bearing functions., 3. It provide surface for the attachment of skeletal, muscles to bring about movements., 4. The bone marrow in some bones is the site of, production of blood cells., c)Blood, Blood is a fluid connective tissue containing plasma, red, blood cells (RBC), white blood cells (WBC) and platelets., , iii) Cardiac muscles, , They are the muscles of heart. Communication, junctions (intercalated discs) at some fusion points allow, the cells to contract as a unit, i.e., when one cell receives a, signal to contract, its neighbours are also stimulated to, contract., , D) Neural tissue, , C) Muscular tissue, , Neurons, the unit of neural system are excitable, cells. The neuroglial cells protect and support neurons., Neuroglia make more than one half the volume of neural, tissue in our body, , Muscles play an active role in all the movements of, the body. Muscles are of three types,, i) Skeletal muscles, ii) Smooth muscles, iii) Cardiac muscles, i) Skeletal muscles, , This tissue is closely attached to skeletal bones., This muscles are also called striated muscles or striped, muscles, Eg: biceps and triceps muscles, ii) Smooth muscles, , The smooth muscle fibres taper at both ends, (fusiform) and do not show striations ,hence the name, smooth muscles. Cell junctions hold them together and they, are bundled together in a connective tissue sheath., This type of muscles is present in the wall of, internal organs such as the blood vessels, stomach and, intestine. Smooth muscles are ‘involuntary’ in functions., 4, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , Mouth parts:, • The mouth parts consisting of, • a labrum (upper lip),, • a pair of mandibles,, • a pair of maxillae, • a labium (lower lip)., • A median flexible lobe, acting as tongue, (hypopharynx), lies lies within the cavity, enclosed, by, the, mouthparts, , COCKROACH, •, , •, , •, , •, , Cockroaches are brown or black bodied, animals that are included in class Insecta of, Phylum Arthropoda., Bright yellow, red and green coloured, cockroaches have also been reported in, tropical regions., Their size ranges from ¼ inches to 3 inches, (0.6-7.6 cm) and have long antenna, legs and, flat extension of the upper body wall that, conceals head., They are nocturnal omnivores that live in, damp places throughout the world., , Morphology, • The adults of the common species of, cockroach, Periplaneta americana are about, 34-53 mm long with wings that extend, beyond the tip of the abdomen in males. ., , b)Thorax, • Thorax consists of three parts, • – prothorax, mesothorax and metathorax., • The head is connected with thorax by a short, extension of the prothorax known as the, neck., • Each thoracic segment bears a pair of walking, legs., Wings:,
cockroaches have two pairs of wings.,
The first pair of wings arises from, mesothorax and the second pair from, metathorax.,
Forewings (mesothoracic) called tegmina are, opaque dark and leathery and cover the hind, wings when at rest.,
The hind wings are transparent, membranous, and are used in flight., , • The entire body is covered by a hard, chitinous exoskeleton (brown in colour)., , • In each segment, exoskeleton has hardened, plates called sclerites (tergites dorsally and, sternites ventrally) that are joined to each, other by a thin and flexible articular, membrane (arthrodial membrane)., , • The body of the cockroach is segmented and, divisible into three distinct regions –, a) head, b)thorax and c)abdomen, a)Head, • Head is triangular in shape It is formed by the, fusion of six segments, • Head shows great mobility in all directions, due to flexible neck, • The head capsule bears a pair of compound, eyes, • A pair of thread like antennae arise from, membranous sockets lying in front of eyes., • Anterior end of the head bears appendages, forming biting and chewing type of mouth, parts., , Difference between fore wing and hind, wings, Fore wings, 1.it, arises, from, mesothorax, 2.they are opaque, 3.they are leathery, , Hind wings, 1.it arise from meta, thorax, 2.they are transparent, 3.they, are, membranous, 4.they cover the hind 4.it is used for flight, wings at rest, 5, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , d)Abdomen, The abdomen in both males and females, consists of 10 segments., Abdomen in female:,
In females, the 7th sternum is boat, shaped and together with the 8th and, 9th sterna forms a brood or genital pouch, whose anterior part contains female, gonopore, spermathecal pores and, collateral glands., Abdomen in male:,
In males, genital pouch or chamber lies at, the hind end of abdomen bounded, dorsally by 9th and 10th terga and, ventrally by the 9th sternum. It contains, dorsal anus, ventral male genital pore, and gonapophysis., •, Males bear a pair of short thread like anal, style, which are absent in female., , a)foregut:,  it starts with mouth.,  The mouth opens into a short tubular, pharynx, leading to a narrow tubular passage, called oesophagus.,  This in turn opens into a sac like structure, called crop used for storing of food.,  The crop is followed by gizzard or, proventriculus.,  It has an outer layer of thick circular muscles, and thick inner cuticle forming six highly, chitinous plate called teeth.,  Gizzard helps in grinding the food particles., The entire foregut is lined by cuticle.,  A ring of 6-8 blind tubules called hepatic or, gastric caecae is present at the junction of, foregut and midgut, which secrete digestive, juice., b) midgut:,  At the junction of midgut and hindgut is, present another ring of 100-150 yellow, coloured thin filamentous Malpighian, tubules.,  They help in removal of excretory products, from haemolymph., c)Hindgut:,  The hindgut is differentiated into ileum, colon, and rectum.,  The rectum opens out through anus, , •, In both sexes, the 10th segment bears a pair, of jointed filamentous structures called anal cerci., , Digestive system, Digestive system consist of alimentary canal and, digestive glands, A), alimentary canal, The alimentary canal is divided into three, regions: foregut, midgut and hindgut, , Circulatory system,  Blood vascular system of cockroach is an, open type Blood vessels are poorly developed, and open into space (haemocoel).,  Visceral organs located in the haemocoel are, bathed in blood (haemolymph).,  The haemolymph is composed of colourless, plasma and haemocytes.,  Heart of cockroach. is differentiated into, funnel shaped chambers with ostia on either, side., 6, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, ,  Blood from sinuses enter heart through ostia, and is pumped anteriorly to sinuses again, Haemocoel->ostia->heart->haemocoel, ,  Three ganglia lie in the thorax, and six in the, abdomen.,  The nervous system of cockroach is spread, throughout the body.,  The head holds a bit of a nervous system, while the rest is situated along the ventral, (belly-side) part of its body. That is why if the, head of a cockroach is cut off, it will still live, for as long as one week.,  The brain is represented by supraoesophageal ganglion which supplies nerves, to antennae and compound eyes., , Sensory organs,  In cockroach, the sense organs are antennae,, eyes, maxillary palps, labial palps, anal cerci,, etc.,  The compound eyes are situated at the, dorsal surface of the head.,  Each eye consists of about 2000 hexagonal, ommatidia With the help of several, ommatidia, a cockroach can receive several, images of an object. This kind of vision is, known as mosaic vision with more sensitivity, but less resolution, being common during, night (hence called nocturnal vision).,  Antennae have sensory receptors that help in, monitoring the environment., , Respiratory system,  The respiratory system consists of a network, of trachea, that open through 10 pairs of, small holes called spiracles present on the, lateral side of the body.,  Thin branching tubes (tracheal tubes, subdivided into tracheoles) carry oxygen from, the air to all the parts.,  The opening of the spiracles is regulated by, the sphincters.,  Exchange of gases take place at the, tracheoles by diffusion., , Reproductive system, , Excretory system,  Excretion is performed by Malpighian, tubules.,  They absorb nitrogenous waste products and, convert them into uric acid which is excreted, out through the hindgut.,  Therefore, this insect is called uricotelic.,  In addition, the fat body, nephrocytes and, urecose glands also help in excretion, , •, , Cockroaches are dioecious and both sexes, have well developed reproductive organs., , •, , The male and female cockroach can be, identified by the difference in their, morphological features . This phenomenon is, called sexual dimorphism, , Male reproductive organs, • Male reproductive system consists of a pair of, testes one lying on each lateral side in the 4th, -6th abdominal segments., • From each testis arises a thin vas deferens,, which opens into ejaculatory duct through, seminal vesicle., • The ejaculatory duct opens into male, gonopore situated ventral to anus., , Nervous system,  The nervous system of cockroach consists of a, series of fused, segmentally arranged ganglia, joined by paired longitudinal connectives on, the ventral side., 7, , [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , Oviducts of each ovary unite into a single, median oviduct (also called vagina) which, opens into the genital chamber., • A pair of spermatheca is present in the 6th, segment which opens into the genital, chamber., Fertilization and development :, • Sperms, are, transferred, through, spermatophores. Their fertilised eggsare, encased in capsules called oothecae., • Ootheca is a dark reddish to blackish brown, capsule, 8 mm long., • They are dropped glued to a suitable surface,, usually in a crack or crevice of high relative, humidity near a food source., • On an average, females produce 9-10, oothecae, each containing 14-16 eggs., • The development of P. Americana is, paurometabolous,, meaning, there, is, development through nymphal stage., • The nymphs look very much like adults. The, nymph grows by moulting about 13 times to, reach the adult form., • The next to last nymphal stage has wing pads, but only adult cockroaches have wings., •, , A characteristic mushroom shaped gland, present in the 6th to 7th abdominal segments, which function as an accessory reproductive, gland., • The external genitalia are represented by, male gonapophysis or phallomere (chitinous, asymmetrical structures, surrounding the, male gonopore)., • The sperms are stored in the seminal vesicles, and are glued together in the form of bundles, called spermatophores which are discharged, during copulation., Female reproductive organ, •, , Interaction to mankind/Economical importance,  Many species of cockroaches are wild and are, of no economic importance.,  A few species thrive in and around human, habitat.,  They are pests because they destroy food, and contaminate it with their smelly excreta.,  They can transmit a variety of bacterial, diseases by contaminating food material., , •, , •, , The female reproductive system consists of, two large ovaries, lying laterally in the 2nd –, 6th abdominal segments., Each ovary is formed of a group of eight, ovarian tubules or ovarioles, containing a, chain of developing ova., , 8, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , 7. Prepare 2 correctly matching pairs from the, given terms, (HSE-Sept-2016), (2), Ommatidia, Hepatic caecae, Genital pouch, Sense organ, Excretory organ, Digestive gland, Upper lip, , Previous Year Question Paper, 1. “In cockroaches a special mode of vision is, noticed”, (HSE-July-2017)(2), a)Write speciality of vision in cockroach, b)Name the organ and its basic units that, perform vision in cockroach., 2. Select the connective tissues from the, following and write one characters of each, tissue, , 8. Observe the following chart and answer the, following question (HSE-March-2016), (2), , Areolar tissue, Neural tissue, Adipose tissue, Cardiac tissue, , (HSE-JULY-2017)(2), 3. In cockroach spiracles are present in..........., a)Alimentary canal, b)Tracheal system, c)Malpighian tubule, d)Reproductive system, (HSE-March-2017)(1), 4. Complete the given branching diagram based, on connective tissue, (HSE-March-2017)(2), Fill in the missing word A and B, 9. Name any two secretions of exocrine glands?, (HSE october-2015)(1), 10. Select the odd one out in the following series, a) Areolar tissue, blood, neuron, tendon, b) Hypopharynx, malpighian tubule, maxillae, ,labrum, (HSE October-2015)(1), 11. In a laboratory session, your biology teacher, exhibited blood smear (slides) of cockroach, and human being under microscope. How will, you distinguish them based on the nature of, plasma and blood cell (HSE october-2015)(2), 12. If the head of cockroach is cut off, it will be, alive as long as one week. Give clarification, for this statement, (HSE march-2015)(1), 13. The diagram below is a simple epithelium, (HSE march-2015)(1), , 5., 6. a)Identify the given diagram of connective, tissue A and B, , b)Write the location of tissue B in the human, body, (HSE-Sept-2016), (2), 9, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , 19. Features of a particular tissue visible through, a microscopic observation is presented here, (HSE October-2013)(2), • Cells are closely arranged, • Intercellular matrix absent, • Cells are supported by basement, membrane, a) Identify the animal tissue, b) Classify this tissue based on number of cell, layers, c) Mention their functions, 20. Observe the schematic diagram of a tissue, (HSE September-2012) (2), a) Identify the type of this tissue, b) The fibres in this tissue help the tissue, to perform function. Substantiate, , a) Name the part marked as P, b) Write one function of simple epithelium, 14. The male and female cockroach can be, identified by the difference in their, morphological features (HSE march-2015)(2), a) Name this phenomenon, b) give one external difference between, male and females, 15. Names of two animal tissues are given, (HSE august-2014)(2), a)cardiac muscle tissue, b) Adipose tissue, i) Write the location of these tissues in our, body, ii) Select accurate characters of each, tissue from the items given below, 1. Cells of this tissues are specialised to, store fat, 2. Cells of this tissues (Chondrocyte) are, seen in small cavities within the matrix, 3. presence of intercalated disc, 16. Mention the function of the following, (HSE august-2014)(1), a)Hepatic ceaca of periplaneta Americana, 17. Where do you find the following structure in, human body, (HSE march-2014)(2), a)Collagen fibre b)Axons, c) Squamous epithelium, d)Smooth muscle, 18. Fill in the blanks with suitable terms according, to the indicator shown below, (HSE march-2014)(2), Indicators a and b –food habits, C and d-Excretory organ, a)Cockroach :................, b)Earthworm:..............., c) Cockroach :................, d)Earthworm:..............., , 21. Facts related to two types of tissues are given, below. Arrange them into two columns by, giving suitable headings. Mention the location, of each tissue in the human body, (HSE march-2012)(4), • A sheath of tough connective tissue, • Striations absent, • Bundled together in a parallel fashion, • Fusiform shape, • Involuntary in function, • Striated appearence, , 10, [email protected]

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Zoology/nv, , NAVAS CHEEMADAN, , 22. Observe the following figure. No need to, redraw the diagram, (HSE-march-2011) (2), Cardiac, msucle, Neuron, , Chondrocyte, Flattened, cells, Volkman’s, canal, , diffusion in, lung, Impulse, transmission, Helps in heart, beat, Antibody, formation, , 26. Frogs and cockroaches shows sexual, dimorphism, (HSE march-2009)(1), a) Write any two morphological differences, between male and female cockroach, a. Label the parts a and b, b. Write the functions of b, 23. In an informal discussion in your class, your, friend made a comment that “malpighian, tubules are the kidneys of cockroach “. How, will you evaluate this statement?, (HSE March-2010)(2), 24. A schematic sketch representing the, alimentary canal of a cockroach is given, below. Fill the box with the appropriate, organs from the list. No need to redraw the, diagram, (HSE March -2010) (2), Crop, Salivary gland Gizzard, Rectum, Malpighiantubule, Hepatic caeca, , 25. Arrange the column A,B,C in the tale below, and match them properly (HSE MARCH-2009), A, B, C, Squamous, Intercalated, Present, epithelium, disc, between, vertebrae, Cartilage, Dendrite, Helps in gas, 11, [email protected]