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Showing posts from February, 2022

SKELETAL SYSTEM AND JOINT

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In this post we are going to discuss briefly about the Skeletal System and Joints.  Skeletal   System  : •Skeletal system consists of a framework of bones and a few cartilages. •This system has a significant role in movement shown by the body. •Imagine chewing food without jaw bones and walking around without the limb bones.  •Bone and cartilage are specialised connective tissues. •The former has a very hard matrix due to calcium salts in it and the latter has slightly pliable matrix due to chondroitin salts.  •In human beings, this system is made up of 206 bones and a few cartilages.  •It is grouped into two principal divisions – the axial and the appendicular skeleton. •Axial skeleton comprises 80 bones distributed along the main axis of the body.  •The skull, vertebral column, sternum and ribs constitute axial skeleton.  •The skull is composed of two sets of bones – cranial and facial, that totals to 22 bones.  •Cranial bones are 8 in number. •They form the hard protecti

FUNCTIONING OF MUSCLE

In this post we are going to discuss about the Process of Functioning of Muscle. For the post of Muscle System, Click  here . Structure   of   Contractile   Protein  : •Each actin (thin) filament is made of two ‘F’ (filamentous) actins helically wound to each other.  •Each ‘F’ actin is a polymer of monomeric ‘G’ (Globular) actins.  •Two filaments of another protein, tropomyosin also run close to the ‘F’ actins throughout its length.  •A complex protein Troponin is distributed at regular intervals on the tropomyosin.  •In the resting state a subunit of troponin masks the active binding sites for myosin on the actin filaments. •Each myosin (thick) filament is also a polymerised protein.  •Many monomeric proteins called Meromyosins constitute one thick filament.  •Each meromyosin has two important parts, a globular head with a short arm and a tail, the former being called the heavy meromyosin (HMM) and the latter, the light meromyosin (LMM). The HMM component, i.e.; the head and short arm

MUSCLE SYSTEM

In this post we are going to discuss about Muscle System in brief. For the post of Secondary Growth, Click  here . Types   of   Movement : Cells of the human body exhibit three main types of movements, namely, amoeboid, ciliary and muscular. •Some specialised cells in our body like macrophages and leucocytes in blood exhibit amoeboid movement. It is effected by pseudopodia formed by the streaming of protoplasm (as in Amoeba).  •Cytoskeletal elements like microfilaments are also involved in amoeboid movement. •Ciliary movement occurs in most of our internal tubular organs which are lined by ciliated epithelium.  •The coordinated movements of cilia in the trachea help us in removing dust particles and some of the foreign substances inhaled alongwith the atmospheric air.  •Passage of ova through the female reproductive tract is also facilitated by the ciliary movement. •Movement of our limbs, jaws, tongue, etc, require muscular movement. •The contractile property of muscles are effectivel

ANATOMY OF FLOWERING PLANTS PART-3: SECONDARY GROWTH

In this post we are going to discuss about Secondary Growth. For the post of Plant Tissue System and Anatomy of Monocot and Dicot System, Click  here . Secondary   Growth  : •The growth of the roots and stems in length with the help of apical meristem is called the primary growth.  •Apart from primary growth most dicotyledonous plants exhibit an increase in girth. This increase is called the secondary growth. •The tissues involved in secondary growth are the two lateral meristems: vascular cambium and cork cambium. For the post of Plant Tissue, Click  here . Vascular   Cambium  : •The meristematic layer that is responsible for cutting off vascular tissues – xylem and pholem – is called vascular cambium.  •In the young stem it is present in patches as a single layer between the xylem and phloem. Later it forms a complete ring. <>Formation of cambial ring : •In dicot stems, the cells of cambium present between primary xylem and primary phloem is the intrafascicular cambium.  •The c

ANATOMY OF FLOWERING PLANTS PART-2: PLANT TISSUE SYSTEM AND ANATOMY OF DICOTYLEDONOUS AND MONOCOTYLEDONOUS PLANTS

In this post we are going to discuss the Plant Tissue System and Anatomy of Monocot and Dicot System. For the post of Plant Tissue, Click  here . Tissue   System  : •Tissues vary depending on their location in the plant body.  •Tissue structure and function would also be dependent on location.  •On the basis of their structure and location, there are three types of tissue systems. These are the epidermal tissue system , the ground or fundamental tissue system  and the vascular or conducting tissue system . Epidermal   Tissue   System  : •The epidermal tissue system forms the outer-most covering of the whole plant body and comprises epidermal cells, stomata and the epidermal appendages – the trichomes and hairs.  •The epidermis is the outermost layer of the primary plant body.  •Epidermis is made up of elongated, compactly arranged cells, which form a continuous layer.  •Epidermis is usually single ￾layered.  •Epidermal cells are parenchymatous with a small amount of cytoplasm lining th

ANATOMY OF FLOWERING PLANTS PART-1: PLANT TISSUE

In this post we are going to discuss about Plant Tissue. For the post of Morphology and Anatomy of Frog, Click  here . Plant   Tissue  : •A tissue is a group of cells having a common origin and usually performing a common function.  •A plant is made up of different kinds of tissues.  •Tissues are classified into two main groups, namely, meristematic and permanent tissues based on whether the cells being formed are capable of dividing or not. For the post of Morphology and Anatomy of Cockroach, Click  here . Meristematic   Tissue  : •Growth in plants is largely restricted to specialised regions of active cell division called meristems (Gk. meristos: divided).  •Plants have different kinds of meristems.  •The meristems which occur at the tips of roots and shoots and produce primary tissues are called apical meristems.  •Root apical meristem occupies the tip of a root while the shoot apical meristem occupies the distant most region of the stem axis.  •During the formation of leaves and el

FROG: MORPHOLOGY AND ANATOMY

In this post we are going to discuss about Morphology and Anatomy of Frog. For the post of Morphology and Anatomy of Cockroach, Click  here . Frog  : •Frogs can live both on land and in freshwater and belong to class Amphibia of phylum Chordata.  •The most common species of frog found in India is Rana tigrina. •They do not have constant body temperature i.e., their body temperature varies with the temperature of the environment. •Such animals are called cold blooded or poikilotherms.  •They have the ability to change the colour to hide them from their enemies (camouflage).  •This protective coloration is called mimicry.  •Frogs are not seen during peak summer and winter. •During this period they take shelter in deep burrows to protect them from extreme heat and cold. This is known as summer sleep (aestivation) and winter sleep (hibernation) respectively. For the post of Morphology and Anatomy of Earthworm, Click  here . Morphology   of   Frog : •The skin is smooth and slippery due to t

COCKROACH: MORPHOLOGY AND ANATOMY

In this post we are going to discuss about the Morphology and Anatomy of Cockroach. For the post of Morphology and Anatomy of Earthworm, Click  here . 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.  •They have become residents of human homes and thus are serious pests and vectors of several diseases. Morphology   of   Cockroach : •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.  •The body of the cockroach is segmented and divisible into three distinct regions – head, thorax and abdomen. •The en

EARTHWORM: MORPHOLOGY AND ANATOMY

In this post we are going to discuss about Morphology and Anatomy of Earthworm, Cockroach and Frog. For the post of Animal Tissue System, click  here . Earthworm : •Earthworm is a reddish brown terrestrial invertebrate that inhabits the upper layer of the moist soil.  •During day time, they live in burrows made by boring and swallowing the soil.  •In the gardens, they can be traced by their faecal deposits known as worm castings.  •The common Indian earthworms are Pheretima and Lumbricus. For the post of Morphology of Root, Stem and Leaf, Click  here . Morphology   of   Earthworm : •Earthworms have long cylindrical body.  •The body is divided into more than hundred short segments which are similar (metameres about 100-120 in number).  •The dorsal surface of the body is marked by a dark median mid dorsal line (dorsal blood vessel) along the longitudinal axis of the body.  •The ventral surface is distinguished by the presence of genital openings (pores).  •Anterior end consists of the mo