Category «Animals»

Reflex Action

A reflex is a fast, unpremeditated, automatic response to the changes in the environment. It is a homeostatic mechanism. A reflex that involves the brain as the integrating centre is called a cranial reflex while that which involves the spinal cord is called the spinal reflex. The pathway followed by a nerve impulse resulting in …

Helminthic Diseases

Helminths are animals that belong to the phyla Platyhelminthes and Nematoda (Nemathel- minthes). Many parasitic forms of this group, popularly known as parasitic worms, are endoparasites of gut and blood in human body and cause various diseases called as helminthiasis. Taeniasis Taeniasis is caused by Taenia solium (pork tapeworm) and Taenia saginata (beef tapeworm). The …

AIIMS AIPMT PMT Special Neural Tissues

neuron

• Neural tissue exert the greatest control over the body’s responsiveness to changing conditions. • It generally develops from the ectoderm but microgliocytes (glial cell type) arise from the mesoderm of the embryo. • The special properties of the cells of the nervous tissue are, excitability and conductivity. –– Excitability is the ability to initiate …

Specialised connective tissue

The special connective tissue cartilage, bone and blood – each have unique cells and extracellular matrices that allow specialized functions. I. Cartilage • Cartilage is a soft skeletal tissue. It is not rigid like bone. • It is found more abundantly in vertebrate embryo because most of the bones forming skeleton of the adult are …

Animal Connective Tissues

Animal  Connective tissue • Connective tissue, formed from mesoderm of the embryo, is the most abundant and widely distributed tissue of the body. • This tissue provides the structural framework and support to different tissues and helps in body defense, repair, fat storage, etc. Components of connective tissue • Three components are present in the …

AIPMT PMT Endocrine System MCQs for Medical Entrance Exams

New MCQs 1. Ca2+ level is controlled by (a) thyroid <b) parathyroid (c) both (a) and (b) (d) adrenal. 2. Mammalian thymus is mainly concerned with (a) regulation of calcium level (b) regulation of body growth (c) immunological functions (d) secretion of serotonin. 3. Which one of the following is proteinaceous in chemical nature? (a) …

Hormones of heart, kidney and gastrointestinal tract

(i) Heart The cells, called cardiocytes, of the atria secrete a peptide, atrial natriuretic factor (ANF) which decreases blood pressure. When blood pressure is increased, ANF is secreted which causes dilation of the blood vessels. This reduces the blood pressure. (ii) Kidneys The kidneys secrete three hormones: renin, erythropoietin and calcitriol. Renin acts upon a …

Major Endocrine Glands and their Hormones

Human endocrine system includes the following glands. Hypothalamus (Supreme commander) Hypothalamus produces several neurogenic hormones and its target organ is pituitary. Hypothalamus is the basal part of diencephalon, forebrain and it regulates a wide spectrum of body functions. It contains several groups of neurosecretory cells called nuclei which produce hormones. These hormones regulate the synthesis …

Human Endocrine System

Cell function is broadly controlled by two mechanisms : nervous and endocrinal. 1. Neural control is due to the spread of depolarization through the nerve. It has rapid action (much shorter latent period) and it affects certain groups of cells for a short period. 2. Endocrinal control is by release of physiologically active substances called …

Protozoan Diseases

PROTOZOAN DISEASES • Protozoans are diverse group of eukaryotic, unicellular organisms. • Human diseases caused by protozoa are relatively few, but are individually of devastating consequences. Amoebiasis or Amoebic dysentery • Amoebiasis is a protozoan infestation of upper part of large intestine which is caused by monogenetic protozoan (having one host i.e., man) known as …