HUMAN BODY ANATOMY

The main topic of this blog,as its name points out, is the anatomy and fisiology of the human body. In each post we will talk about the different systems that make up the wonderful machine that our body is. It will always include visual support. Moreover, you will be able to read texts as a source of information so that you can expand your horizons. The information is organized in tags (at the left side) and pages (at the top of the blog) . Both will show you posts that are related to each other (Nervous System, Endocrine System...) in the same order as I have learnt about these topics during my school year. You can choose to click in a tag or in a page. If they have the same name, they will lead you to the same group of posts. Another important thing is that I'm going to upload some of my works. They will be in the posts whose name is ''My work on this subject''. Finally, I will add games and quizzes for you to use the information that you have learnt. Hope y...

Embryogenesis, the first eight weeks of development after fertilization, is an incredibly complicated process. It’s amazing that in eight weeks we’re transforming from a single cell to an organism with a multi-level body plan. The circulatory, excretory, and neurologic systems all begin to develop during this stage. Luckily, like with many complex biological concepts, fertilization can be broken down into smaller, simpler ideas. The big idea of embryogenesis is going from a single cell to a ball of cells to a set of tubes.  Starting from the very beginning Step 1 : a  zygote  is the single cell formed when an egg and a sperm cell fuse; the fusion is known as fertilization Step 2 : the first 12-to 24-hours after a zygote is formed are spent in  cleavage  – very rapid cell division The zygote’s first priority is dividing to make lots of new cells, so it’s first few days are spent in rapid mitotic division. With each round of division, it doubles in c...

Making Tubes Step 5 : During  gastrulation  the three germ layers form; the cell mass is now known as a gastrula Step 5a : The  primitive streak  forms Step 6 : The  notochord   is formed Week 3 of development is the week of  gastrulation . A germ layer is a layer of cells that will go on to form one of our organizational tubes. Our anatomy can really be boiled down to an inner tube (our digestive tract), and a series of tubes that wrap around it. The three germ layers that will translate into these tubes are the  ectoderm , the  mesoderm , and the  endoderm . Germ Layer What does the prefix mean? Goes on to form: Ectoderm Outer, external Epidermis (outer layer of skin), hair, nails, brain, spinal cord, peripheral nervous system Mesoderm Middle Muscle, bone, connective tissue, notochord, kidney, gonads, circulatory system Endoderm Within Epithelial lining of the digestive tract; Stomach, colon, liver, pancreas, bladd...

EMBRYOGENESIS DIVIDED IN PARTS

WHAT IS A TISSUE? The term  tissue  is used to describe a group of cells found together in the body. The cells within a tissue share a common embryonic origin. Microscopic observation reveals that the cells in a tissue share morphological features and are arranged in an orderly pattern that achieves the tissue’s functions. From the evolutionary perspective, tissues appear in more complex organisms. For example, multicellular protists, ancient eukaryotes, do not have cells organized into tissues. Although there are many types of cells in the human body, they are organized into four broad categories of tissues: epithelial, connective, muscle, and nervous. Each of these categories is characterized by specific functions that contribute to the overall health and maintenance of the body. A disruption of the structure is a sign of injury or disease. Such changes can be detected through  histology , the microscopic study of tissue appearance, organization, and function. Th...

EPITHELIAL TISSUE KEY FACTS Epithelial tissue is composed of cells laid together in sheets with the cells tightly connected to one another. Epithelial layers are avascular, but innervated. Epithelial cells have two surfaces that differ in both structure and function. Glands, such as exocrine and endocrine, are composed of epithelial tissue and classified based on how their secretions are released. Functions of the Epithelium Epithelia tissue forms boundaries between different environments, and nearly all substances must pass through the epithelium. In its role as an interface tissue, epithelium accomplishes many functions, including: Protection for the underlying tissues from radiation, desiccation, toxins, and physical trauma. Absorption of substances in the digestive tract lining with distinct modifications. Regulation and excretion of chemicals between the underlying tissues and the body cavity. The secretion of hormones into the blood vascular system. The secretion ...

CONNECTIVE TISSUE DEFINITION Connective tissue , group of tissues in the body that maintain the form of the body and its organs and provide cohesion and internal support. The connective tissues include several types of fibrous tissue that vary only in their density and cellularity, as well as the more specialized and recognizable variants—bone, ligaments, tendons, cartilage, and adipose(fat) tissue. COMPONENTS OF CONNECTIVE TISSUE All forms of connective tissue are composed of (1) extracellular  fibres, an amorphous matrix called ground substance, and  stationary and migrating cells. The proportions of these components vary from one part of the body to another depending on the local structural requirements. In some areas, the connective tissue is loosely organized and highly cellular; in others, its fibrous components predominate; and in still others, the ground substance may be its most  conspicuous  feature. The ana...