Understanding Common Diseases and Medical Advancements
Cancer
Cancer stem cells begin to multiply out of control and, at the same time, are able to specialize and perform the function corresponding to the specific tissue or organ. The rapidly growing cells destroy healthy cells around them. These are malignant. Metastasis occurs when malignant cells spread through blood vessel walls or the lymph system. Cancer is the second leading cause of death after cardiovascular diseases in developed countries. Genetic predisposition may influence the development
Read MoreHuman Reproduction: From Fertilization to Childbirth and Puberty
Human Reproduction: From Fertilization to Childbirth
Human reproduction occurs when the egg produced by a woman combines with the sperm produced by a man. Reproduction is internal, meaning it occurs within the reproductive tract of the woman. The process can be broken down into the following stages:
- Production of gametes in specialized reproductive organs.
- Fertilization: The union of two gametes within the female reproductive system, forming a single cell called the zygote.
- Development of the zygote
Neurons, Nervous System, and Sensory Organs: Biology
Neurons: Structure and Function
Neurons are composed of three main parts:
- Cell Body: The thickest part of the neuron, containing the nucleus and most organelles.
- Axon: A large prolongation extending from the cell body, branching out at its end.
- Dendrites: Small, branching prolongations of the cell body.
Neurons connect through dendrites and axons. The small gap separating the dendrites and the branched ends of the axon is called the synapse. They transmit information via electrical signals at speeds
Read MoreUnderstanding Biomolecules: Carbohydrates, Lipids, and Proteins
Biomolecules: Carbohydrates, Lipids, and Proteins
Heteropolysaccharides and Heterosides
Heteropolysaccharides are formed by two or more classes of monosaccharides. Heterosides are formed by a carbohydrate and a non-carbohydrate part.
Lipids
Lipids are a very heterogeneous set of substances, both structurally and by the functions they perform. They are insoluble in water and soluble in organic solvents. Chemically, they are made of Carbon, Hydrogen, and Oxygen.
Properties of Lipids
- Oily to the touch
Biological
Read MoreKey Concepts in Biology: Evolution, Digestion, and More
Darwin: The Theory of Evolution by Natural Selection
Darwin’s theory of evolution by natural selection is based on the following principles:
- There are heritable differences between individuals in a living population.
- More individuals are born than can survive.
- Some hereditary variations provide individuals with advantages in survival.
The Synthetic Theory of Evolution
This theory incorporates the idea of evolution by natural selection. The evolutionary unit is not the individual but the population. Differential
Read MoreBrain, Nervous & Endocrine Systems: Functions & Hormones
Brain Functions
The two cerebral hemispheres are connected by bundles of nerve fibers, which form the corpus callosum. Most sensory information from the right side of the body passes through the corpus callosum towards the left hemisphere.
The cortex integrates sensory stimuli; in association areas, it produces voluntary motor commands.
Association areas are responsible for higher functions (language, creativity, learning, and memory).
The sensory and motor areas of the brain are so well-known that
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