Human Body: Digestion, Circulation, Respiration
Digestive System Processes
The digestive system’s mission is to transform ingested food, both physically and chemically. It breaks food down into molecules small enough for absorption and transport via the blood to all body cells.
Digestion Processes
Digestion begins in the mouth, where chewing and insalivation occur. With the help of teeth, tongue, and the muscular walls of the mouth, food is formed into a bolus.
- Mucin: A lubricant in saliva, also secreted in other parts of the alimentary tract, protects
Stem Cells, Carbohydrates, and PHA: Applications
Stem Cells: Types and Applications
Stem cells are undifferentiated cells with the unique ability to develop into various specialized cell types. They can divide and produce more stem cells (self-renewal) and differentiate into specialized cells (differentiation).
Types of Stem Cells
- Embryonic Stem Cells: Derived from embryos, these cells can become any cell type in the body.
- Adult or Somatic Stem Cells: Found in various tissues, they generate cells specific to their tissue of origin.
Applications of
Read MoreUnderstanding the Cardiovascular System
Cardiovascular System
The cardiovascular system is the network of channels through which blood flows and consists of:
- The heart
- Blood vessels
In anatomy, the heart is the principal organ of the circulatory system. It is a striated muscle that acts as a suction pump and impeller, which aspirates blood flowing through the veins into the atria and drives it from the ventricles into the arteries.
Heart Anatomy
Location: The heart is situated practically in the middle of the chest (mediastinum), between the
Read MoreEvolution: Natural Selection, Mutation, and Speciation
Understanding Evolution: Key Concepts and Theories
Reproduction, Asexual Source Variability
Variability: Generates gene recombination during meiosis and random union of gametes during fecundation.
Selection Pressure and Adaptation
Factors that adversely affect individual survival constitute selection pressure. Adaptation arises from the pressure of natural selection.
Evidence for Evolution
Evidence supporting the theory of evolution comes from multiple fields:
- Anatomical Studies: Organisms are studied
Genetic Engineering, Cell Structures, and Key Differences
Genetic Engineering
Genetic engineering is a science that occupies the manipulation of genetic material. The human genome is the complete sequence of DNA.
Techniques
- Recombinant DNA: A gene is inserted into a plasmid (circular DNA different from bacterial chromosome). Before the DNA has been cut with restriction enzymes, it is a way to clone the bacterial gene. Applications: Synthesis of medicines (insulin, coagulation factors, growth hormone, interferon, vaccines), livestock (cows with less fat),
Cilia and Flagella: Structure, Movement, and Function
Cilia and flagella are mobile extensions found in various cell types. A cilium is typically 5-10 μm in length and found in tubular epithelia, measuring about 2 μm in thickness. Their pedaling or undulating movements help to drag particles, agitate, and circulate fluids on the cell surface.
Ciliary Structure
Structurally, a cilium is integrated with the ciliary membrane and the axoneme, which is embedded in the ciliary matrix. Key components include the stem, transition zone, and ciliary basal body.
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