Human Reproduction: Anatomy, Life Stages, and Sexual Health
1. Reproduction and Sexuality Fundamentals
Reproduction is a key function: the birth of new individuals. Sexual reproduction is characterized by two main features:
- The new individual is formed from a single cell, called a zygote.
- A zygote originates from the union (fertilization) of two gametes (sex cells).
While male and female reproductive systems are different, they both have gonads. Humans have two kinds of gametes: sperm and ova.
Key characteristics of human sexual reproduction:
- Maturation into an
Textile Fiber Characteristics: Wool, Silk, Cotton, and Linen
Fundamental Fiber Terminology
Fiber Definition
A fiber is a single filament, often characterized by a very small diameter relative to its length. Fibers contribute significantly to the hand feel and texture of fabrics.
Filaments
Filaments are continuous, long strands of indefinite length. They can be smooth or textured.
Continuous Filament Cable
This refers to a rope or a bundle composed of thousands of artificial fibers twisted together in a defined torsion.
Protein Fibers (Natural Animal Fibers)
Protein
Read More3D Bioprinting and Tissue Engineering for Medical Advancement
What Is Tissue Engineering?
Tissue engineering is a multidisciplinary field that applies the principles of engineering and life sciences to understand and recreate the function of normal and pathological tissues. It combines cells, engineering techniques, materials, and biochemical factors to repair or replace damaged tissues like bone, cartilage, and blood vessels. The primary goal is to restore, maintain, or improve biological functions. This field significantly overlaps with regenerative medicine,
Read MoreCell Division Processes: Interphase, Mitosis, and Meiosis
The Cell Cycle and Cellular Division
Interphase: Preparation for Division
Interphase is the period of cell growth and DNA synthesis, preceding cellular division. It includes several key phases:
- G1 Phase (Growth 1): Intense growth occurs. The cell synthesizes new cytoplasmic material (proteins and RNA).
- G0 Phase (Inactivity): May occur when the cell cycle is temporarily halted or permanently exited (non-proliferative state).
- S Phase (Synthesis): DNA replication occurs, resulting in the doubling of DNA
Diagnostic Imaging and Therapeutic Radiology Essentials
Musculoskeletal Radiology and Trauma Imaging
Imaging Methods in Musculoskeletal Radiology
Musculoskeletal radiology utilizes various methods to assess bone lesions and fractures.
- Plain Film Radiography: Used primarily for assessing bone lesions and fractures. For small bones and children, single emulsion films are often used.
- Computed Tomography (CT): Provides good visualization for sclerotic lesions of the spine, pelvis, wrist, ankle, foot, or when soft tissue tumors are present on normal film.
- Magnetic
Molecular Biology: DNA Replication and Gene Transcription
DNA Replication: The Process of Duplication
DNA replication is the process by which a DNA macromolecule produces two identical copies of the original.
Key Steps and Enzymes in DNA Replication
Arthur Kornberg studied the DNA replication process in 1956. In bacteria, there is typically a single origin of replication.
Initiation and Strand Separation
The process starts with an enzyme called Helicase. This enzyme breaks the hydrogen bonds (H-bonds) between the chains, allowing their separation. As the two
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