Heart and Vessel Formation: A Detailed Look at Embryonic Development
Cardiovascular System Development
Cardiac Development
The cardiovascular system originates from the mesoderm. Around day 22 of development, a pair of heart tube structures forms, eventually fusing into a single heart tube composed of an inner endocardial tube and a surrounding myocardial layer. Between weeks 4 and 7, the heart develops into its characteristic four-chamber structure.
Formation of the Cardiac Septum
The heart’s septa develop from endocardial cushions in the atrioventricular canal and
Read MoreGenetics: Inheritance, Traits, and DNA Profiling
Genetics Fundamentals
Chromosomes and Genes
Homologous Chromosomes: Pairs of chromosomes with the same size, shape, and gene locations (one from each parent).
Gene: Basic hereditary unit, made of DNA sequences.
Alleles: Different forms of the same gene (e.g., yellow (Y) vs. green (y) seed color in peas).
Genetic Terminology
Homozygous: Two identical alleles for a gene (e.g., YY or yy).
Heterozygous: Two different alleles for a gene (e.g., Yy).
Dominant Allele: Expressed even if only one copy is present
Read MoreHydrogenation, Fermentation, and Polymerization: Chemical Processes
Hydrogenation
Hydrogenation is a type of chemical reaction (redox) in which the visible end result is the addition of hydrogen (H2) to another compound. The usual targets of this reaction are unsaturated organic compounds such as alkenes, alkynes, ketones, nitriles, and amines. Most hydrogen is produced by direct addition of diatomic hydrogen under pressure and in the presence of a catalyst.
A typical example of hydrogenation is the addition of hydrogen to double bonds, converting alkenes to alkanes.
Read MoreUnderstanding Human Anatomy and Physiology
Factors Influencing Follicle Count in Women
Q: What factors modify the number of follicles a woman has?
A: Women are born with approximately 1 million follicles. During the aging process, they lose follicles, and by puberty, they have around 300,000 to 500,000 follicles. By the age of 40, women have only 3% of their original follicle count. Smoking, stress, poor diet, and lack of exercise can decrease the quantity and quality of follicles.
Perineum Structure
Q: What structures make up the Perineum?
Read MorePhotosynthesis: The Process of Plants Creating Food
The process that plants carry out in the presence of radiant energy in order to create their food is known as photosynthesis.
The Role of Chlorophyll
Chlorophyll is a chemical found in most plants that gives them their green color. The process of photosynthesis is possible due to the chlorophyll present in plant leaves. During this process of food generation, the following reaction takes place:
6 CO2 + 6 H2O → (in the presence of sunlight) C6H12O6 + 6 O2
Plant photosynthesis occurs in leaves and green
Read MoreUnderstanding the Human Cardiovascular System and Blood
The Cardiovascular System: Heart and Blood
The heart is the pump that moves blood through the cardiovascular system. It consists of two halves separated by a muscular wall.
Structure of the Heart
Each half of the heart is divided into an upper and lower cavity. The heart is enclosed in the pericardium, a double sac that provides a fluid-filled space for it to beat freely.
- Myocardium: Muscle tissue that forms the heart wall.
- Atria: The upper chambers of the heart.
- Ventricles: The heart’s lower chambers.