Human Reproduction: Anatomy, Processes, and Development
Sexual Reproduction
We humans have a sexual reproduction, which means that we need two people to generate the sexual cells, called gametes (sperm and ovum), for them to take part in a process called fertilization, fusing into the zygote (which will eventually become the new individual). The gametes are produced in special organs called gonads (testicles and ovaries).
Sexuality
The way each of us feel as being sexed is called sexuality, and includes gender identity, physical attraction, romantic trends,
Read MoreHistology of Skin, Bone, Joints, and Muscles
Histology of the Skin
The skin consists of an epithelium and connective tissue. The outermost layer is a stratified keratinized epithelium called the epidermis. The most superficial cells in the epidermis are dead and their nucleus and cytoplasm have been replaced by a keratin layer. This layer forms a strong, resistant, waterproof, and virtually impenetrable barrier against bacteria, adapted for protection. The fibrous connective tissue beneath the epidermis is called the dermis, which contains
Read MoreTypes of Disinfectants and Antiseptics: Uses, Precautions, and Spectrum of Action
- ALCOHOLIC: ANTISEPTIC DISINFECTANT, LEVEL: LOW CONCENTRATION: 70% or 96%, disinfection times: Greater or equal to 10 min, SPECTRUM OF ACTION: Bacteria and mycobacteria, fungi and enveloped viruses. MECHANISM OF ACTION: dehydrating and DENATURED PROTEINS. DIRECTIONS: NO CRITICAL EQUIPMENT, SURGICAL HAND WASHING. DISADVANTAGES: OFF WITH ORGANIC MATTER, IRRITANT SKIN, heals wounds. CAUTION: FLAMMABLE.
FORMALDEHYDE: DISINFECTANT. LEVEL: HIGH. DISADVANTAGES: CORROSIVE, carcinogenic, IRRITATING Niriz
Read MoreFunctions and Types of Nutrients
Functions of Nutrients
1. Energetic
- They provide energy to develop vital functions and provide heat.
- Sugar and fats are the most energetic nutrients. When they lack, proteins can also have this function.
- Basal metabolism rate: Amount of energy needed to maintain our vital functions when we are at rest.
2. Structural or Plastic
- They form our own materials. They are used to build membranes.
- Proteins are the most important structural nutrients. Some lipids and mineral salts also have this function.
3. Regulatory
- They
Understanding the Cardiovascular System: Functions, Components, and Health
What Functions are Performed by the Cardiovascular System?
The cardiovascular system circulates blood, delivering nutrients and oxygen to all cells in the body. It also collects waste products from the cells and transports them to the lungs (for CO2 removal) or excretory organs (for waste elimination).
What if the Heart Valves Allowed Blood to Circulate in Both Directions?
If the heart valves allowed blood to flow in both directions, several problems would arise:
- Blood cells would collide.
- Blood flow
Biology & Chemistry Basics: Cells, Systems, and Chemical Reactions
Biology
Plant & Animal Cells
Prokaryotes
No nucleus or other membrane-bound organelles.
Eukaryotes
Have a nucleus & other organelles.
Plant cells have a cell wall & chloroplasts while animal cells don’t.
Organelles
Cytoplasm
Suspends organelles in the cell.
Endoplasmic Reticulum
Transports materials throughout the cell.
Nucleus
Stores genetic data & performs mitosis.
Mitochondria
Converts glucose with oxygen to make energy for the cell.
Cell Membrane
Supports the cell & allows diffusion.
Chloroplast
Absorbs
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