Human Biology and Nutrition
Sense Organs
Hearing
Hearing consists of three parts: the external ear, middle ear, and inner ear.
External Ear
This is formed by the pinna, the ear canal, and the eardrum.
- It is in charge of collecting and transmitting sound waves into the middle ear.
- The ear canal contains small hairs and wax-producing glands that are responsible for protecting the inside.
- The eardrum is a membrane that separates the outer ear and middle ear.
Middle Ear
This is formed by the tympanic cavity, which contains three holes.
Read MoreUnderstanding Cells and Tissues: A Comprehensive Overview
Chapter 3: Exploring the Cell
What is a Cell?
The cell is the fundamental structural and functional unit of the body. It is the smallest living unit.
Three Main Regions of a Cell
- Cell Membrane: The outer boundary of the cell.
- Cytoplasm: Includes the cytosol (watery fluid) and organelles.
- Nucleus: The control center of the cell.
Structure of the Cell Membrane
The cell membrane is a phospholipid bilayer, composed of two layers of phospholipids. Embedded within this bilayer are proteins and cholesterol. Carbohydrates
Read MoreThe Immune System, HIV/AIDS, and the Respiratory System: A Comprehensive Overview
4 Phagocytic Leucocytes and Pathogen Ingestion
Phagocytes, found in the blood and body tissues, play a crucial role in the immune system. They identify and engulf pathogens through endocytosis. Lysosomes, enzymes within phagocytes, then break down these pathogens. Phagocytes can move through capillary pores, allowing them to ingest pathogens both in the bloodstream and within tissues.
5 Antigens vs. Antibodies
Antibodies are proteins that defend the body against pathogens. They bind to antigens, foreign
Read MoreFetal Development: Cognitive Functioning and Learning
Fetal Development: Cognitive Functioning and Fetal Learning
Prenatal Development
The case for 9 months in a pattern that is not uniform. Throughout this period, changes of varying intensity and importance occur. The periods during which prenatal life is conventionally divided are: conception, zygote (development until the 2nd week), embryo (3rd-8th week), and fetus (9th to 38th week).
Phases of Development
Conception
Every 28 days, an egg leaves the ovary and travels to the uterus through the fallopian
Read MoreUnderstanding the Plasma Membrane and Cellular Transport
V. Plasma Membrane and Homeostasis
1. Plasma Membrane Composition
The plasma membrane is a crucial component of all cells, forming a barrier between the internal environment and the external surroundings. It’s primarily composed of a phospholipid bilayer, with each phospholipid molecule having a hydrophilic (water-loving) head and two hydrophobic (water-fearing) tails. This arrangement creates a selectively permeable barrier that regulates the passage of substances in and out of the cell.
Drawing of
Read MoreUnderstanding Energy in Living Organisms: ATP, ADP, and Cellular Processes
Energy
(Physics) The Capacity of a Physical System to Do Work
Needed by all living things.
What are the cells busy using energy for when you are sleeping?
The cells use energy to build new molecules and get rid of wastes.
What would happen if cells didn’t have the ability to get and use energy?
The cells would die.
What are 3 forms of energy?
Light, heat, and electricity.
Chemical Bond
An attractive force that holds together the atoms, ions, or groups of atoms in a molecule or compound.