Human Senses: How We Perceive the World
How Do We Hear?
- An object vibrates.
- The air particles are pushed, creating sound waves.
- The outer ear picks up these vibrations and directs them to the middle ear, specifically the eardrum.
- In the middle ear, vibrations are amplified and transmitted to the inner ear.
- In the inner ear, hair cells (cilia) accumulate and transmit electrical impulses to the brain.
Diseases of the Ear
- Otitis: Inflammation of various parts of the ear, often caused by bacterial or fungal infections.
- Deafness: The diminution
Arterial and Venous Systems: Anatomy and Relationships
Arterial System
Radial Artery Branches
- Recurrent radial artery
- Muscular artery
- Palmar carpal branches
- Superficial palmar branch
- Principal artery of the thumb
- Dorsal carpal branch
- Artery of the first dorsal metacarpal space
Ulnar Artery
- More voluminous than the radial artery
- From the ulnar fossa
- Inferior and medial
- Passes the flexor retinaculum
- Forms the palmar arch
Ulnar Artery Branches
- Recurrent ulnar artery
- Common interosseous artery (anterior and posterior)
- Muscular branches
- Palmar carpal branch
- Dorsal carpal branch
- Deep
Epithelial, Connective, and Muscle Tissues: Structure and Function
**Epithelial Tissue**
Epithelial tissue is characterized by cells that are tightly packed together, leaving no gaps between them. This means that there is minimal intercellular substance. Its cells have abundant cell junctions, including tight junctions, desmosomes, and hemidesmosomes. Epithelial tissue originates from the ectoderm, mesoderm, and endoderm, and it is renewed by stem cells.
**Types of Epithelial Tissue**
**Covering Epithelium**
This type of epithelium forms the outer covering of the animal’
Read MoreCellular Organelles: Structure and Function in Eukaryotic Cells
Centrosome
The centrosome is a cellular organelle found in animal cells. It is not surrounded by a membrane and consists of two paired centrioles embedded in a set of protein aggregates that surround it, called the pericentriolar material. The walls of centrioles are composed of nine groups of three microtubules (9 + 0 structure). Its primary function is the nucleation and anchoring of microtubules (MTs), so that generically these structures (in conjunction with polar bodies spindle in yeast) are
Read MoreOrgan and Tissue Donation: Medical and Ethical Considerations
Organ and Tissue Transplantation
Transplanting involves the replacement of a diseased organ or tissue that endangers a person’s life. This is done so that the receptors, on the other hand, can function properly. A donor is usually a person who is encephalic-dead or brain-dead (their brain stops working, but their heartbeats are kept artificially). A donor can also be a living person.
Spanish Legislation on Organ Donation
- Definition of brain death as a scientific, legal, and ethical concept of the individual.
Understanding Fermentation and Cellular Respiration
- Fermentation: The process by which the glucose molecule is broken down by enzymatic action, giving rise to simpler compounds and a net gain of two molecules of ATP. This process may occur in the absence of oxygen.
- Importance of Fermentation: The most important aspect is that this allows cells to obtain energy without the need for oxygen.
- Utility: It enriches the diet through the development of flavors, aromas, and textures in food substrates, food preservation, and converts the wort into beer, barley,