Notes, summaries, assignments, exams, and exercises for Biology for University

Why Is Restorative Dentistry Important?

Restorative dentistry is essential because it prolongs the life of the tooth, prevents further damage, and helps avoid tooth loss.

What Is a Dental Bridge?

A bridge is a fixed replacement for one or more missing teeth.

Understanding Dental Crowns

A crown (or cap) is used to strengthen a tooth or improve its appearance. It completely covers the natural tooth. For teeth near the front of the mouth, crowns are usually made of porcelain-like materials, while crowns on back teeth may be made of stronger alloys.

The Crown Fitting Process

To fit a crown, the dentist will:

• Administer a local anesthetic injection to numb the area.
• Drill down the existing tooth structure.
• Take an X-ray to assess the tooth's health.
• Shape

Understanding Parasites

A parasite is any living animal or plant that spends part or all of its existence inside or outside another living being (the host), feeding at its expense and potentially causing apparent or unapparent damage.

What is Parasitology?

Parasitology is the scientific discipline that studies organisms (parasites) that live inside or outside another host, extracting food and shelter. This association is not always harmful to the host.

Defining Parasitism

Parasitism occurs when a living organism (the parasite) lives on or in another organism of a different species (the host), from which it obtains nourishment. This relationship encompasses a wide range of organisms, from viruses to arthropods.

Zooparasites

Zooparasites are parasites...

Oxygen Therapy: Definition and Principles

Oxygen therapy is defined as the administration of O₂ with an elevated fraction of inspired oxygen (FiO₂) above the ambient air concentration (0.21). This process promotes:

• Increasing alveolar O₂ pressure;
• Creating a larger pressure gradient between the alveoli and capillaries;
• Ideal delivery: Oxygen that is heated and humidified.

Clinical Indications for Oxygen Therapy

• Reversal of hypoxemia:
  • Newborns: PaO₂ < 50 mmHg or O₂ saturation < 88%;
  • Young Infants (up to 6 months): PaO₂ < 60 mmHg or O₂ saturation < 92%;
  • Children (> 6 months): PaO₂ < 80 mmHg or O₂ saturation < 96%.
• Reduced labored breathing;
• Resorption of air cavities;
• Reduced pulmonary vascular resistance.

Modes of Administration

Common...

Heavy Metals in the Food Chain

One of the primary mechanisms by which heavy metals reach human beings is through plants, which absorb metals through their roots. In turn, animal species consume these plants, allowing the metals to enter the food chain. The metals most dangerous to all life forms are mercury, cadmium, and lead. Additionally, iron, aluminum, copper, and zinc are particularly hazardous for salmon populations.

Mobility and Soil Retention of Heavy Metals

Heavy metals can be retained in the soil, either dissolved in soil solutions or fixed by adsorption, complexation, and precipitation. Their mobility is characterized by the following processes:

• Absorption: Metals are absorbed by plants and incorporated into food chains, or they may

Occupational Hazards

Hearing Loss

Occupational hearing loss, or deafness, is the functional deficit that occurs when an individual experiences a partial or complete loss of hearing. This is determined by the hearing threshold, which is the weakest sound stimulus that a particular ear can perceive. While the terms "deafness" and "hearing loss" are often used interchangeably, they are distinct conditions.

Pneumoconiosis

Pneumoconiosis encompasses a group of lung diseases caused by inhaling and accumulating inorganic dust particles, and the subsequent reaction within lung tissue. Disease development depends on the dose of inhaled and retained particles, the particles' biological activity, the induced tissue reaction, and individual sensitivity.

Drug

Economic Entomology

It refers to the study of all aspects of insects that are related in a way or another with human activity involving the economic, ecological and social.

Ecology of Insects

Species: A group of individuals who share common characteristics, can interbreed and produce fertile offspring under natural conditions.

Population: Group of organisms of the same species that occupy a certain space at a given time.

Community: A group of populations of several species of plants or animals that share a certain time regardless.

Ecosystem: Habitat where biotic and abiotic factors interact to exchange energy and matter in a continuous cycle.

Agroecosystem: Artificial system manipulated by man but stable in nature.

Ecological Niche: Resources that...

Osseous Tissue

Functions:

• Support
• Movement
• Protection: housing the spinal cord and organs
• Storage of ions (99% of calcium)

Constituents of Osseous Tissue

• A - Bone matrix
• B - Cells
• C - Endosteum (microscopically)
• D - Periosteum

A - Bone Matrix

• Mineralized (about 65%): inorganic crystals of hydroxyapatite (calcium and phosphorus), also containing carbohydrates, citrates, etc.
• Non-mineralized (about 35%): organic components, including type I collagen and a non-collagenous protein group (osteoinduction), e.g., bone morphogenetic proteins (BMPs)

B - Cells

• Undifferentiated osteogenic cells: found in the endosteum and periosteum
• Osteoblasts: located at the periphery of the bone tissue. Function: synthesize the bone matrix.
• Osteocytes: located in the interior of the

Physiological Effects of Glucocorticoids

Glucocorticoids exert significant effects on various tissues and organs:

• Anti-inflammatory and immunosuppressive action: They inhibit inflammatory and allergic reactions at four levels: capillary, lymphatic cells, and organs.
• Action on the kidney and gastrointestinal tract: The elimination of corticosteroids restores glomerular plasma flow and favors the excretion of water and uric acid. High amounts of glucocorticoids can lead to gastric ulcers.
• Action on the cardiovascular system: Cortisol increases the effect of norepinephrine to stimulate smooth muscle and increases the strength of heart contractions.
• Action on growth: Cortisol demonstrates anti-growth effects by acting at digestive, bone, and muscle

Factors Determining Blood Flow

The factors that determine blood flow include:

• Fluid properties: Density
• Forces: Pressure
• Vessel structure: Variations in the radius

Structure of Blood Vessels

The role of blood vessel components is to monitor blood flow and achieve vascular stability by varying the radius. They consist of three parts:

• Elastic fibers: Formed by elastin and collagen.
• Smooth muscle fibers: Responsible for contraction and dilation.
• Endothelial tissue: A thin layer located between the vessel wall and the blood that absorbs energy loss caused by friction.

Elasticity of Blood Vessels

Variations in the radius of the vessel are the result of the relationship between two forces:

Transmural Pressure and Radial Forces

Transmural pressure acts from the...

Heart Muscle

The heart is the ultimate aerobic tissue. Its activity depends heavily on glucose oxidation. It utilizes the following fuels and metabolic pathways:

• Glucose: Oxidation
• Fatty Acids: Beta-oxidation
• Ketone Bodies: Oxidation of acetoacetate

The heart also plays a role in the clearance of lactic acid produced by muscles.

Nervous System

The nervous system primarily utilizes:

• Glucose: Oxidation
• Ketone Bodies: Oxidation of acetoacetate

Adipose Tissue

Adipocytes serve as the body's energy reserves, storing free fatty acids as triacylglycerols. Because these cells lack the enzyme to catalyze the conversion of glycerol to glycerol-3-phosphate, they must utilize glucose.

Glucose concentration is a determinant factor in the esterification and release of...