Notes, summaries, assignments, exams, and problems for Biology

Physical Assessment of a Patient with Cancer

Skin

• Inspection: Color, integrity, turgor, humidity, temperature.
• Check for: Injuries (type, size, and location), purpura, petechiae, edema, and appearance of nails.

Head and Neck

• Inspect: Face (asymmetry), eyes, mouth, trachea, maxillary sinuses.
• Palpation: Thyroid.

Thorax

• Inspection: Breathing movements and rate.
• Palpation, percussion, auscultation: Tone, intensity, and duration of breath sounds.

Breasts and Armpits

• Inspection and palpation.

Cardiovascular

• Inspection: Tremors and palpitations in the chest.
• Auscultation, palpation, blood pressure.

Musculoskeletal

• Inspection: Hair distribution, abnormal masses or lesions, asymmetries, nodules.
• Palpation: Painful masses, joint range of motion.

Neurologic

• Presence of

Plant Vascular Systems: Xylem and Phloem Function

Vascular Tissues: Nutrient Transport Systems

Vascular tissues (or drivers) transport nutrients from the roots to the leaves and vice versa. There are two main types:

Xylem (Woody Tissue)

The primary function of the xylem is to conduct crude sap from the roots to the leaves. It is a complex tissue composed of several cell types:

1. Tracheary Elements

These are the most characteristic features: non-living elements through which water circulates. These cells are elongated and tapered at both ends. They can be hollow, with thickened walls often reinforced with lignin. They are arranged one after the other, forming alignments that run longitudinally along the root and stem.

Tracheids (Pteridophytes and

Types of Transplants

• Autotransplant: Donor and recipient are the same patient. Used for tissues or organs such as skin portions or bone.
• Isotransplant: Donor and recipient are identical twins. No rejection occurs.
• Xenotransplant: Donor and recipient are distinct species (e.g., using pig heart valves in humans). There is a risk of rejection.
• Allogeneic Transplant: Donor and recipient are of the same species but genetically different. This is the most common type, and there is a risk of rejection.

Immune Rejection Problems

Our immune system distinguishes self from foreign. If it locates foreign tissue, it attempts to destroy it. This is of great importance when dealing with viruses and bacteria, but it also applies to donor tissue. It is crucial that... Continue reading "Medical Transplants and Regenerative Medicine" »

Dermis

The dermis is the part of the skin located below the epidermis, separated by the dermoepidermal junction. It is the connective tissue that holds the epidermis and contains the skin's nerves and sensory receptors. It is formed by a complex network of fibers embedded in a fundamental substance with few of its own cellular elements.

Function

• Provides resistance and flexibility to the skin.
• Acts as a protective barrier against internal agents, thus preventing infections.
• Serves as a reservoir for liquids.
• Stimulates the production of keratinocytes through keratogenesis.
• Participates in wound healing.

Structure

Papillary Dermis

This layer has a greater proportion of reticular fibers that participate in the dermoepidermal junction. Its function is to... Continue reading "The Dermis, Hypodermis, and Essential Skin Functions" »

Nutrition: Function and Importance Nutrition includes all processes to get the materials of development and the energy we need to live like .--- La Nutricion: Nutrition is a long process. One step is to take food. Function in the 4 processes involved Nutrition: Circulation - the digestive process, respiration, and excretion Feeding and Nutrients To live, we need the nutrients that food contains. The main groups are carbohydrates, fats, proteins, water, vitamins, and minerals - A diet is complete when it contains all types of nutrients. A balanced diet is when it gives us the necessary amount of each nutrient.

The Human Digestive Process

There are three phases in the processing of food: digestion, absorption, and expulsion of waste. This process, driven by peristaltic movements, involves several key steps:

1. Mouth: Digestion begins in the mouth as a result of mastication (chewing) and salivation. Saliva is a liquid produced by the salivary glands in the mouth.
2. Stomach: After swallowing, the food reaches the stomach where gastric digestion begins, and chyme is produced.
3. Small Intestine: The duodenum continues the chemical digestion of the food. Chyme is mixed there with intestinal juices, resulting in chyle, which is then absorbed.

Respiration and Blood Composition

The Respiratory Cycle

During inspiration, the air enters the lungs. During expiration, the air... Continue reading "Human Biology Essentials: Digestion, Blood, and Mitosis" »

Public Health Protection Strategies

Water Treatment and Disinfection

Water must be potabilized (made safe for drinking). This involves two main processes:

1. Pretreatment: This process is intended for physical-chemical correction and the removal of solid particles (e.g., decantation, filtration, aeration).
2. Disinfection: The objective is the elimination of pathogenic microorganisms. Disinfection may be done using chlorine, ozone, or ultraviolet radiation.

Waste Management and Treatment

Wastewater: This includes domestic and industrial sources, rainwater, and street washings. This water needs to undergo a preliminary purification treatment to remove all hazardous components.

Solid Waste: Municipal and industrial solid waste is collected and transported... Continue reading "Public Health Strategies: Water, Waste Management, and Immunization" »

Functions of Muscle Tissue

• Production of body movements
• Stabilization of posture
• Volume regulation of the body
• Movement of chemicals in the body
• Production of heat

Properties of Muscle Tissue

• Electrical excitability
• Contractility
• Extensibility
• Elasticity

Types of Muscle Tissue

There are three types of muscle tissue: striated skeletal, striated cardiac, and smooth.

• Striated skeletal muscle: Called skeletal because the function of these muscles is to move the bones; it often works on a voluntary basis.
• Heart muscle (myocardium): Is located in the heart and is part of its wall. Its movement is involuntary.
• Smooth muscle: Is part of the walls of blood vessels, airways, and some guts. Almost always, this type of muscle movement is involuntary.

Structure of Striated

What is Embryology?

Embryology is the branch of biology that studies the development of an organism from a fertilized egg. It encompasses several key concepts:

• Ontogeny: The transformations that the embryo undergoes during development.
• Phylogeny: The evolutionary history of a species.

Historical Theories of Development

Historically, two main theories attempted to explain embryonic development:

• Preformationism: This theory argued that a miniature version of the organism, called a "homunculus," was present in either the sperm or the egg. Scientists who believed in this were called "animalculists." In 1699, Danlenpatius proposed this theory.
• Epigenesis: This theory proposed that adult body structures were not preformed in the gametes but developed gradually.

Anatomy and Function of Key Body Systems

Organs and Parts of the Digestive System

• The **Digestive Tract** includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.
• **Accessory Glands** include the salivary glands, the pancreas, and the liver.

Maintaining Digestive Health

• Wash hands thoroughly before meals.
• Brush teeth after meals using a fluoride toothpaste. Brushing should take at least three minutes.
• Chew food well and maintain correct posture while sitting at the table to ensure adequate intake.
• Ensure that eating is a moment of relaxation, shared with people with whom you can maintain a peaceful and pleasant conversation.

The Respiratory System

Organs of Respiration

• **Airways:** The nose, pharynx, larynx, trachea,