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

Masticatory muscles share a common characteristic: they are all inserted at the base of the skull and upper jaw, serving the primary purpose of moving the jaw.

Temporal Muscle

This muscle occupies the temporal fossa. It is inserted above the level of the temporal line and the entire fossa. Its fibers are directed downward and converge, ending in a tendon at the level of the coronoid process of the maxilla. Innervation is provided by the temporal nerve, a branch of the mandibular nerve. Its action is to elevate the jaw, attaching it to the upper jaw.

Masseter Muscle

A short, thick muscle with a quadrilateral shape, the masseter is located on the outer face of the ramus of the mandible. Its upper insertion is at the zygomatic arch, and its descending...

Cellular Components: Cytoplasm and Cytosol

The cytoplasm is the material or protoplasm within a living cell, excluding the nucleus. It comprises the *cytosol* (also known as the hyaloplasm or cytoplasmic matrix), a gelatinous substance composed of ions and dissolved inorganic and organic molecules in water, and various organelles such as centrioles, ribosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, and chloroplasts (in plant cells). These structures play specific roles in cellular function.

The cytosol is the site of various chemical reactions of metabolism, including the first stage of cellular respiration (glycolysis) and the synthesis of several substances.

The Cytoskeleton

In eukaryotic cells, the cytoskeleton is a complex network...

Key Definitions in Health and Disease

Agent: An animate or inanimate entity whose presence or absence can disrupt host health.

Host: Any organism capable of harboring an agent.

Environment: The complex of factors influencing a system, determining its course and way of life.

Stimulus Trigger: A factor or condition arising after a disturbance in the ecological triad's balance, initiating the disease process.

Sign: A measurable or quantifiable manifestation in an individual.

Symptom: A subjective expression of a condition reported by an individual.

Latency: A stable phase in disease evolution without subclinical manifestations, signs, or symptoms.

Causality: Conditions involving agent, host, environment, and transmissibility factors that generate a stimulus...

Regulation of Secretion in the Adrenal Cortex

The adrenal cortex is primarily controlled by the hypothalamic-pituitary axis. However, other mechanisms also influence the release of adrenal cortical hormones.

Negative Feedback

The primary feedback mechanism involves the hormone cortisol and its derivative, cortisone. An increase in cortisol levels inhibits Adrenocorticotropic Hormone (ACTH) secretion, while a decrease stimulates it. An excess of cortisol also leads to a decrease in Corticotropin-Releasing Factor (CRF).

Circadian Rhythm

The levels of adrenal cortical hormones are dependent on the circadian rhythm. Cortisol, in particular, exhibits a pronounced circadian rhythm, with the highest levels in the morning and the lowest at night. This rhythm...

Estrutura Bacteriana

Mesossomo: invaginação da membrana
Cápsula: a base camufla e protege
Plasmídeos: conferem resistência às bactérias
Flagelos: servem para a locomoção
Vacúolos: reservam fosfato e glicose
Ribossomo: fabricação de proteínas
Cytoplasmic membrane: lipoproteína (fosfolipídeos). Função: surge

Coloração de Gram

Coloração de Gram: cristal violeta, iodo, acetona e fucsina alcoólica
Gram +: cora em roxo
Gram -: cora em rosa

Coloração de Ziehl-Neelsen

Coloração de Ziehl-Neelsen: fucsina de Zehl, álcool ácido, azul de metileno
AFB: bacilo álcool-ácido resistente. Constituído por lipídeos, peptídeo e glicano

Metabolismo e Energia

ATP: ciclo de Krebs, fermentação, respiração aeróbica

Anabolismo: biossíntese, é a...

Classification of Drugs and Their Effects

Nervous system drugs include various types of illegal substances:

• Stimulants: Cocaine and amphetamines.
• Depressants: Derived from opium, morphine, and heroin.
• Hallucinogens: Barbiturates, marijuana, toxic substances, LSD, and synthetic drugs.

Legal drugs include alcohol, caffeine, and tobacco.

Impact of Alcohol on the Body

Effects of alcohol: It causes damage and maladies to various organs. It affects the digestive system, leading to conditions such as cirrhosis, gastritis, cancer, and ulcers. It also causes obesity due to the calories produced by alcohol. In the nervous system, it leads to intellectual deterioration, memory loss, and addiction. Furthermore, it causes disorders in the reproductive tract, such...

Cardiac Output, Blood Flow, and Blood Pressure Relationships

To understand the relationship between cardiac output, blood flow distribution, and blood pressure, we must first define these core physiological concepts:

Defining Cardiac Output

Cardiac output is the volume of blood the heart pumps per minute. This parameter varies based on the body's state, such as rest or exercise. Key components include:

• Stroke Volume: The amount of blood ejected per heartbeat (approximately 70 ml at rest).
• Heart Rate: The number of heart contractions per minute (approximately 70 beats per minute).

Blood Flow Distribution and Redistribution

Blood flow varies based on the metabolic demands of specific body tissues. We observe distinct distribution patterns during rest...

Physiology and Structure of Enterobacteriaceae

Enterobacteria are Gram-negative bacilli ranging from 1 to 6 μm in size. They are non-spore-forming, generally motile, and function as facultative anaerobes. Some species possess capsules, fimbriae, and pili.

These bacteria utilize a wide variety of enzymes, which are used for biochemical diagnosis. They are nutritionally undemanding, ferment glucose, reduce nitrate, and are catalase-positive and oxidase-negative.

Clinical Significance and Pathogenic Species

The Enterobacteriaceae family includes several clinically relevant species:

• Citrobacter freundii and C. koseri
• Enterobacter aerogenes and E. cloacae
• Escherichia coli
• Klebsiella pneumoniae and K. oxytoca
• Morganella morganii
• Proteus mirabilis and P. vulgaris
• Salmonella

Class Mollicutes and the Spiroplasmataceae Family

The Class Mollicutes (Division Tenericutes) includes the family Spiroplasmataceae. Within this family, the genus Spiroplasma consists of helical forms that lack flagella. A notable species is Spiroplasma citri, which is a quarantine pest for Chile.

Characteristics of Spiroplasma

• Cell Structure: They lack a cell wall and are highly pleomorphic.
• Morphology: Found as spiral-shaped bodies in the vessels of infected plants.
• Mobility: They are highly mobile, exhibiting wave-like and helical motions.
• Cultivation: They may develop in culture on special media, where they appear rolled.
• Membrane: The cell membrane can consist of up to three layers.
• Growth Requirements: They require sterols in the culture medium