Notes, abstracts, papers, exams and problems of Biology

Thalamus

Regulates communication between several parts of the brain and the endocrine system.

Corpus Callosum

Structure made of nerves that bridges two hemispheres.

Hippocampus

Part of the limbic system, responsible for long-term memory.

Cerebellum

Responsible for motion, balance, and new learning. Exterior grey matter, interior grey matter.

Brainstem

Several regions including medulla oblongata (elongates into the spinal column). Location of several centers of involuntary nervous control.

Hypothalamus

Master gland of the endocrine system, controlling most of its activity.

Two Cerebral Hemispheres

Surfaces known as cerebral cortex and comprised of grey matter. Folder structure made of rounded gyri and recessed sulci divide the lobes.

Spinal Cord

Brings messages... Continue reading "Understanding the Human Brain and Nervous System" »

Chemical Evolution

Artificial Selection and Evolution

Possible Misconceptions

• Populations evolve, not individual organisms. Individuals may have certain heritable variations, but they do not evolve these traits during their lifetime.

Evidence of Evolution

The Study of Fossils

Support for Evolution

• Charles Darwin proposed a possible explanation for the origin of species, explaining various data and suggesting areas for further research.
• The theory of evolution suggests that all organisms on Earth share a common ancestor.

Fossil Record

• Fossils provide significant evidence of evolutionary change, offering a record of species that existed long ago.
• Ancient species often show similarities to species living today.
• Not all extinct fossils have modern counterparts, and some ancient

Rheumatic Fever

Is a multisystem inflammatory disease that can involve the heart, joints, skin, and brain. The disease develops after a streptococcal infection (A beta-hemolytic – Streptococcus pyogenes) – mostly pharyngitis

Clinical Features

• Occur most often in children
• Develop 2-4 weeks after streptococcal infection
• Fever, malaise, and increased erythrocyte sedimentation rate
• Rheumatic heart disease – pancarditis; inflammation of the entire heart (3 layers)

Pericarditis

Leads to serous effusions

Myocarditis

Leads to cardiac failure

Endocarditis

Leads to valvular damage

• Rheumatic endocarditis – mitral and aortic valves (mostly); the valves become thickened, fibrotic, deformed, & calcification (may)

• Joint involvement – arthralgia, arthritis,

1. Know the functions of the lymphatic system

· Produce, maintain, and distribute lymphocytes and other lymphoid cells that provide defense against infections and foreign substances PRIMARY FUNCTION. Return of excess fluid to bloodstream. Transport of lipids absorbed in digestive tract

2. Know the three subtypes of lymphocytes and what type of immunity each is responsible for

· T cells à Cell-mediated immunity (4+ subtypes)

• Cytotoxic T Cells (T_c) - direct cellular attack
• Helper T Cells (T_H) and Suppressor T Cells (T_S) - regulatory roles
• Memory T Cells.

B Cells à Antibody-mediated immunity

• Antibodies (immunoglobulins)
• Antigen - usually proteins (specific chemical targets)

· NK Cells à Immunological surveillance

3. Know where the three types of lymphocytes

Cell Structure and Function

A cell is the smallest structural and functional unit of life that can carry out the three vital functions: nutrition, reproduction, and interaction.

• Nutrition: obtaining energy, renewing the cellular structure, and obtaining biomolecules.
• Interaction: cells can adapt to changes in their environment and continue performing the activities they need to live.
• Reproduction: formation of new cells.

Types of Cells

Prokaryotic Cells

Prokaryotic cells do not have membrane-bound structures, are relatively small, have a single circular chromosome, have isolated ribosomes in their cytoplasm, and have cavities in their cytoplasm that function as mitochondria. Organisms belonging to the Monera kingdom have prokaryotic cells.

Eukaryotic

Vowels and Consonants

A vowel is a sound produced without any closure in the mouth or throat. There's no obstruction in the buccal cavity. A consonant, conversely, involves at least one stoppage of airflow during vocalization.

Places of Articulation

The place of articulation describes where the obstruction occurs in the vocal tract. It's the point of contact between an active articulator (usually part of the tongue) and a passive articulator (typically part of the roof of the mouth).

• Bilabial: Both lips.
• Labio-dental: Upper lip and upper front teeth.
• Dental: Tongue tip/blade and upper front teeth.
• Alveolar: Tongue tip/blade and alveolar ridge.
• Post-alveolar: Tongue blade and back of the alveolar ridge.
• Palatal: Tongue front and hard palate.
• Velar: Tongue

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