Fisiología Humana - Guía Tema 1

Fisiología Humana - Guía Tema 1

• Fisiología: Study of the functions of living organisms and how the human body performs vital activities. Its purpose is maintaining homeostasis in the patient.

Fisiología Celular

• Cell: The basic unit of the human body, responsible for oxygen, nutrient, fat, protein uptake, and reproduction.

• Homeostasis: Maintaining stable internal conditions (e.g., parameters) in the body.

Membrana Celular

• Cell membrane: A structure that surrounds the cell, separating the inside from the outside. It maintains cell components, protects the cell, and allows regulated entry/exit of substances due to its lipid nature.

Porcentaje de Agua en el Cuerpo

• Body water: The human body is approximately 60% water. Intracellular water accounts for 40%, extracellular water is 20% (15% interstitial fluid and 5% plasma; 1% transcellular).

Iones Extracelulares e Intracelulares

• Extracellular ions: Primary ions are Sodium (Na+), Chloride (Cl-), and Bicarbonate (HCO3-).

• Intracellular ions: Primary ions are Potassium(K+), Magnesium(Mg2+), proteins, and negative phosphates.

Electroneutralidad

• Electroneutralidad: Equilibrium between positive and negative charges both inside and outside the cell. This balance ensures proper cellular function.

Calcio (Ca2+)

• Calcium (Ca2+): Outside the cell, there's about four times more calcium than inside.

Bomba de Sodio-Potasio

• Sodium-Potassium Pump: Maintains the correct balance of ions across the cell membrane by removing Na+ and bringing in K+ against their concentration gradients, using ATP energy.

ATP

• ATP: The key energy source for cellular processes.

Difusión Simple

• Simple diffusion: Movement of substances across the membrane from a high concentration to a low concentration, without energy input.

Difusión Facilitada

• Facilitated diffusion: Movement that is aided by carrier proteins that help transport substances across the membrane down their concentration gradients. This process requires no direct energy input.

Transporte Mediado por Acarreador

• Characteristics of Carrier-Mediated Transport: Includes saturation (limited binding sites), stereospecificity (specific proteins for certain substances), and competition between similar substances.

Transporte Primario Activo

• Primary active transport: Movement against the concentration gradient; it requires energy (ATP).

Transporte Secundario Activo

• Secondary active transport: Coupled transport where movement of one substance with its concentration gradient powers the movement of another substance against its gradient.

Cotransporte

• Cotransport: Substances move in the same direction.

Contratransporte

• Countertransport: Substances move in opposite directions.

Potencial de Membrana en Reposo

• Resting membrane potential: The electrical difference across the membrane of a neuron when it's not transmitting signals (-70mV to -80mV).

Potencial de Acción

• Action potential: A rapid, temporary change in the membrane potential of excitable cells (e.g., neurons, muscle cells) in response to a stimulus, allowing for cellular communication/ signaling. This consists of specific phases and thresholds.

Sinapsis

• Synapse: The junction between two nerve cells or a nerve and a muscle; crucial for signal transmission. There are two main types: Electrical and Chemical.
• Chemical Synapse: Neurotransmission involves the release of neurotransmitters.

Neurotransmisores

• Neurotransmitters: Chemical messengers that transmit signals across synapses. Specific examples of neurotransmitters are mentioned.