BIO169 FINAL

Feedback Loops

Essential mechanisms in biological systems that help maintain homeostasis and regulate physiological processes.

Positive Feedback

Amplifies changes in a system, leading to an even greater change in the same direction.

Negative Feedback

Detects changes and initiates responses to reverse those changes, maintaining homeostasis.

Active Transport

Requires energy (ATP) to move substances against their concentration gradient (from low to high concentration).

Passive Transport

Does not require energy; substances move down their concentration gradient (from high to low concentration).

Osmosis

Movement of water molecules from an area of low solute concentration to high solute concentration.

Diffusion

Process where particles spread from areas of high concentration to low concentration until equilibrium is reached.

Filtration

Involves pressure forcing water and solutes through a membrane.

Cilia

Short, numerous hair-like structures that move substances across cell surfaces.

Flagella

Long, whip-like structures that propel entire cells.

Microvilli

Short, finger-like projections that increase surface area for absorption.

Serosal Membranes

Two-layered membranes that reduce friction and enclose cavities.

Parietal Membrane

Lines the walls of body cavities, providing a protective layer.

Visceral Membrane

Directly covers the organs within the cavities.

Macronutrients

The three primary macronutrients are carbohydrates, proteins, and fats.

Vitamin D

Crucial for bone health, supporting immune function, and facilitating muscle and nerve function.

Gluconeogenesis

The synthesis of new glucose molecules occurs during fasting.

Glycogenolysis

The breakdown of glycogen into glucose during fasting.

Glycogenesis

The process of synthesizing glycogen from glucose occurs in the fed state.

Lipogenesis

Converts excess carbohydrates and proteins into fatty acids and fats during the fed state.

Lipolysis

The breakdown of triglycerides into free fatty acids occurs during fasting.

Antidiuretic Hormone (ADH)

Targets the kidneys to stimulate water reabsorption, increasing blood volume.

Aldosterone

Promotes sodium reabsorption in the kidneys, increasing blood volume.

Renin-Angiotensin-Aldosterone System (RAAS)

Monitors blood pressure and triggers mechanisms to raise blood volume and pressure.

Blood Composition

Blood consists of plasma (liquid matrix) and formed elements (RBCs, WBCs, platelets).

Plasma

Makes up 55% of blood volume and contains water, electrolytes, proteins, hormones, and waste products.

Erythrocytes (RBCs)

Transport oxygen and carbon dioxide.

Leukocytes (WBCs)

Involved in immune response.

Thrombocytes (Platelets)

Essential for blood clotting and hemostasis.

Antigens

Substances that determine blood type; Type O is the universal donor.

Heart Structure

The heart consists of four chambers and valves that regulate blood flow.

Chambers of the Heart

Include two atria and two ventricles that manage blood flow through the heart.

Cardiac Output (CO)

Amount of blood pumped by each ventricle per minute, calculated as CO = Heart Rate × Stroke Volume.

Oxygenated Blood

Blood that carries oxygen, found in the left atrium, left ventricle, aorta, and pulmonary veins.

Deoxygenated Blood

Blood that returns carbon dioxide-rich blood to the heart, found in the right atrium and right ventricle.

Breathing Mechanism

Involves changes in thoracic volume and pressure to facilitate gas exchange.

Gas Exchange

Occurs in the lungs (pulmonary gas exchange) and tissues (systemic gas exchange).

Digestive System Functions

Responsible for breaking down food into absorbable nutrients and eliminating indigestible waste.

Lymphatic System Structures

Includes the thymus, spleen, and lymph nodes, essential for immune function.

Innate Immunity

Provides a fast response without memory, including cells like neutrophils and macrophages.

Adaptive Immunity

Slower response that involves B and T cells, providing memory for future exposures.