Intro To Physiology Flashcards
What is physiology?
Physiology is a branch of biology that studies the functions and activities of life, including the physical and chemical phenomena involved in living matter.
How does anatomy relate to physiology?
Anatomy focuses on the structure of body parts, while physiology studies their function. Changes in physiology (especially pathophysiology) can alter anatomy.
What is the simplest structure that has functional properties of life?
The cell is the basic unit of life.
What are the levels of organization in the human body?
Molecules → Cells → Tissues → Organs → Organ Systems → Organism
What is the difference between an organ and an organ system?
An organ is a collection of tissues working together, while an organ system consists of multiple organs that perform a general function.
Name the 11 organ systems in the human body.
Circulatory, Digestive, Endocrine, Immune, Integumentary, Lymphatic, Musculoskeletal, Nervous, Reproductive, Respiratory, Urinary.
What is the functional unit of the kidney?
The nephron.
What percentage of body mass is water in a healthy 70kg male?
Approximately 60% (42 liters).
What are the two main fluid compartments of the body?
- Intracellular fluid (ICF) – 67% (28L)
- Extracellular fluid (ECF) – 33% (14L), which includes:
• Blood plasma (20-25%)
• Interstitial fluid (75-80%)
What is homeostasis?
The maintenance of a relatively constant internal environment.
Who introduced the concepts of internal environment and homeostasis?
• Claude Bernard – Internal environment
• Walter Cannon – Homeostasis
Give examples of physiological parameters controlled by homeostasis.
Temperature, blood glucose, pH, blood pressure.
What are the general characteristics of homeostatic control systems?
- Change occurs in the system.
- A homeostatic mechanism restores balance.
- This ensures effective functioning.
What are the two main types of feedback mechanisms?
- Negative feedback – Restores balance (e.g., blood glucose regulation).
- Positive feedback – Enhances change (e.g., oxytocin release during childbirth).
What is the difference between equilibrium and steady state?
• Equilibrium: No energy required, a stable state.
• Steady state: Energy is required to maintain stability.
What is the “resetting of set points”?
The body’s ability to physiologically adjust a normal value in response to external factors (e.g., fever).
What is a reflex arc?
The pathway linking a stimulus to a response in reflexes.
What are the two types of biological responses to imbalance?
- Local homeostatic responses – Occur in a specific area.
- Reflexes – Involuntary responses controlled by the nervous system.
What are learned reflexes?
Reflexes that require training, such as driving a car.
What are the three categories of intercellular chemical messengers?
- Hormones (endocrine system, e.g., epinephrine).
- Neurotransmitters (nervous system, e.g., dopamine).
- Paracrine & Autocrine agents (local communication).
What is the difference between paracrine and autocrine agents?
• Paracrine agents act on nearby cells.
• Autocrine agents act on the same cell that produced them.
What are the three subatomic particles of an atom?
- Protons (+ charge, nucleus).
- Neutrons (no charge, nucleus).
- Electrons (- charge, orbitals).
What is an isotope?
Variants of a chemical element that differ in the number of neutrons.
What are electrolytes?
Ions that conduct electricity when dissolved in water.
