Physiology, Cells, Homeostasis and Feedback Flashcards
(26 cards)
What is physiology?
The study of how the body functions, including the role of cells, tissues, organs, and systems in maintaining life.
How are anatomy and physiology related?
Anatomy is the study of structure, while physiology is the study of function; they are closely linked as structure determines function.
What are the levels of biological organization from smallest to largest?
Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism
What is the smallest unit of life?
The cell.
What is an example of an organ system?
The cardiovascular system, which includes the heart and blood vessels.
Name some different types of human cells and their functions.
Red blood cells (erythrocytes): Carry oxygen.
Skeletal muscle cells: Enable movement (voluntary).
Smooth muscle cells: Involuntary control of organs and blood vessels.
Nerve cells (neurons): Transmit electrical signals.
Fat cells (adipocytes): Store energy.
White blood cells (macrophages): Fight infections.
How many types of human cells are there?
Over 200 types, differing in shape, size, and function.
What are the three main principles of cell theory?
All living organisms are made of one or more cells.
The cell is the basic unit of life.
All cells come from pre-existing cells.
Why is understanding cell function important in medicine?
Many diseases result from cell abnormalities.
What is the plasma membrane and its function?
A bilayer of lipids and proteins that regulates what enters and exits the cell (selectively permeable).
What is the ‘fluid mosaic model’?
The plasma membrane is dynamic (‘fluid’) and consists of proteins embedded in a lipid bilayer (‘mosaic’).
What are the three major components of the cytoplasm?
Cytosol (fluid where organelles are suspended)
Organelles (functional cell structures)
Inclusions (stored substances like glycogen)
What is the function of the nucleus?
It acts as the control center of the cell, housing DNA for cell replication, repair, and protein synthesis.
What organelle produces ribosomes?
The nucleolus.
What are the four main tissue types in the body?
Epithelial Tissue: Covers surfaces (e.g., skin, organ linings).
Connective Tissue: Supports and connects (e.g., bone, blood, tendons).
Muscle Tissue: Enables movement (skeletal, cardiac, and smooth muscle).
Nervous Tissue: Conducts electrical signals (brain, spinal cord, nerves).
What is a unique feature of connective tissue?
It has an extracellular matrix that separates the cells.
What are the three types of muscle tissue?
Skeletal muscle: Voluntary, moves the body.
Cardiac muscle: Involuntary, heart function.
Smooth muscle: Involuntary, lines organs and blood vessels.
How does nervous tissue transmit signals?
Through neurons, which have dendrites (receive signals) and axons (send signals).
What is homeostasis?
The body’s ability to maintain a stable internal environment despite external changes.
Give two examples of homeostatic regulation.
Body temperature: Sweating when hot, shivering when cold.
Blood sugar levels: Insulin lowers high sugar, glucagon raises low sugar.
What happens if homeostasis is disrupted?
It can lead to diseases, such as diabetes or metabolic imbalances.
What are the two types of feedback mechanisms?
Negative feedback: Maintains stability by reversing a change (e.g., temperature regulation).
Positive feedback: Enhances a process (e.g., oxytocin in childbirth).
How does negative feedback work in temperature regulation?
Body temperature rises.
Sensors detect the change and send signals to the brain.
The brain triggers sweating to cool down the body.
Once normal temperature is restored, sweating stops.
What is an example of positive feedback in the body?
During childbirth, oxytocin increases uterine contractions, which triggers more oxytocin release, strengthening contractions until birth occurs.
