Cell Biology and Integumentary System Lecture Notes

These flashcards cover key concepts in cell biology, the integumentary system, muscle physiology, and the nervous system based on the lecture notes provided.

What are the common features of a cell?

Plasma membrane, cytoplasm, DNA/genetic material, ribosomes.

What is the function of the plasma membrane?

It acts as a selectively permeable barrier that regulates what enters and exits the cell, providing protection, communication, and structural support.

What are integral and peripheral proteins in the plasma membrane?

Integral proteins span the bilayer and are often transporters or receptors, while peripheral proteins are attached to the inner or outer membrane surface and are often involved in signaling or structure.

Define passive transport.

Movement of molecules down the concentration gradient without the need for energy.

What is the difference between simple diffusion and facilitated diffusion?

Simple diffusion occurs directly through the lipid bilayer (for small, nonpolar molecules), while facilitated diffusion requires channel or carrier proteins (for ions and glucose).

What is osmosis?

Movement of water across a selectively permeable membrane from low solute concentration to high solute concentration.

What is primary active transport?

Active transport that directly uses ATP to move substances against their concentration gradient.

What are the two types of secondary transport?

Symport (two substances move in the same direction) and antiport (two substances move in opposite directions).

What is exocytosis?

The process in which a vesicle fuses with the plasma membrane to release materials outside the cell.

What are the four types of tissues in the body?

Epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

List some functions of the integumentary system.

Protection, sensation, temperature regulation, metabolic functions, excretion/secretion, and immune defense.

What types of cells are found in the epidermis?

Keratinocytes, melanocytes, Langerhans/dendritic cells, and Merkel/tactile cells.

What is the role of keratin in the skin?

Keratin is a tough protein that protects the skin and waterproofs it.

What are the two types of melanin?

Eumelanin (brown/black pigment) and pheomelanin (red/yellow pigment).

Describe the regeneration process in tissue healing.

Regeneration is the replacement of damaged tissue by the same tissue type, restoring full function.

What is muscle fatigue?

Inability to maintain force of contraction, often caused by ATP depletion, ion imbalances, lactic acid accumulation, central fatigue, or oxygen depletion.

What components make up a homeostatic system?

Receptor, control center, and effector.

What are the basic functions of the nervous system?

Sensory (input), integrative (processing), and motor (output).

What happens during depolarization in an action potential?

Voltage-gated Na⁺ channels open, allowing Na⁺ to rush into the cell.

What is the definition of a motor unit?

A motor neuron plus all the muscle fibers it controls.

What process occurs at the neuromuscular junction?

The motor neuron communicates with the muscle fiber via the neurotransmitter acetylcholine (ACh).