Anatomy & Physiology: Core Concepts and Cellular Structures Study Guide

Core Concepts in Anatomy & Physiology

Definitions and Fundamental Principles

This section introduces foundational terms and concepts essential for understanding anatomy and physiology at the college level.

• Physiology: The scientific study of the normal functions and mechanisms in a living system.

• Pathophysiology: The study of disordered physiological processes associated with disease or injury.

• Teleological vs Mechanistic: Teleological explanations focus on the purpose of a process ("why" it occurs), while mechanistic explanations describe the physical or chemical steps ("how" it occurs).

• Homeostasis: The maintenance of a stable internal environment despite external changes. Example: Regulation of body temperature, blood glucose levels.

• Crossover Study: A type of clinical study where participants receive a sequence of different treatments, allowing each participant to serve as their own control.

• A Placebo: An inactive substance or treatment given to a control group in experiments.

• A Hypothesis: A testable statement or prediction about the relationship between variables.

• A Theory: A well-substantiated explanation of some aspect of the natural world, based on a body of evidence.

• Meta-analysis: A statistical technique that combines the results of multiple scientific studies to identify overall trends.

• Dependent vs Independent Variables: The independent variable is manipulated by the researcher, while the dependent variable is measured to assess the effect.

• Glycosylated Molecules: Molecules that have carbohydrate groups attached to them, often affecting their function and recognition.

• Elements That Make Up More Than 90% of the Body's Mass: Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N).

Biomolecules and Their Structure

Understanding the structure and function of biomolecules is essential for grasping physiological processes.

• Structure and Naming of Carbohydrate: Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio. Example: Glucose (C6H12O6).

• Essential Amino Acids: Amino acids that cannot be synthesized by the body and must be obtained from the diet. Example: Leucine, lysine, tryptophan.

• Structure of Amino Acids: Each amino acid has a central carbon atom bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a variable R group.

• Structure and Derivative of Fatty Acid: Fatty acids are long hydrocarbon chains with a terminal carboxyl group. Example: Palmitic acid (C16H32O2).

• ATP (Adenosine Triphosphate): The primary energy carrier in cells. Equation: $\text{ATP} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

• pH Scale: A measure of hydrogen ion concentration; ranges from 0 (acidic) to 14 (basic), with 7 being neutral. Equation: $\text{pH} = -\log_{10}[\text{H}^+]$

Cellular Processes and Functions

Cells are the basic units of life, and understanding their components and functions is crucial in anatomy and physiology.

• Endocrine Glands: Glands that secrete hormones directly into the bloodstream to regulate body functions.

• Apoptosis: Programmed cell death, a normal process for removing unneeded or damaged cells.

Cell Structure and Function

Functions of Key Cell Organelles

Each organelle within a cell has specialized functions that contribute to the cell's survival and activity.

• Phospholipid Bilayer: Forms the fundamental structure of the cell membrane, providing a barrier and mediating transport.

• Nucleus: Contains genetic material (DNA) and controls cellular activities.

• Nucleoli: Dense regions within the nucleus where ribosomal RNA is synthesized.

• Endoplasmic Reticulum (ER): Network of membranes involved in protein and lipid synthesis.

  • Rough ER: Studded with ribosomes; synthesizes proteins.

  • Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies chemicals.

• Golgi Complex: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

• Centrioles: Involved in organizing microtubules during cell division.

• Ribosomes: Sites of protein synthesis, found free in cytoplasm or attached to rough ER.

• Mitochondria: The "powerhouse" of the cell, generating ATP through cellular respiration.

• Lysosomes and Peroxisomes: Organelles containing enzymes for digestion (lysosomes) and detoxification (peroxisomes).

• Cytoskeleton: Network of protein filaments providing structural support, shape, and movement.

Cell Junctions and Tissue Types

Cells are organized into tissues and connected by specialized junctions to perform collective functions.

• Types of Cell Junctions:

  • Tight Junctions: Seal adjacent cells to prevent leakage of molecules.

  • Desmosomes: Provide mechanical strength by anchoring cells together.

  • Gap Junctions: Allow direct communication between cells via channels.

• Primary Tissue Types:

  • Epithelial Tissue: Covers body surfaces and lines cavities.

  • Connective Tissue: Supports, binds, and protects organs.

  • Muscle Tissue: Responsible for movement.

  • Nervous Tissue: Conducts electrical impulses for communication.