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 functions and mechanisms occurring in living organisms.

• 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 happens), while mechanistic explanations describe the physical or chemical steps ("how" it happens).

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

• 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, carbon, hydrogen, and nitrogen.

Biomolecules and Their Structure

Understanding the structure and function of biomolecules is crucial 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.

• Structure of Amino Acids: Each amino acid has a central carbon, 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. Derivatives include triglycerides and phospholipids.

Cellular Energy and Signaling

Cells require energy and communication mechanisms to function and respond to their environment.

• ATP (Adenosine Triphosphate): The primary energy carrier in cells. Energy is released when ATP is hydrolyzed to ADP and inorganic phosphate.

• pH Scale: A measure of hydrogen ion concentration; ranges from 0 (acidic) to 14 (basic), with 7 being neutral.

• Endocrine Glands: Ductless glands that secrete hormones directly into the bloodstream. Example: Thyroid gland.

• Apoptosis: Programmed cell death, a controlled process that removes damaged or unnecessary 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):

  • Rough ER: Studded with ribosomes; synthesizes and processes proteins.

  • Smooth ER: Lacks ribosomes; involved in lipid synthesis and detoxification.

• 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 the cytoplasm or attached to rough ER.

• Mitochondria: The "powerhouse" of the cell; site of aerobic respiration and ATP production.

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

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

Table: Major Cell Organelles and Their Functions

Organelle	Main Function
Nucleus	Stores genetic information; controls cell activities
Rough ER	Protein synthesis and processing
Smooth ER	Lipid synthesis; detoxification
Golgi Complex	Modification and packaging of proteins/lipids
Mitochondria	ATP production via aerobic respiration
Lysosomes	Digestion of cellular waste and foreign material
Peroxisomes	Breakdown of fatty acids; detoxification
Cytoskeleton	Structural support; cell movement

Cell Junctions and Tissue Types

Types of Cell Junctions

Cell junctions are specialized structures that connect adjacent cells, facilitating communication and maintaining tissue integrity.

• Tight Junctions: Seal adjacent cells to prevent passage of molecules between them.

• Desmosomes: Provide strong adhesion between cells, important in tissues subject to mechanical stress.

• Gap Junctions: Allow direct communication between cells through channels that permit the passage of ions and small molecules.

Primary Tissue Types

The human body is composed of four primary tissue types, each with distinct functions and characteristics.

• Epithelial Tissue: Covers body surfaces and lines cavities; functions in protection, absorption, and secretion.

• Connective Tissue: Supports, binds, and protects other tissues and organs. Example: Bone, blood, adipose tissue.

• Muscle Tissue: Responsible for movement; includes skeletal, cardiac, and smooth muscle.

• Nervous Tissue: Conducts electrical impulses; forms the brain, spinal cord, and nerves.

Example: The intestinal wall contains epithelial tissue (lining), connective tissue (support), muscle tissue (movement), and nervous tissue (regulation).

Additional info: Where the original notes were brief, standard academic definitions and examples have been provided for clarity and completeness.