Anatomy & Physiology Exam 1 Study Guide: Core Concepts and Systems

Lecture 1: Levels of Organization & Homeostasis

Levels of Organization in the Body

The human body is organized into hierarchical levels, each with specific functions and structures.

• Chemical Level: Atoms and molecules form the basis of all matter.

• Cellular Level: Cells are the basic structural and functional units of life.

• Tissue Level: Groups of similar cells performing a common function.

• Organ Level: Structures composed of two or more tissue types working together.

• Organ System Level: Groups of organs that perform related functions.

• Organism Level: The complete living being.

Example: The digestive system includes organs such as the stomach, intestines, and liver, all working together to process food.

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite changes in external conditions.

• Negative Feedback System: A process that reverses a change to keep conditions within certain limits. Example: Regulation of body temperature.

• Positive Feedback System: A process that amplifies a change, moving the system away from its starting state. Example: Blood clotting.

Lecture 2: Atomic Structure & Chemical Bonds

Atomic Structure

Atoms consist of a nucleus (protons and neutrons) and electrons in shells around the nucleus.

• Valence Shells: The outermost electron shell, important for chemical bonding.

• Octet Rule: Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Chemical Bonds

Chemical bonds are forces that hold atoms together in molecules.

• Ionic Bonds: Formed by the transfer of electrons from one atom to another.

• Covalent Bonds: Formed by the sharing of electrons between atoms.

• Polar vs. Non-polar Bonds: Polar bonds have unequal sharing of electrons; non-polar bonds have equal sharing.

• Hydrogen Bonds: Weak attractions between polar molecules, important in water and DNA structure.

Isotopes

Isotopes are atoms of the same element with different numbers of neutrons.

• Radioactive Isotopes: Unstable isotopes that decay over time, emitting radiation. Used as tracers in medical research.

Atomic Number & Mass Number

• Atomic Number: Number of protons in the nucleus.

• Mass Number: Sum of protons and neutrons.

Lecture 3: Hydrolysis Reactions

Hydrolysis Reactions

Hydrolysis is a chemical reaction in which water is used to break down a compound.

• General Formula: $\text{AB} + \text{H}_2\text{O} \rightarrow \text{AOH} + \text{BH}$

• Application: Digestion of macromolecules such as proteins and carbohydrates.

Lecture 4: Cell Structure & DNA

Organelle Characteristics

Organelles are specialized structures within cells that perform distinct functions.

• Plasma Membrane: Controls entry and exit of substances; composed of a phospholipid bilayer.

• Junction Types: Structures that connect cells, including tight junctions, desmosomes, and gap junctions.

DNA Structure

DNA is the molecule that carries genetic information.

• Double Helix: DNA consists of two strands twisted into a helix.

• Nucleotide: The building block of DNA, consisting of a sugar, phosphate, and nitrogenous base.

Cell Theory

Cell theory is a fundamental concept in biology.

• All living things are composed of cells.

• Cells arise from the division of pre-existing cells.

• Cells are the basic unit of structure and function in living things.

Cell Transport & Golgi Apparatus

• Transport Vesicles: Move products within the cell.

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for delivery.

Lecture 5: Membrane Transport & Gradients

Concentration Gradients

A concentration gradient is the difference in the concentration of a substance across a space.

• Iso-, Hypo-, Hypertonic Solutions: Refer to the relative concentration of solutes in solutions compared to the cell.

Lecture 6: Tissues & Membranes

Epithelial Tissue Characteristics

Epithelial tissue covers body surfaces and lines cavities.

• Functions: Protection, absorption, filtration, secretion.

• Characteristics: Closely packed cells, avascular, high regenerative capacity.

Connective Tissue Types

Connective tissue supports, binds, and protects other tissues and organs.

• Types: Loose connective tissue, dense connective tissue, cartilage, bone, blood.

Membrane Characteristics

Body membranes cover surfaces, line cavities, and form protective sheets around organs.

• Types: Mucous membranes, serous membranes, cutaneous membranes, synovial membranes.

Additional Info: Sample Questions Table

The file includes multiple-choice questions for each topic, which can be used for self-assessment and exam preparation.

Topic	Sample Question	Answer Choices
Body Systems	The human body is divided into ____ major systems.	11, 12, 13, 14
Chemical Bonds	A sulfur atom has 6 electrons in its outer shell. As a result, it forms ____ covalent bonds with other atoms.	2, 3, 4, 6
Radioactive Isotopes	Radioactive isotopes are useful as "tracers" in medical research because organisms incorporate radioactive isotopes of an element into their molecules (True/False).	True/True, True/False, False/True, False/False
DNA Structure	The structure of DNA is properly described as a ____ in which a single strand of DNA is made up of ____.	Double helix; nucleotide, Double helix; amino acid, Triple helix; amino acid, Twisted ladder; random
Cell Theory	The "cell theory" as stated by Schleiden & Schwann states that:	All living things are made of cells, Tissues form the basic unit of structure in all living things, Cells arise from the division of pre-existing cells, Cells form from the basic unit of cell structure