Anatomy & Physiology Midterm Study Guide: Core Concepts and Systems

Chapter 1: Introduction to Anatomy and Physiology

Key Definitions in Anatomy and Physiology

Anatomy and Physiology are foundational sciences for understanding the structure and function of the human body. Several specialized fields exist within these disciplines:

• Anatomy: Study of internal and external body structures and their physical relationships among other body parts.

• Physiology: Study of how living organisms perform their vital functions.

• Histology: Study of tissues. Groups of specialized cells that work together to perform specific functions.

• Cytology: Study of cells. Internal structure of individual cells, simplest units of life.

Anatomical Position

The anatomical position is a standard reference for describing locations and relationships of body parts.

• Definition: Standing upright, hands at the sides with palms facing forward, and feet together.

Directional Terms and Body Planes

Directional terminology is used to describe the location of body structures:

• Anterior (ventral): Front view

• Posterior (dorsal): Back view

• Supine: Lying down, face up

• Prone: Lying down, face down

• Medial: Toward the midline (middle or navel)

• Lateral: Away from the midline

• Superior (cranial): Above, at a higher level (toward the head)

• Inferior (caudal): Below, at a lower level (toward the feet)

• Superficial: Close to the body's surface

• Deep: Toward the interior of the body, far from surface

Body planes divide the body for anatomical study:

• Sagittal: Separates left and right sections

• Frontal (coronal): Separates front (anterior) and back (posterior)

• Transverse (horizontal): Separates superior and inferior portions

Serous Membranes

Serous membranes line body cavities and cover organs:

• Pericardium: Associated with the heart

• Visceral pleura: Covers the direct surface of the lung

• Parietal pleura: Covers the mediastinal surface (chest wall and inner body wall)

• Parietal peritoneum: Lines the abdominal wall

• Visceral peritoneum: Covers abdominal organs

Organ Systems and Their Functions

The human body consists of 11 organ systems, each with specific functions:

System	Main Organs	General Function
Integumentary	Skin, hair, sweat glands, nails	Protects against environmental hazards, regulates body temperature, provides sensory information
Skeletal	Bones, cartilage, ligaments, bone marrow	Support, protection, mineral storage, blood cell production
Muscular	Skeletal muscles, tendons	Movement, support, heat generation
Nervous	Brain, spinal cord, nerves, sense organs	Immediate responses, coordination, interpretation of sensory information
Endocrine	Pituitary, thyroid, pancreas, adrenal glands, gonads	Long-term changes, metabolic activity, structural and functional changes
Cardiovascular	Heart, blood vessels, blood	Transport of nutrients, waste, gases; temperature regulation
Lymphatic	Spleen, thymus, lymph nodes, vessels, tonsils	Defense against infection, returns fluids to bloodstream
Respiratory	Nasal cavities, sinuses, larynx, trachea, bronchi, lungs	Delivers air, gas exchange, sound production
Digestive	Teeth, tongue, pharynx, esophagus, stomach, intestines, liver, gallbladder, pancreas	Processes and digests food, absorbs nutrients, stores energy
Urinary	Kidneys, ureters, bladder, urethra	Excretes waste, controls water balance, regulates blood ion concentrations and pH
Reproductive (Male)	Testes, epididymis, ductus deferens, seminal vesicles, prostate, penis, scrotum	Produces sex cells and hormones
Reproductive (Female)	Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands	Produces sex cells and hormones, supports developing embryo

Homeostasis and Feedback Mechanisms

Homeostasis is the maintenance of a stable internal environment. Feedback mechanisms regulate physiological processes:

• Negative Feedback: Stabilizes body systems by counteracting changes (e.g., body temperature regulation).

• Positive Feedback: Amplifies changes until a specific outcome is reached (e.g., blood clotting, childbirth).

Chapter 2: The Chemical Level of Organization

Metabolism

Metabolism refers to the sum of all chemical reactions that occur in the body to maintain life.

Enzymes

• Definition: Proteins that speed up chemical reactions in the body without being consumed.

• Function: Specific enzymes catalyze specific reactions, increasing efficiency.

Electrolytes and Homeostasis

• Electrolytes: Soluble inorganic compounds whose ions conduct electrical current in solution.

• Role in Homeostasis: Electrolyte balance is essential for nerve function, muscle contraction, and fluid balance.

pH Scale

• Definition: Indicates hydrogen ion concentration; measures acidity or basicity of a solution.

• Range: 0–7 = acidic, 8–14 = basic

Major Biological Molecules

• Carbohydrates: Organic molecules containing carbon, hydrogen, and oxygen in a 1:2:1 ratio. Function: Primary energy source.

• Proteins: Most abundant organic molecules; large polypeptides with complex structures. Function: Structure, transport, enzymes.

• Lipids: Contain C, H, O in a ratio < 1:2. Hydrophobic, energy reserves, cell membranes.

• Amino Acids: Building blocks of proteins; contain carbon, oxygen, nitrogen. Chemical structure: R-CHNH2-COOH

Nucleic Acids: DNA and RNA

• DNA: Double chain of nucleotides; contains deoxyribose sugar and bases adenine, guanine, cytosine, thymine. Function: Stores genetic information, controls protein synthesis.

• RNA: Single chain of nucleotides; contains ribose sugar and bases adenine, guanine, cytosine, uracil. Function: Directs protein synthesis as instructed by DNA.

ATP: Cellular Energy

• ATP (Adenosine Triphosphate): High-energy compound with three phosphate groups. Function: Stores and releases energy for cellular processes.

Cell Structure and Function

Key Cell Components

• Cell membrane (plasma membrane): Outermost layer; lipid bilayer. Functions: Isolation, protection, sensitivity, support, controls entry/exit of materials.

• Receptor proteins: Sensitive to specific extracellular ions or molecules (ligands).

• Transport proteins: Bind solutes and transport them across the plasma membrane.

• Cilia: Slender extensions of the plasma membrane; motile cilia move materials over cell surfaces, primary cilium acts as a sensor.

• Gated channels: Pores that form passageways, can open or close.

• Mitochondria: Double-membrane organelles; produce 95% of ATP required by the cell.

• Cytoplasm: Material between the plasma membrane and the nuclear membrane; contains cell contents.

• Nucleus: Brain of the cell; controls metabolism, stores and processes genetic information, controls protein synthesis.

Example: ATP Production

• Glycolysis: Occurs in cytoplasm; glucose split into pyruvate, produces small amount of ATP.

• Krebs Cycle: Occurs in mitochondria; produces ATP, CO2, and electron carriers.

• Electron Transport Chain: Uses O2 to generate large quantities of ATP.

Additional info: These notes cover the foundational concepts for Anatomy & Physiology, including terminology, organ systems, chemical principles, and cell structure. For exam preparation, students should be able to define terms, describe processes, and apply concepts to examples.