Introduction to Anatomy & Physiology and Cell Chemistry: Study Guide Notes

Introduction to Anatomy & Physiology

Anatomy and Physiology: Definitions and Relationship

Anatomy is the study of the structure of body parts and their relationships to one another. Physiology is the study of the function of the body’s structural machinery. The two fields are closely related, as structure often determines function.

• Anatomy: Focuses on body structures, such as organs, tissues, and cells.

• Physiology: Explains how those structures work and interact.

• Main Divisions:

  • Gross (macroscopic) anatomy: Study of large, visible structures.

  • Microscopic anatomy: Study of structures too small to be seen with the naked eye (e.g., cytology, histology).

  • Systemic physiology: Study of the function of organ systems.

Example: The structure of the heart (anatomy) enables it to pump blood (physiology).

Levels of Organization in Organisms

Living organisms are organized in a hierarchy from simplest to most complex:

• Chemical level: Atoms and molecules

• Cellular level: Cells and their organelles

• Tissue level: Groups of similar cells

• Organ level: Contains two or more types of tissues

• Organ system level: Organs that work closely together

• Organismal level: All organ systems combined to make the whole organism

Basic Functions of Living Organisms

• Metabolism: All chemical reactions in the body

• Responsiveness: Ability to sense and respond to stimuli

• Movement: Includes movement of the body, organs, cells, and molecules

• Growth: Increase in size and number of cells

• Reproduction: Production of new cells or organisms

• Homeostasis: Maintenance of a stable internal environment

Homeostasis and Feedback Mechanisms

Homeostasis is the maintenance of a stable internal environment despite external changes. It involves:

• Receptor: Detects changes (stimuli)

• Control (integration) center: Processes information and determines response

• Effector: Carries out the response

Feedback mechanisms:

• Negative feedback: The response reduces or shuts off the original stimulus (e.g., regulation of body temperature, blood glucose levels).

• Positive feedback: The response enhances or exaggerates the original stimulus (e.g., blood clotting, labor contractions).

Example: When blood sugar rises, insulin is released to lower it (negative feedback).

Body Cavities and Major Organs

The body contains several cavities that house organs:

• Cranial cavity: Contains the brain

• Thoracic cavity: Contains pleural (lungs) and pericardial (heart) cavities

• Abdominopelvic cavity: Contains abdominal (digestive organs) and pelvic (bladder, reproductive organs) cavities

• Other cavities: Oral, nasal, orbital, synovial, peritoneal

Body Surface Areas and Anatomical Landmarks

• Cranial: Head/skull

• Facial: Face

• Cephalic: Head

• Axillary: Armpit

• Thoracic: Chest

• Lumbar: Lower back

• Pelvic: Pelvis

• Brachial: Arm

• Antebrachial: Forearm

• Antecubital: Front of elbow

• Carpal: Wrist

• Palmar: Palm

• Inguinal: Groin

• Umbilical: Navel

• Pubic: Genital region

• Gluteal: Buttock

• Popliteal: Back of knee

• Calcaneal: Heel

• Femoral: Thigh

• Plantar: Sole of foot

• Patellar: Kneecap

Abdominopelvic Regions and Quadrants

• Quadrants: Right upper, left upper, right lower, left lower

• Regions: Right/left hypochondriac, epigastric, right/left lumbar, umbilical, right/left iliac, hypogastric

Directional and Sectional Terms

• Directional terms: Superior, inferior, lateral, medial, dorsal, ventral, superficial, deep, proximal, distal, cranial, caudal

• Sectional planes: Frontal (coronal), sagittal, transverse (horizontal)

Anatomical Position and Body Positions

• Anatomical position: Body erect, feet slightly apart, palms facing forward, thumbs pointing away from body

• Prone: Lying face down

• Supine: Lying face up

Cell Chemistry & Cell Components

Atoms and Subatomic Particles

An atom is the smallest unit of matter that retains the properties of an element. Atoms are composed of:

• Protons: Positive charge, located in the nucleus

• Neutrons: No charge, located in the nucleus

• Electrons: Negative charge, orbiting the nucleus

The number of protons defines the element. Electrons are involved in chemical bonding.

Chemical Bonds, Molecules, and Compounds

• Chemical bond: Force that holds atoms together (e.g., ionic, covalent, hydrogen bonds)

• Molecule: Two or more atoms joined by chemical bonds (e.g., O2)

• Compound: Molecule containing two or more different elements (e.g., H2O)

Difference: All compounds are molecules, but not all molecules are compounds.

Organic vs. Inorganic Compounds

• Organic compounds: Contain carbon and hydrogen (e.g., carbohydrates, lipids, proteins, nucleic acids)

• Inorganic compounds: Do not contain both carbon and hydrogen (e.g., water, salts, acids, bases)

Carbohydrates

• Structure: Composed of carbon, hydrogen, and oxygen (C:H:O ratio is 1:2:1)

• Monosaccharides: Simple sugars (e.g., glucose)

• Disaccharides: Two monosaccharides joined (e.g., sucrose)

• Polysaccharides: Many monosaccharides (e.g., glycogen, starch)

• Bond formation: Dehydration synthesis forms glycosidic bonds

• Main functions: Energy source, structural support

Example: Glucose is a monosaccharide used for cellular energy.

Lipids

• Structure: Mostly carbon and hydrogen, with some oxygen

• Components: Glycerol and fatty acids

• Saturated lipids: No double bonds between carbon atoms (solid at room temperature)

• Unsaturated lipids: One or more double bonds (liquid at room temperature)

• Main functions: Energy storage, insulation, cell membrane structure (phospholipids), hormones (steroids)

Proteins

• Structure: Chains of amino acids joined by peptide bonds

• Components: Amino group, carboxyl group, R group (side chain)

• Levels of structure:

  • Primary: Sequence of amino acids

  • Secondary: Alpha helices and beta sheets

  • Tertiary: 3D folding of a single polypeptide

  • Quaternary: Multiple polypeptides (not always present)

• Dipeptide: Two amino acids joined

• Polypeptide: Many amino acids joined

• Main functions: Enzymes, structural support, transport, defense, movement

Bond formation: Dehydration synthesis forms peptide bonds.

Nucleic Acids

• Structure: Nucleotides (sugar, phosphate, nitrogenous base)

• DNA: Double-stranded, stores genetic information

• RNA: Single-stranded, involved in protein synthesis

• Difference: DNA contains deoxyribose; RNA contains ribose

ATP (Adenosine Triphosphate)

• Structure: Adenine base, ribose sugar, three phosphate groups

• Function: Main energy currency of the cell

• ATP hydrolysis releases energy for cellular processes

$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$

Relationship Between Chemicals and the Cell

All cellular structures and functions are based on chemical interactions. Macromolecules (carbohydrates, lipids, proteins, nucleic acids) are essential for cell structure, function, and energy.

Table: Comparison of Macromolecules

Macromolecule	Monomer	Main Elements	Main Functions
Carbohydrates	Monosaccharide	C, H, O	Energy, structure
Lipids	Glycerol & fatty acids	C, H, O (less O)	Energy storage, membranes
Proteins	Amino acid	C, H, O, N (sometimes S)	Enzymes, structure, transport
Nucleic Acids	Nucleotide	C, H, O, N, P	Genetic information

Additional info: The above notes expand on the study guide by providing definitions, examples, and a comparison table for clarity and completeness.