Anatomical Terminology, Chemistry, and Cell Structure: Study Guide for Lab Quiz #1

Anatomical Terminology, Chemistry & Cell

Directional Terminology

Directional terms are used to describe the locations of structures in relation to other structures or locations in the body.

• Superior: Above or toward the head

• Inferior: Below or toward the feet

• Anterior (ventral): Toward the front of the body

• Posterior (dorsal): Toward the back of the body

• Lateral: Away from the midline of the body

• Medial: Toward the midline of the body

• Superficial: Toward or at the body surface

• Deep: Away from the body surface; more internal

• Proximal: Closer to the point of attachment or origin

• Distal: Farther from the point of attachment or origin

Planes of Reference

Body planes are imaginary lines used to divide the body into sections for anatomical study.

• Frontal (coronal) plane: Divides the body into anterior and posterior sections (e.g., as seen in the heart, kidney, and stomach models).

• Transverse (cross-sectional) plane: Divides the body into superior and inferior sections (e.g., as seen in the skull, eye, and spinal cord models).

• Sagittal plane:

  • Midsagittal (median) plane: Divides the body into equal left and right sections (e.g., as seen on the brain and head models).

  • Parasagittal plane: Divides the body into unequal left and right sections.

Body Regions

Body regions are specific areas used to describe locations on the body.

• Facial region: Lower half of head

• Thoracic region (thorax): Chest

• Axillary region (axilla): Armpit

• Brachial region (brachium): Upper arm

• Antecubital region (cubital fossa): Anterior of elbow

• Antebrachial region (antebrachium): Forearm

• Palmar region: Palm of hand

• Umbilical region (umbilicus): Center of abdomen

• Pubic region: Genital area

• Inguinal region: Groin area

• Lumbar region: Lower back

• Gluteal region: Buttocks

• Popliteal region (popliteal fossa): Back of knee

• Patellar region: Anterior of knee

• Plantar surface: Sole of foot

• Sacral region: End of spine (sacral area)

• Femoral region: Thighs

• Calcaneal region: Heel of foot

Body Cavities

Body cavities are spaces within the body that contain vital organs.

• Dorsal Cavity (general):

  • Cranial cavity (specific): Brain

  • Vertebral cavity (specific): Spinal cord

• Ventral Cavity (general):

  • Thoracic cavity (specific):

    • Mediastinum (most specific): Esophagus, thymus, heart, trachea

    • Pleural cavity (most specific): Lungs

  • Abdominal cavity (most specific): Liver, spleen, stomach, small intestines, large intestines, bladder

  • Pelvic cavity (most specific): Bladder, internal genitalia (ovary, testis)

  • Retroperitoneal: Kidney, pancreas

Serous Membranes of the Ventral Cavity

Serous membranes line body cavities and cover organs, providing lubrication and reducing friction.

• Visceral pericardium: Lines organ (heart)

• Parietal pleura: Lines cavity wall (lungs)

• Visceral pleura: Lines organ (lungs)

• Parietal pericardium: Pericardial sac

• Parietal peritoneum: Lines abdominal cavity

• Visceral peritoneum: Covers abdominal organs

Organ Systems

Organ systems are groups of organs that work together to perform complex functions.

• Nervous System: Brain, spinal cord, peripheral nerves

• Cardiovascular System: Heart, veins, arteries, capillaries

• Respiratory System: Nasal passage, trachea, lungs, nasal cavity, larynx, bronchi, bronchioles

• Digestive System: Stomach, liver, gallbladder, large and small intestine, esophagus, oral cavity, salivary glands, pharynx

• Urinary System: Kidneys, urinary bladder, urethra

Definition: An organ is a structure with a specific shape, containing two or more types of tissue, performing a specific function. An organ system is a group of organs working together.

Abdominopelvic Regions

The abdominopelvic cavity is divided into regions for anatomical study.

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

• 9 Regions: Right and left hypochondriac, right and left lumbar, right and left iliac (inguinal), umbilical, epigastric, hypogastric

Chemistry for Anatomy & Physiology

Electrolytes and pH

Electrolytes are substances that dissociate in water and conduct electricity. pH is a measure of hydrogen ion concentration in a solution.

• Electrolyte: Substance that dissociates in water and conducts electricity (e.g., acids, bases, salts)

• pH: Measure of hydrogen ion concentration ($pH = -\log[H^+]$); lower pH = higher [H+], higher pH = lower [H+]

• Buffer: Mixture of weak acids and bases that resists changes in pH by combining with or releasing H+ ions

• Acid: Compound that releases hydrogen ions (H+) when dissolved in water (proton donor); lowers pH

• Base: Compound that accepts hydrogen ions or releases hydroxyl ions (OH-) or bicarbonate ions (CO3-); increases pH

• Neutral pH: pH 7; solution is neither acidic nor basic

Strong acids dissociate completely in water, releasing all H+ ions. Weak acids do not dissociate completely.

Atoms and Molecules

Atoms are the basic units of matter, composed of subatomic particles. Molecules are formed by atoms bonded together.

• Subatomic particles:

  • Proton: In nucleus, + charge, mass ≈ 1 AMU

  • Neutron: In nucleus, no charge, mass ≈ 1 AMU

  • Electron: In orbitals, - charge, mass ≈ 0 AMU

• Molecule: Two or more similar atoms bonded together

• Atomic number: Number of protons in nucleus (also equals number of electrons in a neutral atom)

• Atomic weight (mass number): Sum of protons and neutrons in nucleus (approximate mass of atom)

Examples:

• Carbon: P = 6, E = 6, N = 6.011

• Hydrogen: P = 1, E = 1, N = 0.0078

• Oxygen: P = 8, E = 8, N = 8.00

• Sodium: P = 11, E = 11, N = 11.99

• Potassium: P = 19, E = 19, N = 20.098

• Calcium: P = 20, E = 20, N = 20.078

Molecular Models

Students should be able to identify the following molecular models:

• DNA: C15H31N3O13P2 – Guanine, cytosine, thymine, adenine

• Water: H2O

• Glucose: C6H12O6 – Monosaccharide of carbohydrates

• Fatty acid: CH3(CH2)nCOOH

• Amino acids: Monomers (20 types) with amino group, carboxyl group, and functional groups

Cell Structure and Function

Cell and Organelles

The cell is the basic living unit of the human body. Organelles are specialized structures within the cytosol that perform specific functions.

• Plasma membrane: Phospholipid bilayer that surrounds the cell; barrier for the cell, regulates transport of materials in and out

• Cytoplasm: Region between nucleus and plasma membrane; site of cellular metabolism

• Endoplasmic reticulum (ER):

  • Rough ER: Has ribosomes; synthesizes proteins

  • Smooth ER: Lacks ribosomes; synthesizes lipids

• Ribosome: Site for protein synthesis; provides attachment sites for mRNA

• Mitochondrion: Powerhouse of the cell; ATP production during cellular respiration

• Golgi complex: Packages cellular products for transport

• Lysosome: Contains enzymes that break down materials or release enzymes to digest

• Centriole: Involved in cell division

• Nucleus: Large structure containing DNA; main function is to contain the DNA

• Nuclear envelope: Regulates transport of materials between nucleoplasm and cytoplasm

• Nucleolus: Site of RNA synthesis

• Chromatin: DNA which contains the genes

Cell Cycle and Mitosis

The cell cycle consists of interphase and mitosis, which is the process of nuclear division.

• Interphase:

  • G1 phase: Cell doubles organelles

  • S phase: DNA replication (synthesis)

• Mitosis (nuclear division):

  • Prophase: Nuclear membrane disintegrates, chromosomes condense

  • Metaphase: Sister chromatids line up along the metaphase plate

  • Anaphase: Centromere divides, sister chromatids separate, move to opposite sides

  • Telophase: New nuclear envelopes form around daughter chromosomes

• Cytokinesis: Cytoplasmic division

• Mitotic structures: Mitotic spindle, spindle fibers, sister chromatids, cleavage furrow

Osmosis

Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

• Osmotic pressure: The pressure generated within a cell as water presses against the cell membrane

• Hypotonic solution: Lower osmotic pressure; water enters the cell, causing swelling or lysis (e.g., 0.45% NaCl)

• Hypertonic solution: Higher osmotic pressure; water leaves the cell, causing shrinkage or crenation (e.g., 10% NaCl)

Summary Table: Body Cavities and Major Organs

Body Cavity	Major Organs
Cranial	Brain
Vertebral	Spinal cord
Thoracic	Heart, lungs, esophagus, trachea
Abdominal	Liver, stomach, spleen, intestines
Pelvic	Bladder, reproductive organs

Additional info: This study guide covers foundational terminology and concepts for the first lab quiz in Anatomy & Physiology, including anatomical language, body regions, cavities, chemistry basics, and cell structure and function. It is suitable for exam preparation and lab practical review.