BIOL 2101 Lab Exam One Study Guide: Anatomy & Physiology Essentials

Body Regions and Terms

Anatomical Position and Directional Terminology

The anatomical position is a standardized posture used to describe locations and directions on the human body. Understanding directional terminology is essential for accurately identifying and describing anatomical structures.

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

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

• Superior (cranial): Toward the head or upper part of a structure.

• Inferior (caudal): Away from the head; toward the lower part of a structure.

• Proximal: Closer to the point of attachment or origin.

• Distal: Farther from the point of attachment or origin.

• Medial: Toward the midline of the body.

• Lateral: Away from the midline of the body.

• Superficial: Toward or at the body surface.

• Deep: Away from the body surface; more internal.

Example: The heart is medial to the lungs; the skin is superficial to the muscles.

Regional Terminology

Regional terminology refers to specific areas of the body, which are used to describe locations of structures or injuries.

• Cranial: Head

• Frontal: Forehead

• Ocular: Eye

• Otic: Ear

• Occipital: Back of head

• Nasal: Nose

• Buccal: Cheek

• Mental: Chin

• Cervical: Neck

• Thoracic: Chest

• Sternal: Breastbone

• Mammary: Breast

• Abdominal: Abdomen

• Umbilical: Navel

• Pelvic: Pelvis

• Inguinal: Groin

• Pubic: Genital region

• Acromial: Shoulder

• Axillary: Armpit

• Brachial: Arm

• Antecubital: Front of elbow

• Cubital: Back of elbow

• Carpal: Wrist

• Manual: Hand

• Coxal: Hip

• Femoral: Thigh

• Patellar: Kneecap

• Crural: Leg

• Fibular: Side of leg

• Scapular: Shoulder blade

• Vertebral: Spine

• Lumbar: Lower back

• Sacral: Area above tailbone

• Gluteal: Buttocks

• Perineal: Area between anus and genitals

• Popliteal: Back of knee

• Sural: Calf

Planes of Section

Anatomical planes are imaginary lines used to divide the body for study and description.

• Sagittal: Divides the body into left and right portions.

• Midsagittal: Divides the body into equal left and right halves.

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

• Frontal (coronal): Divides the body into anterior and posterior portions.

• Transverse (horizontal): Divides the body into superior and inferior portions.

Body Cavities, Abdominopelvic Quadrants and Regions

Body cavities house and protect internal organs. The abdominopelvic region is divided for clinical and anatomical reference.

• Cranial cavity: Contains the brain.

• Vertebral cavity: Contains the spinal cord.

• Pleural cavity: Contains the lungs.

• Pericardial cavity: Contains the heart.

• Abdominal cavity: Contains digestive organs.

• Pelvic cavity: Contains urinary bladder, reproductive organs.

Example: The stomach is located in the abdominal cavity.

Cells and Organelles

Composite Cell Structure

The cell is the basic unit of life. Understanding the structure and function of organelles is fundamental to cell biology.

• Nucleus: Contains genetic material (DNA); controls cell activities.

• Nucleolus: Site of ribosome production within the nucleus.

• Ribosomes: Sites of protein synthesis; can be free or attached to rough ER.

• Rough Endoplasmic Reticulum (RER): Studded with ribosomes; synthesizes proteins.

• Smooth Endoplasmic Reticulum (SER): Synthesizes lipids; detoxifies chemicals.

• Mitochondrion: Produces ATP through cellular respiration.

• Lysosome: Contains digestive enzymes; breaks down waste.

• Peroxisome: Breaks down fatty acids and detoxifies harmful substances.

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

• Centrioles: Involved in cell division; form spindle fibers.

• Centrosome: Region containing centrioles; organizes microtubules.

• Microvilli: Increase surface area for absorption.

• Flagellum: Provides motility (e.g., sperm cell).

• Cilia: Move substances across cell surface.

• Nuclear Pore: Allows transport of molecules between nucleus and cytoplasm.

• Nuclear Envelope: Double membrane surrounding nucleus.

• Plasma Membrane: Controls entry and exit of substances; maintains cell integrity.

• Cytoskeletal Elements: Provide structural support; include microtubules, microfilaments, intermediate filaments.

• Cytosol: Fluid component of cytoplasm.

Example: Mitochondria are abundant in muscle cells due to high energy demand.

Histology: Tissues

Epithelial Tissue

Epithelial tissue covers surfaces, lines cavities, and forms glands. It is classified by cell shape and number of layers.

• Cell Shape:

  • Squamous: Flat, pancake-like cells.

  • Cuboidal: Cube-shaped, as tall as wide.

  • Columnar: Tall, column-shaped cells.

• Number of Cell Layers:

  • Simple: One cell layer thick.

  • Stratified: More than one cell layer thick.

Types of Epithelial Tissue:

• Simple Squamous Epithelium: Single layer of flat cells; allows diffusion and filtration.

• Simple Cuboidal Epithelium: Single layer of cube-shaped cells; found in glands and kidney tubules.

• Simple Columnar Epithelium: Single layer of tall cells; lines digestive tract.

• Pseudostratified Columnar Epithelium: Appears layered but all cells touch basement membrane; often ciliated.

• Stratified Squamous Epithelium: Multiple layers; protects against abrasion.

• Stratified Cuboidal Epithelium: Two or more layers of cube-shaped cells; rare, found in ducts.

• Stratified Columnar Epithelium: Two or more layers of column-shaped cells; rare, found in some glands.

• Transitional Epithelium: Cells appear to transition between squamous and cuboidal; found in urinary bladder.

Example: Simple squamous epithelium lines alveoli of lungs for gas exchange.

Connective Tissue

Connective tissue supports, protects, and binds other tissues. It is classified into three main categories.

• Fibro-connective Tissue:

  • Loose Fibrous Connective Tissue: Loosely arranged fibers; includes areolar, reticular, and adipose tissues.

  • Areolar: Randomly arranged fibers; most common connective tissue.

  • Reticular: Predominantly reticular fibers; forms framework for organs.

  • Adipose: Fat storage; few fibers, small extracellular matrix.

  • Dense Fibrous Connective Tissue: Densely packed fibers; includes dense regular and dense irregular tissues.

  • Dense Regular: Parallel fibers; found in tendons and ligaments.

  • Dense Irregular: Irregularly arranged collagen fibers; found in dermis.

• Supportive Connective Tissue:

  • Cartilage:

    • Hyaline Cartilage: Smooth, glossy; ends of long bones.

    • Elastic Cartilage: Flexible, elastic fibers; external ear.

    • Fibrocartilage: Tough, bundles of collagen; intervertebral discs.

  • Bone (Osseous Tissue): Two forms: spongy and compact bone.

• Blood: Fluid connective tissue; extracellular matrix is plasma. Contains erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.

Example: Adipose tissue stores energy and insulates the body.

Muscle Tissue

Muscle tissue is specialized for contraction and movement. There are three types of muscle tissue.

• Skeletal Muscle: Long, cylindrical, multinucleate cells with striations; voluntary movement.

• Cardiac Muscle: Thick, branching, uninucleate cells with striations; found in heart; involuntary.

• Smooth Muscle: Spindle-shaped, uninucleate cells; no striations; found in walls of hollow organs; involuntary.

Example: Cardiac muscle contracts to pump blood throughout the body.

Nervous Tissue

Nervous tissue is responsible for transmitting electrical signals and supporting neurons.

• Neurons: Cells with processes (dendrites and axon) branching from a nucleus-containing cell body (soma); transmit impulses.

• Neuroglial Cells: Support and protect neurons; do not transmit impulses.

Example: Neurons in the brain process sensory information.

Skin: Structure and Function

Epidermis and Its Layers

The epidermis is the outermost layer of skin, composed of several distinct layers.

• Stratum Basale: Deepest layer; site of cell division.

• Stratum Spinosum: Provides strength and flexibility.

• Stratum Granulosum: Cells begin to die; contain granules.

• Stratum Lucidum: Present only in thick skin (palms, soles).

• Stratum Corneum: Outermost layer; dead, keratinized cells.

Dermis and Its Layers

The dermis lies beneath the epidermis and provides structural support.

• Papillary Region: Superficial layer; contains dermal papillae.

• Reticular Region: Deep layer; dense irregular connective tissue.

Hypodermis

The hypodermis (subcutaneous layer) is not technically part of the skin but anchors it to underlying tissues and stores fat.

Accessory Structures

• Sebaceous Gland: Produces sebum (oil); lubricates skin and hair.

• Hair Follicle: Structure from which hair grows.

• Arrector Pili Muscle: Small muscle attached to hair follicle; causes "goosebumps".

• Sweat Gland: Produces sweat for thermoregulation.

Example: The stratum corneum protects against environmental damage.

Summary Table: Types of Tissues

Type	Key Features	Location/Function
Simple Squamous Epithelium	Single layer, flat cells	Alveoli, diffusion
Simple Cuboidal Epithelium	Single layer, cube-shaped	Kidney tubules, secretion
Simple Columnar Epithelium	Single layer, tall cells	Digestive tract, absorption
Pseudostratified Columnar Epithelium	Appears layered, all cells touch basement membrane	Respiratory tract, movement of mucus
Stratified Squamous Epithelium	Multiple layers, flat cells	Skin, protection
Transitional Epithelium	Cells transition between shapes	Urinary bladder, stretching
Areolar Connective Tissue	Loose, random fibers	Under skin, support
Adipose Connective Tissue	Fat storage, few fibers	Subcutaneous, insulation
Dense Regular Connective Tissue	Parallel fibers	Tendons, ligaments
Hyaline Cartilage	Smooth, glossy	Ends of bones, support
Bone (Compact)	Dense, hard matrix	Skeletal system, support
Blood	Fluid, cells in plasma	Transport, immunity
Skeletal Muscle	Striated, multinucleate	Voluntary movement
Cardiac Muscle	Striated, branching	Heart contraction
Smooth Muscle	No striations, spindle-shaped	Walls of organs, involuntary
Nervous Tissue	Neurons, neuroglia	Signal transmission