Bio 16 Unit 1 Study Guide: Human Body Orientation, Cells, Tissues, Integumentary, Skeletal System, and Joints

Chapter 1: The Human Body - An Orientation

Organ Systems

The human body is organized into 11 major organ systems, each with distinct functions and representative organs. The mnemonic MIND CURLERS helps recall these systems.

• Muscular: Muscle - movement, heat production

• Integumentary: Skin - protection, thermoregulation

• Nervous: Brain - control, communication

• Digestive: Stomach - nutrient breakdown, absorption

• Cardiovascular: Heart - transport, regulation

• Urinary: Kidney - waste removal, water balance

• Respiratory: Lungs - gas exchange, pH balance

• Lymphatic: Spleen - immunity, fluid balance

• Endocrine: Thyroid - hormone regulation, metabolism

• Reproductive: Ovary/Testes - reproduction, hormone production

• Skeletal: Femur - support, protection, movement

Levels of Structural Organization

The human body is organized hierarchically from smallest to largest:

• Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism

Definition: Each level represents increasing complexity, with atoms forming molecules, molecules forming organelles, and so on.

Orientation to the Human Body (Language of Anatomy)

Anatomical terms describe the location and orientation of body parts:

• Anatomical Position: Standing upright, facing forward, arms at sides, palms forward.

• Directional Terms: Superior/Inferior, Anterior/Posterior, Dorsal/Ventral, Medial/Lateral, Proximal/Distal, Superficial/Deep

Sectional Planes

• Sagittal: Divides body into left and right

• Frontal (Coronal): Divides body into anterior and posterior

• Transverse: Divides body into superior and inferior

Body Cavities

• Dorsal: Cranial and vertebral cavities

• Ventral: Thoracic (pleural, pericardial), abdominopelvic

• Abdominopelvic Quadrants: Right/Left Upper, Right/Left Lower

Organ	Quadrant
Liver	Right Upper
Stomach	Left Upper
Spleen	Left Upper
Small Intestines	All quadrants
Appendix	Right Lower
Gallbladder	Right Upper
Pancreas	Left Upper

Chapter 2: Cells - The Living Units

Cell Theory

Cell theory is foundational to biology:

• All living things are composed of cells.

• Cells are the basic unit of structure and function.

• All cells arise from pre-existing cells.

Cell Membrane Structure and Function

• Lipid Bilayer: Composed of phospholipids with hydrophobic (water-repelling) tails and hydrophilic (water-attracting) heads.

• Cholesterol: Stabilizes membrane fluidity.

• Hydrophobic/Hydrophilic: Allows selective permeability.

Transport Across Membranes

• Small molecules: Diffusion, facilitated diffusion

• Large molecules: Endocytosis (into cell), Exocytosis (out of cell)

• Golgi Apparatus: Packages and ships molecules

• Lysosomes: Digest wastes and toxins

Energy and Matter Usage

• Mitochondria: Site of cellular respiration, ATP production

• Nucleus: Contains DNA, directs protein synthesis

• Ribosomes: Protein synthesis

• Endoplasmic Reticulum: Synthesis and transport of proteins/lipids

Cell Junctions

• Tight Junctions: Prevent leakage (e.g., intestines)

• Desmosomes: Provide strength (e.g., skin)

Structure = Function

Cell Type	Structural Feature	Function
Adipocyte	Large fat droplet	Stores energy
Sperm cell	Flagellum	Motility
Neuron	Long axon	Signal transmission
Red blood cell	Biconcave shape	Gas transport
Intestinal cell	Microvilli	Absorption
Muscle cell	Contractile proteins	Movement
Oocyte	Large size	Fertilization

Cell Life Cycle

• Interphase: Growth, DNA replication

• Mitosis: Division of nucleus and cytoplasm

• Cancer: Uncontrolled cell division

Chapter 3: Tissues - The Living Fabric

Definition and Types of Tissues

Tissues are groups of similar cells and their intercellular substances functioning together. Four major types: CEMN (Connective, Epithelial, Muscular, Nervous).

Epithelial Tissue

• Functions: Protection, absorption, secretion, filtration

• Characteristics: Cellularity, polarity, avascularity, regeneration

• Classification:

  • Layers: Simple, stratified, pseudostratified

  • Shape: Squamous, cuboidal, columnar, transitional

• Examples:

  • Skin: Stratified squamous

  • Lungs: Simple squamous

  • Vagina: Stratified squamous

  • Trachea: Pseudostratified ciliated columnar

  • Mammary gland: Simple cuboidal

  • Small intestine: Simple columnar

  • Bladder: Transitional

• Glandular Epithelium: Modes of secretion:

  • Merocrine: Exocytosis

  • Apocrine: Part of cell lost

  • Holocrine: Entire cell lost

Connective Tissue

• Functions: Support, protection, transport, storage

• Characteristics: Few cells, abundant extracellular matrix

• Types:

  • Loose CT: Adipose, areolar

  • Dense CT: Regular (tendons), irregular (dermis)

  • Fluid CT: Blood

  • Cartilage

  • Bone

Embryology

• Three Germ Layers: Endoderm, mesoderm, ectoderm

• Origin:

  • Ectoderm: Nervous, epithelial

  • Mesoderm: Connective, muscle

  • Endoderm: Epithelial (internal organs)

Chapter 4: The Integumentary System

Functions of the Integumentary System

• Protection

• Thermoregulation

• Sensation

• Vitamin D synthesis

• Excretion

• Water retention

Epidermis

• Five Layers: Stratum basale, spinosum, granulosum, lucidum, corneum

• Tissue: Keratinized stratified squamous epithelium

• Mitosis: Occurs in stratum basale

• Keratin: Provides strength, waterproofing

• Melanocytes: Found in lower epidermis, produce melanin for UV protection

• Fingerprints: Dermal papillae and epidermal ridges

Dermis

• Layers: Papillary (loose CT), reticular (dense irregular CT)

• Hypodermis: Adipocytes, insulation

• Tattoo ink: Deposited in dermis

Accessory Structures

• Hair: Follicles, shaft, root

• Arrector pili: Goosebumps, vestigial

• Sebaceous glands: Holocrine, sebum, pimples

• Sweat glands: Apocrine (odor), merocrine (cooling, excretion)

Protection Mechanisms

• Keratinized cells resist abrasion

• Melanin protects against UV

• Sweat and sebum inhibit microbes

• Thermoregulation via sweat and blood flow

Chapter 5: The Skeletal System - Osseous Tissue

Functions of the Skeleton

• Support

• Protection

• Movement

• Mineral storage

• Fat storage

• Blood cell formation

Fat Storage

• Yellow bone marrow: Adipose tissue, found in medullary cavity

Blood Cell Formation

• Red bone marrow: Hematopoietic tissue, found in spongy bone of epiphyses

Mineral Storage and Microscopic Anatomy

• Mineral: Calcium phosphate (hydroxyapatite)

• Microscopic structures: Osteon, lamellae, central canal, perforating canal, osteocyte, lacunae, canaliculi

• Matrix: Collagen fibers (flexibility), calcium phosphate (hardness)

Support and Structure

• Collagen provides flexibility, minerals provide hardness

• Spongy bone: Trabeculae, found in epiphyses

• Compact bone: Dense, found in diaphysis

Movement

• Periosteum: Dense irregular CT, attachment for muscles

• Articular cartilage: Hyaline cartilage, reduces friction

Protection

• Skull: Protects brain

• Rib cage: Protects heart and lungs

• Vertebrae: Protect spinal cord

Bone Growth and Remodeling

• Osteoblasts: Build bone

• Osteoclasts: Break down bone

• Osteocytes: Maintain bone

• Chondrocytes: Cartilage cells

• Endochondral Ossification: Cartilage replaced by bone, growth at epiphyseal plate

• Epiphyseal plate: Growth region in children; becomes epiphyseal line in adults

Bone Diseases

• Achondroplasia: Defective cartilage growth

• Marfan's syndrome: Connective tissue disorder

• Osteoporosis: Loss of bone density; prevention includes diet, exercise, hormones

Chapter 6: The Skeletal System - Axial Division

Axial Division Bone Marking Functions

Bone and Marking	Function
Paranasal sinuses	Lighten skull, produce mucus, resonate sound
Temporal-Mandibular fossa	Articulation point with condylar process of mandible
Sphenoid-Optic canal	Passageway for optic nerve
Ethmoid-Nasal conchae	Increase surface area for warming/filtering air
Vertebra-Body	Weight bearing
Vertebra-Vertebral foramen	Passage for spinal cord
Sacrum-Sacral foramina	Passage for nerves and blood vessels

Chapter 7: The Skeletal System - Appendicular Division

Appendicular Division Bone Marking Functions

Bone and Marking	Function
Scapula-spine	Attachment for supraspinatus and infraspinatus muscles
Humerus-olecranon fossa	Articulates with olecranon process of ulna
Femur-head	Articulates with acetabulum of pelvis
Tibia-medial malleolus	Stabilizes ankle joint

Chapter 8: The Skeletal System - Articulations

Joints (Articulations)

Joints are where two bones meet. They are classified structurally:

• Fibrous: Bones held by fibrous tissue, no cavity (e.g., sutures)

• Cartilaginous: Bones held by cartilage, no cavity (e.g., pubic symphysis, intervertebral discs)

• Synovial: Bones held by joint capsule, cavity present

Herniated Disc

• Annulus fibrosis: Tough outer ring

• Nucleus pulposus: Gel-like center

• Herniation: Nucleus pulposus protrudes, compresses nerves

Synovial Joints

• Features: Periosteum, ligament (dense regular CT), joint capsule (fibrous layer and synovial membrane), articular cartilage (hyaline), synovial fluid (secreted by synovial membrane)

• Additional features: Meniscus (shock absorption), bursae (reduce friction), fat pads, accessory ligaments, tendons

• Stability factors: Shape of articular surfaces, ligaments, muscle tone

Types of Movements

• Gliding

• Flexion/Extension (sagittal plane)

• Abduction/Adduction (frontal plane)

• Rotation: Supination/Pronation

• Circumduction

• Inversion/Eversion

• Elevation/Depression

• Dorsiflexion/Plantar flexion

Types of Synovial Joints

Type	Movement	Example
Gliding	Monaxial	Carpals
Hinge	Monaxial	Humerus and ulna
Pivot	Monaxial (rotation)	Atlas and axis
Ellipsoid	Biaxial	Phalanges to metacarpals
Saddle	Biaxial	Thumb to metacarpals
Ball-and-socket	Triaxial	Humerus to scapula