Integumentary System

Functions of the Integument

The integumentary system, primarily the skin, serves as the body's first line of defense and performs several vital functions.

• Protection: Acts as a barrier against pathogens, chemicals, and physical injury.

• Regulation: Helps regulate body temperature through sweat and blood flow.

• Sensation: Contains sensory receptors for touch, pain, and temperature.

• Excretion: Removes waste products via sweat.

• Synthesis: Produces vitamin D when exposed to sunlight.

Types of Glands

Skin contains several types of glands, each with distinct functions.

• Sudoriferous (Sweat) Glands: Eccrine and apocrine glands involved in thermoregulation and scent production.

• Sebaceous Glands: Secrete sebum to lubricate and waterproof the skin and hair.

Tissues in Dermis

The dermis is composed mainly of connective tissue, providing strength and elasticity.

• Collagen fibers: Provide tensile strength.

• Elastic fibers: Allow skin to stretch and recoil.

Pigments in Epidermis

Skin color is determined by several pigments:

• Melanin: Produced by melanocytes; protects against UV radiation.

• Carotene: Yellow-orange pigment from diet.

• Hemoglobin: Red pigment in blood, visible in fair skin.

Properties/Locations of Layers of the Skin

The skin consists of three main layers:

• Epidermis: Outermost layer; provides protection.

• Dermis: Middle layer; contains blood vessels, nerves, and glands.

• Hypodermis (Subcutaneous): Deepest layer; stores fat and anchors skin.

Skeletal System

Anatomy and Function of Osteons and Their Parts

Osteons are the structural units of compact bone.

• Central (Haversian) Canal: Contains blood vessels and nerves.

• Lamellae: Concentric rings of bone matrix.

• Lacunae: Small spaces housing osteocytes.

• Canaliculi: Tiny channels for nutrient/waste exchange.

Bone Types

Bones are classified by shape:

• Long bones: e.g., femur, humerus

• Short bones: e.g., carpals, tarsals

• Flat bones: e.g., skull, ribs

• Irregular bones: e.g., vertebrae

• Sesamoid bones: e.g., patella

Types of Motion

Joints allow various types of movement:

• Flexion/Extension

• Abduction/Adduction

• Rotation

• Circumduction

Types and Properties of Joints

Joints are classified by structure and function:

• Fibrous: Immovable (e.g., sutures in skull)

• Cartilaginous: Slightly movable (e.g., intervertebral discs)

• Synovial: Freely movable (e.g., knee, shoulder)

Functions of the Skeletal System

• Support: Framework for the body

• Protection: Shields vital organs

• Movement: Leverage for muscles

• Mineral Storage: Calcium and phosphorus

• Blood Cell Production: In bone marrow

Key Features of Male/Female Pelvic Girdles

• Male pelvis: Narrower, heavier, more prominent landmarks

• Female pelvis: Wider, lighter, adapted for childbirth

Characteristics/Parts of Long Bones

• Diaphysis: Shaft

• Epiphyses: Ends

• Metaphysis: Growth region

• Medullary cavity: Contains marrow

Properties of Spongy Bone

• Trabeculae: Network of bony struts

• Lightweight: Reduces bone mass

• Houses marrow: Site of hematopoiesis

Muscular System

Parts of Whole Muscles

• Muscle fibers: Individual cells

• Fascicles: Bundles of fibers

• Connective tissue coverings: Epimysium, perimysium, endomysium

Muscle Functions

• Movement: Locomotion and manipulation

• Posture: Maintains body position

• Heat production: Generates warmth

Why Skeletal Muscles Appear Striated

Skeletal muscle fibers have a striped appearance due to the arrangement of actin and myosin filaments in sarcomeres.

• Sarcomeres: Repeating units of contractile proteins

• Striations: Alternating light (I bands) and dark (A bands) regions

Central Nervous System

Functions of Neurons and Their Parts

• Dendrites: Receive signals

• Cell body (soma): Integrates signals

• Axon: Transmits impulses

• Synaptic terminals: Communicate with other cells

What Comprises CNS

• Brain

• Spinal cord

Different/Various Divisions of the Nervous System

• Central Nervous System (CNS): Brain and spinal cord

• Peripheral Nervous System (PNS): Nerves outside CNS

• Somatic: Voluntary control

• Autonomic: Involuntary control (sympathetic and parasympathetic)

Brain Anatomy and Functions of Different Brain Divisions

• Cerebrum: Higher functions (thinking, memory)

• Cerebellum: Coordination and balance

• Brainstem: Basic life functions (breathing, heart rate)

Gray vs White Matter in Spinal Cord and Brain

• Gray matter: Neuron cell bodies, processing centers

• White matter: Myelinated axons, transmission pathways

Meninges in the Spinal Cord and Brain

• Dura mater: Tough outer layer

• Arachnoid mater: Middle, web-like layer

• Pia mater: Delicate inner layer

Peripheral Nervous System

Postganglionic Fibers of the Parasympathetic Division

• Parasympathetic postganglionic fibers: Release acetylcholine, promote 'rest and digest' responses

Sympathetic vs Parasympathetic Responses

Ascending vs Descending Pathways

• Ascending: Sensory information to the brain

• Descending: Motor commands from the brain

Components and Correct Order of a Reflex Arc

• Receptor

• Sensory neuron

• Integration center

• Motor neuron

• Effector

General and Special Senses

Receptor Types

• Mechanoreceptors: Detect touch, pressure, vibration

• Thermoreceptors: Detect temperature changes

• Photoreceptors: Detect light (in eyes)

• Chemoreceptors: Detect chemicals (taste, smell)

• Nociceptors: Detect pain

Eye Structure/Functions

• Cornea: Focuses light

• Lens: Adjusts focus

• Retina: Contains photoreceptors

Layers of the Eye

• Fibrous layer: Sclera and cornea

• Vascular layer: Choroid, ciliary body, iris

• Neural layer: Retina

Properties of Eye Humors

• Aqueous humor: Nourishes lens and cornea

• Vitreous humor: Maintains eye shape

Types of Eye Cones

• Red cones

• Green cones

• Blue cones

Properties of Eye Cavities

• Anterior cavity: Contains aqueous humor

• Posterior cavity: Contains vitreous humor

Ear Structure/Functions

• Outer ear: Collects sound

• Middle ear: Transmits vibrations

• Inner ear: Converts vibrations to nerve impulses

Ear Passages

• External auditory canal

• Eustachian tube