Anatomy & Physiology Study Guide: Integumentary System and Appendicular Skeleton

Integumentary System

Overview of Skin Structure

The integumentary system consists of the skin and its associated structures, providing protection, sensation, and regulation. The skin is a stratified squamous epithelium with several distinct layers and specialized cells.

• Epidermis: The outermost layer of the skin, composed of keratinized stratified squamous epithelium.

• Dermis: The deeper layer beneath the epidermis, containing connective tissue, blood vessels, nerves, and appendages.

• Papillary Layer/Dermal Papillae: The uppermost region of the dermis, characterized by finger-like projections that interlock with the epidermis, increasing surface area for exchange.

• Reticular Layer: The deeper portion of the dermis, providing strength and elasticity.

• Hair Shaft: The visible part of the hair above the skin surface.

• Hair Root: The portion of the hair below the skin surface.

• Hair Follicle: The structure in the dermis from which hair grows.

• Tactile Corpuscle: Sensory receptors for light touch.

• Lamellar Corpuscle: Sensory receptors for deep pressure and vibration.

• Eccrine Sweat Gland: Glands that produce watery sweat for thermoregulation.

• Apocrine Sweat Gland: Glands found in specific areas, producing a thicker secretion.

• Arrector Pili Muscle: Small muscles attached to hair follicles, responsible for 'goosebumps.'

• Sebaceous Gland: Glands that secrete sebum (oil) into hair follicles.

Layers of the Epidermis

The epidermis is organized into several layers, each with distinct functions. These layers are most easily observed in thick skin (palms and soles).

• Stratum Corneum: Outermost layer, composed of dead, keratinized cells providing a barrier.

• Stratum Lucidum: Thin, clear layer found only in thick skin.

• Stratum Granulosum: Layer where keratinization begins; cells contain granules.

• Stratum Spinosum: Layer with spiny-shaped cells, providing strength and flexibility.

• Stratum Basale: Deepest layer, containing stem cells that divide to produce new keratinocytes.

Mnemonic: "Come, Let's Get Sun Burned" (Corneum, Lucidum, Granulosum, Spinosum, Basale)

Layer (Superficial to Deep)	Abbreviation
Stratum corneum	C
Stratum lucidum	L
Stratum granulosum	G
Stratum spinosum	S
Stratum basale	B

Functions and Examples

• Protection: The skin acts as a barrier against pathogens, chemicals, and physical injury.

• Sensation: Specialized receptors detect touch, pressure, pain, and temperature.

• Thermoregulation: Sweat glands and blood vessels help regulate body temperature.

• Excretion: Sweat glands excrete waste products.

• Vitamin D Synthesis: The skin synthesizes vitamin D when exposed to sunlight.

Example: The arrector pili muscle contracts in response to cold or emotional stimuli, causing hair to stand up (goosebumps).

Appendicular Skeleton

Overview and Identification

The appendicular skeleton includes the bones of the limbs and their girdles, enabling movement and manipulation of the environment. Identification of bones and their features is essential for understanding anatomy and for practical exams.

Bone	Identify L/R	Reference	Additional Information
Clavicle	No	Figure 10.1, 10.2	No required markings to identify
Scapula	Yes	Table 10.1, Figure 10.2	Acromion, coracoid process, glenoid cavity, superior border, medial border, lateral border, inferior angle, spine, supraspinous fossa, infraspinous fossa, subscapular fossa
Humerus	Yes	Table 10.2A, Figure 10.3	Head, greater tubercle, lesser tubercle, intertubercular sulcus, deltoid tuberosity, olecranon fossa, lateral epicondyle, capitulum, medial epicondyle, trochlea
Radius	Yes	Table 10.2B, Figure 10.4	Head, radial tuberosity, radial styloid process, ulnar notch
Ulna	Yes	Table 10.2B, Figure 10.4	Olecranon, trochlear notch, coronoid process, radial notch, ulnar styloid process
Bones of the hand		Table 10.5	Phalanges - proximal, middle, distal; Metacarpals - I through V; Carpals - individual carpal bones NOT required
Ilium	see below	Table 10.3, Figure 10.6	Iliac crest, anterior superior iliac spine, posterior superior iliac spine, posterior inferior iliac spine, greater sciatic notch, iliac fossa, acetabulum
Ischium	see below	Table 10.3, Figure 10.6	Ischial tuberosity, ischial spine, obturator foramen, ischial ramus
Pubis	see below	Table 10.3, Figure 10.6	Superior pubic ramus, inferior pubic ramus, pubic crest, pubic symphysis
Tibia	Yes	Table 10.5B, Figure 10.8	Intercondylar eminence, lateral condyle, medial condyle, tibial tuberosity, medial malleolus, fibular notch
Fibula	Yes	Table 10.5B, Figure 10.8	Head, lateral malleolus
Bones of the foot	No	Figure 10.9	Phalanges: proximal, middle, distal; Metatarsals: bones I-V; Tarsals: identify as tarsal bones, and identify specifically the talus and calcaneus

Key Terms and Definitions

• Phalanges: The bones of the fingers and toes, classified as proximal, middle, and distal.

• Metacarpals/Metatarsals: The bones of the hand and foot, numbered I-V from thumb/big toe to little finger/little toe.

• Tarsals/Carpals: The bones forming the wrist (carpals) and ankle (tarsals).

• Acetabulum: The socket in the hip bone that receives the head of the femur.

• Obturator Foramen: A large opening in the hip bone for passage of nerves and blood vessels.

Examples and Applications

• Clinical Application: Knowledge of bone landmarks is essential for identifying fractures and for surgical procedures.

• Practical Exams: Students may be asked to identify bones and features on models or specimens, including distinguishing left from right.

Additional info: The study notes have expanded brief points into full academic explanations and included inferred context for completeness.