Gen ana

• Skin is the largest single organ of the body, typically accounting for 15–20% of total body weight
• Integumentary system

  Also known as the integument or cutaneous layer
• Functions of the skin ("Protect VETS")

  • Protection
  • Vitamin D Production
  • Excretion
  • Temperature Regulation
  • Sensation
• Main layers of the skin


  • Epidermis
  • Dermis
  • Hypodermis or subcutis
• Cells in the epidermis ("KeMe Lang Merk")


  • Keratinocytes
  • Melanocytes
  • Langerhans cells
  • Merkel cells
• Strata of the epidermis

  • Stratum Basale / Germinativum
  • Stratum Spinosum
  • Stratum Granulosum
  • Stratum Lucidum
  • Stratum Corneum
• Melanin

  Group of pigments responsible for skin, hair, and eye color
• Melanocytes

  Specialized cells of the epidermis that produce melanin
• Langerhans cells

  Antigen-presenting cells (APCs) usually most clearly seen in the spinous layer
• Merkel cells

  Epithelial tactile cells that are sensitive mechanoreceptors essential for light touch sensation
• Neuronal endings of the skin

  • Free nerve endings: Detect touch, temperature, pain
  • Pacinian corpuscles: Pressure and vibration receptors
  • Meissner's corpuscles: Touch receptors
  • Ruffini endings: Mechanoreceptors
• Hair

  Elongated keratinized structures derived from invaginations of the epidermal epithelium
• Hair follicles

  Produce long thin cylindrical structures (hair shafts) composed largely of keratin
• Hair shafts

  Composed of central medulla surrounded by a cortex with a surface cuticle composed of single layer of flattened scales
• Hair growth cycle ("AnCaTe")

  • Anagen
  • Catagen
  • Telogen
• Nail

  Hard, flexible plates of keratin on the dorsal surface of each distal phalanx
• Parts of the nail

  • Nail Body/ plate
  • Cuticle or eponychium
  • Nail root
  • Nail bed
• Skin glands

  • Sebaceous
  • Sweat (Merocrine/eccrine and Apocrine)
• Functions of the muscular system

  • Body Movement
  • Maintenance of Posture
  • Respiration
  • Production of Body Heat
  • Communication
  • Constriction of Organs and Vessels
  • Heart beat
• Some skeletal muscles are not attached to bone at both ends, e.g. facial muscles
• Tendons

  Connect the muscle to the bone
• Origin (head)

  Most stationary end of the muscle
• Insertion

  End of the muscle attached to the bone undergoing the greatest movement
• Belly

  Part of muscle between origin and insertion
• Criteria for naming muscles

  • Location
  • Origin and Insertion
  • Number of heads
  • Function
  • Size
  • Shape
  • Orientation of fasciculi
• Muscles of the pectoral region

  • Pectoralis major
  • Pectoralis minor
  • Subclavius muscles
• Muscles of the thorax

  • External Intercostals
  • Internal Intercostals
  • Inner Intercostals
  • Transversus thoracis
• Muscles of the abdominal wall

  • Rectus Abdominis
  • External Abdominal oblique
  • Internal Abdominal oblique
  • Transversus Abdominis
  • Pyramidalis
• Posterior abdominal muscles

  • Psoas Major and minor (medial)
  • Quadratus lumborum (lateral)
  • Iliacus muscle (inferior)
  • Diaphragm (superior)
• Back muscles

  • Trapezius
  • Latissimus Dorsi
  • Levator Scapulae
  • Rhomboideus
• Upper arm muscles

  • Deltoid
  • Biceps brachii
  • Triceps brachii
  • Brachialis
  • Brachioradialis
  • Supraspinatus
  • Infraspinatus
  • Subscapularis
  • Teres Major
  • Teres Minor
• Rotator cuff muscles ("SITS")

  Supraspinatus, Infraspinatus, Teres Minor, Subscapularis
• Movements of the arm at the elbow

  • Flexion: Biceps, Brachialis, Coracobrachialis
  • Extension: Triceps, Anconeus
• Lower arm muscles

  • Flexors
  • Extensors
  • Palmaris longus
  • Pronators
  • Supinators
• Pronation

  Pronator quadratus, pronator teres
• Supination

  Supinator, biceps
• Thigh muscles (Anterior Compartment)

  • Rectus Femoris
  • Vastus Lateralis
  • Vastus Medialis
  • Vastus Intermedius
  • Sartorius
• Thigh muscles (Posterior Compartment)

  • Biceps Femoris
  • Semimembranosus
  • Semitendinosus
• Thigh muscles (Medial Compartment)

  • Adductor Longus
  • Adductor Magnus
  • Gracilis
  • Pectineus
  • Obturator Externus
• Leg muscles (Anterior Compartment)

  • Tibialis Anterior
  • Extensor Digitorum Longus
  • Fibularis Tertius