Integumentary, Muscular, and Skeletal Systems: Functions and Disorders

Posted on Dec 8, 2023 in Biology

Integumentary System

Functions

  • Protection
  • Regulation of temperature
  • Sensory perception
  • Regulate water loss
  • Chemical synthesis

Physical barriers

  • Waterproofing keratinized skin
  • Certain waterproofs & protects

Biological barriers

  • Langerhan’s cells
  • Macrophages
  • DNA

Temperature Regulation

  • Sweat
  • Constriction when cold

Cutaneous sensations

  • Messiner’s corpuscles: light touch
  • Merkel discs: light touch
  • Pascinian receptors: pressure ducts
  • Hair root plexus: sensations from movement of hairs
  • Hair follicle receptors: movement across surface of skin
  • Bare nerve endings: painful stimuli

Excretion/Absorption

  • Elimination of nitrogen waste
  • Water loss regulation

Metabolic functions

  • Synthesis of vitamin D
  • Chemical conversion of substances
  • Blood reservoir

Types of membranes

  • Serous membrane: lines cavities, secretes watery fluid
  • Mucous membrane: lines cavities & tubes that open to the outside
  • Synovial membranes: form inner lining of cavities, secrete thick fluid
  • Cutaneous membrane: skin

Skin characteristics

  • Covers body
  • 16% of body mass
  • Epidermis + dermis
  • Thin: lacks stratum lucidium
  • Thick: hairless, palms, soles, stratum lucidium
  • Structure Corn: sheds continuously
  • Structure lucid: thick skin ONLY
  • Structure gran: keratinocytes undergo apoptosis
  • Structure spin: Cell division, stretch & flexibility
  • Structure basale: new cells

Dermis

  • Second layer
  • Mainly connective tissue
  • Vessels, glands, follicles are embedded
  • 2 layers: Papillary, Reticular
  • Provides strength & elasticity

Hypodermis

  • Lies below dermis
  • Connective + adipose

Skin appearances

  • White skin: appears pink due to blood
  • Albinism: inherited trait-lacking color
  • Cyanotic: blue
  • Jaundice: yellow, build up of bilirubin
  • Erythema: red, capillary damage due to skin injury
  • Pallor: paleness, emotional state, low blood pressure
  • Bronzing: Addison’s disease, adrenal cortex
  • Bruising: escaped blood as clotted hematomas (lack of vit. D/hemophilia)
  • Leathery skin: overexposure clumping of elastin fibers-depressed immune system
  • Photosensitivity: to antibiotics/antihistamines
  • Skin color: genes, environment, volume of blood
  • Skin pigments: melanin, Carotene: yellow/orange, Hemoglobin
  • Environment: UV, tan
  • Skin markings: friction ridges, flexion lines, freckles, moles
  • Aging: stem cell activity declines, thinner hair, blood supply decline, increased dryness
  • Derivatives of skin: embryonic development, thousands of epidermal cells from the stratum basale push down into dermis
  • Skin Receptors: Light touch: Meissner’s corpuscles, Paccinian corpuscles, Pain: skin receptors register pain
  • Temp: Cold receptors, Hot receptors, Thermoreceptors
  • Hair: Shaft, Root, Base, Bulb, Matrix, Arrector pili, Hair root plexus, Hair growth, Hair function
  • Skin glands: Sudoriferous, Eccrine sweat glands, Appocrine sweat glands, Sebaceous, Ceruminous
  • Nails: Nail body, Free edge, Nail root, Lunula, Eponychium or cuticle, Growth of nails
  • Homeostasis imbalance: Skin Imbalances, Skin lesions, Infections, Genetic disorders, Burns, Rule of 9’s, Skin cancer

Muscular System

Muscle function

  • Stabilizing joints
  • Maintaining posture
  • Producing movement
  • Moving substances within the body
  • Stabilizing body position and regulating organ volume
  • Producing heat– muscle contraction generates 85% of the body’s heat

Characteristics of tissue

  • Excitability
  • Contractility
  • Extensibility
  • Elasticity

Skeletal Muscle

  • Each muscle is a discrete organ composed of muscle tissue, blood vessels, nerve fibers, and connective tissue
  • Motor unit
  • Contraction
  • Muscle fatigue
  • Oxygen debt
  • Muscle & tendon injuries
  • Muscular disorders
  • Homeostatic imbalance
  • Exercise & muscular system

Skeletal System

Functions

  • Support & shape to body
  • Protection of internal organs
  • Movement in union with muscles
  • Storage of minerals (calcium, phosphorus) & lipids
  • Blood cell production

Skeleton

  • 206 bones
  • Types of bone
  • Types of vertebrae
  • Types of synovial joints
  • Cartilage+Types
  • Long bone: Compact, Spongy
  • Bone composure
  • Marrow
  • Bone structure
  • Bone membranes
  • Bone markings
  • Bone fracture terminologies
  • Bone repair
  • Skeletal disorders
  • Inflammatory/Degenerative Disorders