Integumentary system - general knowledge Flashcards
What is the integumentary system
- the body’s largest organ - skin
- best indicator of health
- used in differential diagnosis of more disease
Functions of the integumentary system
- protection
- containment
- heat regulation
- sensation
- synthesis and storage of Vitamin D
What is the epidermis?
- tough outer protective layer of the skin
- keratinized epithelium
- avascular; nourished by underlying vascular dermis
- contains only a few nerve terminals
What is the dermis?
- dense layer composed of collagen and elastic fibers
- provides skin tone and toughness
- supplied by arteries in its deep surface
- contains nerve terminals
- contains hair follicles
- contains sebaceous glands
What is the hypodermis (superficial facia, subcutaneous tissue)?
- between dermis and deep facia
- composed of loose connective tissue and stored fat
- thickness varies greatly
- contains sweat glands
- contains superficial blood vessels, lymphatic vessels and cutaneous nerves
- functions to wrap, package and insulate deep structures of the body
Features of the superficial facia?
- fatty layer found deep to dermis
- composed of two layers: outer fatty layer, inner membranous layer
Features of the deep facia?
- dense connective tissue, devoid of fat
- thickness varies greatly
- blends with periosteum to give rise to muscle attachments
- invests deeper to surround muscles and neurovacqlar bundles
- never passes freely over bone
- limits outward expansion of contracting muscle
- pushes blood out of veins as muscles are compressed
What are facial compartments?
- contained groups of muscles with similar function and nerve supply
- located in limbs
- they are separated by intermuscular septa
- may contain or direct spread of infection and tumors
What are intermuscular septa?
-thick sheets of deep fascia that extend from surrounding fascial sleeve to attach the bone and separate fascial compartments
What are retinacula?
-thickening of deep fascia near joints that hold tendons in place during flexion and extension
What are bursae?
- closed sacs of serous membrane that are capable of secreting lubricating fluids
- found in areas of friction to enable free movement of structures
- they are normally collapsed and only realized if filled which can have pathological indications
- they also communicate with synovial joints
Types of bursae?
- subcutaneous: between skin and bony structure
- subfascial: beneath deep fascia
- subtendenous: between bone and tendon
- synovial tendon sheaths: specialized, wrap around tendons as they pass through osseofibrous tunnels
What are collapsed bursal sacs?
- Double layer of membranes that surrounds but does not contain important organs
- composed of parietal (outer) and visceral (inner) layer
- they allow for freedom of movement
ex: pericardial (heart) sac, plural (lungs) sac, peritoneal (abdominal viscera) sac
What are subserous fascia?
-fascia with varying amounts fo fatty tissue that are between musculoskeletal walls and serous membranes lining body cavities
ex: end-thoracic fascia, endoabdominal fascia
endopelvic fascia
