Skin and fascia Flashcards
Skin
It is the structure that covers the body and protects it from the environment
Layers of the skin
Epidermis
Dermis
Epidermis structure
Consists of stratified squamous keratinized epithelium
Epidermis sites
Thick on the palms of the hands and the soles of the feet
Thin everywhere else
Dermis structure
Strong connective tissue mostly made of collagenous and some elastic fibers
Contains many blood vessels, lymphatic vessels and nerves
Dermis thickness
Thinner on the anterior than the posterior
Thinner in women than men
Flexure lines (skin creases)
Folds of the skin over the joints
The skin is thinner and firmily attatched to the underlying structures by strong bands of fibrous tissue
Papillary ridges
Confined to the palms and soles and felxor surfaces of digits
They form narrow ridges seperated by fine parallel groove
Wrinkle lines
On face, they become permemnat with aging due to loss of skin elasticity
Langer lines (tension lines) (lines of langerhans)
Shapped by arrangement of collagen fibres
They represent skin tension in rigor mortis
Langer lines (tension lines) (lines of langerhans)
Shapped by arrangement of collagen fibres
They represent skin tension in rigor mortis
Surgical insicions made parallel to them heal with minimum amount of scar tissue
Functions of the skin
Protection
Prevention of loss of body fluids
Regulation of body temperature through sweat
Sensation by nerve endings
Moistening of the skin by secretions of the sebacous glands
Skin appendages
Nails
Hair and hair follicles
Sebacous glands
Sweat glands
Nails
Nails are keratinized plates on the dorsal surfaces of the tip of the fingers and toes
Sites with no hair
Lips Palms of the hands Soles of the feet The sides of fingers The sides of toes The glans penis and clitoris The labia minora and the internal surface of the labia majora
Sebaceous glands and their diseases
They pour their sebum onto the shaft of the hair
It is oily
Choked –> Blackheads
Infected –> Acne
Sweat glands
Long, spiral, tubular glands
Sites with no swaet glands
The red margins of the lips
The nail beds
The glans penis and clitoris
Types of fascia
Superficial fascia (subcutaneous tissue) Deep fascia
Superficial fascia positions
In the scalp, the back of the enck, the palms of the hand and the soles of the feet it contains bundles of collagen fibres
In the eyelids, auricle of the ear, penis, scrotum and clitoris, it is devoid of adipose tissue
In anterior abdominal wall, it is differentiated into superficial fatty layer and a deep membranous layer.
Functions of superficial fascia
Gives certain parts of the body their specific contour
Acts as a heat insulator
Acts as a source of energy
Acts as a medium for passage of cutaneous nerves and vessels
Deep fascia description
It is a membranous layer of connective tissue that invests musclesand other deep structures
Functions of deep fascia
Holds underlying tendons in position
Invests the deep structures to bones
Gives origin and insertion of some muscles
Sends septa to bone forming compartements
Forms retinacula to hold the long tendons
Forms palmar and plantar aponeuroses to protect the palm and soles
Deep fascia in the neck
Forms well defined layers that play a role in the path taken by pathogenic bacteria
Deep fascia in the Thorax and Abdomen
A thin film of areolar tissue covering the muscles and aponeuroses
Deep fascia in the regions of the joints
Thickened to form restraining bands called retinacula
Deep fascia in the limbs
Forms a defenite sheath around muscles holding them in place
Fibrous septa extend from the deep surface of the membrane between the group of muscles
