Skin (Anatomy and Physiology) PDF

Skin (Anatomy and Physiology) By Dr. Ali Abdel Kader Saturday, March 4, 2023 1  INTENDED LEARNING OBJECTIVES (ILO) By the end of lec...

Skin (Anatomy and Physiology) By Dr. Ali Abdel Kader Saturday, March 4, 2023 1  INTENDED LEARNING OBJECTIVES (ILO) By the end of lecture the student will be able to: 1. Define layers of skin and their contents 2. Locate sites of thick skin , thin skin, loose skin and adherent skin 3. Describe Langer’s lines and skin creases and their clinical significance 4. Describe the features and functions of superficial and deep fascia 5. Physiological Functions of the Skin 2 Saturday, March 4, 2023  Lecture Structure ❑ Introduction ❑ Skin : definition and features ❑ Fascia : superficial and deep ❑ Basic Physiology of the Skin ❑ Summary ❑ Quiz ❑ References 3 Saturday, March 4, 2023  Skin ❑ Skin is the largest organ in body ❑ It is divided into superficial layer called epidermis & deep layer called dermis ❑ Epidermis is thick in palm and sole ❑ Dermis is made of dense connective tissue containing https://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/articles/image_ article_collections/anatomy_pages/skin.jpg?resize=646px:*&output-quality=100 blood vessels, nerves & lymphatics ❑ Dermis contains also sweat glands, sebaceous glands & hair follicles 4 Saturday, March 4, 2023  Skin Appendages ❑ Nails: Keratinized plates on dorsal of fingers & https://kidshealth.org/EN/images/illustrations/skin-325x192-rd1-enIL. toes gif ❑ Hair follicles ❑ Sweat glands Deepest structure in dermis ❑ Sebaceous glands Present in dermis & secret sebum 5 Saturday, March 4, 2023  Skin lines Skin creases: They are grooves opposite joints Skin is always thin at these sites and firmly adherent to underlying structures Creases are prominent on flexor surfaces of palm, sole & digits to facilitate movements Langers lines: or cleavage lines They correspond to natural orientation of collagen in dermis Incisions made parallel to lines heal better than those made across the lines Lines runs longitudinal in the limbs& transversely in the neck and trunk 6 Saturday, March 4, 2023  Skin Creases https://encrypted- tbn0.gstatic.com/images?q=tbn:ANd9GcTASa6PgG7dzqnYO4AjnbZ8RnaGD_p1GeGrPlc3p3vXc CckPSSS 7 Saturday, March 4, 2023  Skin Creases Skin creases in palm of hand https://www.scienceabc.com/wp-content/uploads/2017/04/Arrow-showing-hand-palm- lines.jpg  Langer lines https://i0.wp.com/i.pinimg.com/originals/07/2d/c7/072dc7a6b115a64adb4353ffcccc0441.jpg Saturday, March 4, 2023  Langer lines Transverse in trunk Longitudinal in limbs https://media.springernature.com/original/springer-static/image/chp%3A10.1007%2F978-3- 642-20641-2_7/MediaObjects/978-3-642-20641-2_7_Fig2_HTML.gif  Fascia Fascia: ❑ A layer that lies beneath skin ❑ It is divided into 2 layers 1- Superficial fascia 2- Deep fascia 11 Saturday, March 4, 2023  Superficial Fascia Superficial Fascia : A layer of loose connective tissue containing fat It is firmly attached to the skin in Scalp Back of neck Palm & sole It is loosely attached to the skin in Dorsum of hand Dorsum of foot https://yogalifestylecom.files.wordpress.com/2017/03/img_0137.jpg?w=1400 Saturday, March 4, 2023  Superficial Fascia It is devoid of fat in Eye lids & auricle of ear Penis & scrotum Clitoris It is rich in fat in Breast Gluteal region https://encrypted- tbn0.gstatic.com/images?q=tbn:ANd9GcQ3ugmihyitYdQxi5AwrgLOOdiaNFBM44emuay5- YoAAbRkOcBmbg 13 Saturday, March 4, 2023  Superficial Fascia Breast Gluteal region https://i.pinimg.com/236x/2a/d7/82/2ad782d727a9ad6b609618e872ea9774--fascia-blaster-revolutions.jpg  Functions of Superficial Fascia ❑ Facilitate movements of skin ❑ Bad conductor of heat ❑ Gives body its shape ❑ Contains blood vessels , nerves & sometimes muscles ❑ Holds skin firmly to deeper structures by bundles of collagen 15 Saturday, March 4, 2023  Deep Fascia ❑ It is a membranous layer of connective tissue that invests muscles. ❑ It is well developed in limbs thin in thorax & abdomen ❑ absent in most of the face https://www.researchgate.net/profile/Patrick_Deheer2/publication/312560288/figure/downl oad/fig9/AS:546698537562112@1507354496207/Chung-retractor-in-place-to-expose-deep- fascia-overlying-the-gastrocnemius-and-soleus.png 16 Saturday, March 4, 2023  Deep Fascia https://i.ytimg.com/vi/cK49wx75FN8/hqdefault.jpg  Deep Fascia Surrounds the muscles Netter Atlas of human anatomy 6th edition 18 Saturday, March 4, 2023  Deep Fascia Forms planter aponeurosis Netter Atlas of human anatomy 6th edition 19 Saturday, March 4, 2023  Deep Fascia Forms palmer aponeurosis Netter Atlas of human anatomy 6th edition 20 Saturday, March 4, 2023  Deep fascia Forms retinacula Netter Atlas of human anatomy 6th edition 21 Saturday, March 4, 2023  Deep fascia Forms retinacula Netter Atlas of human anatomy 6th edition Saturday, March 4, 2023  Deep Fascia Deep fascia forms fibrous flexor sheath Netter Atlas of human anatomy 6th edition Saturday, March 4, 2023  Functions of Deep Fascia ❑ Covers the muscles & assist in their action ❑ Deep surface of fascia gives rise to septa &it is thickened in palm & sole forming palmer & planter aponeuroses ❑ It is thickened around joints forming retinacula & ❑ Thickened opposite the flexor surface of fingers forming fibrous flexor sheaths ❑ In neck forms well defined layers that may play a role in the path of spread of infection ❑ Helps in venous return 24 Saturday, March 4, 2023 Deep fascia and Venous Return https://www.earthslab.com/wp-content/uploads/2017/03/031817_0059_Perforating1.jpg  Physiology Of Skin 1- Protection Against: Physical and Chemical Trauma. Microorganisms. Radiations. 2- Thermoregulation By negative feedback between Skin, Skeletal muscles, sweat glands,and hypothalamus. 3- Sensation High number of Sensory Receptors in the Skin Specially the Face and Fingertips. Provide immediate sensory feedback to sensory cerebral cortex to protect the body against injury.  Physiology Of Skin 4- Water Storage Protection and Maintenance of normal of water and electrolytes. 5- Absorption Drugs ( Dermal patches and creams ). Toxic Organisms ( if the barrier is injured or weak ). 6- Expression The Skin of the face can express wide range of emotions, behavior, and communication.  Physiology Of Skin 7- Synthesis of Vitamin D Deficiency of Vitamin D In infants leads to Rickets and in Adults leads to Oteoporosis.  Summary ❑ Skin : is thick in palm and hand ❑ It shows skin creases and langers lines ❑ Fascia is either superficial or deep ❑ Superficial fascia contains fat, nerves and vessels,It keeps body temperature ,Gives the body its shape ❑ Deep fascia surrounds muscles, forms septa , retinacula, fibrous flexor sheaths and helps in venous return 29 Saturday, March 4, 2023  Quiz 1- For better healing , an incision in limbs should be done: a) Transverse b) Longitudinal c) Circular d) Spiral e) Anti- Clockwise 2- Which of the following is a function of deep fascia : a) Gives body its shape b) Keep body temperature c) Contains muscles d) Connect skin to underlying structure e) Helps in venous return 30 Saturday, March 4, 2023  SUGGESTED TEXTBOOKS Clinical Anatomy by regions by Richard Snell 9th edition Saturday, March 4, 2023 31