Introduction to Anatomy

• بسم الله الرحمن الرحيم translates to "In the name of God, the Most Gracious, the Most Merciful".

Introduction to Anatomy

• Anatomy is the study of the structure of the human body.
• Standard anatomical position is used for accurate description of body parts and regions.
• Prepared by Dr Sayed Mostafa
• Modified by Dr. Eid Nassar Ali

Anatomical Position

• Erect posture is assumed
• Eyes face forward
• Upper limbs are at the sides
• Palms face forward
• Thumbs point outwards
• Legs are close together
• Feet point forwards

Other Body Positions

• Supine: lying face up
• Prone: lying face down
• Right lateral: lying on the right side
• Left lateral: lying on the left side

Anatomical Terms of Position

• Superior (cranial): towards the head
• Inferior (caudal): towards the feet
• Anterior (ventral): towards the front
• Posterior (dorsal): towards the back
• Medial: towards the midline
• Lateral: away from the midline
• Proximal: closer to the point of attachment
• Distal: farther from the point of attachment
• Superficial: closer to the surface
• Deep: farther from the surface

Anatomical Planes

• Median plane: divides the body into right and left halves
• Paramedian plane: parallel to the median plane
• Frontal (coronal) plane: divides the body into anterior and posterior parts
• Transverse plane: divides the body into upper and lower parts

Common Anatomical Terms of Movements

• Flexion: decreasing the angle between two parts
• Extension: increasing the angle between two parts
• Abduction: moving away from the midline
• Adduction: moving towards the midline
• Pronation: turning the palm downward.
• Supination: turning the palm upward.
• Inversion: moving the sole of the foot inward.
• Eversion: moving the sole of the foot outward.
• Dorsiflexion: lifting the foot so that its superior surface approaches the shin.
• Plantar flexion: depressing the foot (pointing the toes).

Coverings of the Body

• The coverings include the skin and the fascia.

The Skin

• The skin protects underlying tissues, defends against microorganisms, regulates body temperature, forms vitamin D, absorbs certain substances and provides sensory input about the external environment.
• The skin has a superficial epidermis layer and a deep connective dermis layer.
• Deep to the dermis is the superficial fascia or hypodermis.
• In Greek the word for anatomy means "to cut"
• In Latin the word for anatomy means "to dissect"
• Macroscopic anatomy and gross anatomy are the same thing
• Microscopic anatomy is also known as histology
• A third type of anatomy is radiological anatomy

Skin Structure

• Epidermis is the most superficial layer with 4 to 5 cell layers.
• The superficial layer contains keratin.
• Keratin is a water-insoluble protein.
• The Epidermis is devoid of blood vessels.
• Deep layer cells regenerate mitotically.
• Epidermis is generally thin except on the palms of the hands and soles of the feet.

Dermis

• Dermis lies deep to the epidermis.
• Dermis contains blood vessels, lymph vessels, sensory nerve endings, smooth muscles, hair follicles, sweat and sebaceous glands.

Appendages of the Skin

• These items include hairs, sweat glands, sebaceous glands, and nails.

Hairs

• Hairs cover surfaces except palms, soles, and the red margin of the lip.
• Arrector pili are smooth muscle responsible for hair movement.
• Sympathetic nerve fibers innervate the arrector pili muscles.

Sebaceous Glands

• Sebaceous glands lie within the dermis.
• Secrete sebum into a hair follicle.
• Sebum lubricates hair and skin.
• Sebaceous glands are not on palms or soles.

Sweat Glands

• Sweat glands are long, tubular.
• They extend through the entire dermis thickness.
• They are present over all the body except the red margins of the lips, nail beds, glans penis, and clitoris.

Nails

• Nails are a flat, horny plate on the dorsal surface of the distal phalanx of fingers and toes.
• Nails have a root, body, nail fold, and nail bed.

Clinical Applications regarding infections of the cutaneous system

• Pathogenic organisms, usually staphylococci, can enter through nail folds, hair follicles, and sebaceous glands.
• Paronychia occurs if the infection happens between the nail and nail fold.

The Fascia

• Fascia is connective tissue between skin, underlying muscles, and bones.
• It is divided into superficial and deep layers.

Superficial Fascia

• Superficial fascia lies immediately under the skin uniting it to the underlying tissues.
• It consists of a loose connective tissue layer with fat, blood vessels, and nerves.
• This fascia is extremely thin in the eyelids, external ear, penis, and scrotum.
• Superficial fascia keeps the body temperature, gives the body a rounded contour, stores fat, contains vessels/nerves and allows free skin mobility.
• It contains muscles in the face (muscles of facial expressions) and neck (platysma).

Functions of superficial fascia.

• Keeps the body temperature.
• Gives the body a rounded contour especially in females.
• Stores fat
• It contains blood vessels, lymphatics and nerves of the skin
• It allows free mobility of the skin on the underlying structures.
• It contains muscles: in Face and the Neck

Deep Fascia

• Deep fascia is dense, inelastic, fibrous membrane that separates superficial fascia from deeper structures.
• Covers most of the body but is absent in the face, scalp, and anterior abdominal wall
• Invests muscles to separate muscle groups.
• Thickened in distal joints for protection, forming retinaculae, and in the palm/sole forming aponeuroses.
• Acts as pulleys around which tendons can move.
• Surrounds vessels/nerves, forming the carotid sheath in the neck.

Learn about the basics of human anatomy, including standard anatomical position and related terminologies. Understand body positions like supine, prone, and lateral views, and directional terms such as superior, inferior, anterior, and posterior to navigate the human body.