INTRODUCTION TO HUMAN ANATOMY Definition Anatomy is the

INTRODUCTION TO HUMAN ANATOMY

Definition • Anatomy is the study of the structure of the human body.

The Anatomical Position • The body is standing upright , with the eyes looking forward in a horizontal plane (Frankfurt plane) , the two upper limbs hanging beside with the palms looking forwards and the two lower limbs beside each other.

ANATOMICAL PLANES • Sagittal plane is vertical plane that passes through the body from front to back. • The median or midsagittal plane is the vertical plane that divides the body into right and left halves. • Coronal plane is vertical plane which pass through the body from side to side. • Horizontal (transverse) plane is parallel to the floor.

Superior view of the skull

METHODS OF STUDYING ANATOMY (1) Systematic anatomy: is studying the different body systems. (2) Topographical or regional anatomy: is studying anatomy of the body region by region.

Regions of the human body I- Head and neck II- Trunk is divided into: 1. Thorax 2. Abdomen 3. Pelvis 4. Perineum 1. III- limbs: 1. upper limb 2. lower limb

TERMS OF POSITION

TERMS OF POSITION 1. Superior: means nearer to the head. 2. Inferior: means farer from the head or nearer to the feet. 3. Anterior: means nearer to the front of the body. 4. Posterior: means nearer to the back of the body. 5. Medial: means toward or nearer the midline of the body. 6. Lateral: means away from the midline or toward the side of the body.

Superior Median sagittal plane Paramedian plane Lateral Posterior Medial Anterior Inferior

7 - Proximal (A) means nearer to the root of the limb. 8 - Distal (B) means further away from the root of the limb. . A B

9 - Superficial (A): means closer to the surface of the body(nearer to the skin). 10 - Deep (B): farther away from the skin. A B

TERMS OF MOVEMENT Flexion: bending anteriorly (approximation of the two anterior surfaces of the bone forming the joint). Extension: straightening or bending posteriorly (approximation of the two posterior surfaces of the bone forming the joint).

extension flexion extension flexion Flexion and extension of the upper limb at shoulder joint and lower limb at hip joint Flexion and extension of the forearm at elbow joint and of leg at knee joint Flexion and extension of vertebral column at intervertebral joints

extension flexion extension Flexion and extension of hand at the wrist joint Flexion and extension of the fingers at the metacarpophalangeal and the interphalangeal joint Flexion and extension of the thumb

• abduction: movement away from the median plane • Adduction: movement toward the median plane Lateral abduction Medial abduction Abduction of the middle finger Abduction and adduction of the fingers adduction abduction adduction Adduction and abduction of the thumb

Circumduction: is a circular movement

STRUCTURES MET IN DISSECTION • Skin. • Superficial fascia • Deep fascia • Muscles. • Blood vessels. • Lymph vessels and lymph glands. • Nerves. • Bones

STRUCTURES MET IN DISSECTION skin Superficial fascia Deep fascia Blood vessels nerves Muscles Bones

SKIN

SKIN • Skin is the outer covering layer of the body. • The skin consists of two layers: • (a) Superficial or outer layer called the epidermis. • (b) Deeper or inner layer called the dermis.

Skin appendages

Skin appendages 1. Hair. 2. Nails 3. Sebaceous glands 4. Sweat glands

Skin and skin appendages

Functions of skin 1. Covers and protect the underlying structure. 2. Regulation of body temperature. 3. Excretion of waste products.

SUPERFICIAL FASCIA • Definition: • It’s a fibro fatty layer that lies directly under the skin. Contents: • • • cutaneous nerves Superficial blood vessels Lymphatics Parts of sweat glands and hair follicles. In some regions the superficial fascia may contain superficial muscles and mammary gland(pectoral region)

Deep fascia Definition : It’s a membranous layer that lies underneath the superficial fascia Functions of deep fascia: 1 -the investing deep fascia: it’s the third envelope of the body. 2 -Capsule: it envelopes some organs forming their capsules.

3 -Muscle sheath: it envelopes muscles forming their sheath and sends septa between muscles forming Intermuscular septa or septa between the muscles. 4 -It envelopes blood vessels and nerves forming their sheathes. 5 -It envelopes bones forming the periosteum. 6 -In some regions of the body, the deep fascia forms thick bands called retinacula as flexor and extensor retinacula of the wrist.

DEEP FASCIA

MUSCLES Definition: Muscles are the red flesh of the body and forms nearly half of the body weight TYPES a. Smooth muscle tissue makes up the muscular portion of the various visceral organs (stomach, blood vessels, etc. ). b. Cardiac muscle tissue makes up the muscular wall of the heart- the myocardium. c. Skeletal muscles: attached to and moves bones

Functions of the muscles • They produce movements Parts of skeletal muscles • The larger contractile part is called the belly • The fibrous part in the form of cord like structure in fusiform muscles called a tendon or flattened part called aponurosis in flat muscles

Skeletal muscle forms

Forms of skeletal muscles (1)parallel: includes the following forms: (a) Quadrilateral muscles: as the Thyrohyoid (b) Fusiform muscles as biceps. (c) Strap-like as Sartorius

strap Quadrilateral Strap with tendinous intersections fusiform

(2)Triangular The fibers are convergent e. g. , the Temporalis. Triangular

(3) Pennate The fibers are oblique and converge: (a) unipennate : as palmar interossi (b) bipennate : as the Rectus femoris. (c) multipennate as deltoid muscle. (d) circumpennate as flexor policis longus muscle.

unipennate Bipennate Radial Multi-pennate

The human skeleton: • The human skeleton consists of a series of bones articulated together to form joints. • The human skeleton is divided into: 1. Axial skeleton 2. Appendicular skeleton

THE AXIAL SKELETON: It includes: 1. skull, 2. vertebral column (spine), 3. Ribs and sternum. 4. NB: The thoracic cage includes ribs, sternum and thoracic vertebrae.

The Skull

Vertebral Column

THE APPENDICULAR SKELETON

FUNCTIONS OF BONES : (a) Bodily Support: provides a framework for the human body. (b) Protection protects certain soft structures within the human body. An example is the skull, which surrounds the brain and the thoracic cage which protect the heart and lungs. . (c) Motion Muscles are attached to and move the bones. (d) Formation of Blood Cells (Hematopoiesis). (e) Storage for salts (e. g. , calcium).

TYPES OF BONES I- According to the shape

According to the shape: 1. Long Bones. Each bone has two ends and a shaft Example: femur and humerus. 2. Short Bones. Example: carpal and tarsal bones. 3. Flat Bones. The flat bones are constructed with two plates of compact bone, which enclose between them a layer of spongy bone. The spongy bone is richly supplied with blood vessels and red marrow. Example: the scapula and the cranial bones. 4. Irregular Bones. The irregular bones are those that do not fit into the three categories above. Example: a vertebra. 5. Pneumatic Bones: it has multiple air filled spaces Example: para nasal sinuses.

Joints Definition: A joint, or articulation, is the location where two or more bones meet Classification (a) Fibrous Joints (b) Cartilagenous Joints (c) Synovial Joints I- Fibrous Joints Here the bones are connected together by a fibrous tissue and there’s no movement. Ex: sutures

II Cartilagenous Joints • Here the bones are bounded together by intervening cartilage and permit a limited degree of movement. • They are of two types: (1) Primary (Synchondrosis) (2) Secondary (Symphysis).

(1) Primary (fibrocartilagenous) joint • A fibrocartilaginous joint is a joint in which the bones are held together by a hyaline cartilage. • Example: Epiphyseal plate in long bones Upper epiphysis Epiphyseal plate diaphysis Epiphyseal plate Lower epiphysis

(2) Secondary cartilagenous joint • A secondary cartilaginous joint is a joint in which the bones are held together by a fibrocartilage. • Example: Pubic symphysis and the inter vertebral disc between bodies of vertebrae.

III Synovial Joints Structure of the synovial joint 1. The articular bones 2. Articular cartilages are hyaline cartilage covering the adjacent surfaces of articular bones. 3. Fibrous capsule surrounds the articular bony parts 4. Synovial membrane lines the inner surface of the capsule and reflects to cover the articular bones till the margin of the articular cartilage. It secretes synovial fluid.

5. Synovial fluid is a colorless, viscous fluid secreted by synovial membrane. It lubricates the articular surfaces of bones. 6. Ligaments: are either extracapsular or intracapsular. The extracapsular ligaments provide additional support to the capsule while the intracapsular share in the support of joint

Structure of the synovial joint Articular bone

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