INTRODUCTION TO HUMAN ANATOMY

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

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.

Lateral

Medial

AnteriorPosterior

Superior

Inferior

Paramedian plane

Median sagittal plane

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).

flexion

flexion

flexion

flexion

flexion

extension

extension

extension

extension

extension

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

flexion

flexion extension

extension

Flexion and extension of hand at the wrist joint

Flexion and extension of the fingers at the metacarpophalangeal and the interphalangeal joint

flexion

extension

Flexion and extension of the thumb

• abduction: movement away from the median plane

• Adduction: movement toward the median plane

adduction

adduction

abduction

abduction

Abduction of the middle finger

Abduction and adduction of the fingers

abduction adduction

Adduction and abduction of the thumb

Lateral abductionMedial abduction

Circumduction: is a circular movement

STRUCTURES MET IN DISSECTION

•Skin.•Superficial fascia •Deep fascia •Muscles.•Blood vessels.•Lymph vessels and lymph glands.•Nerves.•Bones

skin

Superficial fascia

Deep fascia

Muscles

Bones

Blood vessels

nerves

STRUCTURES MET IN DISSECTION

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

Skin appendages

1. Hair.2. Nails3. Sebaceous glands4. Sweat glands

Skin appendages

Skin and skin appendages

Functions of skin

1. Covers and protect the underlying structure.

2. Regulation of body temperature.

3. Excretion of waste products.

• 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)

SUPERFICIAL FASCIA

Definition :It’s a membranous layer that lies underneath the superficial fascia

Deep 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

TYPESa. 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

Definition:

Muscles are the red flesh of the body and forms nearly half of the body weight

MUSCLES

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

(1)parallel: includes the following forms:

(a) Quadrilateral muscles: as the Thyrohyoid

(b) Fusiform muscles as biceps.

(c) Strap-like as Sartorius

Forms of skeletal muscles

Quadrilateral

strap 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

RadialBipennate 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.

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) .

Long bone short bone flat bone irregular bone pneumatic bone (femur) (tarsal bones) (scapula) ( hip bone) (paranasal sinuses)

I- According to the shape

TYPES OF BONES

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.

JointsDefinition: 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

• 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).

II Cartilagenous Joints

Cartilaginous joint: Synchondrosis Epiphysis (end of long bone)

Diaphysis (Shaft) of long bone

Epiphyseal plate of hyaline cartilage

Epiphyseal plate (growth plate) allows for growth of bone in longitudinal axis. Plates found in children; Diaphysis and epiphysis fused after teen years (no

more growth plate).

Synchondrosis: Bones joined by hyaline cartilage in children; no

movement of bones

Upper epiphysis

diaphysis

Epiphyseal plate

Lower epiphysis

Epiphyseal plate

)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

• 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.

)2 (Secondary cartilagenous joint

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

parts4. 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.

III Synovial Joints

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

Articular bone

Articular boneStructure of the synovial joint

The end