Human Anatomy Lecture 1 PDF

INTRODUCTION TO HUMAN ANATOMY DR/Mona Ibrahim  what is anatomy ? Anatomy – It is the science which studies the body structures and the relationship of the various parts of the body LEVELS OF STUDY It extends from smallest structure to the largest one: Chemical level –structures of ato...

INTRODUCTION TO HUMAN ANATOMY DR/Mona Ibrahim  what is anatomy ? Anatomy – It is the science which studies the body structures and the relationship of the various parts of the body LEVELS OF STUDY It extends from smallest structure to the largest one: Chemical level –structures of atoms like hydrogen or carbon Cellular level - structures of cell tissue level - group of cells Organ level - group of tissues Systemic level – groups of organs Organismal level – groups of systems which form living individual  ANATOMICAL POSITION 1- Anatomical erect position: For descriptive purposes: · Human body is regarded as standing erect. · Eyes are looking forwards. · Upper limbs are hanging by the sides. · Palms are facing forwards. · Thumbs are directed laterally. · This position is used as a reference in describing the anatomy of the body. ANATOMICAL POSITION 2- Supine position: The body lies on its back. 3- Prone position: The body lies on its face. 4- Lateral decubitus position: The body lies on its side (right or left). 5 - Lithotomy position: The body lies on its back with flexion of hip and knee and abduction of hip joints.  Anatomical Planes: Median plane (Sagittal): Coronal (Frontal) plane: It is the vertical plane It is the plane which cuts the which passes in the middle body vertically into an line of the body dividing it anterior part towards the longitudinally into equal front of the body and a halves, right and left. posterior part towards the back. Horizontal plane: It is the transverse plane Paramedian plane: It is a plane which runs horizontally parallel to and nearby the median cutting the body into an plane. upper (superior) and lower (inferior) parts  Terms of Position: Anterior (Ventral) In front of (Nearer to the front of the body) Posterior (Dorsal) Behind (Nearer to the back of the body) Superior (upper or cranial): Nearer to the upper end of the body. Inferior (lower or caudal): (Nearer to the lower end of the body). Median exactly in the middle line or median plane. Medial nearer to the median plane. Lateral- away from the median plane. Proximal nearer to the root of the limb. Distal away from the root of the limb. Superficial= towards the skin or the surface of the body. Deep further away from the skin or the surface of the body Internal (inner) = inside the organ or the body. External (outer) = near or on the surface of the organ, or body. Terms of Position:  Types of tissues Tissues are groups of similar cells and extracellular products that carry out a common function. There are four Types of Tissues: 1. Epithelial tissue 2. Connective tissue 3. Muscle tissue 4. Nervous tissue Epithelial tissue: Originate from any of the three germ layers (ectoderm, mesoderm and endoderm). Usually resets on a basement membrane. Connective Tissue: 1.It is developed from the middle germ layer (Mesoderm). 2.It connect other tissue together and to the skeleton. 3.Does not rest on a basement membrane. 4.Have large amount of intracellular matrix.  SKIN & Fascia The skin is thick in palms and soles and thin all over the body. The skin consists of: ·Epidermis: Keratinized stratified squamous epithelium. The epidermis is covered by a keratin layer making it waterproof. Epidermal ridges are seen on the palmar aspect of hands and fingers (prints). ·Dermis: Consists of collagen and elastic fibers through which run blood vessels, lymphatics and nerves. A bundle of muscle fibers (arrector pill musde) congedts the side of the hair follicle to the junction between the dermis and epidermis  SKIN & Fascia Skin appendages: 1. Hairs. Skin pigments: 2. Nails: Develop from epidermis. It is formed 1- Melanin. of a root, body, and free border. 2- Carotenes. 3. Sebaceous glands: Their ducts open in the 3- Reduced haemoglobin. hair follicles. 4- Melanoid. 4. Sweat glands: Simple coiled tubular glands 5- Oxyhaemoglobin. which open on the surface of the skin.  FASCIA It is a collection of connective tissue under the skin. It covers the body wall limbs; it is divided into two layers: Superficial and Deep. A- Superficial Fascia: A layer of lose connective tissue, lies Immediately deep to the skin. the superficial fascia contains a variable quantity of fat which is more females than in males. Functions of the superficial fascia: 1- It prevents heat loss from the body, so it acts as thermal insulator (due to the presence of fat). 2- It acts as a medium conducting the cutaneous nerves, blood vessels and lymphatics which supply the skin.  A- Superficial Fascia: 3- It contains skin muscles, as in face (muscles of expression), in the neck (platysma) and in the scrotum (dartos muscle). 4- It contains many types of glands as mammary glands, sweat glands, sebaceous glands and superficial lymph nodes. 5- It softens and smoothens the surface of the body. -6It facilitates the movement of skin over the underlying structures. B- Deep Fascia: A membrane composed of compact and regular collagen fibers; it is inelastic. It is well defined in the limbs and very strong and thick in the palm and sole. It is absent in the face and in the anterior wall of abdomen.  B- Deep Fascia: →Parts and Functions of the Deep Fascia: 1 - -Formation of broad sheets: They surround the muscles of the different parts of the upper and lower limbs. They give attachment to some muscles and keep the underlying structures in position. 2- - Formation of intermuscular septa and interosseous membranes: They separate different groups of muscles which have different actions and nerve supply. 3- Formation of retinacula: They are localized transverse thickened bands of deep fascia present at wrist and ankle joints. They keep the tendons in position during movements of joints.  B- Deep Fascia: 4- Formation of palmar aponeurosis (in palm) and plantar aponeurosis (in sole): They are very thick, strong and protective layers of deep fascia. They protect blood vessels, nerves and tendons. 5- Formation of sheaths around big blood vessels, e.g.: Femoral sheath around the femoral blood vessels in lower limb. Carotid sheath around the carotid arteries and internal jugular vein in the neck CARTILAGE a- In the developing Properties: 1- It is a rubbery type of connective tissue, it is tough and resilient 2- It has no blood vessels, nerves or lymphatics. It gets its nutrition by diffusion from the blood vessels of the perichondrium. 3- It consists of mature cartilage cells (chondrocytes), fibers and matrix. 4- Its function is to resist and prevent friction and forces of compression. · Types of Cartilage A- Hyaline Cartilage: (Glass like) B- White Fibrocartilage C- Yellow Elastic Fibrocartilage:  A- Hyaline Cartilage: (Glass like) ·Structure: 1- Matrix: Homogenous and translucent. 2- Cartilage cells: Numerous, small rounded cells, present as single separate cells or 2-3 cells present in one capsule (cell nest). 3- Fibers: Collagen fibers which are very thin and few. 4- This cartilage is covered with perichondrium. 5- It is present in the following sites: examples : bones in the fetus. b- In the epiphyseal plates of the long bones in children. c- The articular cartilage in joints. d- The cartilages of the larynx (except the epiglottis). 6- In certain sites it is replaced by bone in old age e.g. in larynx and epiphyseal cartilages.  B- White Fibrocartilage: 1- Matrix: It is obaque and not translucent because it is rich in collagen fibers. 2- Cells: They are few in number. 3- Fibers: It contains large amount of collagen fibers. 4- This cartilage is tough and has a great tensile strength. 5- It is present in the following structures: Intervertebral discs, symphysis pubis, menisci of knee joint and articular disc in temporomandibular joint. 1-It does not show ossification in old age.  C- Yellow Elastic Fibrocartilage: 1- Matrix: Its yellow in appearance because it is rich in yellow elastic fibers. 2- Cells: They are abundant. 3- Fibers: Very rich elastic fibers. 4- This cartilage is covered with perichondrium. 5- It is present in tip of nose, auricle of ear, epiglottis (larynx) and eustachian tube. 6- It does not show ossification in old age.  BONES ·Functions of Skeleton: Gives a specific shape to the body and provides it with a central axis. Protects the vital organs, the skull protects the brain, and thoracic cage prote the heart and lungs. Provides surface area for muscular attachment. Forms the joints which make the important part of the locomotor system. Transmits and supports the body weight. The vertebral column transmits the weight of the head and trunk to the bony pelvis then through the bones of lower limbs to the feet and lastly to the ground. -Forms the blood elements in the bone marrow. Stores calcium salts.  BONES ·Classification of Bones (Skeleton): I. According to their position in the body: a- Axial skeleton: Skull, mandible, hyoid bone, sternum, ribs and vertebral column. b- Appendicular (peripheral) skeleton: Bones of upper and lower limbs. II. According to the process of ossification: The process of bone formation is called ossification. It is of two types: a- Intra-membranous ossification: Occurs in some bones, e.g. davidle, roof of skull (skull cap). The bones are developed directly from connective tissue membrane (mesenchyme). b- Intra-cartilaginous ossification: It occurs in long bones, vertebrae, ribs and base of skull. The connective tissue membrane (mesenchyme) is changed at first into a cartilage model, then into bones.  BONES III. According to their shape: They are: A- Long bones: Present in upper and lower limbs e.g. femur and humerus. Structure: Each bone consists of two ends called epiphysis and a shaft in between called (diaphysis) ·Epiphysis: The expanded upper and lower ends of the long bone. In living subjects, the epiphysis is used for articulation and its articular surface is covered with a layer of hyaline cartilage called articular cartilage. ·Diaphysis (Shaft): tube of compact bone with a central medullary cavity which is lined by endosteum and filled with soft vascular tissue called bone marrow.  BONES ii.The shaft is covered with fibrous sheath called periosteum which increase the long bones in width (diameter). iii.In the growing long bones, the epiphysis and the diaphysis are separated by a disc of hyaline cartilage called epiphyseal plate of cartilage which is responsible for the growth of long bones in length. · Metaphysis: It lies in the upper and lower parts of the diaphysis of long bone just beneath the epiphyseal cartilage. (It is the most active part of the long bone).  BONES B- Short Bones: e.g. carpal bones (in hand) and tarsal bones (in foot). C- Flat Bones: e.g. bones forming roof of skull, scapula and ribs. D- Pneumatic Bones: They are bones containing air sinuses. They are present in skull bones surrounding the nose as frontal and maxillary bones, so the air sinuses are called paranasal sinuses, e.g. maxillary and frontal sinuses. ·Functions: 1- They decrease the weight of skull. 2- Resonance of voice. 3- They act as air bags protecting the brain and eye.  BONES E- Irregular Bones: Bones of irregular shape with projecting processes e.g vertebrae. F- Sesamoid Bones: Small nodules of bones which are embedded in some muscle tendons near their insertion or origin. ·Function: They diminish friction between tendons and underlying bones e.g. patella which is the largest sesamoid bone, embedded in the tendon of the quadriceps femoris muscle in front of knee joint. PRACTICAL PART THANK YOU