Systemic Anatomy PDF

Systemic Anatomy Anatomical Terminology Anatomists and health care providers use terminology to increase precision and reduce medical errors. Without anatomical terms one cannot accurately discuss or record any abnormal changes occurring in the body structure. 1) Terms re...

Systemic Anatomy Anatomical Terminology Anatomists and health care providers use terminology to increase precision and reduce medical errors. Without anatomical terms one cannot accurately discuss or record any abnormal changes occurring in the body structure. 1) Terms related to position: a)Anatomical position. b)Anatomical planes. c) Directional terms. d) Regional terms (Names of parts of the body). 2) Terms related to movement: 1. TERMS RELATED TO POSITION (A)ANATOMICAL POSITION To further increase precision, anatomists standardize the way in which they view the body. When the subject:  standing upright  Head facing forward  eyes facing forward  feet flat on the floor  arms at the sides  palms turned forward (ventral)  Thumb directed laterally Figure (2): anatomical position 5  Systemic Anatomy (B)ANATOMICAL PLANES The various parts of the body are described in relation to certain imaginary planes. Median sagittal (median )plane: It is a vertical plane passing through the center of the body, dividing it into equal right and left halves. Sagittal (Para median) plane: These are vertical planes which pass antero-posterioly parallel to the median plane, dividing the body into unequal right and left halves. Coronal (frontal) plane: These are imaginary vertical planes at right angles to the median plane dividing the body into unequal anterior and posterior parts. Transverse (horizontal) plane: Are imaginary horizontal plane which pass through the body at the right angle to the median, sagittal or coronal planes. It divides the body into unequal upper and lower parts. Figure (3): anatomical plans 6  Systemic Anatomy C. DIRECTIONAL TERM: Most of the directional terms used to describe the relationship of one part of the body to another can be grouped into pairs that have opposite meanings. Terms to describe location and position: Figure (3): Terms of location and position. Terms to describe the movements: Various terms describe movements of the limbs and other parts of the body while most movements occur at joints where two or more bones or cartilages articulate with one another. 7  Systemic Anatomy 2. TERMS RELATED TO MOVEMENTS Figure (4): Terms related to movement. 8  Systemic Anatomy Abdominal Regions and Quadrants: The abdomen is a large area of the lower trunk of the body. If a patient reported abdominal pain, the physician or nurse would want to know more precisely where the pain was. To determine this, the abdomen may be divided into smaller regions or areas Four quadrants of the abdomen: ▪ at the umbilicus, A transverse plane and a mid-sagittal plane are used to divide the abdomen into four quadrants. ▪ Clinically, this is probably the division used more frequently. The pain of gallstones might then be described as in the right upper quadrant. Figure (6): Anterior view showing division of the abdomen into four quadrants. 11  Systemic Anatomy Nine regions of the abdomen: Two transverse planes and two sagittal planes are used to divide the abdomen into nine areas: Upper areas: the right hypochondriac, epigastric, and left hypochondriac. Middle areas: the right lumbar, umbilical, and left lumbar. Lower areas: the right iliac, hypogastric, and left iliac. ♦ The nine-region division is more widely used for anatomical studies to determine organ location. The liver, for example, is located in the epigastric and right hypochondriac areas. ♦ quadrants are more commonly used by clinicians for describing the site of abdominopelvic pain, tumour, injury, or other abnormality. Figure (7): Anterior view showing nine regions of the abdomen 12  Systemic Anatomy BODY CAVITIES ♦ The body has two major cavities: the dorsal cavity (posterior) and the ventral cavity (anterior). Each of these cavities has further subdivisions. ► Dorsal Cavity: ▪ It contains the central nervous system ▪ It consists of the cranial cavity and the vertebral or spinal cavity that lined with meninges. The cranial cavity is formed by the skull and contains the brain. The spinal cavity (vertebral canal) is formed by vertebral column and contains the spinal cord. ►Ventral Cavity: ▪ The ventral cavity consists of three compartments, the thoracic , abdominal and pelvic cavities. The thoracic cavity is separated from abdominal cavity by the diaphragm, while the abdominal cavity is continuous with the pelvic and termed as abdominopelvic cavities. ▪ Organs inside the thoracic and abdominopelvic cavities are termed the viscera ▪ Organs in the thoracic cavity include the heart and lungs. ▪▪Organs in the abdominal cavity include the liver, stomach, and intestines. ▪ Organs in the pelvic cavity include the urinary bladder, rectum and reproductive organs such as the uterus in women and the prostate gland in men. Other Body Cavities: ▪ The oral (mouth) cavity: contains the tongue and teeth and lined by mucous membrane 13  Systemic Anatomy ▪ The nasal cavity: in the nose and lined by mucous membrane. ▪ The orbital cavities (orbits): contain the eyeballs. ▪ The middle ear cavities (middle ears): contain small bones and muscles in the middle ear. ▪ synovial cavities: are found in freely movable joints which lined by synovial membrane and contain synovial fluid. Serous membranes It’s a closed sac membrane that lining the body cavities. It has one-layer lines the of the cavities (parietal layer) and the other layer is reflected onto the mobile viscera (visceral layer) with a narrow, slit like interval that separates these layers. The slit contains a small amount of serous liquid, to slide readily both layers on each other. parietal layer richly supplied by spinal nerves and sensitive to pain temperature and touch while, the visceral layer supplied by autonomic nerves and sensitive to stretch. Examples pericardium: a serous sac surrounding the heart. Pleura: a serous sac surrounding the lunge one each side. Peritoneum: a serous sac surrounding the abdominal viscera. Synovial sheath: a serous sac surrounding the tendon of the muscle. Bursa: a serous sac between the tendon and bone close to joint to prevent friction. 14  Systemic Anatomy Figure (8): Dorsal and ventral body cavities and their subdivisions. Figure (9): serous membranes 15  Systemic Anatomy 2. TERMS RELATED TO MOVEMENT Figure (10): Movement terms 16  Systemic Anatomy THE MAMMALIAN BODY Levels of Structural Organization of human body: ► From the simplest structure, the atom, to the most complex structure, the organism, the human body is organized by six levels: I- Chemical level: Atoms → Molecule → Macromolecules → Organelles → The cell. II- Cellular level: Cells are the basic living unit. III- Tissue level: Tissue is groups of cells functioning together. ► The human body is organized from four main basic tissues: i. Epithelial tissue. ii. Connective tissue. iii. Muscular tissue. iv. Nervous tissue. IV- Organ level: Organ: is formed of groups of tissues. Examples: liver & lungs V- Organ system level: Organ system, is group of organs function together as organ systems. ► The human body is organized from the following systems: i. Integumentary system. ii. Muscular system. iii. Skeletal system. iv. Cardiovascular system v. Respiratory system. vi. Lymphatic system. vii. Digestive system. vii. Urinary system. ix. Reproductive system x. nervous system: xi. Endocrine. IV- organismal level: Organism or human body, is the highest level of organization of the living human being. N.B. Anatomy can be studied following a regional or a systemic approach 17  Systemic Anatomy INTUGMENTRY SYSTEM (SKIN AND FASCIA) ♦ The integumentary system consists of the skin with its appendages (hair, nails, and sweat glands) and the hypodermis. ♦ The superficial region of the skin is a thick epithelial tissue, the epidermis. ♦ Deep to the epidermis is the dermis, a fibrous connective tissue. ♦ Just deep to the skin lies a fatty layer called the hypodermis, composed of loose areolar connective tissue and adipose tissue which attaches the dermis to the fascia of the body. Figure (12): Skin structure. 19  Systemic Anatomy THE SKIN ▪ It covers the external surface of the body and is the largest organ of the body in weight. ▪ In adult, the skin covers an area of about 2 square meters and weighs 4.5–5 kg, about 7% of total body weight. ▪ It ranges in thickness from 0.5 mm on the eyelids to 4.0 mm on the heels. However, over most of the body it is 1–2 mm. ► The skin performs a variety of functions: Protection: skin protects the body from bumps and scrapes, from chemicals and invading microorganisms. Body temperature regulation: the skin is rich by capillary networks and the sweat glands which regulate the loss of heat from the body, helping to control body temperature. Sensory reception: The skin contains sense organs called sensory receptors that are associated with nerve endings. Excretion: The skin acts as a miniature excretory system where urea, salts, and water are lost through sweat. Production of vitamin D: The epidermal cells use UV radiation to synthesize vitamin D, a molecule necessary for absorbing calcium from the digestive tract. ► Structurally, the skin consists of two main parts: Epidermis: The superficial, thinner portion, which is composed of epithelial tissue. it is avascular, so there is no bleeding if the skin is scratched. Dermis: The deeper, thicker, connective tissue portion. It is vascular and a cut that penetrates to the dermis produces bleeding. 20  Systemic Anatomy In thick skin, which covers the palms and soles, the epidermis consists of five layers, or strata In thin skin, which covers the rest of the body, only four strata are present Skin appendages: ♦ These skin appendages include hair and hair follicles, nails, sweat glands, and sebaceous (oil) glands. Figure (13): Structure of a nail. 21  Systemic Anatomy THE FASCIA Fascia is connective tissue containing varying amounts of fat that separate, support, and interconnect organs and enable movement of one structure relative to another There are two types of fascia: 1- superficial 2- deep.  Superficial fascia: lies just deep to and is attached to the dermis of the skin. It is made up of loose connective tissue, usually containing a large amount of fat. The thickness of the superficial fascia varies considerably, both from one area of the body to another and from one individual to another. At the lower part of the anterior abdominal wall and perineum, the superficial fascia is differential into outer fatty layer and deep membranous layer Functions of superficial fascia: 1- Allows movement of the skin over deeper areas of the body. 2- It conducts vessels and nerves to and from the skin. 3- Due to its high fat content, it serves as: - Heat insulator. - Energy store. - Factor which gives the body its rounded contours.  Deep fascia: usually consists of dense, organized connective tissue. The outer layer of deep fascia is attached to the deep surface of the superficial fascia and forms a thin fibrous covering over most of the deeper region of the body. It is absent in certain regions, e.g., in the face, scalp and anterior abdominal wall. 22  Systemic Anatomy Functions of deep fascia: 1. It invests the deeper structures and binds them to the bones. 2. It gives origins or receives insertions of some muscles. 3. In the limbs, it forms intermuscular septa which attach deeply to the bones with a resulting formation of different muscular compartments with similar functions and innervations. 4. Near the distal joints (e.g., ankle and wrist), it is thickened forming retinaculae. These fascial retinacula hold tendons in place and prevent them from bowing during movements at the joints. 5. In certain sites, the deep fascia is thickened for protection, e.g., palmer aponeurosis in the palm of the hand and planter aponeurosis in the sole of foot. Figure (14): Fascia of the arm. Figure (15): Fascia of the hand. 23