Anatomy PDF

# Anatomy ## Introduction to Anatomy Anatomy is the study of the structure of the human body and the relations of its different parts to each other. ### Organization of the human body * Cells are the smallest structural and functional units of the body. * Tissues are made up of cells. The body...

# Anatomy ## Introduction to Anatomy Anatomy is the study of the structure of the human body and the relations of its different parts to each other. ### Organization of the human body * Cells are the smallest structural and functional units of the body. * Tissues are made up of cells. The body has four types of tissues: epithelial, connective, muscle, and nervous. * Organs are made up of tissues such as the stomach and lungs. * Systems are made up of organs that have an integrated activity such as the respiratory and cardiovascular systems. * The body of the organism comprises different systems performing different vital functions. ## Anatomical position It is the standard reference position of the body used for description where: * Body stands erect. * Feet together. * Upper limbs are along the sides. * Palms of hands are facing forward. * Face is directed forward. * Head is erect. * Eyes are looking forward. * Arms are hanging at sides with palms facing forward. ## Body regions and systems ### Body regions * Head and neck. * Trunk: * Thorax (chest). * Abdomen. * Pelvis. * Limbs: * Upper. * Lower. ### Body systems * Integumentary (skin). * Musculoskeletal. * Nervous. * Cardiovascular. * Respiratory. * Gastrointestinal. * Endocrine. * Urinary. * Reproductive. ## Terms of position * **Anterior**: ventral or near to front. * **Posterior**: dorsal or near to back. * **Superior**: above or near the head. * **Inferior**: below or near the foot. * **Medial**: near midline. * **Lateral**: away from midline. * **Superficial**: near the skin. * **Deep**: away from the skin. * **Proximal**: near a certain point. * **Distal**: away from a certain point. ## Anatomical planes * **Median**: A vertical plane that divides the body into equal right and left regions. * **Sagittal (paramedian)**: A vertical plane that divides the body into right and left regions. * **Coronal**: A vertical plane that divides the body into anterior and posterior parts. * **Horizontal (transverse)**: A horizontal plane that divides the body into upper and lower parts. ## Axial skeleton * **Skull**: Skeleton of the head. * **Thoracic cage**: Skeleton of the trunk. * The thoracic cage consists of: * Sternum anteriorly. * Ribs laterally. * Vertebral column posteriorly. ## Appendicular skeleton * **Bones of the upper limb**: * Clavicle-scapula * Humerus * Ulna-radius * 8 Carpal bones * 5 Metacarpal bones * 14 Phalanges * **Bones of the lower limb**: * Two hip bones * Femur * Tibia-fibula * 7 Tarsal bones * 5 Metatarsal bones * 14 Phalanges ## Vessels of the trunk ### Arteries * **Aorta**: * Arises from the left ventricle. * Distributes the blood from the heart to different body parts: * Ascending aorta. * Arch of aorta. * Descending thoracic aorta. * Descending abdominal aorta. * Ends in the abdomen by dividing into right and left common iliac arteries. * **Pulmonary trunk**: * Arises from the right ventricle. * Carries unoxygenated blood. * Divides into right and left pulmonary arteries to supply both lungs. ### Veins * **Superior vena cava**: * Drains the blood from the upper half of the body. * Ends in the right atrium. * **Inferior vena cava**: * Drains the blood from the lower half of the body. * Ends in the right atrium. * **Pulmonary veins**: * There are four pulmonary veins. * Each lung has two pulmonary veins. * They carry oxygenated blood. * They end in the left atrium. ## Blood vessels They are the channels that carry the blood throughout the body. ### Arteries * They carry the blood from the heart to the body tissues. * They have branches where a large artery gives smaller arteries. * They have oxygenated blood except for pulmonary arteries. * They have thick walls and thick muscles that keep the blood flowing. * When injured, bleeding (bright red blood) comes out in spurts. ### Veins * They carry the blood from the body tissues to the heart. * They have tributaries where smaller veins unite to from a larger vein. * They have unoxygenated blood except for pulmonary veins. * They have thinner walls and depend on valves and surrounding muscles to keep blood flowing. * When injured, bleeding (dark red blood) flows steadily. ### Capillaries * They are very small channels with very thin walls. * They have an arterial end and a venous end. * They filter the blood at the arterial end and reabsorb it at the venous end. * They allow the exchange of substances between the blood and the tissue fluid. * They form networks to give a small venule. ## Heart * Lies in the middle of the thorax just above the diaphragm, one-third to the right and two-thirds to the left of the median plane. * Its size is about the size of the individual's closed fist. * It is covered by pericardium. * It has four chambers: * Right atrium * Right ventricle * Left atrium * Left ventricle * The valve between the right atrium and right ventricle is the tricuspid valve. * The valve between the left atrium and left ventricle is the mitral valve. * The heart receives blood supply from the right and left coronary arteries. ## Great vessels attached to the heart * **Right atrium**: Receives unoxygenated blood from the body through the superior vena cava and inferior vena cava. * **Right ventricle**: Pumps the unoxygenated blood to the lungs through the pulmonary trunk. * **Left atrium**: Receives oxygenated blood from the lungs through the four pulmonary veins. * **Left ventricle**: Pumps the oxygenated blood to the body through the aorta. ## **The Cardiovascular System** * The cardiovascular system supplies oxygen and nutrients to cells and removes waste products. * **Heart**: a hollow muscular organ that pumps the blood. * **Blood vessels**: Arteries, veins, and capillaries. * **Blood**: Carries oxygen, nutrients, and waste. ## **The Circulatory System** * The circulatory system is made up of the blood, heart, and blood vessels. **Important Note:** This is a summary of the document and does not include every single detail. Also, there are a couple of instances where the image was too blurry to distinguish the words clearly. However, I made my best guess to provide complete sentences.