Chapter 1 Structural Units Anatomy and Physiology A

Chapter 1 Structural Units

Anatomy and Physiology A branch of biology Anatomy- studies the shape and structure of an organism’s body and the relationship of one body part to another Anatomy means to cut apart Physiology- studies the function of each body part and how body parts work together to complete a living organism

Branches of Anatomy Gross Anatomy- the study of large and easily observable structures on an organism. • Studied with regard to general shape and features • Study of shape is called morphology

Branches of Anatomy Microscopic Anatomy • Subdivided into two branches Cytology- study of structure, function, and development of cells Histology- studies tissues and organs that make up the entire body of an organism

Branches of Anatomy Developmental Anatomy- studies the growth and development of an organism during its lifetime • Embryology- studies the formation of an organism from a fertilized egg to birth

Branches of Anatomy Comparative Anatomy- different body parts and organs of humans can be studied with regard to similarities and differences to other animals

Branches of Anatomy Systematic Anatomy- study of the structure and function of various organs within a particular organ system • Dermatology- study of the integumentary system (skin, hair, nails) • Endocrinology- study of the hormones • Neurology- study of the nervous system

Terminology Anatomical Position • A human being standing erect, with face forward, arms at the side, and palms forward

Terminology Anterior or ventral- front or in front of • Example- the knees are located on the anterior surface of the human body • Example- a ventral hernia may protrude from the front of the abdomen

Terminology Posterior or Dorsal- back or in back of • Example- human shoulder blades are found on the posterior surface of the body • Example- the dorsal aspect of the foot is the back or sole of the foot

Terminology Cranial and Caudal- refer to direction • Cranial means skull or head end • Caudal means tail end Example- a blow to the skull may increase cranial pressure and cause headaches Example- caudal anesthesia is injected into the lower spine

Terminology Superior and Inferior • Superior- means upper or above another • Inferior- refers to lower or below another Example- the heart and lungs are situated superior to the diaphragm while the intestines are inferior to it.

Terminology Medial and Lateral • Medial- means toward the midline of the body • Lateral- means away or toward the side of the body Example- the nose is medial to the eyes and the ears are lateral to the nose

Terminology Proximal and Distal • Proximal- means toward the point of attachment to the body or toward the trunk of the body • Distal- means away from the point of attachment or farthest from the trunk

Body Planes and Sections Planes- imaginary dividing lines that are useful in separating body structures Section- a cut made through the body in the direction of a certain plane Sagittal plane- divides the body into left and right parts Midsagittal plane- when the body is equally divided into left and right halves Coronal (frontal) plane- vertical cut at right angles to the sagittal plane divides the body into anterior and posterior Transverse plane- horizontal cut that divides the body into upper and lower parts

Terminology Superficial and deep • Superficial- on or near the surface of the body Example- a superficial wound involves injury to the outer skin • Deep- involves damage to an internal organ such as the stomach.

Cavities of the Body Dorsal cavity- contains the brain and spinal cord Cranial cavity- contains only the brain Spinal Cavity- contains only the spinal cord Thoracic cavity- esophagus, bronchi, lungs, trachea, thymus gland, and heart are located here Abdominal cavity- contains the stomach, liver, gallbladder, pancreas, spleen, small intestine, appendix, and part of the large intestine Pelvic cavity- urinary bladder, reproductive organs, rectum, and large intestine

Regions in the Abdominopelvic cavity Epigastric region (upper) – located below the sternum. Includes left and right hypocondriac regions located below the ribs Umbilical region (middle)- located around the navel. Includes the left and right lumbar regions Hypogastric region (lower)- also known as the pubic area. Includes the left and right iliac regions

Smaller Cavities Orbital cavity- includes eyes, eyeball muscles, optic nerves, and lacrimal (tear) ducts Nasal cavity- includes parts that form the nose Buccal cavity- encloses the teeth and tongue

Body Processes Metabolism- functional activities of cells that result in growth, repair, energy release, use of food, and secretions • Anabolism- building up of complex materials from simpler ones such as food and oxygen • Catabolism- breaking down and changing complex substances into simpler ones with a release of energy and carbon dioxide