Organization of the Human Body
Organization of the Human Body
Major features of the human body include its cavities, membranes, and organ systems.
Body Cavities
1. The body can be divided into an appendicular portion (upper and lower limbs) and an axial portion (head, neck, and trunk), which includes a dorsal and a ventral cavity. Organs within these cavities are called viscera.
a. The dorsal cavity can be divided into the cranial cavity and vertebral canal.
b. The ventral cavity is made up of a thoracic cavity and an abdominopelvic cavity, separated by the diaphragm.
i. The mediastinum divides the thorax into right and left halves.
ii. The abdominopelvic cavity can be divided into the abdominal cavity and the pelvic cavity.
c. Smaller cavities within the head include the oral cavity, nasal cavity, orbital cavities, and middle ear cavities.
What is in the mediastinum? ________________________________________________
What surrounds the mediastinum? __________________________________________
What divides the abdominopelvic cavity? __________________________________
Thoracic and Abdominopelvic Membranes
1. The thoracic cavity is lined with pleura; the parietal pleura lines the cavities while the visceral pleura covers the lungs. A thin layer of serous fluid separates the two layers.
2. The heart is surrounded by the pericardium. The visceral pericardium covers the heart and the parietal pericardium makes up an outer sac. Serous fluid separates the two layers. Serous fluid acts as a lubricant to reduce friction and prevent pericarditis or “blisters between the layers.”
3. Peritoneum lines the abdominopelvic cavity; a parietal peritoneum lines the wall while visceral peritoneum covers the organs.
It is easier to remember than you think, try this:
Layers are named for 1. where they are located and 2. Inside/outside layer)
What is the word for heart? __________ Lung? _____________ Guts?_____________
What is the word for inside layer? ____________ What does it touch? ______________
What is the word for outside layer? ______________ What does it touch?___________
Name the inside layer of the heart? ________________
Outside layer of the guts? _______________________
Name all the layers -____________________________________________________________