Unit 8 - Body Cavities, Organs & Membranes

What are body cavities?

• Enclosed spaces that house and protect organs

What are the main body cavities? (2)

• Dorsal

• Ventral

What does the dorsal body cavity include? (2)

• Cranial (head) cavity - brain

• Vertebral cavity - spinal cord

What does the ventral body cavity include? (1.2 + 2)

• Thoracic (chest) cavity 

  • pericardial cavity - heart

  • pleural cavity - lungs

• Abdominal cavity - digestive

• Pelvic cavity - urinary bladder, reproductive organs, rectum

What is an organ made of? (1.1)

• two or more tissue types

  • many contain all four major types

What does a membrane consist of? 

• 1 or 2 tissue types - connective tissue w/ or w/o epithelial tissue attached

What is the function of a membrane?

• Lines the inner + outer surfaces of the body + its organs

What are the types of membranes? (4)

• Mucous membranes

• Serous membranes

• Synovial membranes

• Cutaneous membrane

What is the function of the mucous membranes?

• Lines cavities of the organs that open directly → body exterior

What are the layers of the mucous membranes? (1.1 + 1.2)

• Epithelial layer - in contact w/ lumen of organ

  • avascular + many have goblet cells

• Lamina propria - CT layer that connects epithelial tissue → wall of organ

  • made of loose areolar CT => vascular

  • nourishes epithelial cells

What is the function of the serous membranes? (2)

• Lines body cavities - closed cavities that don’t open to exterior

• Covers the exterior surface of organs in these cavities

What is the structure of the serous membrane? (1.2.1)

• Double layered membranes w/ each layer composed of simple epithelium bound → areolar CT

  • parietal layer - against cavity wall

  • visceral layer - against organ

    • the epithelial layers secret serous fluid → serous cavity

What does pericardium mean?

• Heart

What does pleura mean?

• Lung

What does peritoneum mean?

• Abdominal organs

Where are the synovial membranes found?

• In joints

What is the structure of synovial membranes?

• Areolar CT - no epithelium

  • only 1 tissue type = not an organ

What is the cutaneous membrane?

• Skin

What is skin made of? (2)

• Epithelium - stratified squamous

• CT - areolar + dense irregular