CH 2: Human Cells and Body Planes/Cavities

Plasma Membrane

phospholipid bilayer, selectively permeable, protects the cell, controls what moves in and out

Cytoplasm

fluid filling cell interior, mostly water mixed with nutrients/salts/waste products, supports organelles, medium for chemical reactions

Nucleus

structure at cell’s center than contains DNA, the control center, directs growth, reproduction, function

Nuclear Membrane

double-layered membrane with pores surrounding nucleus, protects nucleus, allows materials to pass through

Nucleolus

dark structure in nucleus (contains 1-4 on average), produce ribosomes and RNA

Mitochondria

organelles filled with fluid and their own DNA, convert nutrients into ATP

Ribosomes

granules made of RNA, either in cytoplasm or on rough ER, build proteins

Endoplasmic Reticulum (ER)

membrane network connecting nucleus to other parts of the cell, RER produces and transports proteins, SER produces lipids and detoxifies substances

Golgi Apparatus

stacks of flattened sacs near nucleus, packaging and shipping materials inside or outside cell, also modifies materials before shipping

Lysosomes

sacs containing digestive enzymes, formed by Golgi, break down waste, damaged parts, provide structure, assists with moving organelles

Cytoskeleton

protein filament and tubule network throughout cytoplasm, maintain cell shape, provide structure, assists with moving organelles

Centrioles

pair of cylindrical structures made of microtubules near nuclear, organize cell division, distributes DNA evenly during division

Cilia

hair-like projections on cell’s surface, move substances across surface

Flagella

whip-like extensions from membrane; propel cell forward

Sagittal Plane

divides body into left and right sections

Midsaggital Plane

when division is directly down the midline

Transverse Plane (Horizontal Plane)

divides the body into upper (superior) and lower (inferior) sections

Frontal Plane (Coronal Plane)

divides body into front (anterior) and back (posterior) sections

Major Cavities

hollow spaces that protect and house internal organs

Cranial Cavity

within the skull, houses the brain, protected by meninges

meninges

protective membranes, protects the brain and supports connection to spinal cord

Spinal Cavity

down the midline of the back enclosed by vertebrae, contains spinal cord, protects spinal cord and connects brain to the rest of the body through the nervous system

Thoracic Cavity

inside chest above the diaphragm, houses heart, lungs, major blood vessels, supports breathing and circulation, divided into right and left pleural cavities and mediastinum

Abdominal Cavity

between diaphragm and pelvic region, houses stomach, liver, gallbladder, spleen, pancreas, intestines (most digestive organs), role in nutrient absorption

Pelvic Cavity

below abdominal cavity, houses urinary bladder, reproductive organs, part of large intestine, contains organs involved in excretion and reproduction

Right Upper Quadrant (RUQ)

contains liver, gallbladder, part of pancreas, right kidney, portions of small and large intestine

Left Upper Quadrant (LUQ)

contains stomach, spleen, part of the pancreas, left kidney, portions of small and large intestine

Right Lower Quadrant (RLQ)

contains appendix, right ovary and fallopian tube (female), right ureter, parts of intestines

Left Lower Quadrant (LLQ)

left ovary and fallopian tube (females), left ureter, parts of intestines

Right Hypochondriac

right upper area under ribs, house liver and gallbladder

Epigastric

upper central area just below sternum, contains stomach and pancreas

Left Hypochondriac

left upper area under ribs, contains spleen and part of stomach

Right Lumber (Flank)

middle right area, contains ascending colon and right kidney

Umbilical

center of abdomen around navel, contains small intestine and transverse colon

Left Lumber (Flank)

middle left area, contains descending colon and left kidney

Right Iliac (Inguinal)

lower right area, contains appendix and cecum

Hypogastric (Pubic)

lower central area below navel, contains bladder and reproductive organs

Left Iliac (Inguinal)

lower left area, contains sigmoid colon