Anatomy of the Cell + Tissues Flashcards
What are the three primary parts of an animal cell?
1) plasma membrane
2) nucleus
3) cytoplasm
Describe the structure of the plasma membrane.
Plasma membrane is composed of a phospholipid bilayer, which is two layers of phospholipids back-to-back.
The phospholipids have one head and two tails. The head is polar and hydrophilic, and the tails are hydrophobic.
Describe the structure of the nuclear membrane.
> double membrane (similar to plasma membrane)
outer membrane has embedded ribosomes
outer and inner membranes fuse in some areas to form nuclear pores
outer membrane is continuous with the ER
lumen (space between the 2 membranes), is continuous with the lumen of the ER
Describe the structure of microvilli.
finger-like projections that contain cytoplasm and have a core of actin.
Describe the structure of stereocilia.
composed of actin, are bound together by fimbrin. Longer than microvilli but not motile.
Describe the structure of cilia.
hair-like motile cellular extensions that are composed of microtubules coated by the plasma membrane.
What are the 3 structures that comprise the nucleus?
1) nuclear membrane
2) nucleoli
3) chromatin
Which organelle is the principal site for energy production?
Mitochondria
Which organelle is continuous with the nuclear membrane?
Endoplasmic reticulum (ER)
What is the function of the nucleolus?
Site of assembly of ribosomal proteins, site of rRNA synthesis
Which organelle is responsible for translation, storage, and transport of proteins?
Rough endoplasmic reticulum (ER)
Which organelle is responsible for synthesizing lipids, and drug detoxification?
Smooth endoplasmic reticulum (ER)
Which organelle is responsible for packing substances into vesicles and distributing them?
Golgi apparatus
Describe an endosome.
pH is originally 6; as they mature, pH drops to 5.5. Have proton pumps on their membranes to acidify the contents.
Describe a lysosome.
pH = 5.0, formed from late endosomes. Contain hydrolytic enzymes for intracellular digestion.
Describe a peroxisome.
Oxidative enzymes that form free radicals to destroy certain substances. Detoxification, degrades hydrogen peroxide.
Describe a proteasome.
Small, barrel shaped organelles that degrade cytosolic proteins.
What are the three types of cytoskeletal elements?
1) microfilaments
2) intermediate filaments
3) microtubules
What are histones?
a protein that provides structural support for a chromosome, associated strongly with DNA.
What is chromatin?
complex of DNA and histones.
What is a nuclear pore?
permit exchange (“communication”) between the nucleus and the cytoplasm, transfer of signals.
What is an endothelium?
a thin membrane that lines the inside of the heart and blood vessels
What is cristae?
a fold in the inner membrane of a mitochondrion
What are the four basic tissues in the body?
- Epithelium
- Connective tissue
- Muscle tissue
- Nervous tissue
What are the three basic components of connective tissue?
- Fibers
- Cells
- Matrix (ground substance)
What are the three types of connective tissue fibers?
- Collagenous (most abundant)
- Elastic
- Reticular
What is loose connective tissue?
low fiber density, contains spaces that can be filled with fat or fluid.
What is dense irregular connective tissue?
high density of collagen fibers, oriented in different directions. Chief cells are fibroblasts.
Ex. adhesions. (found in dermis of skin, periosteum, etc.)
What is dense regular connective tissue?
high density of collagen fibers arranged in parallel bundles, forming sheets, bands, or cords. (found in tendons and ligaments)
What is the primary cell type?
Fibroblasts
