Mitosis and Ch.5 Flashcards
What phase is the cell in most of the time?
Interphase
What cells do not replicate?
Neurons and muscle cells
What happens at the end of interphase?
DNA replication
What happens during interphase?
-Centrioles duplicate
-DNA polymerase copies DNA
-Nuclear envelope encloses nucleus
-Nucleus and Nucleolus are clearly visible
-Individual chromosomes not distinguishable
What happens during prophase?
-Nuclear envelope disappears
-Centrioles migrate
-DNA supercoils
-Mitotic Spindle forms
What happens during metaphase?
-Chromosomes attach to spindles and line up midline
What happens during anaphase?
-Sister chromatids pulled to opposite sides of cell
-Sister chromatids separate
What happens during telophase?
-Nuclear envelope reappears
-Mitotic spindle disappears
-DNA uncoils
-Cytokinesis (end of mitosis); cell divided in two
Which cells do not have the same DNA?
Sperm and egg cells
How do cells differentiate?
-Some genes are turned on and some are turned off
What do stem cells do?
-Stem cell is still dividing and changes what genes it is expressing
-Cells differentiate and become specialized cell
What are the functions of the integumentary system?
-Protection
-Sensation (touch, temp, pain)
-Thermoregulation (sweating)
-Excretion (getting rid of waste products)
-Synthesis of Vitamin D
What is another name for the skin?
Cutaneous membrane
What is the outer epidermis’s name and what tissue is it made up of?
Superficial epithelium (made up of epithelial tissues)
What is in the inner dermis and what tissue is the inner dermis made up of?
-made up of connective tissues
-contains lots of fibers
-blood vessels and cutaneous receptors
Where is the hypodermis?
Underlies the skin and is not considered part of the skin
What do epithelial tissues do?
Border cells
What do connective tissues do?
Fill spaces- fibers
What are the accessory structures of the skin and where do they originate?
-Hair, nails, multicellular exocrine glands
-originate in dermis and extend through epidermis to skin surface
What is the full name for the epidermis?
Avascular stratified squamous epithelium
How do nutrients and oxygen get to the epidermis?
They diffuse from capillaries in the dermis
What are characteristics of the epidermis?
-avascular (will not bleed)
-Multiple layers of cells (stratified)
-squamous (thin and flat)
-always sloughing (shedding)
What are the characteristics of thin skin?
-grows hair
-covers most of the body
-has 4 layers of keratinocytes
What are the characteristics of thick skin and where do you find it?
-covers palms of hands and soles of feet
-has 5 layers of keratinocytes