a period between two mitotic or meiotic divisions during which the cell grows, copies its DNA, and synthesizes proteins
Sister chromatids join up to form a chromosome. You now see the nucleus get darker because the area gets denser. They join at the centromere. Spindles form from the centrioles. They form so that the chromosomes can attach to it. First and fourth bullets are important on this slide and really identify prophase. Nucleolis dissapears.
Prophase on Test
Chromosomes become visible, each with two chromatids joined at a centromere AND nuclear envelope fragments and Nucleoli disappear
Metaphase - remember "middle" Centromeres at the poles and chromosomes lined up in the "middle." The "middle" is the metaphase plate.
Chromosomes (V shaped) are pulled toward poles. Pulled to opposite poles by Mitotic Spindles. The Chromosomes are now pulled into a V shape split (once they're pulled apart, they are now chromatids.) Anaphase starts with an A. Think A for Apart. The chromosomes come apart.
Nuclear envelope reappears. Nucleoli reappear. The two sets of chromosomes uncoil back to Chromatin.
Ring of actin microfilaments contracts to form a cleavage furrow. Two daughter cells are pinched apart, each containing a nucleus identical to the original
Cells that don't go through mitosis
Does not occur in most mature cells of nervous tissue, skeletal muscle, and cardiac muscle
Three phases of DNA replication - Replication, Transcription, and Translation
Semi-Conservative nature of replication
Simply means we're conserving the sequence of the DNA when we make a copy. Each new strand ends up being a part of a new molecule.
the process of copying a section of DNA in order to make proteins
process by which the genetic code for a protein copied from DNA to a messenger RNA molecule is translated to the linear sequence of amino acids that define the protein; occurs in the cytosol with the aid of ribosomes
The DNA molecule produces two new complementary strands following the rules of basepairing. Each strand of the double helix is a template for the new strand.
Functions include protection, body temp regulation, Cutaneous Sensations, Metabolic functions, blood reservoir, and excretion
Consists of three major regions: Epidermis, Dermis, and Hypodermis
Deepest Region. Mostly adipose tissue. Not technically part of skin
The three barriers of skin
Chemical, Biological, and physical (block most water; limited penetration.)
500ml of routine, insensible perspiration per day. Increased level occurs at higher body temps
Metabolic functions of skin
Synthesis of vitamin D and chemical conversion of carcinogens and some hormones.
Excretion functions of skin
nitrogenous wastes and salts in sweat
Epidermis Tissue Type
Keratinized Stratified Squamous Epithelium
produce melanin pigment. Found in epidermis.
Dermis Tissue Type
Strong, flexible connective tissue. Cells include fibroblasts, macrophages, and white blood cells. Two layers: papillary and reticular
Areolar connective tissue with collagen and elastic fibers.
80% of the thickness of dermis. Collagen fibers provide strength while elastic fibers provide stretch-recoil.
the process by which skin cells are created at the stratum basale and they move up through the stratum corneum (2 weeks)
Widely distributed glands, most develop from hair follicles. Become active at puberty. Produce Sebum. Softens hair and skin.
Two types: Eccrine and Apocrine
Sweat glands: abundant on palms, soles, and forehead. Function for thermoregulation
Confined to axillary and anogenital areas. Secrete sebum. Ducts connect to hair follicles.
Most superficial, "horn-like" cornified or keratinized, 15-30 layers flat and dead, 15-30 days from stratum basale then 10-14 days until lost, tightly connected
Skin Cancer Risk Factors
Overexposure to UV. Frequent irritation of skin.
Basal Cell Carcinoma
Least malignant, most common form of skin cancer. 80% of skin cancers. Shiny dome-shaped nodules. Central ulcer with pearly beaded edge. Slow growing.
Squamous cell carcinoma
second most common form of skin cancer. Grows rapidly and metastisizes. scalp, ears, and lower lip, and hands.
most dangerous. highly metastatic and resistant to chemo. about 1/3 develop from existing moles. Involves melanocytes.
Asymetrical, Border Irregularity, Color, Diameter
two sides of the pigmented spot or mole do not match
Borders exhibit indentations
Pigmented spot contains multiple colors
Skin spot larger than 6mm in diameter.
First degree burn
involves only epithelium; redness, heat (i.e. sunburn)
Second degree burn
destroys the epidermis and part of the dermis; characterized by pain, blisters, swelling, and discoloration.
Third degree burn
a burn involving all layers of the skin, characterized by destruction of the epidermis and dermis with damage or destruction of the subcutaneous tissue
dense, hard layers of bone tissue that lie underneath the periosteum. Holds the osteons.
much less dense than compact bone; made of interconnecting spicules (trabeculae); cavities between the spicules filled with yellow or red bone marrow
the irregular latticework of thin bony plates in spongy bone tissue. No osteons.
found in compact bone. Weight bearing, column-like matrix tubes, Concentric rings made up of groups of hollow tubes of bone matrix
Central Canal (Haversian)
contains blood vessels and nerves inside compact bone
small spaces between the lamellae which contain osteocytes
hairlike canals that connect the lacunae to each other and the central canal
a dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles
membrane lining the medullary cavity of a bone
Short Bone Examples
Carpals and Tarsals
special type of short bone that forms in tendons; ex: patella; purpose is to alter direction of pull of a tendon
thin, flat, slightly curved. , bones of the ribs, shoulder blades, pelvis, sternum and skull
Vertebra and hip
Joint surfaces (hyaline cartilage.)
cavity within the shaft of the long bones filled with bone marrow, Hollow Center / Children - red bone marrow / adult - yellow bone marrow (fat)
growth zone between epiphysis and diaphysis during development of a long bone
inner most layer of periosteum that consists of stem cells giving rise to osteoblasts
nearly all bones completely ossified by age 25. Hardening of cartilages into bone.
Factors that influence epiphyseal plate
hormones, testosterone, estrogen, thyroid hormones
Five bones: Frontal, sphenoid, ethod and paired maxillary bones. They cluster around the nasal cavity. Allow for two way street of air and mucus.
Areas where the infant's skull has not fused together; usually disappear at approximately 18 months of age.The soft spots in the skull of a newborn and infant where the sutures of the skull have not yet grown together