BIO midterm

Question Answer
Plasma membrane defines the boundary of a cell
Plasma membrane contains membrane lipids: phospholipids(form basic structure or cell membrane:lipid bilayer); cholesterol(affects membrane fluidity); glycolipidsproteins: gives membranes specific functional abilities
Tight junctions membrane junction; impermeable;bind cells into leak proof sheets;limit passage of molecules & ions; block movements of essential membrane proteins
Desmosome junctions proteins packed; anchoring junctions;prevent cells from being pulled apart;enable a tissue to resist mechanical stress; common in epidermis & cardiac muscle
Gap junctions formed by ring of proteins;ions, glucose, amino acids & other small solutes can diffuse through channel directly form cytoplasm; human embryo & cardiac muscle
Interphase First gap (G1) phase(cell growth);Synthesis (S) phase(DNA replicated);Second gap(G2) phase
Mitosis division of nucleus; results in formation of 2 daughter nuclei
Prophase centrioles migrate to poles to direct assembly of mitotic spindle fibers; DNA appears as double stranded chromosomes; nuclear envelope breaks down & disappears
Metaphase chromosomes lie along midline of cell; some spindle fibers attach to centromeres & others to plasma membrane
Anaphase centromeres divide in two; spindle fibers pull sister chromatids to opposite poles of cell; each pole(future daughter cell) now has 2 identical set of genes
Telophase chromosomes gather @ each pole of cell; chromatin decondenses; new nuclear envelope appears @ each pole; new nuclei appear in each nucleus; mitotic spindle vanishes
Membranes cutaneous(skin);mucous;serous;synovial
Cutaneous dry membrane; outermost protective boundary; superficial epidermis composed of keratinized stratified squamous epithelium; underlying dermis mostly connective tissue
Mucous line tracts of body that open to exterior environment(digestive,respitory, urinary, reproductive);stratified squamous epithelium(mouth, esophagus); simple columnar epithelium( rest of digestive tract);underlying loose connective tissue; absorption/secreti
Serous surface layer is simple squamous;underlying layer is thin layer of areolar connective tissue;lines open body cavaties;occur in pairs separated by serous fluid(covers outside of organ)
Serous membranes peritoneum(abdominal cavity); pleura(lungs);pericardium(heart)
Synovial connective tissue only;lines fibrous capsules surrounding joints; secretes synovial fluid(lube)
Skin protects from mechanical damage(bumps);chemical damage(acids&bases);bacterial(dryness of skin&acid mantle);ultra violet radiation(sunlight);thermal damage(heat or cold);dessication(drying out)
Epidermis stratified squamous; keratinized to prevent water loss;avascular;most cells keratinocytes
Stratum corneum 30 layers of dead cells; first layer of and for protection
Stratum lucidum present only in thick skin(soles&plams);thin, clear(lucid) dead cells of deeper strata
Stratum granulosum 3-5 layers of flat keratinocytes w/ coarse dark staining granules; resists water loss; cells die here
Stratum spinosum thickest layer of keratinocytes and deadrites
Stratum basale deepest layer; lies next to dermis; wavy borderline w/ dermis anchoring them together; cell undergoing mitosis; daughter cells pushed upward to become more superficial layers; melanocytes(pigment) color is yellow to brown or black
Dermis dense connective tissue; collagen & elastic fibers located throughout(collagen gives skin toughness; elastic gives skin elasticity);blood vessels play role in body temp regulation
Dermal layer papillary layer(upper dermal layer)-projections called dermal papilla& some contain papillary loops(negative feedback; others house pain & touch receptors
Dermal layer reticular layer-blood vessels;sweat & oil glands; deep pressure receptors
Why do we tan in sun? melanin screens UV rays;melanocytes accelerate their production of melanin to protect from DNA mutations;keratinocytes concentrate in the sunnyside of the nucleus like a parasol over DNA
Sebaceous gland located next to hair root; sebum secretion
Melanin normal skin;yellow, brown or black pigments
Carotene normal skin;orange-yellow pigment from some veggies
Hemoglobin red coloring from blood cells in dermal capillaries ;oxygen content determines the extent of red coloring
Cayanosis blueness; oxygen deficiency in blood
Erythema redness in skin due to embarrassment, inflammation, hypertension, fever, allergy
Pallor pale or ashen skin due to emotional stress, anemia, low BP, impaired blood flow to area
Jaundice yellowing of skin, whites of eyes or nails due to liver disorder
Hematoma bruise
Eccrine gland opens via duct to pore on skin; produces sweat(clear)
Apocrine gland ducts empty to hair follicules; sweat contain fatty acids & protein(milky)
Sweat composition water;salts & vitamin c;some metabolic waste, fatty acids & protein
Sweat function helps dissipate excess heat; excretes waste products; acidic nature inhibits bacteria growth
Central medulla central core of thick hair; composed of loosely arranged cells and air spaces
Hair cortex surrounds medulla; beneath cuticle; makes up most of hair; several layers of elongated keratinized cells
Hair cuticle surface layer of hair; thin scaly cells that overlap each other
Arrector pilli smooth muscle; pulls hair up right
Hair shaft hair portion above surface
Hair root all hair below surface
Hair bulb lower end of hair root
Dermal papilla grows into bulb;provides hair w/ sole source of nutrition
Hair matrix above dermal papilla; site of cellular mitosis & hair growth
Nail structure scale like modifications of epidermis; stratum basale extends beneath nail bed
Free edge extends beyond tip of finger
Nail plate visible portion covering fingertip
Nail bed the epidermis underlying plate
Nail fold cuticle
Nail matrix growth zone
Dangers of burns dehydration;electrolyte imbalance;circulatory shock
First degree burns only the epidermis;skin red and swollen
Second degree burns epidermis & upper dermis are damaged; skin red & blisters
Third degree burns destroys entire skin layer; painless burned area;burn is gray-white or black
Critical burns over 25% of body has 2nd degree burns; over 10% of bod has 3rd degree burns; 3rd degree burns on hands, hands and feet
Infections athletes foot(tinea pedis)-fungal infection;boils and carbuncles-bacterial infection;cold sores-virus
Infections and allergies contact dermatitis-allergic reaction;impetigo-bacterial infection;psorisis-cause unknown, triggered by trauma, stress, infection
Skin cancer abnormal cell mass;benign(doesn't spread;encapsulated);malignant(moves to other parts)
Basal cell carcinoma least malignant;most common;arises from stratum basale
Squamous cell carcinoma metastasizes to lymph nodes;good chance if removed early;sun induced;from stratum spinosum
Malignant melanoma deadliest;cancer of melanocytes;metastasizes rapidly to lymph nodes & blood vessels
ABCD rule of skin cancer asymmetry; border irregularity;color;diameter
Bleeding 1st part of skin healing
Inflammation 2nd part of wound healing;mast cells(injured cells) release histamine(dilates capillary permeability) so immune cells(WBC) can enter tissue; platelets create clot for scab
Formation of scar tissue 3rd part of wound healing;granulation tissue-fibroblasts will lay down collagen to sew edges of wound; platelets release growth factor to grow blood capallaries
Epithelial regeneration and underlying connective tissue fibrosis end of wound healing; left w/ scar
Skeletal system bones, joints, cartilages, ligaments; axial & appendicular
Functions of bones support the body;protects organs;allows movement due to skeletal muscles; stores minerals & fats-calcium & phospherus & fat in internal marrow cavity;blood cell formation(hematopoeisis)
Spongy bone porous lattice of slender rods & plates called trabeculae;between trabeculae lies bone marrow & small blood vessels
Compact bone dense;forms outer shell of spongy bone; parallel layers laid by osteoblasts;osteons;lamellae surrounds central canal; canal has small vessels & nerves; osteocytes occupy lucunae
Yellow marrow mostly fat; happens when older; replaces red marrow; dominates long bone
Long bones longer than wide;shaft w/ heads @ both ends; mainly compact; ex: humerus, ulna, tibia
Short bones wider than long;mostly spongy; ex: wrist and ankle bones
Flat bones thin, flat, sometimes curved;compact-spongy-compact;ex: ribs, skull,hipbones
Irregular fusion of many bones; ex: vertabrae, hipbones
Epiphysis ends of long bone;spongy bone
Diaphysis shaft of long bone; compact bone
Periosteum outside covering diaphysis;fibrous connective tissue membrane
Perforating(sharpeys) fibers secures periosteum to underlying bone
Arteries supply bone cells within nutrients
Articular cartilage covers external surface of ends of bone; made of hyaline cartilage;decreases friction @ joint surfaces
Epiphyseal plate hyaline cartilage on young bones
Epiphyseal line epiphyseal plate turned to bone in adults
Marrow(medullary) cavity cavity inside shaft;yellow marrow in adults;red marrow for blood cell formation
Osteoblasts form bones
Osteoclasts destroy bone;break down bone matirx by remodeling & release of calcium in response to parathyroid hormone(PTH)
Osteoblasts & osteoclasts remodel bone by blood calcium levels(PTH, vitamin D) and weight baring exercise
Osteogenic cells on bone surface;stem cells that give rise to osteoblasts; only bone cell able to divide and make more bone cells
Epiphyseal plates allow for lengthwise growth of long bones during childhood;new cartilage is continuously formed;older cartilage is ossified
Ossification of cartilage cartilage is broken down;enclosed cartilage is digested away, opening up medullary cavity;bone replaces cartilage by osteoblasts;remodeled &lengthened until growth stops(by growth hormone & sex hormones)
Bursae synovial joint-flattened fibrous sacs, lined w/ synovial membranes,filled with synovial fluid,not part of joint
Tendon sheath synovial joint -elongated bursa that wraps around tendon
Bursitis inflammation of a bursa; caused by blow or friction
Sprain damage to tendon or ligament; stretching or tearing from bone
Tendonitis inflammation of tendon sheaths
Arthritis inflammatory or degenerative diseases of joints; causes pain, stiffness, swelling of joint
Osteoarthritis cartilage is worn down; most common; related to aging
Rheumatoid arthritis autoimmune disease that attacks joints
Solution homogenous mixture of 2 or more components: ex: salt water
Solute smaller quantities in a solution;ex: the salt in the salt water
Selective permeability plasma membrane allows some materials and not others
Hypertonic solution the concentration of solutes is greater outside cell than in(more going out than in)
Isotonic solution w/ free movement of water across membrane without changing concentration of solutes
Hypotonic solution w/ less solute & more water than another
Diffusion passive transport process; particles distribute themselves evenly within a solution;movement is high to low concentration gradient
Simple diffusion passive transport;unassisted process; small fat soluble materials through membrane pores
Osmosis passive transport;simple diffusion of water; highly polar water molecules cross plasma membrane through aquaporins
Facilitated diffusion passive transport;substances require a protein carrier;transports lipid insolubles & large substances
Active transport solute pumping;amino acid, some sugars, ions transported by protein carriers(solute pumps);ATP energizes protein; moves from low to high
Endocytosis vesicular transport-extracellular substances are engulfed by being closed in membranous vesicle;phagocytosis(cell eating), pinocytosis(cell drinking)
Exocytosis vesicular transport-moves materials out of cell; carried in membrane vesicle;vesicle migrates to plasma membrane & empties out side
Osteocytes former osteoblasts;trapped in matrix they deposited;reside in lucunae; pass nutrition, wastes, chemical signals through gap junctions
Bone matrix stony matter surrounding osteocytes and lacunae; made of collagen, calcium phosphate;
Joints articulations of bone; holds bone together; allows for mobility
Synarthroses joint immovable
Amphiarthroses joint slightly movable
Diarthroses joint freely moveable
Fibrous joints generally immovable; sutures(skull), syndesmoses(distal end of tib &fib),gomphosis(teeth)
Cartilaginous joints immovable or slightly; synchrondrosis, symphysis

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