University:
Northwest College
Course:
VN 120 | Anatomy & Physiology
Academic year:

2024
Views:

271

Pages:

19
Author:

Reina H

Midterm Ch. 5 Osmolarity: number of osmotically active particles (ions or intact molecules) per liter of solution Osmolality: osmoles of solute per kilogram of water Isosmotic: 2 solutions w/ same number of solutes hyperosmotic hypo-osmotic Tonicity: how solution would affect cell volume isotonic: cell in solution does not change size in equilibrium hypertonic: cell shrinks hypotonic: cell swells permeable vs. impermeable passive transport vs. active transport passive transport simple diffusion facilitated diffusion ion channel (electrochemical) osmosis active transport ATP Vesicular transport exocytosis endocytosis phagocytosis Ficks Law of Diffusion: Factors for diffusion across membranes plus the factor of concentration gradient Membrane proteins - structural proteins enzymes receptors transport proteins Channel proteins Carrier proteins Aquaporin - water channel open channel gated channel chemically gated channel voltage-gated channel mechanically gated channel Carrier proteins Uniport carriers cotransporter symport carriers antiport carriers GLUT transporters - move glucose & related hexose sugars across membranes. Diabetes type 2 elevated insulin levels insulin resistance excercise & lose weight arterials constrict to keep warm arterials dilate to enhance heat lose / cool off sweat cools body off shivering generates heat Heat loss from the body takes place by radiation, conduction, convection, evaporation temperature homeostasis -> hypothalamus Ch. 6 communication, integration, homeostasis Local communication - gap junction allow direct signals between cells Contact-dependent signals cell membrane bind to surface molecules on another cells membrane Long-distance communication chemical/electrical signals carried by nerve cells & chemical signals transported in the blood Gap Junction cell to cell communication cytoplasmic bridge amino acids, ATP, cAMP, diffuse into cell Contact-Dependent require cell-to-cell contact (CAMs) cell adhesion molecules: cell to cell adhesions thru linkages CAMs transfer signals in both directions across cell membrane Local communication -> gap junction paracrine signal: chemical that acts on cells in immediate vicinity of cell that secreted the signal (histamine) Autocrine signal: chemical signal that acts on the cell that secreted it Long distance communication may be electrical or chemical endocrine system communicates by using hormones neurocrine molecules Neurotransmitter Cytokines Cytokines may act as both local and Long distance signals Cytokines associated primarily with immune responses, inflammation they function as autocrine & paracrine signals