Bio2020 Midterm 2

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Bio2020 Midterm 2
2014-05-16 23:57:18
Bio2020 Midterm
Bio2020 Midterm 2
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  1. Autonomic Nervous System (ANS)
    Consists of what?
    Also called what?
    • - consists of motor neurons that Innervate smooth and cardiac muscle and glands; make adjustments to ensure optimal support for body activities; operate via subconscious control.
    • - Also called involuntary nervous system or general visceral motor system.
  2. Somatic vs. Autonomic Nervous systems.
    Both have what?
    How do they differ?
    • - both have motor fibers (carry signals to muscles or glands.)
    • - Differs in effectors, efferent pathways and ganglia, target organ responses to neurotransmitters.
  3. Effectors.

    What does the somatic nervous system control?
    • - Skeletal muscles.
    • - Cardiac, smooth muscles and glands.
  4. Efferent Pathways and Ganglia. 
    What happens in the somatic nervous system (monosynaptic)?
    What happens in the ANS pathway?
    • - cell body in CNS; axons extend in spinal or cranial nerve to skeletal muscle.
    • - ANS pathway uses two-neuron chain (disynaptic)
    • 1. Preganglionic neuron (in CNS) has a thin, lightly myelinated preganglionic axon.
    • 2. Postganglionic (ganglionic) neuron in autonomic ganglion outside CNS has nonmyelinated postganglionic axon that extends to effector organ.
  5. Neurotransmitter Effects.
    What happens in the somatic nervous system.
    What happens in the ANS?
    - all somatic motor neurons release acetycholine  (ACh); Effects always stimulatory (excitatory).

    • - Preganglionic fibers release ACh. Postganglionic fibers release norepinephrine or ACh at effectors.
    • Effect is either stimulatory or inhibitory, depending on type of receptors.
  6. Divisions of the ANS. 
    Has two types of division.
    Define Dual Innervation.
    • - Sympathetic division and Parasympathetic division.
    • - Dual innervation : all visceral organs served by both division, but cause opposite effects.

    - Dynamic antagonism between two divisions maintains homeostasis.
  7. Role of the Parasympathetic Division. 
    What does it promote?
    - maintenance activities and conserves body energy. Directs digestion, diuresis (food levels) and defecation.

    • - As in person relaxing and reading after a meal:
    • Blood pressure, heart rate, and respiratory rates are low; Gastrointestinal tract activity high; Pupils constricted, lenses accommodated for close vision.
  8. Role of the Sympathetic division. 
    What does it do?
    Examples include.
    What happens during vigorous exercise?
    • - mobilizes body during activity; "fight-or-flight" system.
    • - Exercise, excitement, emergency, embarrassment. Increased heart rate, dry mouth, cold, sweaty skin; dilated pupils.
    • - Shunts blood to skeletal muscles and heart; dilates bronchioles (increased ventilation); Causes liver to release glucose (accommodates increased energy needs.)
  9. Interactions of the Autonomic Divisions.
    What mostly have dual innervation?
    What does dynamic antagonism allow at Sympathetic and Parasympathethic division.
    • - most visceral organs.
    • - allows for precise control of visceral activity. 
    • ~ Sympathetic division increases heart and respiratory rates, and inhibits digestion and elimination.
    • ~ Parasympathethic division decreases heart and respiratory rates, and allows for digestion and discarding of wastes.
  10. Control of ANS function.
    What's the purpose of the hypothalamus?
    Location wise?
    Where do other controls come from?
    • - hypothalamus : main integrative center of ANS activity.
    • - Subconscious cerebral input via limbic system structures on hypothalamic centers.
    • - other controls come from cerebral cortex, reticular formation, and spinal cord.
  11. Hypothalamic Controls.
    Two types of control?
    What does the centers of hypothalamus control?
    • - direct or indirect (through reticular system)
    • - controls heart activity and blood pressure; body temperature, water balance and endocrine activity; emotional stages (rage, pleasure) and biological
  12. Special Senses.
    Special sensory receptors are in charge of which types of sense?
    - vision, taste, smell, hearing, equilibrium.
  13. The eye and vision.
    % of receptors in the eye?
    Where is the visual processing is done by what?
    How is the eye mostly protected by?
    • - 70% of body's sensory receptors in eye.
    • - Visual processing by ~ half cerebral cortex.
    • - Most of eye protected by cushion of fat and bony orbit.
  14. Accessory structures of the Eye.
    What helps Protect the eye and aid eye function?
    • - Eyebrows
    • - Eyelids (palpebrae)
    • - Conjunctiva 
    • - Lacrimal apparatus
    • - Extrinsic eye muscles
  15. Light and Optics : Wavelength and Color.
    How do the eyes respond to visible light?
    What is light?
    • - small portion of electromagnetic spectrum with wavelength of 400-700 nm.
    • - Packets of energy (photons or quanta) that travel in wavelike fashion at high speeds. Color of light objects reflected determines color eye perceives.
  16. The chemical senses : Smell and Taste.
    a.k.a what? 
    What do chemoreceptors responds to what?
    • - Olfaction and Gustation.
    • - responds to chemicals in aqueous solution.
  17. Physiology of Smell.
    • - Gaseous odorant must dissolve in fluid of olfactory epithelium.
    • - Activation of olfactory sensory neurons (Dissolved odorants bind to receptor proteins in olfactory cilium membranes.)
  18. Taste Buds and the Sense of Taste.
    What's another way to say taste buds?
    - Receptor organs are taste buds.

    • Most of 10,000 taste buds on tongue papillae. 
    • On tops of fungiform papillae. On side walls of foliate and vallate papillae.
    • - Few on soft palate, cheeks, pharynx, epiglottis.
  19. What are the five basic taste sensations?
    - Sweet, sour, salty, bitter, Umami
  20. Physiology of taste.
    To taste, chemicals must... (3)
    • - be dissolved in saliva.
    • - Diffuse into taste pore.
    • - Contact gustatory hairs.
  21. Activation of Taste Receptors.
    What depolarizes what and what gets released?
    What is initiated?
    Which receptors are the most sensitive?
    • - Binding of food chemical (tastant) depolarizes taste cell membrane -> neurotransmitter release. 
    • - Initiates a generator potential that elicits an action potential.
    • - Different thresholds for activation. Bitter receptors are the most sensitive.
  22. Role of Taste.
    What does it trigger?
    What does it increase?
    What can it protect against?
    • - reflexes involved in digestion.
    • - Secretion of saliva into mouth and increases secretion of gastric juice into stomach.
    • - May initiate protective reactions like gagging and reflexive vomiting.
  23. Influence of other Sensations on Taste.
    • - taste is 80% smell.
    • - Thermoreceptors, mechanoreceptors, nociceptors in mouth also influence tastes. 
    • - Temperature and texture enhance or detract from taste.
  24. The Ear : Hearing and Balance.
    There are 3 major areas of the ear.
    • 1. External (outer) ear : hearing only.
    • 2. Middle ear (tympanic cavity) : hearing only.
    • 3. Internal (inner) ear : hearing and equilibrium. 
    • - Receptors for hearing and balance respond to separate stimuli.
    • - Are activated independently.
  25. Properties of sound. 
    Sound is...?
    Sound waves move...?
    Define Frequency.
    Define Wavelength.
    • - pressure disturbance (alternating areas of high and low pressure) produced by vibrating objects.
    • - Moves outward in all directions and illustrated as an S-shaped curve or sine wave.
    • - Number of waves that pass given point in given time. Pure tone has repeating crests and troughs.
    • - Distance between two consecutive crests. Shorter wavelength = higher frequency of sound.
  26. Properties of sound.
    Define Pitch.
    Define Quality.
    Define Amplitude.
    Define Amplitude perceived as loudness.
    • - Perception of different frequencies. Normal range 20-20,000 hertz (Hz). Higher frequency = higher pitch.
    • - Most sounds mixtures of different frequencies. Richness and complexity of sounds (music)
    • - Height of crests.
    • - Subjective interpretation of sound intensity. Normal range is 0-120 decibels (dB). Severe hearing loss with prolonged exposure above 90 dB.
  27. Blood Composition.
    What's blood?
    What's plasma?
    Which elements form blood? (3)
    • - fluid connective tissues.
    • - non living fluid matrix.
    • - living blood "cells" suspended in plasma. 
    • 1. Erythrocytes (red blood cells, or RBCs)
    • 2. Leukocytes (white blood cells, or WBCs)
    • 3. Platelets.
  28. Blood Composition.
    Spun tube of blood yields three layers...?
    What's Hematocrit?
    • - 1. Plasma on top (~55%).
    • 2. Erythrocytes on bottom (~45%).
    • 3. WBCs and platelets in Buffy coat (<1%)
    • - Hematocrit : percent of blood volume that is RBCs. 47% - 5% for males; 42% - 5% for females.
  29. Physical Characteristics and Volume.
    Describe blood.
    How does the color vary? 
    What's the average volume for Males and Females?
    • - sticky, opaque fluid with metallic taste.
    • - High O2 = scarlet; Low O2 = dark red
    • - 5-6L for males; 4-5 for females.
  30. Functions of blood.
    • - Distributing substances.
    • - Regulating blood levels of substances.
    • - Protection.
  31. Distribution Functions.
    Delivers what to the body?
    Transports what?
    • - O2 and nutrients to the body cells.
    • - Transports metabolic wastes to lungs and kidneys for elimination and transports hormones from endocrine organs to target organs.
  32. Regulation Functions.
    What can it maintain and how? (3)
    • - maintains body temperature by absorbing and distributing heat.
    • - Maintains normal pH using buffers alkaline reserve of bicarbonate ions.
    • - Maintains adequate fluid volume in circulatory system.
  33. Protection Functions. 
    Prevents what? (2)
    • - Prevents blood loss : plasma proteins and platelets initiate clot formation.
    • - Prevents infection using antibodies, complement proteins and WBCs.
  34. Blood Plasma. 
    % of water?
    What else makes up the plasma?
    Which are the most abundant solutes? Where does it remain in, how are proteins mostly produced by?
    • - 90% water.
    • - Nutrients, gases, hormones, wastes, proteins, inorganic ions.
    • - Plasma proteins. Remains in blood; not taken up by cells. Mostly produced by liver.
  35. Formed Elements. 
    What are the only complete cells?
    What's special about the RBCs?
    What are platelets? 
    How long do most formed elements survive in blood stream?
    • - only WBCs.
    • - have no nuclei or other organelles.
    • - cell fragments.
    • - Only few days.
  36. Erythrocytes.
    Describe it.
    Filled with what?
    What's its main function?
    • - Red blood cells
    • - Biconcave discs, anuclate. 
    • - Filled with hemoglobin (Hb) for gas transport.
    • - Major factor contributing to blood viscosity.
  37. Erythrocytes. 
    Why is the structural characteristics helpful when contributing to gas transport?
    - Biconcave shape provides huge surface area relative to volume. >97% hemoglobin (not counting water). No mitochondria; ATP production anaerobic; does not consume O2 they transport.
  38. Erythrocyte Function. 
    What the purpose of RBCs?
    Relationship of hemoglobin and oxygen?
    • - RBCs dedicated to respiratory gas transport.
    • - Hemoglobin binds reversibly with oxygen.
  39. Hemoglobin (Hb).
    What gets produced while O2 is being loaded into the lungs?
    What gets produces while O2 is unloading in tissues?
    Each hemoglobin can transport how many oxygen atoms?
    • - Produces oxyhemoglobin (ruby red)
    • - Produces deoxyhemoglobin (dark red)
    • - 4 O2 atoms.
  40. Hematopoiesis. 
    Where is it found at?
    What are hematopoietic stem cells? 
    What's erythropoiesis?
    • - Blood cell formation in red bone marrow.
    • - In adult, found in axial skeleton, girdles, and proximal epiphyses of humorous and femur.
    • - a.k.a hemocytoblasts. Gives rise to all formed elements. Committed cells cannot change.
    • - Red blood cell production.
  41. Regulation of Erythropoiesis.
    What causes hypoxia?
    What causes increases blood viscosity?
    What does the balance between RBC production and destruction depend on?
    • - Too few RBCs
    • - Too many RBCs
    • - Hormonal controls and adequate supplies of iron, amino acids, and B vitamins.
  42. Fate and Destruction of Erythrocytes.
    What's its lifespan?
    What happens to old RBCs?
    Where do they end up in?
    Where/how are RBCs "destroyed"?
    • - 100 to 120 days
    • - Old RBCs become fragile; Hb behind to degenerate
    • - Gets trapped in smaller circulatory channels especially in spleen.
    • - Macrophages engulf dying RBCs in spleen.
  43. Erythrocyte Disorders.
    What's Anemia?
    Symptoms include?
    What causes it? (3)
    • - blood has abnormally low O2 carrying capacity.
    • - Blood O2 levels cannot support normal metabolism.
    • - Accompanied by fatigue, pallor, shortness of breath and chills.
    • - Blood loss; Low RBC production; high RBC destruction.
  44. Leukocytes. 
    Makes up % of blood volume?
    What's leukocytosis?
    • - less than 1%
    • - defense against disease. 
    • - when WBC count over 11,000/mm3 (Normal response to infection.)
  45. Platelets. 
    What is it?
    How long do they last?
    Normal range?
    • - cytoplasmic fragments of megakaryocytic.
    • - acts in clotting process. Forms temporary platelet plug tat helps seal breaks in blood vessels. 
    • - Circulating platelets kept inactive and mobile Age quickly; degenerate in about 10 days. 
    • - Normal = 150k to 400k platelets/ml of blood.
  46. Hemostasis.
    What is it?
    What three steps does it include?
    - Fast series of reactions for stoppage of bleeding.

    • - 1. Vascular spasm : direct injury to vascular smooth muscle. Triggered by injury, pain reflex and chemicals released by endothelial cells and platelets. Pain reflexes. 
    • 2. Platelet plug formation : platelets (cell fragments) stick to collagen fibers. Swells and becomes spiked and sticky and release chemical messengers.
    • 3. Coagulation (blood clotting) : Fibrin forms a mesh that traps red blood cells and platelets, forming the clot.
  47. Urinary System.
    What do kidneys do?
    Maintains wha?
    Produces wha?
    • - excrete metabolic waste and other substances.
    • - Maintains total water volume/balance, total solute concentrate in water. Maintains acid-base balance.
    • - Produces molecules like Renin (regulates blood pressure) and Erythropoietin (regulates RBC production)
  48. Kidney location and external anatomy.
    Where's it located at?
    What 3 layers is it supported by?
    • - from T12 to L3
    • - 1. Renal Fascia : anchors kidneys & adrenal gland to surrounding structures.
    • 2. Perirenal fat capsule : fatty mass, provides cushioning.
    • 3. Fibrous capsule : prevents infections from spreading to the kidneys.
  49. Kidney Anatomy

  50. Anatomy of the nephron.
    What's the renal corpuscle consist of?
    What's the renal tubule consist of?
    • - Renal corpuscle : glomerulus, glomerular capsule (Bowman's capsule)
    • - Renal tubule : proximal convolutes, nephron loop, distal convoluted.
    • - Collecting ducts.
  51. Anatomy of the nephron : Renal Corpuscle.
    The glomerulus has what?
    What's the Bowman's capsule?
    • - Tuft of capillaries with fenestrated (having a window) endothelium. Very porous - large amount of filtrate passes from blood into the capsule.
    • - Cup-shaped, hollow structure surrounding glomerulus.
  52. Anatomy of the nephron : Renal tubule
    • - Proximal convoluted tubule.
    • - Nephron loop (loop of Henle) 
    • - Distal convoluted tubule.

  53. Anatomy of the Nephron : Collecting dust.
    Receives what?
    Runs through where?
    How does it deliver urine?
    • - filtrate from many nephron.
    • - Runs through medullary pyramids and are responsible for their striped appearances.
    • - As the collecting ducts approach the renal pelvis, they fuse together and deliver urine into the minor calyces vie papillae of the pyramids.
  54. Classes of Nephrons.
    What are the cortical nephrons? Makes up % of nephrons? Located where and what's the exception?

    What are the juxtamedullary nephrons?
    - Cortical nephrons : makes up 80% nephrons. except for the small parts of their nephron loops that dip into the outer medulla, they are located entirely in the cortex.

    - Juxtamedullary nephrons : long nephron loop. Glomerulus closer to cortex-medulla junction. Important in production of concentrated urine.
  55. Mechanisms of urine formation. What are the three major steps?
    • - Glomerular filtration : produces cell and protein free filtrate.
    • - Tubular reabsorption : selectively returns 99% of substance form filtrate of blood in renal tubules and collecting dusts.
    • - Tubular secretion : selectively moves substances from blood to filtrate in renal tubules and collecting ducts.
  56. Mechanisms of urine formation : Glomerular filtration. 
    What type of process is it?
    What forces what through where?
    There is no...?
    • - Passive process - no metabolic energy required. 
    • - Hydrostatic pressure forces fluids and solutes through filtration membrane. 
    • - No reabsorption into capillaries of glomerulus.
  57. The filtration membrane of the glomerular capsule.
    What is it; what can pass and what usually doesn't pass?
    What are the three layers?
    • - porous membrane between blood and interior of glomerular capsule. Water, solutes smaller than plaza proteins pass; normally no cells pass.
    • - Three layers :
    • Fenestrated endothelium (allows blood components except blood to pass);
    • Basement membrane(forms a physical barrier);
    • Foot processes of podocytes (if any macromolecules manage to pass through, prevents them from traveling any further.)
  58. Mechanisms of urine formation : Tubular reabsorption. 
    What does it do?
    What type of process? Why?
    What two things can the reabsorption process be?
    • - Process that reclaims most of the tubule contents and returns them to the blood.
    • - Selective process : Virtually all organic nutrients (e.g., glucose, amino acids) reabsorbed. Water and ion reabsorption regulated in response to hormonal signals.
    • - Reabsorption processes may be active or passive.
  59. Mechanisms of urine formation : Tubular reabsorption. 
    What happens molecularly?
    • - Most active reabsorbs (all glucose and aa, 65% of the Na+ and water)
    • - Na+ is actively pumped into interstitial fluid (Na+ / K+ pump) - creates an electrochemical gradient.
    • - Cl-, K+, Ca2+ and other ions move via diffusion.
  60. Mechanisms of urine formation : Tubular reabsorption. 
    What's proximal convoluted tubule?

    When does obligatory water reabsorption happen? What about facultative water reabsorption.
    • - Water reabsorbed by osmosis, aided by water-filled pores called aquaporins.
    • - Obligatory water reabsorption: occurs in PCT, where aquaporins are always present.
    • - Facultative water reabsorption : occurs in collecting ducts only if ADH is present.
  61. Mechanisms of urine formation : Tubular reabsorption. 
    What's happens in the nephron loop.
    • - Water can leave the descending loop, but not the ascending loop (lacks aquaporins). 
    • - Opposite is true for solutes - no reabsorption in descending, active and passive in ascending.
  62. Mechanisms of urine formation : Tubular reabsorption. 
    What is distal convoluted tubule and collecting tubule.
    • - reabsorption varies with the body's needs.
    • - Fine tuned by hormones (e.g. ADH which makes the collecting ducts more or less permeable to  water, Aldosterone which fine-tunes reabsorption of the remaining Na+)
  63. Mechanisms of urine formation : Tubular Secretion
    This is the movement from where?
    What does the urine contain?
    What is PCT and what are also active?
    • - Movement of selected substances from peritubular capillaries into the filtrate.
    • - Urine contains both filtered and secreted substances.
    • - PCT is the main site of secretion, but cortical parts of the collecting duct are also active.
  64. Countercurrent multiplier.
    • - Descending limb : freely permeable to H2O. H2O passes out of filtrate into hyper osmotic medullary interstitial fluid.
    • - Ascending limb : permeable to H2O. Selectively permeable to solutes (Na+ and Cl- actively reabsorbed in thich segment; some passively reabsorbed in thin segment.)
  65. Countercurrent exchanger. 
    What is the vasa recta highly permeable to? 
    Why does this happen?
    What happens to the osmotic gradient during this time?
    • - Vasa recta is highly permeable to both water and solutes.
    • - Due to counter current exchanges between each section of the vasa recta and the surrounding interstitial fluid, blood remains nearly isoosmotic. 
    • - Osmotic gradient is preserved as they remove reabsorbed water and solutes.
  66. Collecting ducts use gradient.
    What does it do? 
    What is it under the control of?
    • - The collecting ducts determine the final concentration and volume of urine.
    • - Under the control of ADH.
  67. The Endocrine System : Overview
    • - Acts with nervous system to coordinate and integrate activity of body cells.
    • - Influences metabolic activities via hormones transported in blood.
    • - Response slower but longer lasting than nervous system. 
    • - Endocrinology : study of hormones and endocrine glands.
    • - Controls and integrates reproduction; growth and development; maintenance of electrolyte, water and nutrient balance of blood; Regulation of cellular metabolism and energy balance; mobilization of body defenses.
  68. Endocrine System. 
    Exocrine vs endocrine glands?
    • - Exocrine : non-hormonal substances (sweat, saliva.) Have ducts to carry secretion to membrane surface.
    • - Endocrine : produces hormones and lacks ducts.
  69. Chemical Messengers.
    Define hormones, autocrines and paracrines.
    • - Hormones : long-distance chemical signals; travel in blood or lymph.
    • - Autocrines : chemicals that exert effects on same cells that secrete them.
    • - Paracrines : Locally acting chemicals that affect cells other than those that secrete them.

    - Autocrines and paracrines are local chemical messengers; not considered part of endocrine system by all physiologists.
  70. Mechanisms of Hormone Action.
    What does hormone action on target cells do after what?
    What does it stimulate and what happens to enzymes?
    • - Alter plasma membrane permeability an/or membrane potential by opening or closing ion channels.
    • - Stimulate synthesis of enzymes or other proteins.
    • - Activate or deactivate enzymes.
    • - Induce secretory activity.
    • - Stimulate mitosis.
  71. Target Cell Specificity.
    What must they have?
    Where are ACTH found in?
    Where are thyroxin receptors found in?
    • - Target cells must have specific receptors to which hormone binds, for example. 
    • - ACTH receptors found only on certain cells of adrenal cortex.
    • - Thyroxin receptors are found on nearly all cells of body.
  72. Target Cell Activation. What three factors do they depend on?
    - Target cell activation depends on three factors: Blood level of hormone; relative number of receptors on or in target cell; affinity of binding between receptor and hormones.
  73. Target Cell Activation.
    What are the types of regulation?
    • - Up-regulation : target cell form more receptors in response to low hormone levels.
    • - Down-regulation : target cells lose receptors in response to high hormone levels.
  74. Control of Hormone Release. 
    How are blood levels of hormones controlled and how do they vary?
    Where are 3 ways that the endocrine gland is stimulated to synthesize and release hormones in response to...?
    • - Controlled by negative feedback systems and varies only within narrow, desirable range. 
    • - Humoral, Neural and Hormonal stimuli.
  75. Humoral Stimuli.
    What causes the stimulation of secreting hormones?
    Give an example.
    • - Changing blood levels of ions and nutrients directly stimulate secretion of hormones.
    • - Example : Ca2+ in blood. Declining blood Ca2+ concentration stimulates parathyroid glands to secrete PTH (parathyroid hormone.) PTH causes Ca2+ concentration to rise and stimulus is removed.
  76. Humoral Stimuli 

    What is the stimulus and what is the response?
    Stimulus : low concentration of Ca2+ in capillary blood.

    Response : Parathyroid glands secrete parathyroid hormone (PTH), which increases Ca2+.
  77. Neural Stimuli. 

    - Nerve fibers stimulate hormone release. Symphathetic nervous system fibers stimulate adrenal medulla to secrete catecholamines. 

    • - Stimulus : action potentials in preganglionic sympathetic fibers to adrenal medulla.
    • - Response : Adrenal medulla cells secrete epinephrine and norepinephrine.
  78. Hormonal Stimuli.
    What happens here?
    hypothalamic wise?
    Anterior pituitary wise?
    • - Hormones stimulate other endocrine organs to release their hormones. 
    • - Hypothalamic hormones stimulate release of most anterior pituitary hormones.
    • - Anterior pituitary hormones stimulate targets to secrete still more hormones.
    • - Hypothalamic-pituitary-target endocrine organ feedback loop: hormones from final target organs inhibit release of anterior pituitary hormones.

    • - Stimulus : hormones from hypothalamus.
    • - Response : anterior pituitary gland secretes hormones that stimulate other endocrine glands to secrete hormones.
  79. Nervous System Modulation.
    What is it?
    Give an example.
    • - Nervous system modifies stimulation of endocrine glands and their negative feedback mechanisms. 
    • - Examples : under severe stress, hypothalamus and sympathetic nervous system activated; body glucose levels to rise.
  80. Pituitary gland (hypophysis) has two major lobes which are...
    • - Posterior pituitary : neural tissue.
    • - Anterior pituitary : glandular tissue.
  81. Know these hormones:

    Lecture 17