What is the chemical composition of bone?
- 45% ash
- 35% organic matter
- 20% water
What role do osteoblasts play?
Synth/secretion of proteins to form org. matrix
What are osteocytes?
- Osteoblasts entrapped within bone matrix
- Revert back to osteoblasts as bone matrix dissolves
What role do osteoclasts play?
Resorption of bone - macrophage of bone tissue
What are chondrocytes?
Cells that form cartilage
What is the periosteum?
Membrane that lines outer surface of bone
How do bones grow in diameter?
Deposition of new bone by cells withing the periosteum
What is odontogenesis?
What are the stages of tooth development?
- Thickening of oral epithelium, invaginates into mesenchyme
- Bud stage - mesenchyme condenses, tooth bud formed
- Cap stage - cell proliferation/differentiation
- Bell stage - bud takes on diff shape, composition changes
- Crown stage - calcification
What are the steps of bone remodeling?
What 3 hormones regulate calcium in the body?
- PTH - parathyroid hormone
- CT - calcitonin
- Vit D
What role does PTH play in Ca homeostasis?
- Increase Ca absorption/resorption from bone, GIT, kidneys
- Increase P resorption from bone
- Increase synth of vit D3
What role does CT play in Ca homeostasis?
- Decrease bone resorption
- Increase renal excretion of Ca
- Indirectly decrease GI activity
What role does vit D play in Ca homeostasis?
- Increase GIT Ca absorption
- Increase bone resorption
What 3 systems regulate pH in the blood stream?
- Intracellular/extracellular buffers
What 3 proton transport systems are present in the kidney proximal tubule?
- Na/H exchanger
- H/ATPase pump
- H,K/ATPase pump
What are intercalated cells specialized for?
What causes respiratory acidosis/alkalosis?
- Resp Acidosis - build up of CO2 (hold breath)
- Resp Alkalosis -depletion of CO2 (panting)
What is an example of metabolic acidosis/alkalosis?
- Met Acidosis - loss of bicarb due to diarrhea
- Met Alkalosis - Vomiting
What are some processes that are affected by circadian rhythm?
- Sleep/wake cycle
- Metabolism & Body Temp
- Locomotor Activity
- Pheromone Release
What 2 hormones are related to circadian rhythm?
What is the mammary suspensory system made up of in cows?
- Medial ligaments - primary support, intermammary groove
- Lateral ligaments
- 1. Gland cistern
- 2. Annular fold
- 3. Teat cistern
- 4. Furstenburg's rosette
- 5. Streak canal
- 6. Teat meatus
What is the lymph node in the mammary called?
Supramammary lymph node
What are some characteristics of neonatal metabolism?
- Limited fat stores
- Glycogen stores rapidly used up at birth
- Low gluconeogensis
- Low iron
- Immature GIT
- High rennin, lactase, & salivary lipase
What factors influence successful passive immunity transfer from dam to calf?
- Formation of colostrum w/ adequate [IgG] by the dam
- Ingestion of an adequate mass of IgG by neonate
- Timely absorption of IgG by neonate
Which breeds have higher failure of passive transfer, Dairy or Beef?
What are bioactives? Give examples.
Constituents in colostrum and milk w/out nutritive value that have specific physiological actions critical for growth/development.
Ig, maternal leukocytes, growth factors and hormones, antimicrobials, proteins/peptides, nucleotides, oligosaccarides, vitamins/minerals, FAs
What species is affected by IUGR and what is it?
- Intrauterine Growth Restriction
- Impaired in utero growth
- Negatively affects SI development/metabolic function and villus hieght/width
What are the different ways heat is exchanged with the environment?
- Convection - body warms air/water
- Conduction - body warms surface
- Radiation - body infrared radiation absorbed by cooler objects
What is the integrated response to heat stress?
- Peripheral vasodilation
- Increased evaporative cooling
What is the integrated response to cold stress?
- Peripheral vasoconstriction, piloerection
- Increased metabolic heat production via shivering/non-shivering thermogenesis
What is the integrated response to fever?
Elevated body temp dut to increase in thermoregulatory set point
What are the efficiencies of heat inputs?
- Metabolism - 50% efficient
- Work (muscle) - 25% efficient
What is the exchange of heat btwn arteries and veins called?
Countercurrent heat exchange
What vessels regulate blood flow?