Class Notes (811,138)
Canada (494,513)
Physiology (634)
PSL201Y1 (124)
Lecture 4

Endocrine Lecture 4 - Calcium Balance

4 Pages
Unlock Document

University of Toronto St. George
Michelle French

Endocrine L4 Nov 18 11Ca mainly in hydroxypatite crystals small Calcium Balancefractn readily ionizedexchangeable fluid around this areaWhy is calcium critical for normal physiologyGood since has get Ca from here if not enough in lntracellular signallingtrigger neurotransmitter bloodor hormone releaseHormone secretionprot hormonesWhich cells are responsible for bone growthturnover Blood clottingNeural excitability maintain certain levelaffect neuron excitabilityMuscle contractionBuildingmaintaining boneOne of first signals need in reproductnWhen first spermatozoa hits oocyte membranewave of calcium signallingchanges membrane properties so no other sperm can enterCa turnoveryr 100 infants per yr18 2Total body Ca intracellularextracellular adultsECFplasmaboneOsteoblastsforming bone depositing matrix of boneOsteoclasts bone resorptiondissolvingOsteocytes embedded in matrix help to maintain matrix former osteoblasts trapped in boneOsteoclastsHave to maintain approx 25mmol Ca2 in extracellular20mmol taken in per day excrete in feces 16Only absorb 4 by small intestineCan remain in extracellular fluid or go into bone99 stored in minerals of boneCa2 filtered into kidneys filtrate modifiedFormed from immunelike monocytecollects into bladder 4mmol Ca2 filtered but Monocytes fuse together produce lysosomes some reabsorbed 4mmol lost in urine acid secreted lysosomal enzymesacids into balanced by Ca2 brought in thru dietspecialized micro envt w low pHallows If have too much Ca2lose thru urinelysosomes to work optimally sealed off from rest 0001mM in cell allows effect when rushes of structureallows for bone resorptionthru for signallingBone dynamics 100 days osteoclasts resorb Bone is constantly being formedresorbed dynamicosteoblasts form osteocytes retired osteoblastsBone resorptionamt coming inleaving Cavity made by osteoclastsbone is equal2 types of boneparallel compact boneOsteoblasts promote osteoclast formation via spongy boneRANKLRANK interactionHas a lot of extracellular matrix made of collagenCaP minerals
More Less

Related notes for PSL201Y1

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.