L26: Homeostasis of plasma calcuim and glucose

• Plasma calcium is regulated because there needs to be enough calcium in the blood fro cells to use it when they need it.
• the body uses Ca2+.by having G-protein activating 2nd messengers, these affect actions of other proteins.
• how body uses Ca2+

  Ca2+ interacts with vesicles to facilitate the release of neurotransmitter. it also interacts with myofilaments in sarcomeres to facilitate cross-bridge formation
• all muscles require Ca2+ for tension creation (skeletal, cardiac, smooth muscle)
• more than 99% of Ca2+ in the body is stored in bones (hydroxyaptite). Ca2+ is very important for making bones hard and strong.
• how does Ca2+ enter or exit the blood plasma?

  A) Ca2+

  B) digestive tract

  C) absorbed

  D) blood

  E) digestive tract

  F) resorbed

  G) blood

  H) bone broken down

  I) osteoclasts

  J) reabsorbed

  K) blood

  L) kidneys

  M) blood plasma

  N) removed

  O) blood

  P) deposited

  Q) bone

  R) osteoblast

  S) remodelling and growth

  T) filtered out

  U) blood

  V) kidneys

  
• location and structure and hormones released from

  A) thyroid

  B) parathyroid

  C) plasma calcium

  
• kidneys are 2x anterior to lower ribs. they are stimulated by PTH to secrete calcitrol. it filtered blood to make urine, thus are also sites for filtration of Ca2+ out of and reabsorption of Ca2+ back into the blood
• Parathyroid glands (4x) are the endocrine glands on the posterior of thyroid gland. they secrete parathyroid hormone (PTH). it is the most important hormone for Ca2+ homeostasis
• 2 pairs of parathyroid glands are embedded posterior surfaces of the thyroid gland
• calcitonin have opposing effects on the levels of calcium ions. PTH is the primary regulator of blood calcium.
• how does body correct hypocalcemia - low plasma

  A) parathyroid glands

  B) low Ca2+

  C) set-point

  D) more parathyroid hormone

  E) resportion

  F) osteoclasts

  G) more Ca2+

  H) plasma

  I) reabsorption

  J) pre-urine

  K) filtrate

  L) plasma

  M) vitamin D

  N) calcitriol

  O) sensor & control centre

  P) effectors

  Q) absorption

  R) food

  S) increases

  T) increases

  U) negatively

  V) reduce

  W) PTH release

  
• how does body correct hypercalcemia - high plasma

  A) high

  B) less

  C) less Ca2+

  D) osteoclasts

  E) less

  F) plasma

  G) less Ca2+

  H) less

  I) plasma

  J) less vitamin

  K) calcicitrol

  L) less Ca2+ uptake

  M) less

  N) decreases

  O) decreases

  P) negatively

  Q) increase

  R) PTH release

  
• thyroid glands, digestive system and bones are involved in plasma Ca2+ homeostasis
• thyroid gland wraps around the trachea/windpipe in the throat. it secretes calcitonin. calcitonin plays a minor role in Ca2+ homeostasis
• the digestive system absorbs nutrients from food it has digested. absorbed Ca2+ enters the bloodstream. Ca2+ absorption is increased under the influence of Calcitriol
• In bones, osteoblasts remove Ca2+ from plasma, to store in bone. osteoclasts release Ca2+ into plasma when breaking down bone. parathryoid, calcitriol and calcitonin affect those processes.
• all body cells use glucose as the main substrate for making ATP. it is also used to make other substances essential for body functioning (glycoproteins). glucose is stored in the form of glycogen or fat.
• label glucose

  A) single glucose molecule

  
• label glucose molecules

  A) amylose

  B) amylopectin

  C) starch

  D) glycogen

  E) cellulose

  
• how does glucose enter or exit the blood plasma?

  A) carbohydrates

  B) absrobed

  C) blood

  D) digestive tract

  E) released

  F) blood

  G) liver

  H) glycogen breakdown

  I) removed

  J) blood

  K) body cells

  L) excess glucose

  M) blood

  N) stored

  O) liver

  P) skeletal

  Q) glycogen

  R) removed

  S) adipose

  T) fat

  
• The pancreas are involved in plasma glucose homeostasis
• the pancreas sits behind the stomach, on the left side of the abdomen. it is an endocrine organ that secrets hormones for plasma glucose homeostasis.
• the pancreas islet cells secret hormones: glucagon and insulin. alpha islet cells secrete glucagon and beta islet cells secret insulin
• during the fed state, all body cells too use glucose to make ATP. liver and skeletal muscle cells store excess glucose as glycogen. adipose cells store excess glucose as fat
• during fasting state (no food intake for 4 hours, so plasma glucose is low), the glucagon signals to the liver to release glucose into plasma by creating new glucose or by breaking down glycogen into glucose
• labeling pancreas

  A) alpha

  B) glucagon

  C) beta

  D) insulin

  E) island

  F) G

  G) I

  
• fasting state is 4 hours without food
• how does the body correct hypoglycemia - low plasma glucose?

  A) too low

  B) fasting state

  C) alpha

  D) low glucose

  E) set-point

  F) release glucagon

  G) sensor and control centre

  H) liver

  I) building new glucose

  J) release into blood

  K) glycogenolysis

  L) breakdown of glycogen

  M) more glucose

  N) blood

  O) ketone synthesis

  P) building ketones

  Q) blood

  R) increases