KINE 2P97 Lecture Notes - Lecture 11: Anterior Pituitary, Exercise Intensity, Glut4
8 May 2018
School
Department
Course
Professor
KINE 2P97
Muscle Physiology & Exercise Metabolism
Endocrine System
- System of organs that release hormones
Hypothalamus
- Links the autonomic nervous system to the endocrine system
- Releases tropic hormones to act on the anterior pituitary gland or directly on a target
organ
Anterior pituitary
- Releases a series or hormone signals
- These signals stimulate other organs to release hormones that act on various tissues of
the body
Hormone system
1. Catecholamines
a. Epinephrine (80%) & norepinephrine
- Released from the hypothalamus
- NE is also released from SNS nerve endings as neurotransmitters
- Metabolic effects:
o as neurotransmitters and hormonal signals are excitatory
o Stimulate glycogenolysis (muscle & liver) breakdown of glycogen
o Stimulate lipolysis (muscle & adipose tissue) breakdown of fat
o Overall: stimulate provision of substrates for energy metabolism – both CHO &
FAT
- Response to exercise
o As exercise intensity and duration increase the energetic requirements increase
o E and NE play a central role in promoting mobilization of CHO and FAT for energy
o Like Ca2+ in the metabolic pathways, acts as a feedforward mechanism
- Endurance training
o Blunted during exercise at the same absolute workload
o Relative workload vs absolute workload
2. Insulin
a. Increased SNS stimulation of pancreas will decrease insulin secretion
- Increases glycogen synthesis and storage
- Promotes storage of glycogen
- Response to Exercise
o Increased SNS Activity
o As insulin drops storage decreases
o Intracellular signals maintain GLUT4 translocation and muscle glucose uptake
▪ Insulin-dependent vs independent
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Links the autonomic nervous system to the endocrine system. Releases tropic hormones to act on the anterior pituitary gland or directly on a target organ. These signals stimulate other organs to release hormones that act on various tissues of the body. Hormone system: catecholamines, epinephrine (80%) & norepinephrine. Ne is also released from sns nerve endings as neurotransmitters. Endurance training: blunted during exercise at the same absolute workload, relative workload vs absolute workload, insulin, increased sns stimulation of pancreas will decrease insulin secretion. Increased sns activity: as insulin drops storage decreases. Intracellular signals maintain glut4 translocation and muscle glucose uptake. Insulin-dependent vs independent: glucagon, secreted from a-cells of pancreas in response to low blood sugar. Exercise: sns response stimulates glucagon secretion, promotes fuel mobilization, liver. Insulin anabolic and can suppress liver glucose output. Cease anabolic processes: protein, glycogen, and triglyceride synthesis are energy requiring processes. Insulin (fuel storage) decreases and glucagon (cho mobilization) increases.
