Endocrine & Nervous System Health Flashcards
What are the organs & glands of the endocrine system
Pituitary gland, hypothalamus, thyroid gland, parathyroid gland, adrenal glands, pancreas, gonads, pineal gland, gastrointestinal tract
Explain the pituitary gland
It’s at the base of the brain and is called the “master gland” bc it regulates other endocrine glands including thyroid, adrenal glands, and gonads. It’s divided into anterior and posterior sections and produces growth hormones, prolactin, and oxytocin
Explain the hypothalumus
The hypothalamus links the nervous system and endocrine system and produces releasing and inhibiting hormones. It controls the pituitary gland’s secretion and regulates body temp, hunger, and thirst
Explain the thyroid gland
It’s located in the neck and shaped like a butterfly. It produces hormones thyroxine (T4) and triiodothyronine (T3). It regulates metabolism, supports energy production and facilitates growth
Explain the parathyroid glands
Parathyroid glands are small glands on the thyroid gland. They produce the parathyroid hormone (PTH), regulate calcium levels in the blood, and support bone metabolism.
Explain the adrenal glands
The adrenal glands are positioned atop the kidneys. They produce cortisol (stress response), aldosterone (regulates blood pressure), and epinephrine (adrenaline - fight or flight response)
Explain the pancreas
The pancreas endocrine produces hormones that regulate blood sugar levels (insulin lowers blood sugar; glucagon raises blood sugar). Pancreas exocrine involves digestive enzyme production
What is the hormone gastrin
Gastrin stimulates acid production in the stomach
Explain the gonads
The gonads in the ovaries produce sex hormones like estrogen and progesterone. The gonads in the testes produce testosterone
Explain the pineal gland
The pineal gland is a small gland located in the brain that secretes melatonin which is a hormone that regulate sleep-wake cycles and influences circadian rhythms.
Explain the GI Tract
Not traditionally considered an endocrine gland but produces hormones and signaling molecules. Key hormones include: gastrin, cholecystokinin, secretin, ghrelin, leptin
What is the hormone cholecystokinin
Cholecystokinin stimulates bile release and digestion of fats
What is the hormone ghrelin
Ghrelin stimulates hunger and food intake
What is the hormone secretin
Secretin stimulates the release of bicarbonate to neutralize stomach acid
What is the hormone leptin
Leptin regulates energy balance and suppresses appetite
What are feedback loops
Feedback loops are how endocrine glands “talk” to each other and there are two primary types: negative & positive
What is negative feedback
Negative feedback is a regulatory mechanism that helps maintain homeostasis in the body. It counteracts changes in a variable to bring it back to a set point or normal range
What is positive feedback
Positive feedback is a physiological mechanism that amplifies a change or response in the body. It moves the body further away from its starting state rather than maintaining homeostasis. It enhances & accelerates a process. Often leads to a definitive outcome such as childbirth or blood clotting
Components of positive & negative feedback loops
Stimulus, sensor/receptor, control center, effector, response
Hormonal interactions: syngerstic example
Insulin & glucagon work together to maintain glucose homeostasis
Hormonal interactions: antagonistic example
Cortisol and insulin have opposing effects on glucose metabolism
What is glycolysis
Glycolysis occurs in the cytoplasm and converts glucose into pyruvate through 10 enzyme-catalyzed reactions
What is Citric Acid Cycle (Krebs Cycle)
Citric acid cycle is when pyruvate from glycolysis is converted into acetyl-CoA and enters the mitochondria. The cycle generates NADH & FADH2, ATP, and releases carbon dioxide as a waste product
What is oxidative phosphorylation
NADH & FADH2 feed into the electron transport chain, ATP is produced through oxidative phosphorylation, oxygen acts as the final electron acceptor which forms water
What is glycogensis
When insulin promotes the conversion of glucose into glycogen for storage in the liver and muscle. Key enzyme is glycogen synthase which catalyzes the addition of glucose units to a growing glycogen chain using UDP-glucose as the substrate
What is lipogenesis
Excess glucose is converted into fatty
acids in the liver when glycogen
stores are full
Key Enzyme: Acetyl-CoA Carboxylase: Converts
acetyl-CoA into malonyl-CoA,
initiating fatty acid synthesis
