Connective Tissue and Lipid Metabolism

Questions and Answers

How does thyroid hormone (TH) influence lipolysis and lipogenesis?

TH increases lipolysis and decreases lipogenesis in connective tissue cells.

What is the glucose-sparing effect?

The glucose-sparing effect refers to the preservation of blood glucose for the brain by utilizing fatty acids for cellular respiration.

How does TH affect respiration rate?

TH stimulates an increase in respiration rate to meet the higher oxygen demands of the body.

What role do sodium-potassium (Na+/K+) pumps play in the response to TH?

Na+/K+ pumps help to move sodium and potassium ions across the membrane, converting ATP chemical energy into mechanical energy. Signup and view all the answers

Explain the relationship between the second law of thermodynamics and energy conversion in cells.

The second law of thermodynamics states that heat is produced during energy conversion, resulting in increased body temperature. Signup and view all the answers

How does TH affect heart function?

TH increases heart rate and force of contraction to enhance blood flow and nutrient delivery. Signup and view all the answers

Why is increased heat production significant in the context of TH?

Increased heat production is significant because it contributes to the rise in body temperature and reflects heightened metabolic activity. Signup and view all the answers

What is the impact of TH on cellular receptors for epinephrine and norepinephrine?

TH increases the number of cellular receptors for these hormones in cardiac muscle cells. Signup and view all the answers

What role does glucose play in nervous tissue, and why is it considered vital?

Glucose is the primary nutrient for nervous tissue, making it essential for cellular respiration and energy production. Signup and view all the answers

Describe the initial physiological changes that occur during the alarm reaction.

During the alarm reaction, pupils dilate, bronchioles dilate, and respiration rate increases. Signup and view all the answers

How does the hypothalamus contribute to the alarm reaction?

The hypothalamus activates the sympathetic division of the autonomic nervous system, triggering stress responses. Signup and view all the answers

What is gluconeogenesis, and how does it relate to the body's response to stress?

Gluconeogenesis is the process of producing glucose from non-carbohydrate sources, which is increased during stress to meet energy demands. Signup and view all the answers

Explain the effects of lipolysis and its components during the alarm reaction.

Lipolysis leads to an increase in glycerol and fatty acids in the blood, providing alternative nutrients for gluconeogenesis in the liver. Signup and view all the answers

What happens to glucose uptake in cells during the stress response, and what is the consequence?

Glucose uptake in most cells is inhibited during stress, leading to elevated blood glucose levels. Signup and view all the answers

Identify the hormones released by the adrenal medulla during the alarm reaction and their function.

The adrenal medulla releases epinephrine and norepinephrine, which prepare the body for a 'fight or flight' response. Signup and view all the answers

Discuss how protein metabolism is affected during the alarm reaction.

Protein catabolism increases while protein synthesis decreases, resulting in elevated amino acid levels in the bloodstream. Signup and view all the answers

What are the primary functions of the pancreas in the endocrine system?

The pancreas performs both exocrine functions by secreting digestive enzymes and endocrine functions by releasing hormones like insulin and glucagon. Signup and view all the answers

What type of cells in the pancreatic islets are responsible for insulin secretion?

Beta cells in the pancreatic islets are responsible for the secretion of insulin. Signup and view all the answers

How does insulin affect blood glucose concentration?

Insulin lowers blood glucose concentration by facilitating glucose uptake in tissues and promoting storage as glycogen in the liver and muscle. Signup and view all the answers

Describe the role of glucagon in blood glucose regulation.

Glucagon raises blood glucose concentration by stimulating glycogen breakdown in the liver and promoting gluconeogenesis. Signup and view all the answers

What is the relationship between the pancreas and the duodenum?

The pancreas releases digestive enzymes into the duodenum to assist in the digestion of food. Signup and view all the answers

What histological features distinguish different types of islet cells in the pancreas?

Different islet cells, such as alpha and beta cells, are distinguished by their histological appearance and the specific hormones they secrete, like glucagon and insulin respectively. Signup and view all the answers

Explain the importance of homeostasis in relation to insulin and glucagon.

Insulin and glucagon maintain homeostasis by balancing blood sugar levels; insulin decreases them while glucagon increases them. Signup and view all the answers

In what ways might malfunction of the pancreatic islets affect health?

Malfunction of the pancreatic islets can lead to conditions such as diabetes mellitus, characterized by impaired insulin production or action. Signup and view all the answers

What role does CRH play in the regulation of ACTH and cortisol?

CRH stimulates the anterior pituitary gland to release ACTH, which in turn stimulates the adrenal cortex to produce cortisol. Signup and view all the answers

Identify the primary target organs of cortisol and describe its effect on each.

The primary target organs of cortisol include the liver, muscles, and adipose tissue; it promotes gluconeogenesis in the liver, increases protein catabolism in muscles, and stimulates lipolysis in adipose tissue. Signup and view all the answers

Why is the pancreas classified as both an exocrine and an endocrine gland?

The pancreas is classified as an exocrine gland because it secretes digestive enzymes into the small intestine and as an endocrine gland because it releases hormones like insulin and glucagon into the bloodstream. Signup and view all the answers

Compare the functions of alpha cells and beta cells within the pancreatic islets.

Alpha cells secrete glucagon, which increases blood glucose levels, while beta cells secrete insulin, which lowers blood glucose levels. Signup and view all the answers

What is the significance of somatostatin released by delta cells in the pancreas?

Somatostatin regulates the secretion of both insulin and glucagon, thereby playing a critical role in the balance of glucose levels in the blood. Signup and view all the answers

Outline the metabolic effects of glucagon on target tissues.

Glucagon primarily promotes glycogenolysis in the liver and increases blood glucose levels by stimulating gluconeogenesis and releasing glucose into circulation. Signup and view all the answers

Discuss the role of pancreatic polypeptide secreted by F cells and its potential effects.

Pancreatic polypeptide plays a role in the regulation of pancreatic secretions and may influence appetite and food intake. Signup and view all the answers

Explain the structural organization of pancreatic islets.

Pancreatic islets are composed of clusters of alpha, beta, delta, and F cells, with beta cells typically located in the central region, surrounded by alpha cells and other cell types. Signup and view all the answers

What hormone is released in response to low blood glucose levels?

Glucagon. Signup and view all the answers

How does insulin affect blood glucose levels?

Insulin decreases blood glucose levels. Signup and view all the answers

What controls the release of insulin from the pancreas?

Negative feedback mechanisms. Signup and view all the answers

Which cells in the body do not require insulin for glucose uptake?

Neurons, kidney cells, hepatocytes, and erythrocytes. Signup and view all the answers

What is the role of cAMP in glucagon signaling?

cAMP acts as a second messenger in the signal transduction pathway initiated by glucagon. Signup and view all the answers

What are the two main metabolic processes activated by glucagon in response to low blood glucose?

Glycogenolysis and gluconeogenesis. Signup and view all the answers

What effect does decreasing insulin levels have on alternative nutrient usage?

It increases the likelihood of cells using glucose over fatty acids and amino acids. Signup and view all the answers

How is the release of glucagon initiated?

By chemoreceptors in the alpha cells of the pancreas detecting decreased blood glucose levels. Signup and view all the answers

Study Notes

Thyroid Hormone (TH) Effects

Thyroid hormone plays a crucial role in regulating metabolic processes throughout the body.

Connective tissue cells increase lipolysis and decrease lipogenesis in response to TH.
Glycerol and fatty acids are released into the blood, serving as alternative nutrient molecules for cellular respiration, which conserves blood glucose for the brain (glucose-sparing effect).
TH stimulates synthesis of sodium-potassium (Na+/K+) pumps, enhancing movement of these ions across cell membranes.
Increased Na+/K+ pumps lead to greater ATP conversion into mechanical energy, resulting in higher heat production and body temperature.

Alarm Reaction to Stress

The alarm reaction is the body's immediate response to stress, regulated by the sympathetic division of the autonomic nervous system.
The hypothalamus activates this system, leading to adrenal medulla stimulation and release of epinephrine and norepinephrine.
Physiological changes occur: pupil dilation, bronchiole dilation, and increased respiration rate.
To meet energy demand, gluconeogenesis increases in the liver, raising blood glucose levels and providing alternative nutrients for energy production from glycerol and amino acids.

Pancreas Anatomy and Function

The pancreas acts as both an endocrine and an exocrine gland, contributing to digestion and hormone regulation.
Composed of pancreatic islets, which contain alpha cells (produce glucagon) and beta cells (produce insulin).
Minor cell types include delta cells (secrete somatostatin) and F cells (secrete pancreatic polypeptide).

Insulin and Glucagon Regulation

Insulin lowers blood glucose levels by facilitating glucose uptake into cells, especially when glucose levels are high.
Some cells, such as neurons and kidney cells, do not require insulin for glucose uptake.
Glucagon is released in response to low blood glucose levels, stimulating glycogenolysis and gluconeogenesis to raise blood glucose concentration.
Insulin release is regulated by negative feedback; as blood glucose decreases, insulin release diminishes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore how connective tissue cells react to thyroid hormones by adjusting lipolysis and lipogenesis. This quiz highlights the mechanisms that enable the release of glycerol and fatty acids into the bloodstream for energy use in the body.