Endocrine System Flashcards
What are Peptide/AA-Derived Hormones?
Hormones that cannot cross the cell membrane (except thyroid hormones) and bind to receptors on the cell membrane.
How do Peptide/AA-Derived Hormones function?
They use secondary messengers (e.g., cAMP) and typically initiate cascades of biochemical reactions.
What are Steroid Hormones?
Hormones that can easily cross the cell membrane and bind to receptors inside the cell.
How do Steroid Hormones affect gene expression?
The steroid-receptor complex enters the nucleus and directly affects gene expression.
What is the role of chemical messengers in cellular communication?
They bind to receptor proteins in/on target cells, changing cell function.
How do endocrine glands differ from exocrine glands?
Endocrine glands release hormones into the bloodstream to find target cells, while exocrine glands release substances through ducts.
What is the difference in action speed between neurotransmitters and hormones?
Neurotransmitters act faster than hormones.
What is negative feedback?
A mechanism that counteracts change to restore balance (e.g., thermostat).
What is positive feedback?
A mechanism that enhances change (e.g., polar ice melting).
What is the function of the hypothalamus?
It senses body conditions and releases hormones to regulate the pituitary gland.
What hormones does the anterior pituitary gland produce?
Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), Thyroid-Stimulating Hormone (TSH), and Adrenocorticotropic Hormone (ACTH).
What are the standalone effects of the anterior pituitary gland?
Prolactin (PRL) stimulates milk production, and Growth Hormone (GH) increases protein synthesis, fat usage, and carb metabolism.
What hormones are produced by the posterior pituitary gland?
Antidiuretic Hormone (ADH/Vasopressin) regulates water retention, and Oxytocin (OT) stimulates milk ejection and emotional bonding.
What is the function of Thyroxine (T4)?
It regulates metabolism.
What is the role of Calcitonin?
It lowers Ca²⁺ levels in the blood.
Where are the receptors for peptide/AA hormones located?
On the cell membrane.
Where are the receptors for steroid hormones located?
Inside the cell (nucleus/cytoplasm).
What is the biochemical effect of Peptide/AA hormones?
They activate enzymes via secondary messengers.
What is the biochemical effect of Steroid hormones?
They change gene expression.
What does negative feedback do?
Restores balance (e.g., thermostat).
What does positive feedback do?
Amplifies change (e.g., childbirth contractions).
