Hormones and Signal Transduction

<p>Negative feedback (B)</p> Signup and view all the answers

<p>They relay signals within the cell. (D)</p> Signup and view all the answers

<p>Steroid Hormone (D)</p> Signup and view all the answers

<p>G-protein is activated, followed by activation of adenylyl cyclase. (C)</p> Signup and view all the answers

<p>Cytoplasmic receptors (B)</p> Signup and view all the answers

<p>Amino Acid Hormones (D)</p> Signup and view all the answers

<p>Receptor down-regulation occurs. (A)</p> Signup and view all the answers

<p>It activates protein kinase A (PKA) to influence metabolic pathways. (A)</p> Signup and view all the answers

<p>Ion channel receptors (C)</p> Signup and view all the answers

<p>It is phosphorylated and activated as a second messenger. (C)</p> Signup and view all the answers

<p>Leptin (A)</p> Signup and view all the answers

<p>Neurotransmitters (B)</p> Signup and view all the answers

<p>Below the thalamus (D)</p> Signup and view all the answers

<p>They produce and store hormones. (B)</p> Signup and view all the answers

<p>By managing temperature, food intake, and emotional responses. (D)</p> Signup and view all the answers

<p>Oxytocin (A)</p> Signup and view all the answers

<p>It can disrupt temperature regulation. (A)</p> Signup and view all the answers

<p>Posterior and anterior portions (B)</p> Signup and view all the answers

<p>Glutamate and GABA (C)</p> Signup and view all the answers

<p>Pituitary gland (C)</p> Signup and view all the answers

<p>At the base of the brain, near the pituitary gland (B)</p> Signup and view all the answers

<p>Increased serum osmolarity (A)</p> Signup and view all the answers

<p>V1 receptors (A)</p> Signup and view all the answers

<p>High circulating ADH levels (D)</p> Signup and view all the answers

<p>Diabetes Insipidus (DI) (A)</p> Signup and view all the answers

<p>Excessive water retention (A)</p> Signup and view all the answers

<p>Insufficient ADH production (C)</p> Signup and view all the answers

<p>Nephrogenic DI (D)</p> Signup and view all the answers

<p>Nausea and abdominal cramps (B)</p> Signup and view all the answers

<p>Increased concentrations of vasopressin (D)</p> Signup and view all the answers

<p>Syndrome of Inappropriate Antidiuretic Hormone (SIADH) (A)</p> Signup and view all the answers

A chemical substance produced by specialized cells, transported to distant cells to regulate them.

Hormones are classified as peptide, amino acid, or steroid.

Water-soluble hormones that bind to receptors on effector cells and initiate a cellular cascade effect.

Lipid-soluble hormones that pass through cell membranes, bind to cytoplasmic receptors, affect DNA, and initiate gene transcription.

Hormone secretion is controlled by patterns (diurnal, pulsatile), substrate levels, and feedback loops (negative and positive).

Cell responsiveness to a hormone is determined by the number and affinity of its receptors; these can change (up- or down-regulate).

Hormones that carry messages from outside the cell to the interior.

The process by which hormones transmit signals within a cell, causing cellular responses.

Water-soluble hormones bind to plasma membrane receptors, including G-protein linked receptors, ion channel receptors, and enzyme-linked receptors.

Lipid-soluble hormones bind to intracellular receptors, including cytoplasmic and nuclear membrane receptors.

Hormone attachment to a G-protein-linked receptor activates a cascade of events, including enzyme activation, second messenger production, and ultimately protein synthesis.

Cyclic AMP (cAMP) is a second messenger in the G-protein-linked receptor pathway, activating protein kinase (PKA).

Hormones/neurotransmitters directly or indirectly binding to ion channels, change the membrane's potential through opening or closing.

Leptin binds to an enzyme-linked receptor triggering a signaling pathway involving JAK2 and STAT proteins to activate gene transcription and protein synthesis

The hypothalamus is positioned below the thalamus, above the midbrain, and interconnected with the pituitary gland.

The hypothalamus controls various bodily functions and links the nervous system to the endocrine system through its connections to the pituitary gland.

Clusters of neuron cell bodies in the hypothalamus that produce hormones or hormone-stimulating/inhibiting factors, influencing the pituitary gland.

A pea-sized gland at the base of the brain, attached to the hypothalamus, often referred to as the 'master gland' because it controls the activities of other endocrine glands.

The posterior portion of the pituitary gland that stores and releases hormones produced by the hypothalamus, namely oxytocin and antidiuretic hormone (ADH).

A hormone produced by the hypothalamus and stored in the posterior pituitary, involved in social bonding, childbirth, and milk production.

A hormone produced by the hypothalamus and stored in the posterior pituitary, responsible for regulating water balance and blood pressure.

The release of hormones from the posterior pituitary is controlled by neurotransmitters like glutamate and GABA, which stimulate or inhibit the process.

The hypothalamus and pituitary gland work together, with the hypothalamus producing hormones that are stored and released by the pituitary, influencing the endocrine system.

Antidiuretic hormone (ADH) regulates water reabsorption in the collecting tubules of the kidneys, helping to maintain blood osmolarity.

Increased serum osmolarity (high blood salt levels) is detected by osmoreceptors in the hypothalamus, triggering ADH release from the posterior pituitary.

ADH binds to V1 receptors in smooth muscle, causing vasoconstriction and increased blood pressure. ADH binds to V2 receptors in the kidneys, stimulating aquaporin channels to transport water back into the blood.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is characterized by high circulating ADH levels with no appropriate feedback to the hypothalamus, resulting in water retention and dilutional hyponatremia.

SIADH can be caused by hypothalamic/pituitary disruption, ectopic ADH production by tumors, or mutations leading to V2 receptor over-activation.

SIADH can cause hyponatremia and symptoms like thirst, lethargy, confusion, nausea, vomiting, muscle cramps, and seizures.

Diabetes Insipidus (DI) is characterized by insufficient circulating ADH, leading to excessive water loss and hyperosmolar urine.

DI can be neurogenic (caused by inadequate ADH production) or nephrogenic (caused by renal tubular insensitivity to ADH).

DI symptoms include excessive urination (polyuria), excessive thirst (polydipsia), and dehydration due to water loss.

Dipsogenic DI is caused by excessive water intake, diluting the blood below the ADH threshold, leading to excessive water loss through urine.