Exam 1

What is the primary function of the endocrine system?

To regulate body functions by secreting hormones into the bloodstream.

What are hormones?

Chemical messengers carried in blood.

What is the difference between the nervous system and the endocrine system in terms of response time?

The nervous system provides immediate responses, while the endocrine system regulates functions long-term.

Where is the hypothalamus located, and what are its primary functions?

The hypothalamus is located in the brain below the thalamus; it controls the pituitary gland and produces releasing/inhibiting hormones as well as ADH and oxytocin.

What hormones are produced by the anterior lobe of the pituitary gland?

GH, TSH, ACTH, FSH, LH, and Prolactin.

What is the main function of the thyroid gland?

Regulates metabolism through hormones such as T3, T4, and calcitonin.

What does the adrenal cortex secrete?

Aldosterone, cortisol, and androgens.

What are the three classes of chemical messengers in the endocrine system?

Hormones, neurotransmitters, paracrines, and autocrines.

What are the two classes of hormones based on solubility?

Lipid-soluble (steroid and thyroid hormones) and water-soluble (peptide and amine hormones).

What is the mechanism of action for water-soluble hormones?

They bind to membrane receptors, activate G-proteins, convert ATP to cAMP, which activates protein kinases leading to a cellular response.

What is the role of albumin in the blood?

Maintains osmotic pressure.

What is hematocrit?

The percentage of blood volume made of red blood cells (RBCs).

What are the three steps of hemostasis?

Vascular spasm, platelet plug formation, and coagulation (fibrin clot).

What distinguishes type AB blood in the ABO system?

It has both A and B antigens on the surface of red blood cells.

What are the layers of the heart?

Fibrous pericardium, serous pericardium, epicardium, myocardium, and endocardium.

What sequence does blood flow through the heart?

SVC/IVC → Right atrium → Tricuspid valve → Right ventricle → Pulmonary valve → Lungs → Left atrium → Mitral valve → Left ventricle → Aortic valve → Aorta.

What is the role of the SA node in the heart?

It acts as the pacemaker of the heart.

What is cardiac output, and how is it calculated?

Cardiac output is the amount of blood the heart pumps per minute, calculated as heart rate (HR) times stroke volume.