a&p exam 2

How do hormones affect cells?

act as chemical messengers through the bloodstream to target cells, bind and trigger biological response

cell receptors

proteins on or inside target cells that bind to specific molecules

What controls most hormone concentrations?

negative feedback.

What happens when a steroid hormone binds to a receptor in a target cell?

It forms a hormone-receptor influencing gene expression and protein synthesis.

upregulation

increase in the number of receptors on a cell

downregulation

decrease in receptor number

What is the primary action of Growth Hormone (GH)?

increases cell reproduction, enhances protein synthesis, and promotes lipolysis.

How does Antidiuretic Hormone (ADH) regulate water balance?

reabsorption in the kidneys, concentrating urine and decreasing water loss.

What is the main function of Triiodothyronine (T3) and Thyroxine (T4)?

They increase the metabolic rate and influence growth, development, and organ system functions.

What effect does Parathyroid Hormone (PTH) have on blood calcium levels?

stimulating osteoclast activity in bones and enhancing calcium reabsorption in the kidneys.

What is the role of Adrenocorticotropic Hormone (ACTH)?

stimulates the adrenal cortex to produce cortisol, which is important for stress response and metabolism.

What regulates the release of hormones from the anterior pituitary gland?

hypothalamic

What is diabetes insipidus?

A condition where the kidneys cannot conserve water due to insufficient ADH, leading to excessive urination and thirst.

How does cortisol affect the body?

l increases glucose production, suppresses the immune system, and helps the body respond to stress.

What is the function of insulin?

lowers blood glucose by promoting its uptake into cells and storing it as glycogen.

What does glucagon do?

raises blood glucose levels by stimulating the liver to release stored glucose.

What causes Type 1 Diabetes Mellitus?

an autoimmune destruction of insulin-producing beta cells in the pancreas.

What causes Type 2 Diabetes Mellitus?

insulin resistance and eventual beta-cell dysfunction, often linked to obesity and poor lifestyle choices.

What is hypoxemia?

low oxygen levels in the blood, which stimulates the release of erythropoietin (EPO).

What is hematocrit?

percentage of blood volume occupied by red blood cells.

How long do red blood cells (RBCs) live?

120 days

What are platelets?

fragmentation of megakaryocytes live up to 10 days

What is the purpose of the Frank-Starling Law of the Heart?

It states that the heart will pump more blood if the heart muscle is stretched more, up to a point.

What is blood pressure in the large systemic arteries greatest during?

when the ventricles contract.

What is a pulmonary embolism?

A blockage in one of the pulmonary arteries in the lungs, usually caused by a blood clot.

What is atherosclerosis?

buildup of fatty deposits on the inner walls of arteries, which can lead to reduced blood flow and increased risk of cardiovascular events.

Where is the control center for the cardiovascular system located?

medulla oblongata of the brainstem.

What is the function of the systemic circuit?

carries oxygenated blood from the left ventricle to the body tissues and returns deoxygenated blood to the right atrium.

Right Atrium

Receives deoxygenated blood from the vena cava.

Right Ventricle

Pumps deoxygenated blood to the lungs via the pulmonary artery.

left Atrium

Receives oxygenated blood from the lungs.

left Ventricle

pumps oxygenated blood to the body via the aorta.

what are the av valves

Tricuspid Valve Bicuspid valve

blood flow

Vena Cava (Superior and Inferior) → Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Artery → Lungs

Chambers Containing Oxygen-Poor Blood

Right Atrium and Right Ventricle