HA&P2 exam one class

Hormone

A chemical messenger secreted by glands to regulate physiological processes.

Target Cell

A cell that responds to a specific hormone because it has the appropriate receptors.

Receptor

A protein on a target cell that binds to a specific hormone to initiate a response.

Circulating Hormones

Travel through the bloodstream to distant target cells.

Local Hormones

Act near the site of secretion, without entering the bloodstream.

Paracrine Hormones

Affect neighboring cells.

Autocrine Hormones

Affect the same cell that secreted them.

Lipid-Soluble Hormones

Travel bound to transport proteins in the bloodstream.

Water-Soluble Hormones

Travel freely in the bloodstream.

Second Messenger

A molecule inside a cell that is activated by a hormone binding to a cell surface receptor, triggering a cascade of cellular events.

Signal Amplification

The process by which a small signal (e.g., hormone binding) leads to a large cellular response.

Effects of Hormones on Target Cells (Nucleus-related)

Alter gene expression, stimulate protein synthesis, influence cell growth, regulate cellular metabolism.

Effects of Hormones on Target Cells (Cytoplasm-related)

Alter cell metabolism, stimulate secretion.

Lipid-Soluble Hormones (Sub-Types)

Steroids, thyroid hormones.

Water-Soluble Hormones (Sub-Types)

Peptides, amines.

Up-Regulation

Increase in the number of receptors on a target cell, making it more sensitive to a hormone.

Down-Regulation

Decrease in the number of receptors on a target cell, reducing its sensitivity to a hormone.

Antagonistic Hormonal Interaction

Hormones that have opposite effects (e.g., insulin and glucagon).

Permissive Hormonal Interaction

One hormone enhances the effect of another.

Synergistic Hormonal Interaction

Hormones work together for a greater effect.

Endocrine Glands Locations

Hypothalamus, pituitary gland, thyroid, parathyroid, adrenal glands, pancreas, gonads, pineal gland, thymus.

Hypothalamus Role on Pituitary

Releases hormones that stimulate or inhibit hormone release from the anterior pituitary and secretes oxytocin and ADH to the posterior pituitary.

Somatotrophs

Cells in the anterior pituitary that produce Growth Hormone (GH).

Lactotrophs

Cells in the anterior pituitary that produce Prolactin (PRL).

Corticotrophs

Cells in the anterior pituitary that produce Adrenocorticotropic Hormone (ACTH).

Thyrotrophs

Cells in the anterior pituitary that produce Thyroid-Stimulating Hormone (TSH).

Gonadotrophs

Cells in the anterior pituitary that produce Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH).

ADH

Regulates water balance by promoting water reabsorption in the kidneys.

Oxytocin

Stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

Thyroid Hormones Production

Produces T3 and T4 that regulate metabolism; Calcitonin lowers blood calcium.

Parathyroid Hormone (PTH)

Increases blood calcium levels.

Adrenal Cortex Hormones

Produces cortisol, aldosterone, and androgens.

Adrenal Medulla Hormones

Produces adrenaline and noradrenaline (fight-or-flight response).

Pancreatic Islets Alpha Cells

Produce glucagon, which raises blood sugar.

Pancreatic Islets Beta Cells

Produce insulin, which lowers blood sugar.

Pancreatic Islets Delta Cells

Produce somatostatin, which regulates insulin and glucagon.

Ovaries Hormones

Estrogen and progesterone.

Testes Hormones

Testosterone.

Pineal Gland Hormone

Melatonin.

Thymus Hormone

Thymosin.

Functions of Blood

Transport of gases, nutrients, waste products; regulation of temperature, pH; defense against infection.

Blood Components

Plasma, red blood cells (RBCs), white blood cells (WBCs), platelets.

Substances in Blood Plasma

Water, proteins (albumin, globulins, fibrinogen), electrolytes, nutrients, waste products, hormones, gases.

Hematocrit Definition

Percentage of blood volume occupied by RBCs.

Anemia Definition

Low RBC count or hemoglobin.

Polycythemia Definition

High RBC count.

Hemoglobin Function

Carries oxygen.

RBC Life Cycle

Produced in bone marrow, live 120 days, broken down in spleen.

Bilirubin Definition

Breakdown product of hemoglobin.

Transferrin Function

Iron transport protein.

Ferritin Function

Iron storage protein.

Types of White Blood Cells (WBCs)

Neutrophils, lymphocytes, monocytes, eosinophils, basophils.

Leukocytosis Definition

High WBC count.

Leukopenia Definition

Low WBC count.

Platelets Function

Blood clotting.

Hemostasis Definition

Process of stopping bleeding.

Hemorrhage Definition

Excessive bleeding.

Platelet Plug Formation Steps

1. Platelet adhesion. 2. Platelet activation. 3. Platelet aggregation.

Blood Clotting Stages

Vascular spasm, platelet plug formation, coagulation.

Clotting Factors examples

Fibrinogen, prothrombin, and others in the coagulation cascade.

Vitamin K Role in Clotting

Essential for the production of clotting factors.

Fibrinolytic System Function

Breaks down fibrin and dissolves clots.

Blood Group Definition

Classification based on antigens on RBCs.

Blood Type Definition

Specific group (A, B, AB, O, Rh).

ABO Blood Group Definition

Based on A and B antigens.

Rh Blood Group Definition

Based on Rh factor (positive or negative).

Blood Type Differences

A, B, AB, O blood types; Rh+ and Rh- distinctions.

Sickle-Cell Anemia Definition

Abnormal RBC shape.

Hemophilia Definition

Lack of clotting factors.

Leukemia Definition

Cancer of WBCs.

Thrombosis Definition

Clot formation.

Embolus Definition

Clot that travels.

Cyanosis Definition

Bluish skin due to low oxygen.

Hemochromatosis Definition

Iron overload.

Jaundice Definition

Yellowing of the skin.

Septicemia Definition

Blood infection.