Endocrine and Cardiovascular Systems: Hormones, Blood, and Disorders

Functions of hormones

Regulate chemical composition and volume of internal environment, regulate metabolism, regulate glandular secretions, control growth and development.

Hormone

A molecule that is released in one part of the body but regulates the activity of cells in other parts of the body.

Up-regulation

Hormone deficiency.

Down-regulation

Hormone present in excess.

Local Hormones

Act locally; two types: autocrine and paracrine.

Paracrine

Act on neighboring cells.

Autocrine

Act on the same cell that secreted them.

Circulating Hormones

Circulate in blood throughout the body.

Steroids

Derived from cholesterol; each steroid hormone is unique due to the presence of different chemical groups attached to various sites on the four rings at the core of its structure.

Differences between lipid-soluble and water-soluble hormones

Lipid-soluble hormones bind to receptors inside target cells; water-soluble hormones bind to receptors on the plasma membrane and activate the SECOND messenger system.

Antagonistic Effects

One hormone opposes the actions of another.

Methods of stimulating hormone secretion

Hormonal stimuli, humoral stimuli, neural stimuli.

Hormonal Stimuli

Endocrine organs are stimulated into action by hormones.

Humoral stimuli

Chemical changes in the blood trigger hormone release.

Neural stimuli

Nerve fibers stimulate hormone release.

What controls hormones released from the anterior pituitary gland

The hypothalamus.

Hormone associated with body growth

Thyroid gland (metabolism).

Hormone and milk production

Oxytocin (OT) stimulates milk ejection from mammary glands.

Hormone related to cortisol

Adrenocorticotropic hormone (ACTH) or corticotropin.

Hormone and progesterone and testosterone

Ovaries produce progesterone; testes produce testosterone.

Hormones related to the posterior pituitary gland

Oxytocin (OT) and Antidiuretic hormone (ADH, aka vasopressin).

Parathyroid hormones regulate what?

Calcium.

Blood glucose lower hormone

Insulin.

Hormone released in response to a decrease in blood glucose

Glucagon.

Hematocrit

The percentage of total blood volume occupied by RBCs.

What % of blood plasma is water?

91.5%.

Hemopoiesis

The process by which formed elements of the blood develop (blood cell formation).

Erythropoietin

A hormone that stimulates the production of red blood cells (RBCs) in the bone marrow.

Function of red blood cells

Gas transportation.

Platelet

Reduce blood loss (clot formation) help stop blood loss by forming platelet plug.

Steps that occur during hemostasis

Vascular Spasm, Platelet Plug Formation, Blood Clotting (coagulation).

Clot Formation (also called hemostasis)

The process your body uses to stop bleeding after a blood vessel is injured.

Antigens

Proteins or carbohydrates found on the surface of red blood cells (RBCs).

Antibodies

Found in the plasma and attack foreign antigens.

Type AB

Universal recipient for RBC transfusion.

Type O

The universal donor for RBC transfusion.

Anemia

Lower than normal # of RBCs.

Lifespan of a red blood cell

120 days in humans.

Polycythemia

Abnormally high # of RBCs.

Blood Types

Type A, A+, A-; Type B, B+, B-; Type AB, AB+, AB-; Type O, O+, O-.

Universal Recipient

AB+.

Universal Donor

O-.