Bio Unit Study Guide: Diseases, Endocrine, and Circulatory Systems

Flashcards covering key terminology from the lecture on neurodegenerative diseases, the endocrine system, and the circulatory system, including blood composition and heart anatomy.

Multiple Sclerosis

An autoimmune disorder that inflames and/or damages the myelin sheath of the Central Nervous System, leading to symptoms like memory changes, numbness, and paralysis.

Alzheimer's Disease

A disease where sticky proteins (plaques) clump together and kill brain cells, leading to memory loss, confusion, and paranoia.

Parkinson's Disease

A condition where dopamine-producing brain cells in the Substantia nigra die, resulting in shaking, stiffness, slow movement, and potential psychosis.

Hormones

Chemical messengers that travel through the bloodstream to reach target cells and induce a specific effect on particular tissues.

Target cells

Cells that possess specific receptors for hormones, allowing those hormones to have a physiological impact.

Endocrine Glands

Ductless glands that secrete hormones directly into the bloodstream, such as the ovaries, pituitary, and pancreas.

Exocrine Glands

Glands that secrete substances like enzymes through ducts into specific areas, such as salivary glands, tear ducts, and the pancreas.

Steroid Hormones

Hydrophobic, fat-soluble hormones made from cholesterol that require transport proteins in the blood and bind to receptors in the cytoplasm or nucleus to cause changes at the gene level.

Non-steroid Hormones

Hydrophilic hormones made of proteins that are not fat-soluble and require surface receptors to initiate a cascade (chain of chemical reactions) inside target cells.

Negative Feedback loop

A regulation mechanism where the presence of one hormone inhibits the secretion of another hormone, such as in blood glucose regulation or thyroxin.

Positive Feedback loop

A regulation mechanism where the presence of a hormone promotes an increase in hormone secretion, such as with Oxytocin or prolactin.

Insulin

A hormone from the Islets of Langerhan (Pancreas) that converts glucose into glycogen for storage.

Glucagon

A hormone found in the pancreas that converts glycogen back into glucose when blood sugar is low.

Plasma

The non-cellular, fluid portion of blood ($55\%$ of volume) consisting of $92\%$ water, $7\%$ proteins, and $1\%$ organic or inorganic substances.

Red Blood Cells (RBC's)

Also known as erythrocytes, these disk-shaped cells make up $44\%$ of total blood volume and specialize in oxygen transport; they lack a nucleus when mature.

Hemoglobin

A respiratory pigment containing $4$ iron ($Fe$) atoms that binds up to $4$ molecules of oxygen ($O_2$) to transport it through the bloodstream.

White Blood Cells (WBC's)

Also known as leukocytes, these nucleated cells make up $1\%$ of total blood volume and function as part of the immune system.

Macrophages

Phagocytic white blood cells that engulf foreign particles as part of the body's innate immune system and can pass through capillary walls.

Lymphocytes

Non-phagocytic white blood cells that play a role in the body's acquired immune response by recognizing specific pathogens.

WBC Types

The five different types of white blood cells are Basophil, Neutrophil, Eosinophil, Lymphocyte, and Monocyte.

Blood Platelets

Non-cellular cell fragments created in the bone marrow that lack nuclei and are essential for blood clotting.

Thromboplastin

An enzyme produced from ruptured platelets and clotting agents that reacts with prothrombin in the presence of calcium ($Ca^{2+}$) ions.

Fibrin

A material produced when thrombin reacts with fibrinogen, creating a 'mesh net' to catch cells and physically clot the blood.

Anemia

A condition caused by a lack of hemoglobin or a low number of RBC's, leading to dizziness, weakness, and pale skin.

Sickle-cell Anemia

A condition caused by an abnormal form of hemoglobin where cells become sickle-shaped, carry little oxygen, and clog blood vessels.

Left and Right Ventricle

Hollow lower chambers of the heart; the right pumps deoxygenated blood to the lungs and the left pumps oxygenated blood to the body.

Bicuspid valve

An atrioventricular valve with two cusps located between the left atrium and the left ventricle.

Tricuspid valve

An atrioventricular valve with three cusps located between the right atrium and right ventricle.

Semilunar valve

Valves located in the ventricles that prevent the backflow of blood as it leaves the heart.

Aorta

The largest artery in the body that brings blood to the capillary networks for material exchange with tissues.

Pulmonary Vein

A blood vessel that carries oxygenated blood from the lungs back to the heart.

Pulmonary Artery

A blood vessel that allows deoxygenated blood to leave the heart and travel to the lungs to pick up oxygen.

Septum

The wall that separates the right and left ventricles of the heart.

Vena Cava

The main veins (Superior and Inferior) that collect blood from the upper and lower body and return it to the right atrium.

Systolic Blood Pressure

The maximum pressure exerted on the arteries when the left ventricle contracts; the upper number in a blood pressure reading.

Diastolic Blood Pressure

The minimum pressure on arterial walls between heartbeats when the heart is relaxed; the lower number in a blood pressure reading.

Sphygmomanometer

An instrument used to measure blood pressure in the arteries by temporary stopping blood flow and recording pressures as it is released.

Hypotension

A blood pressure category defined by levels less than $90$ systolic and less than $60$ diastolic.

Hypertensive Crisis

A medical emergency characterized by blood pressure readings of $180$ or higher systolic or $110$ or higher diastolic.