BIOL Ch 36-39 (Exam 2)

Excretory System

Excretory System

The system that restores and maintains the proper internal regulation of materials in the body despite differences in diet.

Flame Cells

Produce a current that draws interstitial fluid into the tubules through slit-like openings

Nephridia

The excretory organ of a segmented worm that filters fluid in the coelom. There is a pair in nearly every segment.

Nephrostomes

Cilia-lined openings in the nephridia.

Kidney

A pair of complex organs that filter waste from the blood like urea, water, salt and proteins.

Urea

A chemical that comes from the breakdown of proteins. It's a waste that is composed of ammonia, which is toxic to the body.

Liver

The organ that converts ammonia to urea.

Nephrons

The filtering units in the outer layer of the kidney that remove wastes from the blood and produce urine.

Renal Artery

Blood vessel that carries blood to the kidney.

Renal Vein

Blood vessel that carries blood away from the kidney and toward the heart.

Ureter

A duct leading from the kidney to the bladder. It moves urine by peristalsis.

Bladder

Muscular organ that provides temporary storage for urine.

Cortex

The outermost layer of the kidney.

Medulla

Part of the outer layer of the kidney, located just below the cortex.

Renal Pelvis

The hollow inner chamber that collects the urine and passes it to the ureter.

Glomerulus

A ball of capillaries surrounded by Bowman's capsule in the nephron and serving as the site of filtration of blood inside the kidney. Its capillary walls are permeable to water and dissolved substances.

Bowman's Capsule

This collects filtrate, which is fluid filtered from the blood. The arterioles in this structure subdivide into a capillary network called the glomerulus.

Renal (Nephron) Tubule

Long, twisted tube of the nephron that functions in tubular reabsorption and secretion.

Proximal Tubule

The part of the renal tubule closest to the glomerulus. Substances are secreted or absorbed in this part of the renal tubule.

Loop of Henle

The part of the renal tubule that conserves water and minimizes the volume of urine.

Distal Tubule

The part of the renal tubule that refines filtrate and empties it into the collecting duct.

Antidiuretic Hormone (ADH)

This hormone regulates the amount of water reabsorbed into the body and how concentrated the urine becomes. Also called vasopressin.

Tubular Reabsorption

The movement of substances from the tubular fluid back into the blood.

Tubular Secretion

The movement of substances from the blood into the tubular fluid.

350

The approximate number of times that human kidneys filter the blood daily.

Hypothalamus

Releases antidiuretic hormones (ADH/vasopressin).

Innate Immune Response

A quick, nonspecific immune response that all living things are born with.

Adaptive Immune Response

A relatively slow but very effective immune response that targets specific pathogens.

External Barriers

Skin and mucous membranes.

Lysozyme

An enzyme found in saliva, sweat, and tears that destroys the cell walls of bacteria.

Phagocytic Cells

White blood cells that engulf and ingest foreign bodies or toxins. The "eaters."

Macrophages

Phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.

Natural Killer Cells

White blood cells that attack and kill infected or compromised body cells, especially cancer cells and those harboring viruses. They do this by forming holes in the surface of the targeted cells. The "killers."

Phagocytosis

The process in which amoeboid cells destroy invading microbes by engulfing them.

Inflammatory Response

An innate immune response to tissue damage caused by wounds.

Histamine

The chemical that is released by cells in response to injury or allergic reactions, causing contraction of smooth muscle and dilation of capillaries.

Leukocytes

White blood cells.

Fever

This slows down microbial reproduction and enhances the body's own fighting abilities by increasing the set-point in the hypothalamus of the brain. Low-grade can be beneficial.

Endogenous Pyrogens

Hormones that increase the set-point in the hypothalamus of the brain during a fever. Released by white blood cells.

Interferon

A protein produced by cells in response to being infected by a virus; helps other cells resist the virus.

T-Cells

Cells created in the thymus that produce substances that attack infected cells in the body.

B-Cells

Cells created in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses.

Recognition, Attack, Memory

The three steps of a specific immune response.

Antibodies and Receptors

The two types of proteins that accomplish the function of recognition.

Antibodies

Y-shaped proteins that attach to particular kinds of antigens. They are made of 4 peptide chains consisting of a large (heavy) chain and a small (light) chain on each half of the Y.

Antigens

Foreign material that invades the body.

Constant Region

The stem of the "Y" in antibodies that is similar in all antibodies.

Variable Region

The two tips of the "Y" in antibodies that differs widely from one antibody to another.

Binding

This action between antigens and antibodies will trigger an immune response.

Humoral Immunity

Specific immunity produced by B-cells that produce antibodies that circulate in body fluids.

Cell-Mediated Immunity

Specific immunity produced by T-cells that attack infected or abnormal body cells.

Clonal Selection

The rapid production of specific B-cell clones that occurs during an immune response.

Plasma Cells

Cells that develop from B-cells and produce large amounts of antibodies into the bloodstream, but usually only live a short period.

Memory Cells

Cells that develop from B-cells or T-cells. They remain dormant until reactivated by a familiar antigen, and may respond so rapidly that the body experiences no symptoms of reinfection. These cells are the basis for immunizations and can survive for many years.

Neutralization, Promotion of Phagocytosis, Agglutination, Complement Reactions

Antibodies circulating in the bloodstream can cause these four effects.

Agglutination

Clumping of microorganisms.

Effector Cells

Short-lived cells produced by T-cells that take effect immediately against an antigen and any pathogens producing that antigen.

Helper, Killer (Cytotoxic), Suppressor

The three types of effector cells produced by T-cells.

Helper T-Cells

T-cells that produce interferon and increase the activity of killer (cytotoxic) and suppressor T-cells.

Killer (Cytotoxic) T-Cells

T-cells that bind to antigens on the surface of enemy cells and release proteins that disrupt their plasma membranes. These cells usually only live a few days.

Suppressor T-Cells

T-cells that appear after a pathogen has been conquered to shut off the immune response in B- and killer (cytotoxic) T-cells.

Receptors

Special structures that allow living organisms to sense the conditions of their internal or external environment. These are located on the cell membrane (water-soluble) or inside the cell, usually in the cytoplasm.

Target Cells

Cells that have receptors for a particular hormone.

Endocrine System

This system uses hormones to communicate either locally (cell-to-cell) or over a greater distance inside the body.

Hormone

secreted by cells in one part of the body to be transported, usually in the bloodstream, for exerting action on target cells.

Endocrine Glands

Ductless structures that release hormones into the bloodstream.

Peptide, Modified Amino Acids, Steroids, and Prostaglandins

The four classes of hormones in animals.

Prostaglandins

Local hormones that are modified fatty acids. They have a number of diverse roles in humans and are sometimes linked to chronic pain.

Second Messenger

This transfers the information from the first hormone to target molecules in the cell.

Cyclic AMP (c-AMP)

A second messenger that activates cellular enzymes.

c-AMP Cascade

The process in which a hormone binds to the receptor on a cell surface, stimulating the synthesis of c-AMP, which then activates cellular enzymes.

Hypothalamus/Pituitary Complex

Much of the action of the mammalian endocrine system is coordinated and control by this complex.

Hypothalamus

The portion of the brainstem that houses neurosecretory cells.

Pituitary Gland

A major gland of the hypothalamus. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Anterior Pituitary

Part of the pituitary gland. A "true" endocrine gland.

Tropic Hormones

Hormones that stimulate certain endocrine glands to secrete other hormones.

Thyroxine

This is produced and secreted by follicle cells in the thyroid gland. It is an iodine-containing modified amino acid that controls overall body metabolism.

Medulla

In the adrenal gland, this part releases adrenaline.

Anterior and Posterior

The two lobes that make up the pituitary gland.

Posterior Pituitary

This part of the pituitary gland is neurally connected to the brain, containing nerve endings of neurosecretory cells that originate in the hypothalamus. They create, store, and release peptide hormones into the bloodstream.

Antidiuretic Hormone (ADH)

A hormone released by the posterior pituitary gland that regulates water retention.

Oxytocin

A hormone released by the posterior pituitary gland that stimulates uterine contractions during childbirth and milk ejection during breastfeeding. It's also responsible for muscle contractions of the penis during ejaculation.

Calcitonin

Hormone created by the thyroid gland that lowers blood calcium levels.

Parathyroid Glands

Glands that increase the blood calcium levels in your body and regulates bone growth.

Goiter

Enlarged thyroid gland caused by a lack of iodine in the diet.

Pancreas

A double gland. Its exocrine part makes digestive enzymes that flow to the small intestine, and its endocrine part contains clusters of cells called islets.

Islets

Pancreatic endocrine cells.

Insulin and Glucagon

The two types of pancreatic islet cells.

Insulin

Pancreatic islet cells that reduce blood sugar.

Glucagon

Pancreatic islet cells that increase blood sugar.

Diabetes Mellitus

Defects in insulin production, release, or reception results in this.

Testis

This sex organ secretes androgen hormones, mainly testosterone.

Ovary

This sex organ secretes estrogen and progesterone.

Adrenal Glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

Local Hormones

Hormones that act on their surroundings without first entering the blood stream.

Glucocorticoids

Hormone that raises blood sugar levels, secreted by the adrenal cortex.

Nervous Cell Communication

This type of communication within the body has a much shorter distance than hormonal communication and a fewer number of affected cells. The speed of the communication is extremely fast.

Neuron

A nerve cell; the basic building block of the nervous system.

Dendrite, Cell Body, Axon, Synaptic Terminal

The four parts of a neuron.

Dendrites

A tangle of fibers that branch from the cell body. They receive information and convert it into electrical signals.