bad but whatever

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

Sensor

detects a change in the internal environment

Integrator

compares existing conditions with ideal conditions

Effector

acts to return the system to its optimal state

Negative feedback

A type of regulation that responds to a change in conditions by initiating responses that will counteract the change. Maintains a steady state.

Positive feedback

A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.

vasoconstriction

Reduces blood flow and heat transfer by decreasing the diameter of superficial blood vessels.

vasodilation

A widening of the diameter of a blood vessel, increasing blood flow

Endotherms

Animals (such as birds or mammals) that can regulate their body temperature.

Ectotherms

An animals that warms itself mainly by absorbing heat from its surroundings

Pikilotherm

An organism that does not have constant body temperature

Osmoregulation

regulation of solute concentrations and water balance by a cell or organism

Excretory system

the system that removes waste from your body and controls water balance

Nitrogenous

__________________ waste is excreted through the excretory system

Inferior vena cava

A vein that is the largest vein in the human body and returns blood to the right atrium of the heart from bodily parts below the diaphragm.

Renal artery

blood vessel that carries blood to the kidney (C)

Renal vein

blood vessel that carries blood away from the kidney and toward the heart (D)

Aorta

Largest artery in the body

Urinary Bladder

stores urine

Urethra

tube leading from the urinary bladder to the outside of the body

Kidneys

Filter waste from the blood like urea, water, salt and proteins.

Renal cortex

outer region of the kidney

Renal medulla

inner portion of the kidney

Nephron

functional unit of the kidney

Glomerulus

A ball of capillaries surrounded by Bowman's capsule in the nephron and serving as the site of filtration in the vertebrate kidney.

Bowmans capsule

cup-shaped strucutre of the nephron of a kidney which encloses the glomerulus and which filtration takes place.

Proximal tubule

In the vertebrate kidney, the portion of a nephron immediately downstream from Bowman's capsule that conveys and helps refine filtrate.

Loop of Henle

section of the nephron tubule that conserves water and minimizes the volume of urine

Distal tubule

In the vertebrate kidney, the portion of a nephron that helps refine filtrate and empties it into a collecting duct.

Collecting duct

A segment of the nephron that returns water form the filtrate to the bloodstream.

Renal pelvis

funnel-shaped reservoir that collects the urine and passes it to the ureter

Ureter

tube that carries urine from the kidney to the urinary bladder

Blood vessels

tubelike structures that carry blood throughout the body

Glomerular filtration

The first step in urine formation in which substances in blood pass through the filtration membrane and the filtrate enters the proximal convoluted tubule of the nephron.

Tubular reabsorption

process of reclaiming water and solutes from the tubular fluid and returning them to the blood

Tubular secretion

selectively moves substances from blood to filtrate in renal tubules and collecting ducts

water reabsorption

removes water from the filtrate and returns it to the blood

Endocrine glands

Glands of the endocrine system that release hormones into the bloodstream

Hormones

chemical substances that carry messages through the body in blood

neurons

The nervous system uses _______, while the endocrine system uses hormones.

Stimulus

A change in an organism's surroundings that causes the organism to react

Receptor protein

a protein that binds specific signal molecules, which causes the cell to respond

Hypothalamus

brain region controlling the pituitary gland

Pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, this gland regulates growth and controls other endocrine glands.

circulatory

Hormones are secreted into the _______________ system

target cells

cells that have receptors for a particular hormone

Reception

The target cell's detection of a signal molecule coming from outside the cell.

Signal transduction

A series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell.

Response

An action or change in behavior that occurs as a result of a stimulus.

Protein hormones

class of hormones that cannot pass through the cell membrane; less likely to be stored in the body. Composed of chains of amino acids

Steroid hormones

enter the target cells and have a direct effect on the DNA of the nucleus. Composed of cholesterol

Water

Protein hormones are __________ soluble

Hydrophilic

Having an affinity for water.

Hydrophobic

Having an aversion to water; tending to coalesce and form droplets in water.

Lipid

Steroid hormones are _________ soluble

gene expression

process by which a gene produces its product and the product carries out its function

Epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

pineal gland

secretes melatonin

thyroid gland

produces hormones that regulate metabolism, body heat, and bone growth

parathyroid gland

any one of four endocrine glands situated above or within the thyroid gland

adrenal gland

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

Pancreas

Regulates the level of sugar in the blood

Ovary

Gland that produces the egg cells and hormones in women

Testis

male reproductive organ that produces sperm and hormones

Nontropic hormones

directly stimulate cellular metabolism and other activities

Tropic hormones

hormones that stimulate other glands to release their hormones

anterior pituitary gland

Makes and secretes six different hormones: FSH, LH, ACTH, TSH, prolactin, and growth hormone. Controlled by releasing and inhibiting factors from the hypothalamus

posterior pituitary gland

Stores and releases two important hormones, ADH and oxytocin, into the bloodstream.

ADH

antidiuretic hormone

oxytocin

A hormone released by the posterior pituitary that stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

Insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues

Glucagon

A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels; an antagonistic hormone to insulin.

diabetes mellitus

a group of metabolic disorders characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both

Islets of langerhans

cell clusters in the pancreas that form the endocrine part of that organ

Alpha

_________ cells secrete glucagon

Beta

______ cells secrete insulin

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

Type I Diabetes Mellitus

destroys pancreatic beta cells that produce insulin (insulin-dependent)

Type II Diabetes Mellitus

pancreas produces normal to high levels of insulin but cells fail to respond; tends to develop later in life (non-insulin dependent)

Hormone cascade pathway

A hormone can stimulate the release of a series of other hormones, the last of which activates a nonendocrine target cell

Hypothyroidism

condition of hyposecretion of the thyroid gland causing low thyroid levels in the blood that result in sluggishness, slow pulse, and often obesity

Hyperthyroidism

excessive activity of the thyroid gland. Consequently, they feel warm, do not tend to gain weight, sweat profusely, and are sometimes irritable

Calcitonin

Lowers blood calcium levels

Parathyroid hormone

increases blood calcium levels

central nervous system

consists of the brain and spinal cord

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

Reflex arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.

Neuron

a nerve cell; the basic building block of the nervous system

Glial cells

cells in the nervous system that support, nourish, and protect neurons

Dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Cell body

Largest part of a typical neuron; contains the nucleus and much of the cytoplasm

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

Axon terminal

The endpoint of a neuron where neurotransmitters are stored

Afferent neurons

Nerve cells that carry impulses towards the central nervous system

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Efferent neurons

Nerve cells that conduct impulses away from the central nervous system

Schwann cells

Supporting cells of the peripheral nervous system responsible for the formation of myelin.

Myelin

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

membrane potential

The voltage across a cell's plasma membrane.

nerve impulse

A signal transmitted along a nerve fiber.