Nervous, Endocrine, and Reproductive Biology Practice Flashcards

Vocabulary practice flashcards covering the nervous system, endocrine system, reproductive biology, cell division, genetics, and population dynamics based on the lecture notes.

Central Nervous System (CNS)

Your body's command center, responsible for coordination.

Peripheral Nervous System (PNS)

A network of cells that transmits signals between your brain and the rest of your body.

Somatic Nervous System

The part of the nervous system responsible for voluntary movements involving skeletal bones and skin.

Autonomic Nervous System

The part of the nervous system responsible for involuntary actions, subdivided into sympathetic and parasympathetic branches.

Sympathetic Nervous System

Triggers the 'fight or flight' response, increasing adrenaline, cortisol, heart rate, and breathing rate while decreasing digestion.

Parasympathetic Nervous System

Promotes the 'rest and digest' state, decreasing heart rate and breathing rate while increasing digestion.

Neuron

A specialized cell of the nervous system composed of three main parts that transmits signals.

Node of Ranvier

Gaps between Schwann cells that help speed up signal transmission.

Osmoreceptor

A receptor that responds to changes in water ($H_2O$) levels.

Baroreceptor

A receptor that responds to changes in pressure.

Resting Membrane Potential

The membrane potential of a neuron at rest, typically $-70 \text{ mV}$, characterized by high $Na^+$ outside and high $K^+$ inside.

Depolarization

The phase of an action potential where $Na^+$ channels open and $Na^+$ moves into the neuron, causing a charge reversal.

Threshold Potential

The minimum voltage the membrane must reach to trigger an all-or-nothing action potential response.

Refractory Period

The time between impulses when the $Na^+/K^+$ pump reestablishes the resting potential, ensuring signals travel in one direction.

Cerebellum

The brain structure responsible for balance and coordination.

Hypothalamus

The brain region that maintains homeostasis by regulating thirst, releasing hormones, and controlling the pituitary gland.

Medulla Oblongata

The connection between the brain and spinal cord that regulates breathing rate and digestion.

Aqueous Humor

The gel-like substance behind the cornea that maintains shape and pressure in the eye.

Cochlea

A fluid-filled structure in the inner ear lined with hair cells (mechanoreceptors) that respond to sound waves.

Tropic Hormone

A hormone that targets other glands to stimulate the release of further hormones.

Antidiuretic Hormone (ADH)

A hormone targeting the kidneys to increase water reabsorption, released in response to dehydration.

Calcitonin

A thyroid hormone that moves calcium ($Ca^{2+}$) from the blood into the bones, lowering blood calcium levels.

Parathyroid Hormone (PTH)

A hormone that moves calcium ($Ca^{2+}$) from bones into the blood, increasing blood calcium levels.

Insulin

A hormone secreted by beta cells in the pancreas that stimulates the uptake of glucose into cells, lowering blood glucose.

Glucagon

A hormone secreted by alpha cells in the pancreas that stimulates the liver to convert glycogen to glucose, raising blood glucose.

Sertoli Cells

Cells located inside the seminiferous tubules that nourish and support developing sperm.

Luteinizing Hormone (LH)

In males, it stimulates interstitial cells to produce testosterone; in females, a surge triggers ovulation.

Endometrium

The inner lining of the uterus that changes in thickness during the menstrual cycle and is the site of implantation.

Gastrulation

The process after implantation where embryonic cells fold into three layers: ectoderm, mesoderm, and endoderm.

human Chorionic Gonadotropin (hCG)

A hormone secreted by the outer cells of the blastocyst that maintains the corpus luteum and progesterone levels; used to detect pregnancy.

Crossing Over

The exchange of genetic material between homologous chromosomes during Prophase I of meiosis, creating recombinant chromatids.

Nondisjunction

A mistake in meiosis where chromosomes do not separate properly, resulting in gametes with an abnormal number of chromosomes.

Transcription

The first part of protein synthesis occurring in the nucleus where DNA is transcribed into an mRNA transcript.

Missense Mutation

A point mutation that results in a change to a different amino acid.

Codominance

A genetic scenario where both alleles are dominant and the heterozygote expresses both phenotypes simultaneously.

Hardy-Weinberg Principle

The principle describing genetic equilibrium where allele frequencies stay constant, defined by the equation $p^2 + 2pq + q^2 = 1$.

Genetic Drift

A random event that changes the frequency of alleles in a population, including the bottleneck and founder effects.

Climax Community

The stable community at the end of ecological succession, often characterized by lower biodiversity than the recovering community.