Biology 1203: Human Anatomy and Physiology II - Unit 1: The Endocrine System

Fill-in-the-blank practice flashcards for Biology 1203 Unit 1: The Endocrine System, focusing on cell communication, hormone categories, signaling pathways, feedback regulation, and endocrine glands.

Communication between cells is called __________ signaling.

intercellular

Communication within a cell is called __________ signaling.

intracellular

Intercellular signaling requires chemical signals that are released by signaling cells in the form of small, usually soluble molecules called __________.

ligands

Ligands interact with proteins in target cells, which are called __________.

receptors

When the cell that secretes the ligand also has the receptor for the ligand, allowing it to respond to its own signal, this is known as __________ signaling.

autocrine

In autocrine signaling, immune cells can become activated in response to their own secretion of __________.

interleukin

Platelets respond to their own __________ molecules during blood clotting as an example of autocrine signaling.

prostaglandin

Signals that act locally between cells that are close together are called __________ signals.

paracrine

Paracrine signals move by diffusion through the __________ matrix.

extracellular

Neurotransmitter signaling at synapses and neuromuscular junctions is an example of __________ signaling.

paracrine

Prostaglandins are specialized lipids produced by many cell types from lipids in their own __________ membranes.

plasma

Prostaglandins usually act as a ligand in __________ or paracrine signaling pathways.

autocrine

Prostaglandins are involved in causing fevers, regulating blood pressure, regulating stomach secretions, regulating uterine contractions, and transmission of __________ impulses.

nerve

In __________ signaling, ligands secreted by signaling cells enter into the bloodstream and affect distant cells anywhere in the body.

endocrine

Ligands secreted in endocrine signaling are referred to as __________.

hormones

Structures that secrete hormones directly into the bloodstream are known as __________ glands.

endocrine

The hormones of the human body can be divided into two major groups: those derived from amino acids and those derived from __________.

lipids

Amine hormones are derived from the modification of __________.

amino acids

Epinephrine and norepinephrine are examples of __________-derived amine hormones.

amino acid

Peptide hormones consist of short chains of amino acids, whereas __________ hormones are longer polypeptides.

protein

Antidiuretic hormone is categorized as a __________ hormone.

peptide

Growth hormone and Follicle-stimulating hormone are examples of __________ hormones.

protein

Steroid hormones are derived from the lipid __________.

cholesterol

Testosterone, Estrogens, Aldosterone, and Cortisol are examples of __________ hormones.

steroid

Because blood is water-based, hydrophobic steroid hormones must travel to their target cell bound to a __________ protein.

transport

A hormone's __________ is the time required for half the concentration of the hormone to be degraded.

half-life

The lipid-derived hormone cortisol has a half-life of approximately $60$ to $90$ minutes, compared to epinephrine which has a half-life of approximately $1$ __________.

minute

Intracellular hormone receptors are located inside the cell, so hormones binding to them must be able to cross the __________ membrane.

cell

After steroid hormones bind with their receptors in the cytoplasm, they __________ and translocate to the nucleus.

dimerize

Dimerized steroid hormone receptors in the nucleus drive __________ expression of target genes.

gene

Hydrophilic or water-soluble hormones are unable to diffuse through the lipid bilayer and must bind to __________ receptors.

cell-surface

Binding of hydrophilic hormones to cell-surface receptors initiates a series of sequential activation of __________ within the cell.

enzymes

Transcriptional activators stimulate mRNA transcription, leading to __________ of a protein being made.

more

Transcriptional repressors inhibit mRNA transcription, leading to __________ of a protein being made.

less

By changing the __________ composition of a cell, hormones can change the behavior of a cell.

protein

A __________ is the physiological value around which the normal range fluctuates.

set point

A __________ is the restricted set of values that is optimally healthful and stable.

normal range

__________ feedback is a mechanism that reverses a deviation from the set point, maintaining parameters within their normal range.

Negative

__________ feedback is a mechanism that intensifies a change in the body's physiological condition rather than reversing it.

Positive

Positive feedback loops end when the original __________ is removed from the system.

stimulus

In a feedback loop, a sensor or receptor detects when the stimulus produces a deviation in a physiological value away from the __________.

set point

The __________ signal in a feedback loop reports the change in value from the sensor to the control center.

afferent

The __________ center is the component in a feedback system that compares the value to the normal range.

control

The __________ signal carries instructions from the control center to an effector.

efferent

An __________ is the component in a feedback system that produces a response.

effector

A __________ stimulus for hormone release refers to blood levels of non-hormone chemicals such as nutrients or ions.

humoral

A __________ stimulus involves the presence of another hormone produced by a different endocrine gland.

hormonal

In hormonal regulation of glucocorticoids, the hypothalamus releases corticotropin-releasing hormone (CRH) when it perceives low blood concentrations of __________.

glucocorticoids

The nervous system uses two types of intercellular communication: electrical and __________ signaling.

chemical

In nervous signaling, the target cell responds within __________ of receiving the chemical signal.

milliseconds

Nervous signaling affects and receives stimuli from both the internal environment of the body and the __________ environment around it.

external

Endocrine signaling uses chemical signaling through hormones that travel in the __________.

blood

Hormone signaling only affects and responds to stimuli in the __________ environment of the body.

internal

Endocrine signaling is typically __________ specific than neural signaling.

less

__________ glands have tubes or ducts to carry their secretions to another part of the body.

Exocrine

Salivary glands, mammary glands, and sweat glands are examples of __________ glands.

exocrine

__________ glands do not have ducts and release hormones directly into blood and lymph.

Endocrine

Organs containing both endocrine and exocrine tissue include the pancreas, stomach, and __________ intestine.

small

The pineal gland and pituitary gland are located in the region of the __________.

head

The __________-pituitary complex can be thought of as the 'command center' of the endocrine system.

hypothalamus

The hypothalamus is located anterior and inferior to the __________ in the diencephalon.

thalamus

The pituitary gland is suspended from the hypothalamus by a stem called the __________.

infundibulum

The anterior pituitary consists of __________ tissue, whereas the posterior pituitary consists of neural tissue.

glandular

Releasing hormones secreted by the hypothalamus __________ the secretion of hormones from the anterior pituitary.

stimulate

Inhibiting hormones secreted by the hypothalamus __________ the secretion of hormones from the anterior pituitary.

inhibit

Corticotropin-releasing hormone (CRH) stimulates the release of __________ hormone.

adrenocorticotropic

Thyrotropin-releasing hormone (TRH) stimulates the release of __________ hormone.

thyroid-stimulating

Gonadotropin releasing hormone (GnRH) stimulates the release of follicle-stimulating hormone and __________ hormone.

luteinizing

The two inhibiting hormones produced by the hypothalamus are Growth hormone inhibiting hormone and __________ inhibiting hormone.

Prolactin

Hormones that travel to and affect the function of other endocrine glands are collectively referred to as __________ hormones.

tropic

Growth hormone promotes protein synthesis, increases catabolism of fats, and __________ down the catabolism of carbohydrates.

slows

Prolactin promotes __________ (milk production) in women.

lactation

In a non-pregnant woman, prolactin secretion is inhibited by prolactin-inhibiting hormone released from neurons in the __________.

hypothalamus

Adrenocorticotropic hormone stimulates the adrenal __________ to secrete corticosteroid hormones such as cortisol.

cortex

Follicle-stimulating hormone promotes follicular growth in females, which then release __________.

estrogens

Luteinizing hormone triggers __________ in women and stimulates testosterone production in males.

ovulation

The posterior pituitary does not produce hormones, but stores and releases oxytocin and __________ hormone.

antidiuretic

Oxytocin facilitates childbirth via a __________ feedback loop.

positive

In the oxytocin feedback loop during childbirth, stretch receptors in sensory neurons send an afferent signal to the __________.

hypothalamus

Antidiuretic hormone (ADH) regulates blood osmolarity, and high blood osmolarity is detected by __________ in the hypothalamus.

osmoreceptors

In response to ADH, the kidneys reabsorb __________ water during urine formation.

more

The thyroid gland is located anterior to the trachea, just inferior to the __________.

larynx

Thyroid hormone consists of two compounds: thyroxine and __________.

triiodothyronine

Thyroid hormones influence the body's __________ metabolic rate, which is energy used at rest.

basal

Calcitonin is released by the thyroid gland to __________ blood calcium levels.

decrease

Calcitonin decreases blood calcium levels by inhibiting __________ in bones and preventing calcium reabsorption in kidneys.

osteoclasts

The parathyroid glands are tiny structures embedded in the __________ surface of the thyroid gland.

posterior

Parathyroid hormone (PTH) acts to __________ blood calcium levels.

increase

Parathyroid hormone triggers kidney production of __________, the active form of vitamin D3.

calcitriol

The adrenal glands adhere to the top of the __________.

kidneys

The outer cortex of the adrenal gland is glandular tissue, while the inner medulla is __________ tissue.

nervous

Aldosterone is a mineralocorticoid that causes the kidneys to reabsorb more __________ from urine filtrate.

sodium

In response to low blood pressure, the kidneys release the enzyme __________ to start the cascade producing aldosterone.

renin

Cortisol is a glucocorticoid that promotes the conversion of fats and proteins into sugars, a process called __________.

gluconeogenesis

The adrenal medulla produces epinephrine and __________.

norepinephrine

The first stage of the general adaptation syndrome is called the __________ reaction.

alarm

In the second stage of stress response, the stage of resistance, the primary stress hormone is __________.

cortisol

Alpha cells of pancreatic islets secrete glucagon, while beta cells secrete __________.

insulin

The metabolic breakdown of glycogen into component glucose building blocks is called __________.

glycogenolysis

The hormone gastrin is produced by the stomach and secretin is produced by the __________.

duodenum