Chapter 13: Endocrine System

The pancreas works as a(n) ______ gland that secretes digestive juices into the pancreatic duct and as a(n) ______ gland that releases hormones into the bloodstream.

exocrine; endocrine

Hormones are released into the ______ space surrounding endocrine cells and then diffuse into the bloodstream.

extracellular

Histologically, the thyroid is composed of sacs called thyroid ______.

follicles

The cavities of follicles in the thyroid gland are lined with cuboidal epithelial cells called ______ cells.

follicular

Where is the thymus located?

in the mediastinum

Stress responses include ______ activity of the sympathetic nervous system and ______ secretion of adrenal hormones.

increased; increased

The two hormones produced by follicular cells in the thyroid gland are known as T3 and T4 because they contain 3 and 4, respectively, atoms of ______.

iodine/I

The ______ and the ______ function mainly in reproduction, but also produce and secrete hormones.

ovaries/ovary; testes/testis

The organ that lies posterior to the stomach and is attached to the small intestine is the ______.

pancreas

Which endocrine organ also acts as an exocrine organ?

pancreas

The glands located on the posterior surface of the thyroid gland are called the ______ glands.

parathyroid

There are four ______ glands, each a small, yellowish brown structure covered by a thin capsule of connective tissue.

parathyroid

The adrenal glands are also known as the ______ glands because they are located atop each kidney.

suprarenal

The ______ are the male organs that secrete testosterone.

testes/testis/testicles/testicle

The testes secrete ______.

testosterone

The hormone sensitivity of a target cell is determined by what factor?

the presence and number of appropriate receptors

The ______ lies in the mediastinum posterior to the sternum and between the lungs.

thymus

The isthmus connects the two lobes of the ______.

thyroid gland

The hormones thyroxine and triiodothyronine are collectively known as ______.

thyroid hormone

Indicate some mechanisms by which hormones exert their effects.

-They alter the metabolic activities of tissues. -They may change the activity of an enzyme. -They may alter the rate of transport of chemicals across the cell membrane.

Choose all characteristics of prostaglandins.

-They are paracrine substances. -They are rapidly inactivated after their release. -They are not stored in cells and are synthesized just before they are released.

Choose all changes that are typically observed in endocrine glands with age.

-They decrease in size. -The proportion of each gland that is fibrous in nature increases. -Lipofuscin accumulates in cells.

Choose all of the following that exhibit increased activity as a response to stress.

-adrenal gland -sympathetic division of the autonomous nervous system

Which two hormones are produced by the adrenal medulla?

-epinephrine -norepinephrine

Which of the following are cells found in the pineal gland?

-pineal cells -neuroglia

Where is the pancreas located?

-posterior to the parietal peritoneum -posterior to the stomach

What are some effects of glucagon?

-raises blood glucose levels -stimulates the conversion of noncarbohydrates (e.g., amino acids) into glucose -stimulates the liver to break down glycogen

What two stages occur during the stress response (general adaptation syndrome)?

-resistance stage -alarm stage

Choose all of the following that are major glands of the endocrine system.

-thymus -thyroid -pancreas

The thyroid gland is a vascular structure made of two lateral ______ connected by a broad isthmus.

lobes

Epinephrine and norepinephrine are synthesized in the portion of the adrenal gland called the adrenal ______.

medulla

The adrenal glands consist of an inner region called the ______ and an outer region called the ______.

medulla; cortex

The blood levels of MOST hormones are regulated by ______ feedback systems.

negative

There are three general mechanisms that regulate hormone secretion and they all involve ______.

negative feedback

Together, the ______ system and the ______ system coordinate and execute communication throughout the body.

nervous; endocrine

The pineal gland consists of specialized pineal cells and supportive ______.

neuroglia

What gland is a small, yellowish brown structure covered by a thin capsule of connective tissue?

parathyroid gland

Environmental factors that are harmful or potentially harmful to tissues can result in ______ stress.

physical

What type of stress results from environmental factors that are harmful or potentially harmful to tissues?

physical stress

Which endocrine gland is located in the brain?

pineal gland

Which endocrine gland is housed in the sella turcica of the sphenoid bone?

pituitary gland

The parathyroid glands are small glands located on the ______ surface of the thyroid gland.

posterior

Compounds called ______ are potent paracrine substances that are made when needed and released in small amounts.

prostaglandins

Match the types of secretory cell in the anterior lobe of the pituitary to the hormones they secrete. Instructions

somatotropes : GH mammatropes : PRL thyrotropes : TSH corticotropes : ACTH gonadotropes : FSH LH

Which of the following is a unique feature of the endocrine system?

Its organs are not anatomically adjacent to each other.

What is the meaning of the word root cort-?

bark

The secretions of the neuronal axons found in the posterior pituitary are considered hormones and not neurotransmitters because they enter the ______.

bloodstream/blood

Steroid hormones are synthesized from ______, while nonsteroid hormones are synthesized from ______ ______.

cholesterol; amino acids

Bark or rind is the meaning of the prefix ______

cort/cort-

What hormones are produced by the anterior pituitary lobe (adenohypophysis)?

-ACTH -LH -PRL -GH

What are characteristics of the pituitary gland?

-It is located in the sella turcica of the sphenoid bone. -It is connected to the hypothalamus by the infundibulum.

What are the two main functions of the pancreas?

-It secretes certain hormones. -It secretes digestive enzymes.

The half-life of a hormone is the time required for ______ of the hormone molecules to be removed from plasma.

50%

Consider a hormone with the half-life of twenty minutes. If secretion were to stop, its concentration would drop by ______% in twenty minutes.

50/fifty

True or false: The inner core of the adrenal gland is called the adrenal cortex.

False

The parathyroid gland secretes the hormone ______.

PTH

True or false: Certain cells of the digestive tract, the heart, and the kidneys are components of the endocrine system.

True

True or false: Hormones are released into the extracellular space surrounding endocrine cells and then diffuse into the bloodstream.

True

True or false: The posterior lobe of the pituitary consists mainly of nervous tissue.

True

The parathyroid hormone is ______.

a protein

Steroids such as aldosterone, cortisol and certain sex hormones are produced by the ______.

adrenal cortex

What gland produces cortisol and aldosterone?

adrenal cortex

The body's stress response begins with an immediate ______ stage, followed by a long-term ______ stage.

alarm; resistance

Growth hormone, prolactin, thyroid-stimulating hormone, and others are secreted by which gland?

anterior pituitary

With age, the glands of the endocrine system generally ______ in size, and ______ in the proportion of each gland that is fibrous in nature.

decrease/shrink; increase

The pancreatic hormone that stimulates an increase in blood glucose levels is ______.

glucagon

The adrenal glands are located atop each ______.

kidney

Hormones are classified into two categories based on their chemical composition, ______ hormones and ______ hormones.

steroid; nonsteroid

The term general adaptation syndrome refers to the body's response to ______.

stress/stressors