exam 1 a&p2

What stimulates the parathyroid glands to release parathyroid hormone (PTH)?

low blood calcium levels

When blood glucose levels are too low, ____ in the pancreatic islets secrete _____

alpha cells

glucagon

When blood glucose levels are too high, _____ in the pancreatic islets secrete _____

beta cells

insulin

Which thyroid hormone lowers blood calcium levels?

Calcitonin

Which hormone is part of the acute stress response (“fight or flight”)

epinephrine

Which part of the adrenal gland secretes epinephrine and norepinephrine

adrenal medulla

In the HPT axis, the ______ releases thyrotropin-releasing hormone (TRH) which stimulates thyrotrophs in the _____ to secrete thyroid-stimulating hormone (TSH).

hypothalamus

anterior pituitary gland

TSH stimulates follicular cells in the ____ to produce and secrete thyroid hormones

thyroid gland

_____ diabetes mellitus occurs when beta cells in the pancreas are destroyed by the immune system.

type I

_____ diabetes mellitus occurs when cells are resistant to the effects of insulin and don't take up glucose.

type II

Lipid-soluble hormones require a carrier protein in the blood to reach their target cells.

true

What happens when hormone levels are chronically low?

target cells up-regulate receptors to increase sensitivity

The chemical messengers released by endocrine glands are called ___

hormones

Negative feedback loops help maintain homeostasis by amplifying changes in the body

False

What is the main function of insulin

lower blood glucose levels

Binds to receptors on the cell surface

water-soluble hormones

Can pass through the cell membrane

lipid-soluble hormones

Made from cholesterol

steroid hormones

What is the primary function of cortisol

regular metabolism and stress response

When is melatonin secretion typically highest

night

_______ hormones usually trigger a response by directly altering gene expression inside the target cell

lipid-soluble

The posterior pituitary gland (neurohypophysis) does not make its own hormones

true

What is an environmental toxin that can disrupt endocrine function

Bisphenol A (BPA)

Two hormones amplify each other’s effects on the same pathway

Synergistic

One hormone is required for another to have its full effect

permissive

two hormones oppose each other’s effects or downregulate each other’s receptors

antagonistic

What is most directly influenced by melatonin?

sleep-wake cycles

What best describes the endocrine system?

A collection of glands that secrete hormones into the bloodstream to regulate body functions

What disorder is associated with underproduction of thyroid hormones?

hypothyroidism

Which gland is known as the “master gland”?

pituitary gland

What hormone is secreted by the zona glomerulosa of the adrenal cortex?

aldosterone

The ____ pituitary is regulated by releasing hormones from the hypothalamus via the hypophyseal portal system.

anterior

What stimulates the parathyroid glands to release parathyroid hormone (PTH)?

low blood calcium levels

The activity of hormones in the bloodstream is determined by:

Rate of secretion, rate of hormone inactivation and rate of hormone removal from the body

Which pancreatic cells produce glucagon?

alpha cells

What best describes the primary function of the endocrine system?

Hormonal regulation of body functions

What hormone is primarily released during stress to raise blood glucose levels?

cortisol

Which of the following is a symptom of diabetes mellitus?

excessive thirst and frequent urination

The hypothalamus sends hormonal signals to control pituitary gland activity

true

What is NOT a function of parathyroid hormone (PTH)?

Lowering blood calcium levels by promoting calcium excretion

Water-soluble hormones circulate freely in the blood, while lipid-soluble hormones require transport proteins.

True

Which type of disorder is associated with overproduction of thyroid hormones?

hyperthyroidism

What is the primary function of cortisol?

regulate metabolism and stress response

Which hormone raises blood calcium levels?

parathyroid hormone

axis: HPA

function: stress response

axis: hpg

function: reproduction

axis: hps

function: growth

axis: hpt

function: metabolism

In the HPT axis, the ____ releases thyrotropin-releasing hormone (TRH) which stimatulates thyrotrophs in the _____ to secrete thyroid-stimulating hormone (TSH).

TSH then stimulates follicular cells in the ____ to produce and secrete thyroid hormones. 

hypothalamus, anterior pituitary gland, thyroid gland

In the HPA axis, the hypothalamus releases ____ which stimatulates _____ in the anterior pituitary gland to secrete _____

ACTH then stimulates in the adrenal ____ to produce ______

corticotropin-releasing hormone (CRH), corticotrophs

adrenocorticotropic hormone (ACTH), cortex, cortisol

Posterior pituitary function

releases hormones made by the hypothalamus

anterior pituitary function

synthesizes and secretes hormones

What is the effect of positive feedback on hormone secretion?

it amplifies the original stimulus

what molecule is essential for the synthesis of thyroid hormones?

iodine

____ hormones activate a signaling cascade using secondary messengers

water-soluble

The endocrine system helps regulate growth, metabolism, and reproduction by releasing hormones directly into the bloodstream.

true

What hormone is secreted by the anterior pituitary

Growth Hormone (GH)

The pineal gland primarily secretes which hormone?

melatonin

What behavior is most likely to support healthy endocrine function?

consistent exercise and a balanced diet

after production, most hormones are secreted into which part of the body?

bloodstream

Which blood type is considered the universal donor for red blood cell transfusions?

O-

Which pathway is primarily activated by trauma to the outer portion of blood vessels (external trauma)?

Extrinsic pathway

Which of the following is NOT a function of blood?

nutrient transport

pH regulation

thermoregulation

hormone production

hormone production

What is the most abundant component of whole blood?

plasma

What correctly lists the three major phases of hemostasis in order?

Vascular spasm → Platelet plug formation → Coagulation

Which type of anemia results from a deficiency in vitamin B12 absorption, often due to lack of intrinsic factor?

pernicious anemia

Which of the following leukocytes is primarily responsible for producing antibodies?

B lymphocytes

Why is Rh incompatibility a concern during pregnancy?

Rh-negative mothers can produce antibodies that attack Rh-positive fetal red blood cells

What is the correct sequence of events in the breakdown of heme and the fate of bilirubin?

Heme → Biliverdin → Bilirubin → Liver processing → Excreted in bile and urine

What is the main function of platelets in the blood?

blood clotting

Which plasma protein is most responsible for maintaining osmotic pressure and fluid balance in the blood?

albumin

Why is the flat, biconcave shape of red blood cells beneficial?

because it increases their surface area for gas exchange

where does hemolysis usually take place in the body?

liver and spleen

what is an infarction?

a localized area of tissue death due to lack of oxygen

which enzyme is primarily responsible for breaking down fibrin during fibrinolysis?

plasmin

Regular aerobic exercise tends to:

lower resting heart rate

when blood enters the aorta from the left ventricle, what valve must is pass through?

aortic semilunar

which intercellular junction allows ions to directly flow between neighboring myocytes, creating fast and synchronized contractions?

intercalated discs

during which phase of the cardiac cycle are the semilunar valves open?

ventricular ejection

the right side of the heart acts as the ____ pump, sending blood to the ____

pulmonary, lungs

what can cause an abnormal heart sound or murmur?

valvular stenosis and valvular regurgitation

Exercise involves activation of the ____ nervous system. When norepinephrine binds to B1-adrenergic receptors, this ____ heart rate.

sympathetic, increases

Identify the statements below that describe the pressure within the ventricles during ventricular ejection.

• the pressure within the ventricles is higher than the pressure within the atria

• the pressure within the ventricles is lower than the pressure within the aorta and pulmonary trunk

• the pressure within the ventricles is lower than the pressure within the atria

• the pressure within the ventricles is higher than the pressure within the aorta and pulmonary trunk

the pressure within the ventricles is higher than the pressure within the atria

the pressure within the ventricles is higher than the pressure within the aorta and pulmonary trunk

which blood vessels drain oxygen-poor blood from the myocardium and returns it to the right atrium?

coronary veins

Cardioinhibitory centers use the ____ nerve to send ____ signals to the heart, causing heart rate to ____

vagus, parasympathetic, decrease

When blood enters the right ventricle from the right atrium, what valve must it pass through?

tricuspid

What best describes the function of the pericardium?

it anchors the heart in place and reduces friction during heartbeats

Which blood vessels supply oxygen-rich blood to the heart muscle itself?

coronary arteries

The volume of blood ejected from each ventricle during a contraction is called the _______

stroke volume

the “dub” sound of the heartbeat is primarily due to:

closing of the semilunar valves

Which ECG component indicates ventricular depolarization?

QRS wave

Which of the following best defines afterload and its effect on stroke volume (SV) and cardiac output (CO)?

afterload is the resistance the ventricles must overcome to eject blood; increased afterload decreases SV and CO

Which heart layer is responsible for the contractile force that pumps blood?

myocardium

Which ECG component indicates ventricular repolarization?

T-wave

In order to effectively function as a two-sided pump, the right and left sides of the heart must be kept separate. Which heart layer forms the interatrial and interventricular septa?

myocardium

Which component of the heart's electrical conduction system is known as the pacemaker?

sinoatrial (SA) node

What is the primary function of the auricles of the heart?

to increase the volume capacity of the atria for receiving blood

The “lub” sound of the heartbeat is primarily due to:

closing of the atrioventricular valves

Spontaneous depolarization in autorhythmic cells is primarily caused by:

leaky Na+ channels that allow Na+ influx, leading to a pacemaker potential

Which ECG component indicates atrial depolarization?

P wave