TEST 1

The pancreas secretes

- insulin -glucagon

hematocrit definition

% of blood occupied by RBC

Whole blood consists of

55% plasma and 45% formed elements -Erythrocytes (RBC) - Leukocytes (WBC) - Platelets

Summarize the main functions of aldosterone.

Aldosterone has several main functions. 1) Aldosterone maintains the concentrations of extracellular sodium and potassium ions within their normal ranges, 2) Aldosterone regulates extracellular fluid volume, 3) Aldosterone maintains blood pressure, 4) Aldosterone maintains acid-base homeostasis.

Explain the negative feedback loop by which erythropoiesis is regulated.

Answer: The negative feedback loop that maintains erythropoiesis primarily involves the hormone erythropoietin (EPO), with the concentration of oxygen in the blood influencing the production of this hormone. When blood oxygen levels fall below normal, kidney cells detect the falling oxygen levels. The kidneys produce more EPO and release it into the blood. Erythrocyte production in the red bone marrow increases and homeostasis is restored when blood oxygen levels return to normal.

Each of the following is a characteristic of whole blood except A) the ability to absorb heat from active skeletal muscles. B) viscosity about the same as water. C) the ability to neutralize acids. D) a built-in system for clotting.

B

1) Which of the following is a function of the blood? A) transport of nutrients and wastes B) transport of body heat C) transport of gases D) defense against toxins and pathogens E) All of the answers are correct.

E

Discuss some of the effects of epinephrine and norepinephrine in response to a stressor.

Epinephrine and norepinephrine increase heart rate and force of contraction; dilate the bronchioles; constrict the blood vessels supplying the skin, digestive organs, and urinary organs; dilate blood vessels supplying the skeletal muscles; dilate the pupils; and decrease digestive and urinary functions.

Can hormones target all cells of the body?

No, hormones are not able to target all cells of the body. Hormones are only able to affect particular cells known as target cells. Target cells contain specific proteins, referred to as receptors, to which hormones can bind.

Explain how oxyhemoglobin differs from deoxyhemoglobin.

Oxyhemoglobin is formed when oxygen binds hemoglobin. Oxidized hemoglobin turns bright red. Deoxyhemoglobin is formed when hemoglobin releases oxygen into surrounding tissues from systemic capillaries. Blood with a low oxygen concentration is dark red.

Endocrine Signaling

Signals from distant cells are called endocrine signals; they originate from endocrine cells with long acting effects.

paracrine signaling

Signals that act locally between cells that are close together are called paracrine. Neuronal synapses are an example, they have short acting effects

what kind of glands does ES contain?

The endocrine system consists of ductless glands.

Discuss the roles of the first messenger and the second messenger in the second-messenger system.

The first messenger is the hydrophilic hormone that binds to a receptor in the plasma membrane. The binding of the first messenger to the receptor activates an enzyme, which catalyzes the formation of a second messenger inside the cell. The second messenger initiates a series of events in the cell that leads to changes in its activity. The second messenger, not the first messenger, is the molecule actually initiating the cellular change in activity

Hormones released from the posterior pituitary include ?

antidiuretic hormone (ADH) and oxytocin.

Autocrine signaling

are produced by signaling cells that can also bind to the ligand that is released.

A plasma protein essential for blood coagulation is A) albumin alpha. B) fibrinogen. C) immunoglobulin A. D) platelets. E) transport proteins.

b

All leukocytes arise from: A) myeloid stem cells. B) hematopoietic stem cells (HSCs). C) lymphoid stem cells. D) leukoblasts.

b

The process of white blood cell production goes on in all of the following except A) the spleen. B) the kidney. C) the lymph nodes. D) red bone marrow. E) the thymus.

b

What cells are categorized as agranulocytes? A) neutrophils and basophils B) lymphocytes and monocytes C) reticulocytes and erythrocytes D) eosinophils and basophils

b

Which of the following is not a component of plasma? A) electrolytes B) platelets C) fibrinogen D) albumin E) amino acids

b

Which of the following statements about blood is false? A) It contains buffers that control pH. B) Normal pH is 6.8 to 7.0. C) It is more viscous than water. D) It is about 55 percent plasma.

b

Which type of leukocyte may produce antibodies? A) neutrophil B) lymphocyte C) eosinophil D) monocyte

b

Secretion of hormones from a specific gland is controlled by

blood levels of some chemical, another hormone, or nervous system.

what is in the buffy coat?

both leukocytes and platelets.

Each of the following is a way that blood transports materials around the body except A) nutrients from the digestive tract to the body. B) hormones from endocrine glands to target cells. C) carbon dioxide from the lungs to the tissues. D) wastes from the cells to the kidneys. E) stored nutrients from the liver to the tissues.

c

Most of the protein factors that are required for clotting are synthesized by A) platelets. B) megakaryocytes. C) the liver. D) the kidneys. E) the spleen.

c

Plasma proteins essential in body defense are the A) albumins. B) fibrinogens. C) immunoglobulins. D) platelets. E) transport proteins.

c

Red blood cell production is regulated by the hormone A) thymosin. B) angiotensin. C) erythropoietin. D) albumin. E) renin.

c

The combination of plasma and formed elements is called A) serum. B) lymph. C) whole blood. D) extracellular fluid. E) packed blood.

c

The most abundant component of plasma is A) ions. B) proteins. C) water. D) gases. E) nutrients.

c

The most abundant proteins in blood plasma are A) globulins. B) transport proteins. C) albumins. D) lipoproteins. E) fibrinogens.

c

The total volume of blood in the body of an adult male is approximately ________ liters. A) 10 B) 6 to 8 C) 5 to 6 D) 4 E) 3

c

When blood is fractionated, its components are ________ for the purpose of analysis. A) combined B) lysed C) separated D) marked

c

Which of these is not one of the formed elements of blood? A) RBCs B) platelets C) antibodies D) lymphocytes E) basophils

c

Plasma membrane-bound receptors

can produce a response by directly opening ion channels, activating G proteins, or activating enzymes that synthesize intracellular chemical signals, or by phosphorylating proteins inside of the cell. Protein based hormones are not lipid soluble and cannot diffuse through the phospholipid bilayer.

The percent fraction of formed elements relative to whole blood is the A) viscosity. B) specific gravity. C) packed volume. D) hematocrit. E) differential cell count.

d

Which plasma protein is a major contributor to the osmotic pressure of plasma? A) fibrinogen B) steroid-binding protein C) hormone-binding protein D) albumin E) gamma globulin

d

Lipid-soluble hormones, such as the steroids and thyroid hormones... bind where?

enter cell and bind to receptors inside the cell and cause permeability changes or the production of a second messenger inside the cell.

ovaries secrete

estrogen and progesterone. These hormones help control reproductive processes.

RBC mature

flexibility no nucleus cant reproduce life span:120 days

Erythropoietin

from the kidney stimulates erythrocyte production.

The hormones released from the anterior pituitary are?

growth hormone (GH), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, and melanocyte-stimulating hormone (MSH).

Nina is researching hormones that can stimulate and inhibit the release of growth hormone from the anterior pituitary. Predict the type of stimulation that regulates the secretion of growth hormone.

growth hormone is controlled by stimulating and inhibiting hormones. Endocrine cells of the anterior pituitary increase or decrease secretion of growth hormone in response to binding of releasing or inhibiting hormones from the hypothalamus

Mineralocorticoids (aldosterone)

help regulate sodium and potassium levels and water volume in the body. Renin, secreted by the kidneys, helps regulate blood pressure by increasing angiotensin II and aldosterone production. These hormones cause blood vessels to constrict and enhance sodium and water retention by the kidney.

What is the hematocrit?

hematocrit is the percentage of blood composed of erythrocytes (approximately 44%) when whole blood is centrifuged

Monocytes

largest type. leukocyte that is able to migrate into tissues and transform into a macrophage.

basophil

less than 1% associated with release of histamine and heparin

Interior or intracellular receptor

located in the cytoplasm or nuclei and can regulate enzyme activity or regulate the synthesis of specific messenger RNA. Lipid soluble hormones including steroids and thyroid hormones, bind to receptors within target cells because they can cross the phospholipid bilayer

Agranulocytes

lymphocytes (t cells and B cells, and natural killer cells) and monocytes

The pineal body secretes

melatonin, which may help regulate the onset of puberty by acting on the hypothalamus.

The secretion of hormones is controlled by negative-feedback mechanisms.

negative feedback

Hormones secreted from the posterior pituitary are controlled by?

nervous impulses that pass from the hypothalamus through the infundibulum.

Granulocytes

neutrophils, eosinophils, basophils

immature features of red blood cell

nucleus, can reproduce,

Protein and peptide hormones bind to receptors where?

on cell membrane

The parathyroid glands secrete

parathyroid hormone

The adrenal medulla secretes

primarily epinephrine and some norepinephrine.

Glucocorticoids (cortisol)

reduce inflammation and break down fat and protein, making them available as energy sources to other tissues.

Active vitamin D

regulate blood levels of calcium.

The testes secrete

secrete testosterone These hormones help control reproductive processes.

Hormones secreted by cells in the stomach and intestine help regulate

stomach, pancreatic, and liver secretions.

The adrenal cortex secretes

three classes of hormones. Glucocorticoids (cortisol) Mineralocorticoids (aldosterone) help regulate sodium and potassium levels and water volume in the body. Renin, secreted by the kidneys, helps regulate blood pressure by increasing angiotensin II and aldosterone production. These hormones cause blood vessels to constrict and enhance sodium and water retention by the kidney. o Adrenal androgens increase female sexual drive; normally adrenal androgens have little effect in males.

thyroid gland secretes?

thyroid hormones and calcitonin

List the tropic hormones released by the anterior pituitary gland.

thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH)prolactin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH).

thyroid hormones

which control the metabolic rate

calcitonin

which helps regulate blood calcium levels.

parathyroid hormone,

which helps regulate blood levels of calcium

leukocytes

white blood cells, fight infection granulocytes and agranulocytes

What is different about the hormones of the posterior pituitary and how are they transported?

-The posterior pituitary makes no hormones of its own. -it stores and releases two neurohormones, antidiuretic hormone and oxytocin - axons transport ADH for storage in axon terminals in the posterior pituitary

Explain the three types of stimuli that regulate hormone secretion.

1. hormonal stimuli- some endocrine cells increase or decrease their secretion in response to other hormones.2. humoral stimuli.many endocrine cells respond to the concentration of a certain ion or molecule in the blood or extracellular fluid. Third, some cells respond to signals from the nervous system. These cells release neurohormones in response to neural stimuli.

Eosinophils

2-4% of all WBCs numerous in mucous membranes for parasitic infections

neutrophils

50-75% tot. Most abundant white blood cell.Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.

vitamins for erythropoiesis

B12 and folic acid

Explain how glucagon and insulin maintain normal blood glucose levels.

Beta cells of the pancreas increase insulin production when blood glucose levels increase beyond the normal range. Insulin decreases blood glucose levels by increasing glucose uptake by cells and storage of glucose, amino acids, and fats. As the blood glucose level returns to its normal range, negative feedback to beta cells decreases insulin secretion. If the blood glucose level decreases below the normal range, such as through fasting, alpha cells of the pancreas increase glucagon production. Glucagon triggers the breakdown of glycogen into glucose and the formation of new glucose through gluconeogenesis to raise blood glucose levels. As the blood glucose level returns to its normal range, negative feedback to alpha cells decreases glucagon secretion.

Explain how cortisol helps mediate the body's response to stress.

First, cortisol increases blood glucose levels during stress by targeting the liver to convert amino acids and fats into glucose by gluconeogenesis. Second, cortisol targets muscle tissue to induce the breakdown of muscle proteins into amino acids that are sent to the liver for gluconeogenesis. Third, cortisol targets adipose tissue to break down fatty acids and release them into the blood stream. These fatty acids provide additional fuels for continued muscle activity. Finally, cortisol prevents inflammation by decreasing the levels of certain leukocytes.

erythropoiten

From the kidney; this hormone increases production of red blood cells

Direct signaling across gap junctions

Gap junctions in animals are connections between the plasma membrane of neighboring cells. Example is cardia tissue; gap junctions allow the atria and ventricles to contract as a unit because it links depolarization's via gap junctions.

Discuss the relationship between growth hormone (GH) and insulin-like growth factor (IGF).

Growth hormone (GH) acts on the liver and other target tissues to promote the release of insulin-like growth factor (IGF). IGF carries out the long-term effects of GH. IGF acts on nearly every cell type in the body, and triggers rapid protein synthesis and cell division. In children, IGF leads to increased longitudinal bone growth and muscle development in children. IGF also decreases blood glucose concentration by stimulating glucose uptake by cells, an action opposite to acute GH release.

structure of hemoglobin

Hemoglobin is a protein found in erythrocytes that consists of four polypeptide subunits: two alpha chains and two beta chains. Each chain is bound to an iron-containing compound called a heme group. The iron ion in each heme binds to oxygen and becomes oxidized.

Discuss the two basic types of hormones, classified according to their chemical structure.

Hormones are classified as amino acid-based or steroid. Amino acid-based hormones vary in size from single amino acids, to several amino acids, to complete proteins. Steroid hormones are cholesterol derivatives. While amino acid-based hormones are generally hydrophilic, all steroid hormones are hydrophobic and can interact with either intracellular or plasma membrane receptors.

Discuss how parathyroid hormone (PTH) maintains normal blood calcium ion concentration

Hypocalcemia occurs when the calcium ion level in the blood decreases below normal. Parathyroid hormone (PTH) is released by the chief cells of the parathyroid glands to increase blood calcium ion concentration. The main effects of PTH are to 1) increase release of calcium ions from bone by stimulating osteoclasts, 2) increase absorption of dietary calcium ions by the small intestine, and 3) increase reabsorption of calcium ions from the fluid in the kidney

iron

Necessary for red blood cells

Explain how the hypothalamus controls the release of hormones from the anterior pituitary gland.

The hypothalamus controls many functions of the anterior pituitary through the production and release of tropic hormones that affect its secretions. These hormones are called releasing hormones and inhibiting hormones because they either stimulate or inhibit the release of hormones from the anterior pituitary. These releasing and inhibiting hormones are delivered to the anterior pituitary by the hypothalamic-hypophyseal portal system.

Lymphocytes

The two types of white blood cells that are part of the body's immune system: B lymphocytes form in the bone marrow and release antibodies that fight bacterial infections; T lymphocytes form in the thymus and other lymphatic tissue and attack cancer cells, viruses, and foreign substances.

Brenda's blood test that reveals high levels of thyroid-stimulating hormone (TSH) but low levels of triiodothyronine, or T3, and thyroxine, or T4. Determine if these results are normal or if they reveal a homeostatic imbalance. Explain to support your answer.

These blood test results are not normal; these results are consistent with a homeostatic imbalance known as hypothyroidism. With hypothyroidism, the thyroid gland is unable to produce enough T3 and T4. In response, the hypothalamus and pituitary gland continue to prod the thyroid gland through increased secretion of thyrotropic-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) in an attempt to stimulate the thyroid gland. This leads to the characteristic elevated TSH and decreased T3 and T4 levels seen with hypothyroidism.

epinephrine and norepinephrine.

These hormones help prepare the body for physical activity.

Explain how thyroid hormones bind with receptors associated with their target cells.

Thyroid hormones are amino acid-based hormones, but their amino acids are nonpolar and hydrophobic so they are classified as lipid soluble. Therefore, thyroid hormones do not bind to cell-surface receptor proteins. Instead, they diffuse into target cells and then bind to intracellular receptors in the nucleus. Like steroid hormones, the thyroid hormones either activate or inactivate the transcription of certain genes.

Functions of the Endocrine System

Water balance; uterine contractions: milk release from the breasts; metabolism; tissue maturation; sodium, potassium, and calcium ion concentration of blood; heart rate; blood pressure; preparation for physical activity; blood glucose concentration; immune cell production; and reproductive functions in males and females.

List the three distinct zones of the adrenal cortex, from superficial to deep, and identify the group of steroid hormones produced by each.

Zona glomerulosa is the most superficial zone of the adrenal cortex. This region of cells produces mineralocorticoids. Zona fasciculata is the middle zone while the zona reticularis is the inner zone. These two regions secrete glucocorticoids and androgenic steroids.

Plasma composes about ________ percent of whole blood, and water composes ________ percent of the plasma volume. A) 55; 92 B) 92; 7 C) 92; 55 D) 45; 55 E) 50; 50

a

The normal pH of blood is A) slightly alkaline. B) neutral. C) slightly acidic. D) extremely alkaline. E) extremely acidic.

a

hemeoglobulin

a protein in red blood cells that carries oxygen

LH and FSH from the pituitary gland control

hormone secretion from the ovaries and testes.

· The prostaglandins

hormones that have a local effect, produce numerous effects on the body, and play a role in inflammation.

The placenta secretes

human chorionic gonadotropin, estrogen, and progesterone, which are essential to the maintenance of pregnancy.

Secretions from the anterior pituitary are controlled by ?

hypothalamic-releasing hormones that pass through the hypothalamic-pituitary portal system from the hypothalamus.

Insulin

in response to elevated levels of blood glucose and amino acids. increases the rate at which many tissues, including adipose tissue, liver, and skeletal muscles, take up glucose and amino acids.

Glucagon

in response to reduced blood glucose and increases the rate at which the liver releases glucose into the blood.

Adrenal androgens

increase female sexual drive; normally adrenal androgens have little effect in males.