BIO 224 FINAL EXAM

What is the difference between endocrine system and nervous system?

endocrine: uses hormones and can last longer

nervous: does not last that long and mainly uses chemical messengers

What are hormones?

Chemical messengers that regulate functions of other cells

What is a neurohormone?

Chemical signal produced by neuron that function like a hormone

Which group of hormones are made from cholesterol?

Steroid hormones

What is conjugation?

Its direct contact/union of bacteria in which genetic information is shared

What has influence on free hormone concentration?

1. concentration of binding protein - high carrier proteins means less free hormones

2. total hormone level - increase in hormone leads to saturated binding proteins which increases free hormones

3. binding affinity - how strong the hormone can bind to its carrier protein

What is the half-life of a hormone?

time required to reduce a hormones activity by 50%

What do hormones with short half-lives do?

They leave the body quicker, perform rapid action and have a short duration

What happens to a lipid soluble hormone when it is conjugated in the liver?

It becomes water soluble and inactive, making it easier for it to be eliminated

What regulates the secretion of hormones?

Negative feed back loops

What is down regulation?

Decrease in receptors that a target cell displays due to high exposure of hormone

What is up regulation?

Increase in receptors in a target cell due to a temporary increase of hormone in blood

Where are the receptors for water-soluble hormones?

On the plasma membrane they can’t go inside the cell

What is the cascade effect in terms of hormones?

The signaling process of where one hormone triggers the release of another leading to bigger and wider response

Which kinds of hormones diffuse easily through plasma membranes?

Hydrophobic hormones

What are the functions of the endocrine system?

Synthesize and secretes hormones for: Homeostatsis of fluid, electrolyte, and acid-base, Promote growth, Metabolic reactions

What regulates the secretory activity of the pituitary gland?

hypothalamus

Where do you find the infundibulum?

The stalk that connects the hypothalamus to the pituitary gland in the diencephalon

What are the 2 functional units of the pituitary gland?

Adenohypophysis and neurohypophysis

Which system carries hormones from the hypothalamus to the anterior pituitary?

Hypophyseal portal system

What is the hypothalamo-hyphophyseal tract?

Transports neurohormones from the hypothalamus down to the posterior pituitary

Which hormones are secreted by the above method?

ADH and oxytocin

Why is ADH also known as vasopressin?

Water retention it vasoconstricts

What hormone is secreted when we have increased osmotic pressure of body fluids?

ADH, returns osmolarity to normal by increasing water reabsorption in the kidneys

What would happen if there is a decrease in blood volume?

hypovolemia

• lead to organs not getting enough oxygen

• hormones that may be released: renin. angio 2, ADH, epinephrine, etc

What hormone is given to women to induce labor?

oxytocin

What hormone plays a role in the ejection of milk?

oxytocin

Which hormones are synthesized in the hypothalamus?

Oxytocin, ADH,

inhibiting hormones: TRH, GnRH, CRH, GHRH, somastatin

If intake of fluids increase dramatically, what hormone is secreted?

ADH is decreased

What is the role of osmoreceptors?

Are sensory neurons that detect changes in solute concentration to maintain body fluid homeostasis

Regulated water balance by signaling thirst and controlling the release of antidiuretic hormone

What happens to urine volume when ADH secretion decreases?

Urine volume decreases because ADH retains water

Which hormones are secreted in anterior pituitary?

Tropic hormones that control secretion of hormones by endocrine glands in the body

What gland is located on the Sella turcica?

Pituitary gland

What causes gigantism?

Hypersecretion of GH before epiphyseal plates closed

• Tall people

What causes acromegaly?

excessive growth hormone after epiphyseal plates close

• growth in extremities, hands, face, heart

When would someone secrete beta-endorphins?

If they were in pain, extensive exercise

What hormone is required for ovulation?

LH

Which glands are regulated by the pituitary gland?

thyroid gland, adrenal gland, reproductive glands

What symptoms do you have if you have hypersecretion of thyroid hormone?

Hyperthyroidism: weight loss, heat intolerance, goiter, expthalmos

What is required for synthesis of thyroid hormones?

1. iodine, thyroglobulin, TPO enzyme, TSH

2. secreted when the body needs metabolic boost or if the body is cold

What hyposecretion leads to weight gain?

Hypothyroidism: underproduction of thyroid hormone

What hormone regulates secretion of thyroid hormones?

Thyroid stimulating hormone (TSH)

What is the function of PTH?

Increase blood Ca+ from the bones

• increase kidney reabsorption and phosphate excretion

When is PTH increasingly secreted?

When blood Ca is decreased

What are the endocrine glands found superior to kidneys?

Adrenal glands

Which hormones are secreted in the adrenal cortex?

Aldosterone, cortisol and androgens

Which hormones are secreted in adrenal medulla?

Catecholines: epinephrine and norepinephrine

What is Cushing’s syndrome?

Hypersecretion of cortisol

• Symptoms include: weight gain, buffalo hump, moon face and high blood pressure

• Due to a potential tumor or high steroid use

Due to a potential tumor or high steroid use

Symptoms include: weight gain, buffalo hump, moon face and high blood pressure

What is the function of insulin?

Decrease glucose levels in the blood

When is glucagon secreted?

When blood glucose levels are low

What cells are affected by glucagon?

Liver cells (hepatocytes)

• to release glucose in the blood and increase blood sugar level

What would happen if a person forgot their insulin?

Hyperglycemia, increase in glucose levels in the blood

What determines the secretion of melatonin?

light exposure and bodys internal clock

• darkness: increases hormone

• light: decreases hormone

BLOOD

What are the functions of blood?

Transport of gases, nutrients and waste produces, Regulate pH, maintain body temp and protect against foreign substances, clot formation

Which protein is abundant in blood?

albumin

What component of plasma contributes to blood clots?

fibrinogen

Where do RBCs develop from?

From red bone marrow

What carries oxygen in blood?

hemoglobin

How many molecules of O2 molecules are transported by hemoglobin?

4 molecules of Oxygen, 4 polypeptides each bond to a heme group that each binds to oxygen

What gas is also carried by the beta globin and helps regulate blood pressure? -

Nitrous oxide

What metal is required to produce hemoglobin?

iron

What happens when defective erythrocytes are broken down?

What is bilirubin and what does it cause?

Comes from hemoglobin being broken down into heme which is then broken down into biliverdin and then into bilirubin, Yellowish waste product

Which group of cells are numerous among leukocytes?

Neutrophils: active phagocytes that ingest and destroy bacterial cells

What draws white cells to area of infection?

Chemotaxis

If someone has increased eosinophil count, what are they suffering from?

Infection, parasitic worms or allergic reaction

What is the function of platelets?

Involved in hemostasis, process the stops blood loss

Where do platelets come from?

Thrombopoiesis: Mature megakaryocytes that break off into platelets

In the intrinsic pathway, what triggers the cascade by coming into contact with collagen?

Inactive protein clotting factor XII (hagemen factor) comes in contact with collagen fibers

What is Coumadin or warfarin?

Anticoagulant that stops production of vit k-dependent clotting factors

What is the function of plasmin?

An enzyme: it degrades fibrin leading to dissolving of the clot

What vitamin is necessary for clotting factors in liver?

Vitamin K

What is agglutination?

Antibodies that bind to antigens and cause them to clump together

When does agglutination happen during transfusion?

Transfusion reaction: when recipient antibodies bind to donor antigens and destroys donor erythrocytes

Which blood type is the universal recipient?

AB+

Who do we give Rhogam to and why?

Given to the Rh negative mother to clear her of the antiRh antibodies

What is hematocrit?

Percentage of RBC in blood

When do we have hemolytic disease of newborn?

Rh positive fetus, and Rh negative mother, Rh antigen of fetus crosses placenta and mother creates antiRh antibodies which can be fatal to fetus

What is blood typing and cross match?

Typing: the blood group a person has can be A, B AB, and O along with + or – for the Rh blood group

CARDIAC/BLOOD VESSELS

What is pulmonary and systemic circuit?

Pulmonary: blood traveling to the lungs, Systemic circuit: blood pumped to the body

What is cardiac tamponade?

Pericardial filled with fluid that results from trauma, cancers, kidney failure, etc,

• Causes: squeezes the heart, and reduce capacity of ventricles to fill and compromises amount of blood pumped

What is endocardium?

Lines the inside of the heart and it made up endothelium

What is a myocardial infarction?

Heart attack, When plaques in coronary arteries rupture and form a clot leaving the muscle tissue to die since it is not being supplies

What is angioplasty?

A balloon is used to open up the blocked vessel of artery and a stent tube is used to keep it open

What is angina pectoris?

Chest pain/ myocardial ischemia: decreased blood flow and O2 to myocardium

What are the atrial ventricular valves of the heart?

Bicuspid and tricuspid valves

What are chordae tendineae?

Attach valves to papillary muscles

What is the function of heart skeleton?

Insulates the portions of the heart, allows for atriums to contract and ventricles to relax and vice versa

What is the pacemaker of the heart?

SA node

What is the sequence of electrical conduction of the heart?

SA node -> AV node -> AV bundle -> bundle branches -> Purkinje fibers

What do we use Ca+ channel blockers for?

treat high blood pressure, chest pain and arrythmias by dialating blood vessels to decrease heart rate

What is absolute refractory period?

No response to any stimuli