Rios Salado Bio202 Exam 1
The heart is a very important muscle in our body that keeps blood flowing to our tissues
to keep them nourished with oxygen and help transport carbon dioxide waste to the
lungs for gas exchange. The heart uses electrical impulses from specialized nodes to
trigger the cardiac muscles to contract, which in turn leads to the continuous pumping
function of the heart.
The specialized nodes of the heart are the sinoatrial (SA) node and the atrioventricular
(AV) node. The SA node is located in the right atrium and is inferior to the superior vena
cava entrance. The SA node is the pacemaker of the heart and sets the rate of
depolarization that begins the
electrical signal that tells the heart to contract. The AV node is located in the lower
atrial septum at the junction of the atria and ventricles. The AV node's function is to
delay the contraction of the ventricles until the atrial contraction is complete for 0.1s.
The - answerOn Exam 1 you will be presented with an essay question. The essay topic
is cardiac impulse generation.
You will be asked to compose an essay about the cardiac impulse generation and
conduction.
a. A discussion cardiac conduction should begin with description of the specialized
nodes (autorhythmic character) of the heart and their locations.
b. The sequence should be discussed as well as coordinating location in the heart.
c. The actual innervation of the cardiac muscle and appropriate structures should be
considered.
d. Correlation between the stages of impulse should be related to the flow of blood,
contraction of the chambers and open and closing of the valves.
second great control system of the body that interacts with the nervous system to
coordinate and integrate the activity of body cells - answerEndocrine system
o Influences metabolic activity by means of hormones (chemical messengers secreted
by cells into the extracellular fluid)
• Reproduction
• Growth and development
• Maintenance of electrolyte, water, and nutrient balance of the blood
• Regulation of cellular metabolism and energy balance
• Mobilization of body defenses - answerWhat does the Endocrine system influence?
the scientific study of hormones and the endocrine organ - answerEndocrinology
,neural functioning plus releases hormones (hypothalamus) - answerNeuroendocrine
organ
chemicals that exert their effects on the same cells that secrete them, short-distance
signals (smooth muscle cells to contract smooth muscle cells) - answerAutocrines
act within the same tissue, but affect cell types other than those releasing the paracrine
chemicals (somatostatin released by one group of pancreatic cells inhibits the release of
insulin by a different group of pancreatic cells) - answerParacrines
long-distance chemical signals that travel in blood or lymph throughout the body -
answerHormones
produce non-hormonal substances (sweat and saliva) and have ducts that carry these
substances to a membrane surface - answerExocrine glands
ductless glands, produce hormones, release hormones into the surrounding tissue fluid,
and have a rich vascular and lymphatic drainage that receives their hormones, most
cells in these glands are arranged in cords and branching networks (maximizes contact
between cells and surrounding capillaries) - answerEndocrine glands
a. Pituitary, thyroid, parathyroid, adrenal, pineal glands
b. Pancreas, gonads (ovaries and testes), placenta contain endocrine tissue -
answerWhat are examples of endocrine organs?
a. Amino-acid based: hormones are water soluble and cannot cross the plasma
membrane (epinephrine, thyroxine, peptides, protein)
b. Steroids: hormones synthesized from cholesterol, lipid soluble and can cross the
plasma membrane (only gonadal and adrenocortical hormones are steroids) -
answerHow are hormones classified chemically?
tissue cells that have receptors for hormonal activity influences, hormone communicates
with target cell through water-soluble hormones (amino-acid based hormones, no
thyroid, use g proteins) or lipid-soluble hormones (steroid and thyroid hormones) act on
receptors inside the cells which directly activates genes, hormone typically produce one
or more of these changes:
i. Alters plasma membrane permeability or membrane potential, or both, by opening or
closing ion channels
ii. Stimulates synthesis of enzymes and other proteins within the cell
iii. Activates or deactivates enzymes
iv. Induces secretory activity
v. Stimulates mitosis - answerTarget cells
1. cAMP (second messenger)
ii. Hormone binds receptor (hormone acts as first messenger)
iii. Receptor activates G protein (G protein activated by GDP: off, GTP: on)
,iv. G protein activates adenylate cyclase (enzyme)
v. Adenylate cyclase converts ATP to cAMP
vi. Cyclic AMP activates protein kinases (enzymes that add a phosphate group to
proteins, can activate or inhibit certain proteins) - answerThe Cyclic AMP signaling
Mechanism
1. Intracellular calcium ions (second messenger)
ii. Phospholipase C (enzyme) splits a plasma membrane phospholipid, PIP2, into 2
second messengers (DAG: activates protein kinase enzyme and triggers responses
within target cell) (IP3: releases Ca2+ from intracellular storage sites, acts as secondary
messenger and binds to protein calmodulin which activates enzymes that amplify the
cellular response) - answerPIP2-Calcium Signaling Mechanism
Target cells
First Mechanism: Cyclic AMP Signaling Mechanism
Second Mechanism: PIP2- Calcium Signaling Mechanism - answerDescribe the two
major mechanisms by which hormones bring about their effect on their target tissues
a. Negative feedback mechanism: reaction that causes a decrease in function (some
internal or external stimulus triggers hormone secretion)
b. Humoral stimuli: simplest endocrine control, secrete hormones in direct response to
changing blood levels of certain critical ions and nutrients (insulin, Ca2+ levels,
aldosterone)
c. Neural stimuli: nerve fibers stimulate hormone release (stress: norepinephrine or
epinephrine)
d. Hormonal stimuli: release hormones in response to hormones produced by other
endocrine organs (releasing and inhibiting hormones produced by the hypothalamus
regulate the secretion of most anterior pituitary hormones) - answerExplain how
hormone release is regulated
a. Blood levels of the hormone
b. Relative numbers of receptors for that hormone on or in the target cells
c. Affinity (strength) of the binding between the hormone and the receptor -
answerIdentify factors that influence activation of a target cell
persistently low levels of a hormone can cause its targets to form additional receptors
for that hormone - answerUp-regulation
prolonged exposure to high hormone concentrations can decrease the number of
receptors for that hormone - answerDown-regulation
the length of time for a hormone's blood level to decrease by half, varies from a fraction
of a minute to a week (water-soluble hormones have the shortest half-lives -
answerHalf-life
, one hormone cannot exert its full effects without another hormone being present (lack of
thyroid hormone delays reproductive development) - answerPermissiveness
when more than one hormone produces the same effects at the target cell and their
combined effects are amplified (both glucagon and epinephrine cause the liver to
release glucose to the blood) - answerSynergism
when one hormone opposes the action of another (insulin lower blood glucose levels,
which is antagonized by glucagon which raises blood glucose levels) -
answerAntagonism
Permissiveness
Synergism
Antagonism - answerList 3 kinds of interaction of different hormones acting of the same
target cell
a. Structural pituitary gland located on sella turcica and infundibulum connects pituitary
gland to the hypothalamus (above it) maintains connection through nerve bundles called
the hypothalamic-hypophyseal tract
b. Functional: action potentials travel down the axons of hypothalamic neurons, causing
hormone release from their axon terminals in the posterior pituitary, hypothalamic
hormones released into special blood vessels (the hypophyseal portal system) control
the release of anterior pituitary hormones - answerDescribe structural and functional
relationships between the hypothalamus and pituitary gland
composed of neural tissue (pituicytes) and nerve fibers, releases neurohormones
received by the hypothalamus, hormone-storage area, not true endocrine gland -
answerPosterior pituitary lobe
composed of glandular tissue, manufacturers and releases hormones - answerAnterior
pituitary lobe
Oxytocin
ADH - answerWhat two hormones does the posterior pituitary release?
stimulates uterine contractions; initiates labor, initiates milk ejection - answerOxytocin
prevents wide swings in water balance, helping the body avoid dehydration and water
overload, substance that inhibits urine formation, stimulates kidney tubule cells to
reabsorb water - answerADH
i. Effects of hyposecretion (less): diabetes insipidus
ii. Effects of hypersecretion (more): syndrome inappropriate of ADH secretion (SIADH) -
answerEffects of abnormal secretion of ADH
Growth hormone (GH)
The heart is a very important muscle in our body that keeps blood flowing to our tissues
to keep them nourished with oxygen and help transport carbon dioxide waste to the
lungs for gas exchange. The heart uses electrical impulses from specialized nodes to
trigger the cardiac muscles to contract, which in turn leads to the continuous pumping
function of the heart.
The specialized nodes of the heart are the sinoatrial (SA) node and the atrioventricular
(AV) node. The SA node is located in the right atrium and is inferior to the superior vena
cava entrance. The SA node is the pacemaker of the heart and sets the rate of
depolarization that begins the
electrical signal that tells the heart to contract. The AV node is located in the lower
atrial septum at the junction of the atria and ventricles. The AV node's function is to
delay the contraction of the ventricles until the atrial contraction is complete for 0.1s.
The - answerOn Exam 1 you will be presented with an essay question. The essay topic
is cardiac impulse generation.
You will be asked to compose an essay about the cardiac impulse generation and
conduction.
a. A discussion cardiac conduction should begin with description of the specialized
nodes (autorhythmic character) of the heart and their locations.
b. The sequence should be discussed as well as coordinating location in the heart.
c. The actual innervation of the cardiac muscle and appropriate structures should be
considered.
d. Correlation between the stages of impulse should be related to the flow of blood,
contraction of the chambers and open and closing of the valves.
second great control system of the body that interacts with the nervous system to
coordinate and integrate the activity of body cells - answerEndocrine system
o Influences metabolic activity by means of hormones (chemical messengers secreted
by cells into the extracellular fluid)
• Reproduction
• Growth and development
• Maintenance of electrolyte, water, and nutrient balance of the blood
• Regulation of cellular metabolism and energy balance
• Mobilization of body defenses - answerWhat does the Endocrine system influence?
the scientific study of hormones and the endocrine organ - answerEndocrinology
,neural functioning plus releases hormones (hypothalamus) - answerNeuroendocrine
organ
chemicals that exert their effects on the same cells that secrete them, short-distance
signals (smooth muscle cells to contract smooth muscle cells) - answerAutocrines
act within the same tissue, but affect cell types other than those releasing the paracrine
chemicals (somatostatin released by one group of pancreatic cells inhibits the release of
insulin by a different group of pancreatic cells) - answerParacrines
long-distance chemical signals that travel in blood or lymph throughout the body -
answerHormones
produce non-hormonal substances (sweat and saliva) and have ducts that carry these
substances to a membrane surface - answerExocrine glands
ductless glands, produce hormones, release hormones into the surrounding tissue fluid,
and have a rich vascular and lymphatic drainage that receives their hormones, most
cells in these glands are arranged in cords and branching networks (maximizes contact
between cells and surrounding capillaries) - answerEndocrine glands
a. Pituitary, thyroid, parathyroid, adrenal, pineal glands
b. Pancreas, gonads (ovaries and testes), placenta contain endocrine tissue -
answerWhat are examples of endocrine organs?
a. Amino-acid based: hormones are water soluble and cannot cross the plasma
membrane (epinephrine, thyroxine, peptides, protein)
b. Steroids: hormones synthesized from cholesterol, lipid soluble and can cross the
plasma membrane (only gonadal and adrenocortical hormones are steroids) -
answerHow are hormones classified chemically?
tissue cells that have receptors for hormonal activity influences, hormone communicates
with target cell through water-soluble hormones (amino-acid based hormones, no
thyroid, use g proteins) or lipid-soluble hormones (steroid and thyroid hormones) act on
receptors inside the cells which directly activates genes, hormone typically produce one
or more of these changes:
i. Alters plasma membrane permeability or membrane potential, or both, by opening or
closing ion channels
ii. Stimulates synthesis of enzymes and other proteins within the cell
iii. Activates or deactivates enzymes
iv. Induces secretory activity
v. Stimulates mitosis - answerTarget cells
1. cAMP (second messenger)
ii. Hormone binds receptor (hormone acts as first messenger)
iii. Receptor activates G protein (G protein activated by GDP: off, GTP: on)
,iv. G protein activates adenylate cyclase (enzyme)
v. Adenylate cyclase converts ATP to cAMP
vi. Cyclic AMP activates protein kinases (enzymes that add a phosphate group to
proteins, can activate or inhibit certain proteins) - answerThe Cyclic AMP signaling
Mechanism
1. Intracellular calcium ions (second messenger)
ii. Phospholipase C (enzyme) splits a plasma membrane phospholipid, PIP2, into 2
second messengers (DAG: activates protein kinase enzyme and triggers responses
within target cell) (IP3: releases Ca2+ from intracellular storage sites, acts as secondary
messenger and binds to protein calmodulin which activates enzymes that amplify the
cellular response) - answerPIP2-Calcium Signaling Mechanism
Target cells
First Mechanism: Cyclic AMP Signaling Mechanism
Second Mechanism: PIP2- Calcium Signaling Mechanism - answerDescribe the two
major mechanisms by which hormones bring about their effect on their target tissues
a. Negative feedback mechanism: reaction that causes a decrease in function (some
internal or external stimulus triggers hormone secretion)
b. Humoral stimuli: simplest endocrine control, secrete hormones in direct response to
changing blood levels of certain critical ions and nutrients (insulin, Ca2+ levels,
aldosterone)
c. Neural stimuli: nerve fibers stimulate hormone release (stress: norepinephrine or
epinephrine)
d. Hormonal stimuli: release hormones in response to hormones produced by other
endocrine organs (releasing and inhibiting hormones produced by the hypothalamus
regulate the secretion of most anterior pituitary hormones) - answerExplain how
hormone release is regulated
a. Blood levels of the hormone
b. Relative numbers of receptors for that hormone on or in the target cells
c. Affinity (strength) of the binding between the hormone and the receptor -
answerIdentify factors that influence activation of a target cell
persistently low levels of a hormone can cause its targets to form additional receptors
for that hormone - answerUp-regulation
prolonged exposure to high hormone concentrations can decrease the number of
receptors for that hormone - answerDown-regulation
the length of time for a hormone's blood level to decrease by half, varies from a fraction
of a minute to a week (water-soluble hormones have the shortest half-lives -
answerHalf-life
, one hormone cannot exert its full effects without another hormone being present (lack of
thyroid hormone delays reproductive development) - answerPermissiveness
when more than one hormone produces the same effects at the target cell and their
combined effects are amplified (both glucagon and epinephrine cause the liver to
release glucose to the blood) - answerSynergism
when one hormone opposes the action of another (insulin lower blood glucose levels,
which is antagonized by glucagon which raises blood glucose levels) -
answerAntagonism
Permissiveness
Synergism
Antagonism - answerList 3 kinds of interaction of different hormones acting of the same
target cell
a. Structural pituitary gland located on sella turcica and infundibulum connects pituitary
gland to the hypothalamus (above it) maintains connection through nerve bundles called
the hypothalamic-hypophyseal tract
b. Functional: action potentials travel down the axons of hypothalamic neurons, causing
hormone release from their axon terminals in the posterior pituitary, hypothalamic
hormones released into special blood vessels (the hypophyseal portal system) control
the release of anterior pituitary hormones - answerDescribe structural and functional
relationships between the hypothalamus and pituitary gland
composed of neural tissue (pituicytes) and nerve fibers, releases neurohormones
received by the hypothalamus, hormone-storage area, not true endocrine gland -
answerPosterior pituitary lobe
composed of glandular tissue, manufacturers and releases hormones - answerAnterior
pituitary lobe
Oxytocin
ADH - answerWhat two hormones does the posterior pituitary release?
stimulates uterine contractions; initiates labor, initiates milk ejection - answerOxytocin
prevents wide swings in water balance, helping the body avoid dehydration and water
overload, substance that inhibits urine formation, stimulates kidney tubule cells to
reabsorb water - answerADH
i. Effects of hyposecretion (less): diabetes insipidus
ii. Effects of hypersecretion (more): syndrome inappropriate of ADH secretion (SIADH) -
answerEffects of abnormal secretion of ADH
Growth hormone (GH)
