FINAL EXAM LECTURE Flashcards
Be able to name the endocrine glands and identify where they’re located at in the body
pineal gland, hypothalamus, pituitary gland, thyroid gland,
parathyroid glands, thymus, adrenal glands, pancreas and gonads (ovary and testis)
What are hormones?
Chemical messengers (usually long-distance chemical signals that
travel in blood or lymph throughout the body) that bind to receptors on target cells to
cause a specific physiological reaction. Target cells have receptors that only respond to
specific hormones.
What are autocrines?
Short distance chemical signals that exert their effects on the same
cells that secrete them (example is prostaglandins released by smooth muscles that cause
those smooth muscle cells to contract).
What are the types of stimuli that trigger endocrine glands to manufacture and release their
hormones?
The release of hormones is controlled by humoral, neural, hormonal
mechanism
How does the hypothalamus interact with the anterior pituitary?
There is a blood connection
between the hypothalamus and the anterior pituitary gland and releasing and inhibiting
hormones are released.
What hormones are released from the anterior pituitary gland?
Growth hormone (GH), thyroid-stimulating hormone (TSH), adrenocorticotropic
hormone (ACTH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and
prolactin (PRL)
How does the hypothalamus interact with the posterior pituitary?
There is a nerve
connection between the hypothalamus and the posterior pituitary gland. Hypothalamus
neurons synthesize hormones and they are released from the posterior pituitary gland
What hormones are released from the posterior pituitary gland?
Oxytocin and antidiuretic
hormone.
What is the function of oxytocin and where is the target receptor for this hormone?
Oxytocin
is the hormone responsible for causing uterine smooth muscle to cause labor
contractions. It also initiates milk ejection in the breast.
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What homeostatic imbalance occurs when there is a decrease in ADH?
Diabetes insipidus
when a patient is dehydrated, blood pressure may drop. ADH is also inhibited by urine
so this will produce large amounts of urine
What homeostatic imbalance occurs when there is a decrease in GH?
Pituitary dwarfism in
children.
What homeostatic imbalance occurs when there is an increase in GH?
Gigantism
in children and acromegaly in adults
What homeostatic imbalance occurs when there is an increase in TSH?
Hyperthyroidism,
exophthalmos is seen in patients with hypersecretion of thyroxine, also can cause
Graves’ disease when antibodies mimic TSH.
What homeostatic imbalance occurs when
there is a decrease in TSH?
Hypothyroidism, may cause myxedema
Iodine is the central ion in the both thyroid hormones. What can result from a deficiency in
iodine?
Formation of a thyroid goiter
How are the thyroid hormone produced (thyroxine -
T4 and triiodothyronine- T3)?
Produced in the colloid and then taken into the follicular
cell by endocytosis
What homeostatic imbalance occurs when there is an increase in ACTH?
Cushing’s disease
What are the symptoms of this disease or syndrome?
Increased glucose levels, tissue
swelling
What is the function of FSH in females?
Maturation of the oocyte
What is the function of
FSH in males?
Maturation of the sperm
What is the function of LH in females?
Ovulation
What is the function of LH in males?
Sperm production so a male with low LH will have a low sperm count
FSH and LH are referred to as gonadotropins because they stimulate the gonads.
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What is the function of PRL?
Increase milk production in the lactating breast
milk production in the lactating breast
What is the function of calcitonin and parathyroid hormone (PTH)/parathormone?
Both of
these hormones regulate calcium metabolism. Calcitonin is produces by the
parafollicular cells (C cells) of the thyroid gland. Calcitonin can have a bone-sparing
effect at higher doses therefore inhibiting osteoclast activity to inhibit bone resorption
and stimulate calcium uptake from the blood into the bony matrix. PTH causes serum
calcium levels to stimulating osteoclast activity and bone deposition.
What are the layers of the adrenal cortex and what hormones are produced from each layer?
The outermost is the zona glomerulosa which produces aldosterone (a
mineralocorticoid). The middle layer is the zona fasciculata which produces cortisol (a
glucocorticoid). The innermost layer is the zona fasciculata which produces androgens.
What happens if there is a tumor in the zona fasciculata that causes hypersecretion of
hormones produced in that region?
There is an increase in cortisol (glucocorticoids).
What
is the function of these hormones?
Glucocorticoids enable the body to deal appropriately
with stress. They do this by increasing blood glucose levels and blood pressure.
Which layer of the adrenal gland is responsible for the fight/flight/fright response and what
does it produce?
The adrenal medulla is the innermost region of the adrenal gland and it
produces epinephrine and norepinephrine.
Which of hormone will cause dilation of bronchi, dilation of the pupil and increase in heart
rate and would be released if blood volume has sudden become low due to a catastrophic
injury (like a bad car accident)?
epinephrine
Be sure to understand the differences between the short-term and long-term stress response
from the adrenal gland (see Focus Figure 16.2
What is a hypersecretion of hormones from the medulla of the suprarenal gland due to a tumor
called?
Pheochromocytoma
What hormone will be affected by this tumor?
Epinephrine
and causes hypertension
What hormone is produced by the pineal gland and what is its function?
Produces melatonin
which is produced when there is an absence of light (darkness). Therefore, melatonin
helps to signal the brain to start fall asleep
What time of year would you expect people to have higher levels of melatonin?
In the winter
because there is an absence of light.
The pancreas secretes 2 important hormones that control glucose regulation. What are the two
hormones, the cells within the pancreas that produce them and what is the effect on glucose
regulation?
Glucagon is secreted by alpha cells, it increases blood glucose by releasing
glucose from the liver cells. It does this through glycogenolysis (breakdown of glycogen
to glucose) or gluconeogenesis (synthesis of glucose from non-carbohydrate molecules).
Insulin in secreted by beta cells it decreases blood glucose by transporting glucose into
most body cells, especially muscle and fat cells. It also inhibits the breakdown of
glycogen into glucose and inhibits the conversion of amino acids or fats to glucose.
Which pancreatic hormone would be released if you have just had a large meal of sugary
calories?
Insulin lowers the blood glucose levels therefore it is referred to as a
hypoglycemic hormone
Which pancreatic hormone would be released if you haven’t eaten for 8-10 hours?
Glucagon
raises the blood glucose levels therefore it is referred to as a hyperglycemic hormone
What is diabetes mellitus and what are the two types of diabetes mellitus?
Diabetes mellitus
means there is sugar in the urine (whereas diabetes insipidus is very dilute urine due to a
lack of ADH). In diabetes mellitus type 1, insulin is absent so there has to be complete
insulin supplementation. In diabetes mellitus type 2, insulin is present but its effects are
deficient because there are problems with the pancreas producing the insulin. Diabetes
mellitus type 2 it is most often seen in older patients, pancreatic islets (also called Islets
of Langerhans) are not able to produce insulin, most insulin secretion is inadequate, and
most patients are obese. In both cases, blood glucose levels remain high after a mean
because glucose in unable to enter most tissue cells.
What is the name of the gut of continuous muscular tube that winds through the body from the
mouth to the anus?
Alimentary canal
What are the names of GI tract in order?
Mouth, pharynx, esophagus, stomach, small
intestine, and large intestine
What are the names of the accessory digestive organs?
Teeth, tongue, gallbladder, salivary
glands, liver and pancreas.
What is the term that describes the sequence of steps in which large food molecules are
broken down to their building blocks by enzymes is called?
Chemical digestion
That is the term for passage of digested end products from the lumen of the GI tract through
the mucosal cells?
Absorption
What term describes the major means of propulsion, involving alternative waves of
contraction and relaxation of muscles in the organ walls?
Peristalsis
What are the 4 layers of the GI tract?
From inside the mucosa, submucosa, muscularis
externa and serosa
Where in the alimentary canal are these 4 layers located?
Extends from
the esophagus to the anal canal.
If a surgeon had to cut into to the GI tract from the external
sides what layer would be pierced first?
Serosa
What is the name of the membrane that covers the external surface of most digestive organs?
Visceral peritoneum
What is the name of the membrane that lines the body wall of the
peritoneal cavity?
Parietal peritoneum
What are the names of the receptors found lining the GI tract wall?
mechanoreceptors,
chemoreceptors and osmoreceptors.
Where is the nerve plexus that controls digestion in
response to the stimuli from these receptors?
walls of the organs of the digestive tract
What part of the nervous system controls digestion and what does it control?
Branch of the
autonomic nervous system parasympathetic nervous system. This branch of the ANS
controls all of the digestive processes like salivation, peristalsis of the GI tract,
production of enzymes that will trigger digestion.
What are the functions of saliva?
Saliva contains enzymes that begin the breakdown of
carbohydrates and lipids
What substance is released from the pancreas to neutralize stomach acid in the intestine?
Bicarbonate ions are alkaline (basic) and will reduce the pH
What are the 3 phases of gastric secretion?
Cephalic phase, gastric phase, and intestinal
phase.
What controls these phases?
Both neural and hormonal. For example, during the
cephalic phase it occurs before food enters the stomach and is triggered by aroma or
thought
What is the function of the stomach?
Storage and mechanical breakdown of foods,
initiates protein digestion.
What population of cells are found in the stomach and what role
do they play?
Chief cells produce the precursor to the gastric enzyme of digestion
(pepsinogen), Parietal cells produce HCl along with intrinsic factor.
What causes gastric
HCl secretion in the stomach?
parasympathetic nervous system, gastrin and histamine
What are the functional cells within the liver and what is their function?
Hepatocytes and
they secrete bile, process bloodborne nutrients, store fat-soluble vitamins and play a role
in detoxification of the blood. Hepatocytes receive arterial blood and venous blood in
the sinusoids of the liver is and this is an advantage because hepatocytes can take in
oxygen and nutrients at the same time.
What is the function of the gallbladder
Primarily a storage organ for bile
What triggers
contraction of the gallbladder?
Cholecystokinin which is released by the small intestine to
stimulate the gallbladder to contract.
What is the consequence of an absence of bile?
It
would lead to abnormal fat digestion and absorption
The absorptive effectiveness of the small intestine is enhanced by increasing the surface area
of the mucosal lining. Which of the following accomplish the task?
plicae circularis and
intestinal villi
What are the 5 types of cells found in the mucosal epithelium of the villi and crypts?
Enterocytes, goblet cells, enteroendocrine cells, Paneth cells and stem cells
What is the
function of each of these cells?
Enterocytes – simple columnar absorptive cells with
microvilli that have tight junctions in between them, responsibility for absorbing
nutrients and electrolytes in the villi; enterocytes in the crypts secrete intestinal juice.
Goblet cells – mucus-secreting cells in the epithelia of the villi and crypts.
Enteroendocrine cells – secretin and cholecystokinin released from these cells, these
sounds are mostly found in the crypts but also some in the villi. Paneth cells – located
deep in the crypts, secretions promote antibacterial activity. Stem cells – continuously
divide in the crypts, these cells differentiate to become the other 4 cell types (for
example, enterocytes at the tips of the villi undergo apoptosis and are shed to renew the
villus epithelium in 3-5 days)
What specialized structures are in the villi that absorb fat?
lacteals
How and where are carbohydrates digested?
Mouth with salivary amylase, small intestine
with pancreatic amylase and small intestine with brush border enzymes
How and where are proteins digested?
Stomach with pepsin in the presence of HCl, small
intestine with pancreatic enzymes and small intestine with brush border enzymes
(peptidases)
How and where are lipids digested?
Mouth with lingual lipase, stomach with gastric lipase,
small intestine with emulsification by action of bile and with pancreatic lipase
Where does the large majority of digestion take place?
Small intestine
Which gland produces enzymes that break down carbohydrates, proteins, and lipids?
pancreas
How does chyme play a role in digestion?
Acidic chime causes distension and chemical
stimulation of intestinal mucosa, alkaline pancreatic juice neutralizes the acidic chime that
enters small intestine
What are the subdivisions of the large intestine?
Cecum, appendix, colon, rectum and anal
canal.
Metabolism is the sum of all chemical reactions and can be separated into anabolic reactions
and catabolic reactions. What are anabolic reactions?
Monomers added to each other to
produce polymers
What are chemical reactions?
Polymers broken down to produce
monomers
What are examples of anabolic reactions?
Any example of monomers being converted into
polymers such as conversion of glucose into proteins, conversion of glucose into
triglycerides, conversion of glucose into proteins.
What are examples of catabolic
reactions?
Any example of polymers being into monomers such as glycogen broken down
into glucose, lipids being broken down into glycerol and fatty acids, and proteins being
broken down into amino acids
What are the monomers of carbohydrate, lipids, proteins, nucleic acids?
Glucose
(carbohydrates), fatty acids and glycerol (lipids), amino acids (proteins), and nucleotides
(nucleic acids).
What are the polymers of carbohydrate, lipids, proteins, nucleic acids?
Glycogen or starch, triglycerides, proteins formed from many amino acids like
fibrinogen, gamma globulins, hemoglobin, insulin, glycogen, myelin (proteins), ATP,
DNA, RNA
Which are the 3 main phases of cellular respiration?
Glycolysis, Kreb’s cycle and electron
transport cycle.
here do each of these phases occur?
Glycolysis occurs in the cytoplasm
and both the Kreb’s cycle and electron transport pathways occur in the mitochondria.
What is the main product of cellular respiration?
ATP production
What is the main product of the aerobic breakdown of glycolysis?
Pyruvic acid
What is the
main byproduct released from the complete aerobic breakdown of glycolysis?
co2
What is
the main product of the anaerobic breakdown of glycolysis?
Lactic acid
What is the process of gluconeogenesis and what is produced from it?
Gluconeogenesis is
the process of glucose produce from non-carbohydrates.
What other metabolic pathways
increase blood glucose levels?
glycogenolysis
If you have excess blood glucose what will be the fate of those excess carbohydrates and what
is the metabolic process that occurs
Those excess carbohydrates will be taken into the
tissues (liver and skeletal muscle) where they will be stored as glycogen molecules. This
metabolic process is called glycogenesis
How are lipids processed in the body and how are they stored in the body?
Lipids are
transported in the lymph in the form of fatty-protein droplets called chylomicrons.
Fatty acids and glycerol are the monomers of lipids and taken up into tissues for
processing.
What are the 3 metabolic processes for lipids and what happens in each? Which metabolic
process is anabolic and catabolic?
Beta oxidation, lipogenesis, and lipolysis. In beta
oxidation, fatty acids are converted to acetyl CoA so it can enter the Kreb’s cycle. In
lipogenesis, lipids are formed from acetyl CoA and glyceraldehyde-3-phosphate and it is
an example of an anabolic reaction. In lipolysis, lipids are broken down into fatty acids
and glycerol and it is an example of a catabolic reaction
What are metabolic processes of proteins what are examples of proteins?
Fibrinogen,
gamma globulins, hemoglobin, insulin, glycogen, myelin.
What is the metabolic process that produces the maximum amount of ATP?
Electron
transport system
What are the major functions of the kidneys?
Regulating total water volume and electrolyte
concentration, regulating ion concentration in the ECF, regulating long-term acid-base
balance, excreting metabolic wastes, toxins, and drugs, secreting erythropoietin and renin
(hormones produced by kidney), activation of vitamin D and gluconeogenesis
What are the organs of the urinary system?
Kidney, ureter, urinary bladder, urethra
Where
are these organs located?
Kidneys are located retroperitoneally from T12 to L5 and the
ureters and urinary bladder are located in the abdomen and pelvis
What are the coverings of the kidney that protect it
Renal capsule, perirenal fat and renal
fascia
What are the three distinct regions of the kidney?
Renal cortex, renal medulla, and renal
pelvis.
Describe the details of each of these regions
Renal cortex is the outer superficial
region; medulla is deep to the cortex and contains medullary pyramids (renal pyramids are
separated by renal columns, extensions of the renal cortex); renal pelvis is the funnel-
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shaped tube continuous with the ureter. The pelvis contains the minor calyx and the major
calyx
What is the flow of urine through the kidney?
nephronrenal pyramidminor calyxmajor
calyxrenal pelvisureterurinary bladderurethra
What is the functional unit of the kidney?
Nephron
What are the main parts of it?
Renal
corpuscle (glomerulus) and renal tubule (Bowman’s capsule, proximal convoluted
tubulenephron loop/loop of Henledistal convoluted tubule)
What are the blood vessels that lead from the aorta to the glomerulus?
Aortarenal
arterysegmental arteryinterlobar arteryarcuate arterycortical radiate
arteryafferent arterioleglomerulus.
What are the blood vessels that lead from the
glomerulus to the inferior vena cava?
Glomerulusefferent arterioleperitubular capillaries
or vasa rectacortical radiate veinsarcuate veininterlobar veinrenal veininferior
vena cava
What are the two types of nephrons in the kidney?
Cortical nephrons – 85% of each,
juxtamedullary nephrons – 15%
What are the types of capillaries is each type of nephron?
Cortical – glomerulus and peritubular capillaries; juxtamedullary – glomerulus and vasa
recta
What is the juxtaglomerular complex (JGC)?
Involved modified portions of distal portion of
ascending limb of nephron loop and afferent arteriole
Describe the functions of this
complex and the cells found here
This complex is important in regulating the rate of filtrate
formation and blood pressure. The cells in the JGC are the macula densa cells, granular or
JG cells, and extraglomerular mesangial cells.
What are the functions of the cells in the JGC?
Macula densa – chemoreceptors that sense
and monitor electrolyte content of filtrate; granular cells – mechanoreceptors to sense BP
and secrete renin; extraglomerular mesangial cells – pass signals between macula densa
and granular cells
What is filtrate and what does it contain?
Filtrate is the fluid formed at the glomerulus via
filtration. It contains blood plasma minus proteins and whole cells.
What are the major processes that occur within the nephron? Describe each of these processes
Glomerular filtration is the forced movement of solutes and water from the glomerulus into
the Bowman’s capsule. Tubular reabsorption is the selective return of 99% of the
substances from filtrate to the blood. Tubular secretion is the selective movement of
substances from the blood to the filtrate.
What are the layers of the filtration membrane
Visceral layer of glomerulus (Bowman’s
capsule), fused basement membranes and capillary endothelium of glomerulus
What are the pressures that affect the net filtration pressure?
2 hydrostatic pressures and 1
osmotic pressure.
Which pressure is the most significant?
he most significant factor that
affects net filtration pressure is the glomerular capillary hydrostatic pressure due to the
glomerular capillary blood pressure (specifically, the afferent arteriolar hydrostatic
pressure). The net filtration pressure is 10 mmHg from the glomerular capillary into the
glomerular capsular space
How does the myogenic mechanism work to regulate BP?
Increased BP causes muscle to
stretch to lead to constriction of afferent arteriole; decreased BP causes muscle dilation of
afferent arterioles
How does the tubuloglomerular feedback mechanism work? Provide examples of what happens
when GFR increases and decreases
It’s a flow-dependent mechanism directed by macula
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densa cells. If GFR increases, the flow rate of the filtrate increases leading to decreased
reabsorption time causing high electrolyte (NaCl) levels in the filtrate. To counteract this,
the feedback mechanism causes constriction of the afferent arteriole lowering GFR to allow
more time for NaCl reabsorption. If GFR decreases, the flow rate of filtrate decreases
leading to higher reabsorption time causing low electrolyte (NaCl) levels in the filtrate. To
counteract this, the feedback mechanism causes dilation of the afferent arteriole increasing
GFR to allow less time for NaCl reabsorption
What are the extrinsic controls to maintain BP?
Sympathetic nervous system (norepinephrine
to increase BP) and renin-angiotensin-aldosterone system (renin is released in response to a
drop in BP
