exam 4 review Flashcards
(126 cards)
1
Q
what should the ratio of hco3 be to co2?
A
20:1
2
Q
acidosis vs alkalosis
A
if 20:1 ratio goes DOWN you have acidosis
if 20:1 ratio goes UP you have alkalosis
3
Q
respiratory vs metabolic acidosis and alkalosis
A
respiratory involves co2 and respiratory dysfunction
metabolic involves metabolic disturbances and HCO3
4
Q
possible causes of respiratory acidosis and ways our body compensates
A
causes
* HYPOventilation
* lung disease
* depression of respiratory center by drugs or disease
* nerve or muscle disorders that reduce respiratory muscle activity
* holding breath
compensations
* chemical buffers immediately taking up additional hydrogen ions
* KIDNEYS IMPORTANT FOR COMPENSATING
5
Q
respiratory alkalosis possible causes and buffers
A
causes
* hyperventilation
* anxiety
* fever
* aspirin poisoning
* physiologic mechanisms at HIGH ALTITIUDE
compensations
* chemical buffer systems liberate hydrogen ions
* if situation continues kidneys compensate by conserving hydrogen ions and excreting more HCO3
6
Q
metabolic acidosis causes and compensations
A
causes
* severe diarrhea
* diabetes mellitus
* strenous exercise
* uremic acidosis
compensations
* buffers take up extra hydrogen
* ventilation increased so extra hydrogen ion producing co2 is removed from system
* kidneys excrete more H+ and conserve more hco3
7
Q
metabolic alkalosis causes and compensations
A
causes
* vomiting
* ingestion of alkaline drugs
compensations
* buffer systems immediately liberate H+
* ventilation is REDUCED
* if condition persists for several days, kidneys conserve H+ and excrete HCO3 in the urine
8
Q
intracellular fluid
A
- holds fluid WITHIN CELLS
- 2/3 total body fluid
9
Q
extracellular fluid
A
- same thing as interstitial fluid pretty much
- FLUID OUTSIDE CELLS
- remaining 1/3 total body fluid
- interstitial fluid, lymph, and transcellular fluid are all ECF’s
10
Q
interstital fluid
A
fluid immediately surrounding cells
ECF
11
Q
lymph
A
fluid returned from intersitial fluid to plasma
ECF
12
Q
transcellular fluid
A
small, specialized cell volumes secreted
by specialized cells into a particular cavity
* CSF
* intraocular fluid
* synovial fluid
* pericardial, intrapleural, and peritoneal fluids
* digestive juices
13
Q
intracellular vs extracelluar fluid volume
A
intracellular-55% total body water
extracellular- 45% total body water
14
Q
type A vs type B intercalated cells
A
type A= H+ secreting, HCO3-
reabsorbing, K+ reabsorbing cells
type B= HCO3- & K+
secreting H+ reabsorbing cells.
15
Q
osmolarity
A
- Measure of the concentration of individual
solute particles dissolved in a fluid. - Na+, Cl- in ECF
- K+, intracellular anions in ICF
16
Q
hypertonicity
A
- Cells tend to shrink
- Causes
Insufficient water intake
Excessive water loss
Diabetes insipidus
Deficiency of ADH
Symptoms and effects - Shrinking of brain neurons
- Confusion, irritability, delirium, convulsions, coma
Circulatory disturbances - Reduction in plasma volume, lowering of blood pressure,
circulatory shock
Dry skin, sunken eyeballs, dry tongue
17
Q
HYPOtonicity
A
- Cells tend to swell
- Causes
- Patients with renal failure who cannot excrete
a dilute urine become hypotonic when they
consume more water than solutes - Can occur in healthy people when water is
rapidly ingested and kidney’s do not respond
quickly enough - When excess water is retained in body due to
inappropriate secretion of vasopressin - Symptoms and effects
- Swelling of brain cells
- Confusion, irritability, lethargy, headache, dizziness,
vomiting, drowsiness, convulsions, coma, death - Weakness (due to swelling of muscle cells)
- Circulatory disturbances (hypertension and
edema) - Water intoxication: overhydrating,
hypotonicity, and cellular swelling
18
Q
pH
A
- Designation used to express the concentration of H+
- pH 7 – neutral
- pH less than 7 → acidic
- pH greater than 7 → basic
- Every unit change in pH represents a 10 fold change in
[H+].
19
Q
bases
A
Substance that can combine with free H+ and remove it
from solution.
20
Q
acids
A
Group of H+ containing substances that dissociate in
solution to release free H+ and anions.
21
Q
what does acid base balance refer to
A
Refers to precise regulation of free H+ concentration in body fluids
22
Q
pH below 7.35 indicates what?
A
metabolic acidosis
23
Q
pH above 7.45 indicates what?
A
metabolic alkalosis
24
Q
carbonic acid
A
- great buffering system
- bicarbonate ion + hydrogen
25
4 chemical buffer systems in the body
1. H2CO3, HCO3 buffer system= primary ECF buffer for noncarbonic acids
2. protein buffer system= primary ICF buffer; also buffers ECF
3. hemoglobin buffer system= primary buffer against carbonic acid changes
4. phosphate buffer system= important urinary buffer; also buffers ICF
26
insensible vs sensible sweat loss
- Sensible loss – sensory
awareness
* Sweating
* Feces
* Urine excretion
- Insensible loss – no sensory
awareness
* Lungs
* Non-sweating skin
27
vasopressin
* Also known as Antidiuretic Hormone (ADH)
* Produced by hypothalamus
* Stored in posterior pituitary gland
* Released on command from hypothalamus
(NOT! Produced in hypo. Released from post. Pit.)
- Also location of thirst center
28
blood flow and thermoregulation
Narrowing the blood vessels (vasoconstriction) means less heat will be lost this way thereby maintaining the core temperature of the body
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osomolarity and thirst
| homeostasis
-Osmolarity increase → vasopressin secretion
and thirst stimulated.
- Osmolarity decrease → vasopressin secretion decreased and thirst suppressed
35
left atrial receptors
| vasopressin
- Monitor pressure of blood flowing through
(reflects ECF volume)
- Upon detection of significant reduction in
arterial pressure, receptors stimulate
vasopressin secretion and thirst
- Upon detection of elevated arterial pressure,
vasopressin and thirst are both inhibited
36
angiotenson II
| vasopressin; water regulation
- In addition to stimulating aldosterone
secretion.....
- Stimulates vasopressin secretion and thirst
when RAAS mechanism is activated to conserve
Na+
37
diabetes insipidus
Caused by an inability of the pituitary to
secrete ADH (type1) or an inability of the
collecting ducts to respond to ADH (TypeII)
38
all compounds we absorb will have to pass through....
lymphatic tissue (GALT)
39
lamina propria
| digestive
* Houses Gut-Associated Lymphoid Tissue (GALT)
- Important in defense against disease-causing intestinal bacteria
40
how is food digested mechanically in the small intestine?
mixing
41
how does chemical digesting of food occur?
pancreatic enzymes
42
submucosa
| digestive system
* Thick layer of connective tissue
* Provides digestive tract with
distensibility and elasticity
* Contains larger blood and lymph
vessels
* Contains nerve network known as
submucosal (Meissner’s) plexus.
43
what do brush border enzymes ingest?
| secreted by small intestine
responsible for the degradation of di- and oligosaccharides into monosaccharides, and are thus crucial for the energy-intake of humans and other mammals. AKA STARCH BREAKDOWN
44
pancreatic enzymes and their functions
| secreted by acinar cells
* pancreatic amylase=breaks down carbs
* pancreatic lipase=breaks down fat molecules
* proteolytic enzymes= protein digestion
45
two distinct areas of gastric mucosa that secrete gastric fluid
oxyntic mucosa and pyloric gland area (PGA)
46
chief cells
| gastric exocrine secretory cell
* Secrete enzyme precursor, pepsinogen
* When activated by HCl, begin protein digestion VIA PEPSIN
* Pepsinogen stored in Zymogen granules
* Pepsin self activates pepsinogen as well, called “autocatalytic process”.
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parietal (oxyntic) cells
| gastric exocrine secretory cell
* Secrete HCl and intrinsic factor
* Activates pepsinogen, breaks down connective tissue, denatures
proteins, kills microorganisms, facilitates absorption of B12
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mucous cells *goblet cells
| gastric exocrine secretory cell
* Secrete mucin > forms mucous
* Protects mucosa against mechanical, pepsin, and acid injury
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Also three types of Endocrine/Paracrine secretory
cells
| stomach mucosa and the gastric glands
- Enterochromaffin Like (ECL) Cells: Secretes Histamine, stimulates Parietal Cells
- G-Cells: Secretes gastrin, stimulates parietal, chief, and ECL cells
- D-Cells – Secretes somatostatin, inhibits Parietal, G, and ECL cells.
50
primary contribution to digestion is through the delivery of...
bile salts
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pathway of bile
Bile comes from the liver, is stored in the gallbladder, and enters the small intestine through the bile duct
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bile salt pathway
Bile salts leave the small intestine around the end of the jejunum and return to the liver.
53
bile salts
| composition and function
-emulsify fat into droplets
- Derivatives of cholesterol
- Detergent action allows bile
salts to convert large fat
globules into a lipid emulsion.
- After participation in fat
digestion and absorption,
most are reabsorbed into the
blood by special active
transport mechanism in the
terminal ileum
54
enterohepatic circulation
the movement of bile salt molecules from the liver to the small intestine and back to the liver
55
bilirubin
* No role in digestion.
* Break down product of heme group in RBCs,
phagocytized by macrophages in sinusoids.
* Hepatocytes take it up from the plasma, modify it,
and secrete it with the bile.
* Gives feces it’s brown color.
* After processing in the liver, some bilirubin can be
absorbed into the plasma. When excreted, gives
urine its yellow color
56
motility of small intestine
| small intestine is where most digestion occurs
- Segmentation= primary method, contracts SI, mixes chyme
- Migrating motility
complex= sweeps intestines clean in between meals
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secretion of small intestine
| digestion
- Fluid secreted by SI
does not contain any
digestive enzymes.
- Succus entericus:
aqueous salt and
mucus solution – 1.5
liters/day secreted by
exocrine cells in the
mucosa.
- Provides protection and
lubrication.
- Brush-border
membrane (microvilli)
of epithelial cells.
* Enteropeptidase –
activates trypsinogen
* Disaccharidases
(maltase, sucrose-
isomaltase, and lactase)
– targets maltose, α-
limit dextrins and
dietary disaccharides.
* Aminopeptidases –
hydrolyze proteins
* Fat is digested entirely
within SI lumen by
pancreatic lipase
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# 1.
absorption of small intestine
- Absorbs almost everything presented to it.
- Most occurs in duodenum and jejunum, little
in ileum
- Adaptations that increase small intestine’s
surface area
* Inner surface - circular folds – plicae circularese
* Finger-like projections called villi
* Brush border (microvilli) arise from luminal surface
of epithelial cells
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crypts of Lieberkun
| digestion, small intestine, lining replaced about every 3 days
Secretes water and salt
* Also act as nurseries: contain stem cells
for rapid replacement of lining.
* Cells migrate to tip of villus slowly and
change as they go.
* Densest concentration of brush border
enzymes at tip
* As new cells push up, tip cells lost.
* Old cells digested, components reused.
* Paneth cells also in crypts and produce
two antibacterial chemicals:
- Lysozyme
- Defensins
60
what cells secrete HCl and intrinsic factor?
61
functions of HCL
HCl Secretion
* Functions of HCl
- Activates precursor pepsinogen to active enzyme pepsin
and provides acid medium for optimal pepsin activity
- Aids in breakdown of connective tissue and muscle fibers
- Denatures protein.
- Along with salivary lysozyme, kills most of the
microorganisms ingested with food
62
cephalic phase of gastric secretion
- Increased secretion of HCl and pepsinogen that occurs in
response to thinking about, smelling, talking about food
- Feed-forward mechanism
63
gastric phase of gastric secretion
- When food enters the stomach
- Distention of stomach stimulates gastric secretion
- Protein is powerful stimulus, causes increased gastric secretions
- Stimulates release of gastrin
* Stimulates release of HCl and pepsinogen
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intestinal phase of gastric secretion
- Inhibitory phase, helps dampen flow of gastric fluids as chyme
begins to empty into small intestine.
* Protein is withdrawn
* pH falls to a point that somatostatin is released
* Stomach is no longer distended
65
gastrin
a peptide hormone primarily responsible for enhancing gastric mucosal growth, gastric motility, and secretion of hydrochloric acid (HCl) into the stomach
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Cholecystokinin (CCK)
| gastric emptying
Functions
* Inhibits gastric motility and secretion
* Stimulates pancreatic acinar cells to increase
secretion of pancreatic enzymes
* Causes contraction of gallbladder
* Along with secretin, is trophic to exocrine
pancreas
* Important regulator of food intake
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plexuses that make up enteric nervous system
submucosal plexus and myenteric plexus
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crohns
* Inflammatory bowel disease (IBD) affecting the ileum and/or
the colon.
* Inflammation obstructs normal functioning of the digesting
system.
* Results in altered flow and reduction in absorption. Cells of
the intestine that secrete antimicrobial peptides are damaged
or lost.
69
ulcerative collitis
* Chronic inflammatory bowel disease (IBD)
* Abnormal reactions of the immune
system cause inflammation and ulcers on
inner lining of large intestine.
- Symptoms include diarrhea, passing of blood
in stool, and abdominal pain.
- Causes include genetics, abnormal immune
reactions, microbiome issues, and
environment
70
diverticulitis
occurs when small, bulging pouches (diverticula) develop in your digestive tract. When one or more of these pouches become inflamed or infected, the condition is called diverticulitis
71
what is large intestine composed of?
-Colon
- Cecum
- Appendix
- Rectum
72
different regions of large intestine
*** Taeniae coli**
- Longitudinal bands of muscle
*** Haustra**
- Pouches or sacs
- Actively change location as result
of contraction of circular smooth
muscle layer
*** Haustral contractions**
- Main motility
- Initiated by autonomous
rhythmicity of colonic smooth
muscle cells
73
flow of digestion from colon to rectum
The descending colon stores feces that will eventually be emptied into the rectum. The sigmoid colon contracts to increase the pressure inside the colon, causing the stool to move into the rectum. The rectum holds the feces awaiting elimination by defecation
74
iron
Role is to transport oxygen. The body does not make iron, so iron is ingested. Absorption pathway is mediated by the hormone hepcidin. Iron is an ion, so it needs to couple with a transporter to move into and out of the cell
75
ferroportin and transferrin
| iron
* Exits small intestine via membrane iron transporter:
ferroportin
* Controlled by hormone hepcidin – released when iron
levels in body get too high...inhibits absorption.
* Transported in blood by plasma protein carrier - transferrin
76
what small intestine cells contain vili and microvili
Cells that line the upper 2⁄3 of the small intestine contain villi (finger-like projections) and microvilli (hair-like projections).
77
ferritin
Iron not immediately needed is irreversibly stored in
SI cells in a granular form: ferritin
78
brush border enzymes
*** Enteropeptidase –**
activates trypsinogen
* Disaccharidases
**(maltase, sucrose-
isomaltase, and lactase)**
– targets maltose, α-
limit dextrins and
dietary disaccharides.
*** Aminopeptidases –**
hydrolyze proteins
79
motility
Muscular contractions of the stomach and intestines. Peristalsis, mixing, propulsion, retropulsion, etc.
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gastric filling
* Involves receptive relaxation
- When empty, stomach can hold about 50mL, but can expand 20 fold!
- Enhances stomach’s ability to accommodate the extra volume of food with
little rise in stomach pressure.
- Triggered by act of eating.
- Mediated by vagus nerve
81
gastric emptying
** Factors trigger either**
*- Neural response*
* Mediated through both intrinsic nerve plexuses (short
reflex) and autonomic nerves (long reflex)
* Collectively called enterogastric reflex
*- Hormonal response*
* Involves release of hormones from duodenal mucosa
collectively known as enterogastrones.
- Secretin
- Cholecystokinin (CCK)
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6 hormones in anterior pituitary
Cell Types
Thyrotropes - TSH
Corticotropes - ACTH
Somatotropes – GH
Gonadotropes – LH and FSH
Lactotropes - Prolactin
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adenohypophysis
anterior pituitary
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growth hormone (what stimulates it)
**GH primarily promotes growth indirectly by stimulating liver’s production of insulin like growth factor-1** (IGF1)
- IGF-I
* Major growth factor in adults
* Growth-promoting actions: hypertrophy (cell size) and
hyperplasia (cell #).
* Stimulates protein synthesis, cell division, and lengthening and
thickening of bones
* GH and IGF-1 each regulate the othe
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hypophysiotropic hormones
Secretion of each anterior pituitary
hormone is stimulated or inhibited
by one or more of 6 hypothalamic
hypophysiotropic hormones
1= corticotropin releasing hormone (CRH)
2=thyrotropin releasing hormone (TRH)
3=leutinizing hormone releasing hormone (LHRH)
4= growth hormone releasing hormone (GHRH)
5= somatostatin (SST)
6=dopamine
86
what are FSH and LH stimulated by?
growth hormone
87
all hormones coming from the anterior pituitary are what kind of hormones?
trophic hormones
88
endocrine dysfunction
* Most commonly result from abnormal plasma
concentrations of a hormone caused by inappropriate rates
of secretion
- Hyposecretion
* Too little hormone is secreted
- Hypersecretion
* Too much hormone is sec
89
primary vs secondary endocrine dysfunction
Primary hypersecretory disorder would be an issue with the source structure. Secondary hypersecretion would be an effect at the cellular level. Type 1 diabetes is a problem of the islet cells not being able to produce the insulin needed. Type 2 diabetes is due to a problem that insulin has at the cellular level
90
role of 6 hormones in the anterior pituitary
1. Thyrotropes secrete **Thyroid-stimulating
hormone (TSH)**
- Stimulates secretion of thyroid hormone
2. Corticotropes secrete **Adrenocorticotropic
hormone (ACTH)**
- Stimulates secretion of cortisol by and promotes
growth of adrenal cortex
3. Gonadotropes secrete **Follicle-stimulating
hormone (FSH)**
- In females, stimulates growth and development of
ovarian follicles; promotes secretion of estrogen by
ovaries
- In males, required for sperm production
- 4. **Gonadotropes also secrete Luteini**zing
hormone (LH)**
- In females, responsible for ovulation and
luteinization; regulates ovarian secretion of
female sex hormones
- In males, stimulates testosterone secretion
5. Somatotropes secrete **Growth hormone
(GH)**
- Primary hormone responsible for regulating
overall body growth; important in intermediary
metabolism
6. Lactotropes secrete **Prolactin (PRL)**
- Enhances breast development and milk production in females
Adenohypophysis
91
function of GH besides IGF-1
* GH is the most abundant hormone produced by the anterior pituitary.
- GH stimulates the epiphyseal growth plates in the bone,
which are responsible for bone elongation.
- Continues to be released even after growth has stopped.
* GH secretion is regulated by two hypophysiotropic
hormones:
- Growth hormone–releasing hormone
- Growth hormone–inhibiting hormone
92
what do somatrophs produce?
growth hormone
93
what does somatostatin inhibit?
growth hormone
94
hormones that come from posterior pituitary
ADH stimulates fluid absorption at the level of the DCT in the nephron. It inserts water channels called AQP-2 channels into the luminal membrane. Oxytocin results in smooth muscle contraction. These are released from the posterior pituitary, but are produced in the hypothalamus.
95
two hormone categories based on solubility
**- Hydrophilic – work by binding with surface membrane**
receptors. Circulate dissolved in the plasma - *Polar*
- Peptide hormones
- Catecholamines
- Indoleamines
**- Lipophilic – work by binding with receptors within the cell.**
Circulate bound to plasma proteins
- Steroid hormones
- Thyroid hormone
96
circadian rhythms
* Synchronization of Biological Clock depends on
environmental clues.
- Major environmental cues used to adjust and “set” the SCN
master clock
- Melanopsin – protein found in a special type of retinal ganglion
cell not used in “sight” but rather keeps body in tune with
external light
* One of the reasons reading your phone at night is BAD.
- Retinal cells relay message along the retino-hypothalamic tract
to the SCN.
- SCN then relays info regarding light status to pineal gland
97
Hypothalamic-Hypophyseal Portal System
Regulatory hormones coming from hypothalamus enter into an alternative vascular route of two capillary beds, then head to their destination. The benefit of this is that it bypasses general circulation and maintains concentration of these hormones
98
pineal gland produces melatonin
| describe melatonin function
Hormone that is produced during night to maintain biological clock. Regulates reproductive tract due to inhibitory nature to GNRH
99
neurohypophysis
* Posterior pituitary
- Along with hypothalamus forms
neuroendocrine system
- Does not actually produce any hormones
- Stores and releases two small peptide
hormones
100
pituitary gland stalk
Pituitary gland is connected to the
hypothalamus by a stalk.
- Stalk is formed by infundibular stem (inner part of
the stalk) – infundibular process and the median
eminence
101
where is pituitary gland found anatomically?
sell turcica
102
median eminence
important area through which
hormones feedback to regulate hypothalamic
pituitary function
103
suprachiasmatic and paraventricular nuclei
(magnocellular neurons)
originate in the supraoptic nuclei and
paraventricular nuclei.
- Release arginine vasopressin (AVP) and oxytocin
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hyperthemia
Elevation in body temp above normal range
Can occur unrelated to infection
Exercise
Pathological
Abnormally high circulating levels of thyroid hormone or epinephrine
Causes increase in metabolic activity
Malfunction of hypothalamic control center.
Brain lesions
109
fever
Elevation in body temp as result of infection or inflammation
**Macrophages release endogenous pyrogen.
Acts on hypothalamus to “reset” temp.
Caused by release of prostaglandins**
*Aspirin – antipyretic - inhibiting synthesis of prostaglandins.*
110
ghrelin
Hunger hormone
Appetite stimulator produced by stomach and regulated by feeding status
Peaks before mealtime, falls after consumption.
111
PYY
Antagonist of Ghrelin – secreted by digestive tract
Produced by small and large intestines
At lowest level before meal
Rises during meals and signals satiety
Believed to be an important mealtime terminator
112
CCK as it is related to HUNGER AND APETITE
Gastrointestinal hormone – released from duodenal mucosa.
Released in response to nutrients in the small intestine.
CCK facilitates digestion and absorption of nutrients.
Triggers the feeling of being full before nutrients are available to the body.
113
metaflammation
Link between obesity induced chronic inflammation and metabolic consequences.
Adipocytes secrete TNFa and IL-6, can lead to inflammation of obese fat stores.
Adipokines involved
114
4 mechanisms of heat transfer
Radiation
Conduction
Convection
Evaporation
115
apocrine sweat glands
located in arm pit and genital area
Rich in organic constituents – initially odorless
Smell occurs as bacteria break down organics
Apocrine sweat most abundant during stressful times and sexual excitement
116
eccrine sweat glands
Eccrine sweat glands occur over most of the body and open directly onto the skin's surface
117
shivering
When cold, our first action is to shiver. Shivering increases body temperature due to friction created by skeletal muscle contraction/relaxation
118
function of brown fat in new borns
allows maintenance of core body temperature
119
non shivering thermogenesis
Important in newborns because they lack ability to shiver
Brown fat (also seen in other adult mammals such as rats)
Mitochondria in brown fat contain thermogenin
Uncoupling protein – converts ETS from producing atp to producing heat.
120
heat syncope
Circulatory failure as a result from pooling of blood I peripheral veins
This decreases venous return and diastolic filling of the heart, lowered CO, and a fall of arterial pressure.
121
heat exhaustion
State of collapse manifested by fainting
Caused by reduced blood pressure – overtaxed cooling mechanisms
Excessive sweating and vasodilation
Insufficient blood pressure – leads to fainting
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heat stroke
Complete breakdown of the hypothalamic thermoregulatory systems
Heat exhaustion is a safety mechanism to prevent this.
Most often caused by overexertion in a hot, humid environment.
Marked by lack of sweating despite rising temperatures
Heat loss mechanisms totally overwhelmed
Hypothalamic temperature control centers can be damaged
Rapidly fatal if left untreated
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1st law of thermodynamics
Energy cannot be created nor destroyed. Can only be transformed into another form of energy. This occurs in cellular respiration to generate ATP from glucose.
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BMR
Basic rate of metabolic pathways in the body. Measurement of calories needed for specific functions
126
hormone that contributes the most to BMR
thyroid hormone
