Unit 4 - Homeostasis Flashcards
1
Q
homeostasis
A
constant physiological adjustments of the body in response to external environment changes.
2
Q
negative feedback system
A
positive signal, physiological change, neg signal
3
Q
positive feedback (feed-forward) system
A
ex. contractions
positive signal, physiological change, positive signal
4
Q
endocrine system
A
delivery of chemicals within the body; created by one organ to be delivered to another (usu far away)
5
Q
hormones
A
affecting chemicals delivered around the body; to increase / decrease processes
6
Q
glands
A
they secrete
7
Q
endocrine glands
A
organs producing molecules delivered by bloodstream (inside)
8
Q
exocrine glands
A
organs producing molecules delivered by ducts (cellular tubes) (outside)
9
Q
hormone discovery
A
Mering & Minkowski removed pancreas from dogs - rapid weight loss - tired - glucose in urine (pancreas related to regulating body sugars)
10
Q
hormone roles
A
hormone are specific to target cells (protein receptors)
11
Q
two types of hormoens
A
- steroid hormones
2. protein hormones
12
Q
steroid hormones
A
- made from cholesterol
- non-polar (need carrier)
- 3 hexagons and 1 pentagon
1. diffuse from cell of origin through membranes
2. diffuse into target cell
3. often moves into nucleus to affect transcription
13
Q
LDL
HDL
info abt cholesterol
A
low density lipoproteins
high density lipoproteins
cholesterol is hydrophobic (packaged in protein “capsule”)
cholesterol is lower density than protein
14
Q
steroid hormones can affect ____ and how
A
transcription
they find sequence in promoter region to bind to, 2 hormones bring 2 receptors together, recruit transcription factors and affect transcription
15
Q
protein hormones
A
- short peptide sequences
- polar
1. transported from cell of origin (secretory vacuoles)
2. attach to surface receptors of target cells
3. activates enzymes to make other internal signals
16
Q
pituitary gland
A
overlooks operation of all other glands
17
Q
2 lobes in pituitary gland
close to hypothalamus
A
- anterior lobe - produces own hormones; released upon hypothalamus signal (front)
- posterior lobe - stores and releases hormones produced in hypothalamus; released upon signal (back)
18
Q
thermoregulation
A
maintenance of body temp within an acceptable range
ectotherms - cold-blooded
endotherms - warm-blooded
19
Q
what happens when you’re cold
A
- blood vessels contract in skin
- muscles contract (goosebumps, shivering)
- brown adipose (fat) tissue metabolism (high [mitochondria] for heat, newborns have so don’t shiver)
20
Q
what regulates our temp
A
hypothalamus
21
Q
heat stress flow chart
A
high body temp ->
hypothalamus (+) ->
nerve pathway (+) ->
- blood vessels dilate; increased blood flow; heat leaves skin
- sweat glands induced; sweat evaporation
- > body temp drops (-)
22
Q
why frostbite
A
prioritize important organs
23
Q
cryopreservation
A
suspending life through freezing
- frozen cytosol can expand to break the cell membrane
some human parts can be preserved: semen blood tissue samples eggs
24
Q
frozen wood frogs
A
able to freeze whole body and survive
25
organs responsible for excretion
liver
kidneys
bladder
26
excretion
removal of metabolic wastes
| - not feces (not used, therefore not metabolic waste)
27
urine
```
solution of metabolic waste
- urea and uric acid
- salts
- organic compounds
- water
fluid for urine come form filtered blood and extracellular fluid (ECF) which surrounds cells
```
28
urea
product of NH3 and CO2
deamination - removal of amine group (NH3 released when liver breaks down proteins)
reacts w CO2 to produce less toxic urea
29
uric acid
product of nucleic acid (purine bases) breakdown
released through liver metabolism
30
role of kidneys
urea and uric acid are filtered through the kidney
31
how do amoeba remove waste
contractile vacuole
32
how do earthworms remove waste
secretion
33
how do fish remove waste
excrete ammonia through gills
34
how do birds remove waste
excrete uric acid with feces
35
renal system
referring to the kidney
36
role of kidney
1. blood filtration
2. waste excretion
3. acid/base balance
4. blood pressure regulation
5. hormone secretion
37
kidney blood flow
blood enters the kidney through the renal artery
- renal arteries stem from the aorta
filtered blood exits the kidney through the renal vein
- renal veins flow into the inferior vena cava
38
renal artery blood is filtered through ___
nephrons
abt a million nephrons make up the kidney
39
nephrons
nephrons collect liquids to be excreted
fluids are exchanged btw the nephron before blood is returned to renal vein
40
1. the renal artery is split into ___
2. blood goes to ___
3. blood leaves through ___
1. afferent arterioles
2. glomerulus (capillary bed)
3. efferent arterioles
(no veins involved!)
41
efferent arterioles are the beginning of a network of ___ that wrap around the ___
peritubular capillaries
nephron
42
nephrons begin surrounding the glomerulus with the ___ structure
+ the next four steps
Bowman's capsule
- fluids to become urine flow to narrow proximal tubule
- urine goes through loop of Henle
- urine goes through distal tubule
- urine from multiple nephrons go into collecting duct
43
space-interstitial fluid
Extracellular fluid space, around loop of Henle
44
kidney structure
renal cortex - outside of kidney; location of Bowman's capsule
renal medulla - middle of kidney; location of loop of Henle
renal pelvis - location of the ends of collecting ducts
45
urine flow
urine leaves the renal pelvis through the ureters and travels to the bladder. fluid leaves body through urethra.
46
at ___ of urine in bladder, walls stretch and signals are sent to the brain
at ___, urine will be involuntarily released
~200mL
~600mL
47
urinary tract infection (UTI)
caused by bacterial growth in the urethra or bladder
48
symptoms of UTI
- frequent urination
- sensation of needing to urinate
- blood in urine
- discharge in urine (cloudy)
49
nephron structure
```
(check diagram)
efferent arteriole
afferent arteriole
glomerulus
Bowman's capsule
proximal tubule
loop of Henle
distal tubule
collecting duct
```
50
urinary system
```
(check diagram)
aorta
inferior vena cava
renal artery
renal vein
kidney
ureter
bladder
urethra
```
```
renal cortex
renal medulla
renal pelvis
nephrons
ureter
```
51
three functions of urine formation
1. filtration - movement of fluids from the glomerular blood to the Bowman's capsule
2. reabsorption - transfer of fluids from nephron into peritubular capillaries
3. secretion - transfer of fluids from peritubular capillaries into nephron
52
filtration
nutrients move from glomerulus into Bowman's capsule due to high blood pressure
(65 mm Hg; normal ~25 mm Hg)
bigger molecules are filtered (H2O, NaCl, NOT platelets/red blood cells)
53
reabsorption
saves fluids for our body, takes back water and nutrients
- 20% of fluid flowing into kidney is filtered into nephrons
- less than 1% of nephron fluid is used to make urine
54
reabsorption vs secretion
reabsorption
- protein transporters move nutrients into interstitial fluid and blood (btw capillaries and tube)
- kidney tissues will only reabsorb a certain level of nutrients - threshold level
secretion
- protein transporters move wastes from blood to interstitial fluid to nephron
55
order of nephron structures
1. Bowman's capsule
2. proximal tubule
3. loop of Henle - descending limb
4. loop of Henle - ascending limb
5. distal tubule
6. collecting duct
56
bowman's capsule
filtration
| water and dissolved solutes leave glomerulus; enter Bowman's capsule
57
proximal tubule
selective reabsorption of nutrients (need transporters)
pH determined by HCO3- reabsorption of H+ secretion
58
loop of Henle - descending limb
only permeable to H2O (osmosis)
impermeable to salt
fluids in tube are being concentrated
59
loop of Henle - ascending limb
only permeable to salt (need ionic transporters)
impermeable to water
(when salt is reabsorbed, water follows from the descending limb and the flow continues)
60
distal tubule
selective reabsorption of nutrients (need transporters)
pH determined by HCO3- reabsorption and H+ secretion
61
collecting duct
urine formation by concentration of nephron fluid
any urea and urine that is reabsorbed is less than that was filtered into nephron
62
cortex & medulla in the nephron
```
cortex:
- proximal tubule
- distal tubule
medulla:
- loop of Henle (both)
- collecting duct
```
63
kidney stones
crystallization of some urine solutes
2-3mm stone can obstruct flow to ureter
treatment:
- increased water consumption
- surgery
64
three physiological characteristics controlled through the kidney
1. osmotic pressure
2. blood pressure
3. pH balance
65
osmotic pressure
water pressure due to the presence of solutes
66
antidiuretic hormone (ADH)
regulates blood osmotic pressure through kidneys
short peptide hormone
produced in hypothalamus, transported to pituitary gland
67
when would osmotic pressure be increased
sweating/dehydration
68
increased ADH production leads to (2)
increase water resorption
dilute solutes in blood
69
osmoreceptors
located in hypothalamus
detect increased osmotic pressure, sends signal to pituitary gland
70
osmotic pressure (flowchart)
increased osmotic pressure ->
osmoreceptors (+) ->
pituitary gland; release ADH (+)->
1. increased sensation of thirst
2. increased water reabsorption by kidney
decreased osmotic pressure (-) ->
71
ADH increases H2O reabsorption, so
dilutes blood
| concentrates urine
72
what part of the nephron does ADH affect
collecting ducts
73
hormones only active when ___
hormones usually produced, but activated by ___
hormones _______ rather than waiting for transcription/translation
needed
enzyme cleavage
readily available
74
blood pressure
increase force of blood on blood vessels
| increase osmotic pressure, increase blood pressure
75
aldosterone
steroid hormone which increases Na+ reabsorption in kidneys
- increased H2O in blood
- increased blood pressure
produced in adrenal gland (above kidney)
76
decreased water pressure is detected by ______
juxtaglomerular apparatus (receptors next to the glomerulus)
77
what enzyme is released w low blood pressure
renin
78
what does renin do
angiotensinogen ->
| angiotensin
79
functions of angiotensin (2)
1. causes blood vessel constriction
| 2. stimulates aldosterone release
80
blood pressure (flow chart)
low blood pressure ->
juxtaglomerular apparatus (+) ->
cells to release renin; produce angiotensin (+) ->
1. constrict blood vessels
2. induce aldosterone release; increase Na+ reabsorption
blood pressure increases (-) ->
81
buffers
conjugate acid-base pairs
solutions w solutes + strong acid/base ->
no significant change
82
conversion of CO2 to other compounds help regulate blood pH
H2O + CO2
H2CO3
HCO3- + H+
H2CO3 - carbonic acid
HCO3 - carbonate ion
HCO3- is reabsorbed in the proximal and distal tubules
83
in pancreas:
| two cell types? what do they make
digestive enzymes - exocrine acini
| hormones - islets of Langerhans
84
what % of pancreas are the islets of Langerhans
1-2%
85
what two hormones are made in islets of Langerhans? by what type of cell?
1. insulin - beta cells
| 2. glucagon - alpha cells
86
insulin function flowchart
hyperglycemia ->
beta cells (+) ->
cellular signals for insulin release (+) ->
1. increased glucose uptake
2. glycogen production in liver
decreased blood sugar (-) ->
87
glucagon function flowchart
hypoglycemia ->
alpha cells (+) ->
cellular signals for glucagon release (+) ->
1. glucose release from liver
2. glucose production in liver
increased blood sugar (-) ->
88
types of diabetes (3)
1. Diabetes Mellitus - Type 1
2. Diabetes Mellitus - Type 2
3. Diabetes Insipidus
89
Diabetes Mellitus - Type I
| aka, cause, symptoms, treatment
aka juvenile diabetes
Cause
- immune system attacking insulin-producing beta cells
Symptoms
- increased thirst, hunger, and urination
Treatment
- daily dosage of insulin
90
Diabetes Mellitus - Type II
| formerly known as, cause, symptoms, treatment
formerly known as adult-onset diabetes
Cause
- insulin resistance/deficiency
Symptoms
- increased thirst, hunger, and urination
- fatigue/lethargy
Treatment
- healthy diet and exercise
- medication only upon progression of disease state
91
Diabetes Insipidus
cause, symptom, treatment
Cause
- deficiency of ADH
Symptoms
- excessive thirst and urination
- reduction of fluid intake does not affect urination frequency
- no increased blood glucose
Treatment
- ADH replacement/stimulating medication
92
insulin isolation
- tied off ducts to digestive tract
- cell producing digestive enzymes shriveled
- only islets of Langerhans remained
93
hormone type of insulin and glucagon
peptide hormone
94
adrenal meaning
"next to" to the renal system
95
two main sections of adrenal glands
1. adrenal cortex (long-term stress) (outside)
| 2. adrenal medulla (short-term stress) (inside)
96
adrenal cortex
| what happens when theres long-term stress?
long-term stress sends ACTH (adrenocorticotropic hormone)
pituitary -ACTH-> adrenal cortex
makes hormones (2):
1. glucocorticoids
2. mineralcorticoids
97
glucocorticoids
class of steroid hormones for glucose regulation, ex. cortisol
when stressed out:
- glucose not taken in by muscles
- amino acids made into glucose
- fat tissue broken down for energy
98
mineralcorticoids
class of steroid hormones for mineral regulation, ex. aldosterone
when stressed out:
- blood pressure rises due to increase sodium & H2O reabsorption
99
adrenal medulla
| what happens when theres short-term stress
short-term stress detected by hypothalamus
makes hormones (2):
1. epinephrine (adrenaline)
2. norepinephrine (noradrenaline)
100
what are epinephrine and norepinephrine
both are catecholamines, also neurotransmitters
101
type of hormone
| epinephrine and norepinephrine
polar, amino acid-like
102
flight/fight/freeze response
- increased heart rate
- increased breathing
- blood vessel dilation -> more O2 delivery
- iris dilation -> collect max visual info
induced by catecholamine release
103
three glands that help regulate metabolism
1. thyroid gland
2. parathyroid gland
3. anterior pituitary
104
thyroid gland
- regulates glucose metabolism
- regulates growth and tissue differentiation
- base of neck, anterior to larynx
105
thyroid gland produces 2 hormones
what do both contain
1. thyroxine (T4)
2. iodothyronine (T3)
both contain iodine
106
both T3 & T4 are derived from ___
the amino acid tyrosine
107
hormone type
| T3 & T4
hydrophobic
108
thyroid hormone regulation
```
signal?
- change in metabolic rate
What detects?
- hypothalamus
- releases thyroid-releasing hormone (TRH) to signal to
the pituitary
What does TRH do?
- signals pituitary to release thyroid stimulating hormone
(TSH)
```
109
thyroxine regulation flowchart
decreased metabolism ->
hypothalamus (+) -> TRH
pituitary gland to release TSH (+) ->
thyroid gland to release thyroxine (+) ->
increase sugar metabolism
decreased blood sugar (-) ->
110
thyroid disorders
1. hyperthyroidism
2. hypothyroidism
3. goiters
111
hyperthyroidism
cause, symptom, treatment
high thyroxine release
Cause
- "hot" nodules/Grave's disease (whole thyroid)
Symptoms
- high glucose metabolism
- > weight loss with increased appetite
- > anxiety
- > increased heat release
Treatment
- suppressive medication
112
hypothyroidism
cause, symptom, treatment
low thyroxine release
Cause
- iodine deficiency
Symptoms
- low glucose metabolism
- > weight gain
- > fatigue
- > decreased heat release
Treatment
- synthetic hormone medication
113
goiters
low iodine levels result in enlarged thyroid glands
114
why is table salt iodized
to prevent iodine deficiency
115
where is calcium stored
99% is stored in bones for structure
116
roles of calcium
1. required for muscle contraction
2. important in neuronal communication
3. bone structure maintenance
117
bone structure
osteoblasts & osteoclasts
osteoblasts - cell which build bones
osteoclasts - cells which break down bones (release calcium)
118
parathyroid glands
smaller glands within the thyroid gland
increases Ca2+ levels in blood
produces parathyroid hormones (PTH)
119
calcium level regulation flowchart
```
hypocalcemia ->
parathyroid gland (+) ->
release PTH (+) ->
```
1. increased Ca2+ uptake in intestines (diet) & kidneys (reabsorption)
2. increases osteoclast activity
3. activation of vitamin D; required for Ca2+ absorption
increased Ca2+ levels ->
120
what are responsible for decreasing high calcium levels
different organ and hormone responsible from increasing Ca2+
```
organ = thyroid
hormone = calcitonin
```
121
calcium level regulation flowchart
```
hypercalcemia ->
thyroid gland (+) ->
release calcitonin (+) ->
```
1. inhibits Ca2+ absorption by intestines
2. decreases osteoclast activity
decreased Ca2+ levels (-) ->
122
type of hormone
PTH, calcitonin, vitamin D
peptide
peptide
steroid-based
123
parathyroid disorders
1. hypoparathyroidism
| 2. hyperparathyroidism
124
hypoparathyroidism
cause, symptom, treatment
Cause
- absent parathyroid from birth
- accidental removal upon thyroid removal
Symptoms
- decreased Ca2+ levels in blood
- sensitive nerves
- uncontrollable spasms of the limbs
Treatment
- daily calcium and vitamin D supplements
125
hyperparathyroidism
cause, symptom, treatment
Cause
- tumors on the parathyroid gland
Symptoms
- kidney stones
- aches & pains
- osteoporosis
- depression & fatigue
Treatment
- removal of parathyroid tissue
126
gonadotropic hormones
regulate gonad development (male and female)
produced in the pituitary; released upon hypothalamus signal
127
other reproductive hormones
1. follicle stimulating hormone (FSH)
| 2. luteinizing hormone (LH)
128
male reproductive hormones (2)
type
made where
1. androsterone
2. testosterone
both steroid
made in testes
129
types of testes cells (2)
1. Leydig interstitial cells - make hormones
| 2. Sertoli cells - make sperm
130
male gonad development
1. hypothalamus secretes gonadotropin-releasing hormone (GnRH)
2. pituitary gland releases FSH & LH
3. FSH stimulates Sertoli cells to make sperm
4. LH stimulates Leydig cells to secrete testosterone
131
role of testerone
- stimulates spermatogenesis (life time process)
- develops male characteristics at puberty
- increased secretion of body oils (commonly associated to body odour)
132
male reproductive system flowchart
refer to diagram
133
female reproductive system hormones
1. estrogen (steroid)
2. progesterone (steroid)
both made in the ovaries
134
ovary follicle cells (2)
1. primary oocyte - fertilized by sperm
| 2. granulosa cells - provide nutrients for primary oocyte
135
female reproductive system
- monthly cycle until menopause (~12-50 yrs)
- one ovum produced per germ cell
- female hormones responsible for oogenesis and ovulation
136
menstrual cycle
1. menstruation (flow phase)
2. follicular phase
3. ovulation
4. luteal phase/secretory stage
137
menstrual cycle -
| 1. menstruation (flow phase)
- sloughing of endometrial cells
- no ovum fertilization
- estrogen and progesterone levels low
138
menstrual cycle -
| 2. follicular phase
- follicle maturation
| - estrogen secretion by granulosa cells
139
menstrual cycle -
| 3. ovulation
- ovum leaves ovary
- granulosa cells become corpus luteum
- corpus luteum begins to secrete progesterone
- estrogen levels decrease
140
menstrual cycle -
| 4. luteal phase/secretory stage
- corpus luteum secretes progesterone & estrogen
| - progesterone encourages endometrium development
141
female gonad development
- GnRH, FSH, and LH involved
1. hypothalamus secretes gonadotropin-releasing hormone (GnRH)
2. pituitary gland releases FSH & LH
3. FSH matures follicle
4. LH causes ovulation and causes corpus luteum maturation
142
female reproductive system flowchart
check diagram
143
menopause
- ovaries lose responsiveness to FSH and LH
- usu occurs btw ages 46 and 54
- most other mammals do not undergo menopause
144
major subsystems in vertebrate nervous systems (2)
1. central nervous system (CNS)
| 2. peripheral nervous system (PNS)
145
main components of central nervous system (2)
1. brain
| 2. spinal cord
146
main nerve types of peripheral nervous system (2)
1. somatic nerves
- involved w voluntary movement
- > senses/movement
2. autonomic nerves
- involved w involuntary movement
- > sympathetic/parasympathetic systems
147
major cell types of the nervous system (2)
1. neurons
- conduct electrical signals
2. glial cells
- structural & insulating support for neurons
148
neuron structure handout
check diagram
149
how do electrical signals pass through cells
membrane potential (video)
150
neuron signalling (role of glial cells)
- glial cells provide insulation for electrical impulses to pass through axon
- glial cell membrane has a lot of lipid molecules (called a myelin sheath when wrapped around an axon)
151
sensory neuron
aka, function, found where
aka afferent neurons
- carries signals from sensory receptors to the CNS for processing
- > photoreceptors (eyes)
- > chemoreceptors (nose)
- > thermoreceptors (skin)
- found in clusters of neurons - ganglia
152
what are ganglia
clusters of neurons
153
interneuron
aka, function
aka association neurons
- receives incoming signals from sensory neurons
- delivers outgoing signals to neurons responsible for responses
154
motor neuron
aka, connected to?
aka efferent neurons
- connected to tissues that respond according to what was detected
- > muscle contraction
- > gland secretion
155
do neurons regenerate
yes, peripheral system neurons will repair faster than central system neurons
156
action potential
animation (video)
- polarized membrane
- depolarization
- repolarization
157
polarized membrane
positive exterior, negative interior
- maintained by sodium-potassium pump
158
depolarization
negative exterior, positive interior
- voltage-dependent channels open to allow sodium ions to rush into cell
159
repolarization
positive exterior, negative interior
- voltage-dependent channels open to allow potassium ions to leave the cell
- restored by sodium-potassium pump
160
two states of the neurons (action potential)
1. resting potential: -70mV
- required before a signal can be detected
2. action potential: +40mV
- change that occurs to transmit signal
161
action potential factors
1. refractory period
2. threshold
3. axon diameter
4. saltatory conduction
162
refractory period
time is needed to re-establish the resting potential after an action potential has been initiated
- no other action can be initiated, no matter how strong the signal
163
threshold level
different neurons have differing threshold levels before an action potential will proceed
sensitive neurons will have low threshold values
164
all-or-none response
neurons will or will not fire
165
saltatory conduction
Na+ and K+ exchange can only occur where the axons are exposed to the extracellular fluid (node of Ranvier)
- allows for faster signal conduction along the axon
