Coursecram Flashcards
(198 cards)
1
Q
what is the endocrine system?
A
- all the hormone secreting cells of an organism
- composed of endorcrine and neuroendocrine glands
- these glands secrete their hormones and neurohormones into body fluids (blood, hemolymph, etc. )
- think “within the body”
2
Q
what is histamine?
A
- local regulator
- regulation of immune response and and inflammation
3
Q
what are local regulators
A
signals that act like hormones but never enter any circulatory system
4
Q
what are pheromones
A
they are signals that leave the organism and act at a distance on another organism
5
Q
what are the 3 signalling strategies?
A
- autocrine (self signal)
- paracrine (signal beside it, histamine)
- endocrine (within)
6
Q
what are the four groups of hormones?
A
- amino acid derivatives: dopamine, melatonin, thyroid hormones, adrenaline
- peptide hormones: proteins, prolactin,insulin
- steroid: cholestoral derivatives, sex hormones, cortisol
- fatty acid derivatives: in insects
7
Q
what type of soluble are steroid hormones?
A
lipid soluble
8
Q
what are the unique properties and receptor location of peptide hormones?
A
- encoded by genes
- soluble in blood
- receptors found on the plasma membrane
9
Q
what are the unique properties and receptor location of steroid hormones?
A
- insoluble in blood
- need carrier proteins
- made by enzymes
- receptors are found in the cytoplasm
10
Q
what are the steps in the endocrine signalling pathways?
A
- synthesis: translation and enzymatic
- transport: either soluble or insoluble (need carrier proteins)
- reception: only cells with the appropriate receptor expressed can respond
- transduction
- response
11
Q
what are the 2 types a receptor can be?
A
- angonists: stimulatory
- antagonist: inhibitory
12
Q
what are the 2 general kinds a receptor can be?
A
- angonists: stimulatory
- antagonist: inhibitory
13
Q
what can hormone concentration affect for receptors?
A
activity
14
Q
what are peptide hormones synthesized by?
A
genes that are expressed
15
Q
what are steroid hormones synthesized by?
A
enzymes
16
Q
which can travel through the blood stream? soluble or insoluble hormones
A
- soluble: can travel
- insoluble: bind carrier proteins in the blood (Albumin and Globulins)
17
Q
what are signal transduction pathways?
A
- extracellular signals that produce one or more effects in structure, function, of the gene expression profile of the target cell
18
Q
what are the types of receptors? what are the types thar use second messengers?
A
use 2nd messengers
* GCPR
* Ligand gated ion channels
* receptor enzyme
don’t use it
* intracellular receptor (influences gene expression- steroids)
19
Q
what do second messengers do?
A
amplify response and most signalling cascades use them
20
Q
what are protein kinases?
A
act on each other and transmit signals by a casecase of phorphorylations that cause conformational change in phosphorylated protein
21
Q
what does phosphorylation usually change in a protein?
A
changes it from inactive to active form
22
Q
what are the antagnostic hormones in the human endocrine system? what is their general roles
A
- general role: maintain homeostasis
Regulation of Glucose
* insulin: decreases blood sugar levels by stimulating uptake at the tissues
* glucagon: increases blood sugar levels by stimulating glucose released by the liver into the blood
Regulation of Sodium Levels
* ADH: less water in urine
* ANP: more sodium in urine
* alsosterone: more sodium in urine
23
Q
what happens when you eat, in terms of insulin?
A
- blood sugar spikes
- insulin released from pancres
- causes glucose to be taken out of the blood (by tissues) and stuffed into the cells
24
Q
what happens when you fast, in terms of glucagon?
A
- blood sugar is depelted
- glucagon released
- releases glucose from liver and into the blood
25
what does increased sodium levels cause?
* stimulates hypothalamus
* which stimulates the posterior pituitary
* which release ADH
* ADH causes for more water to be abosrbed, and for there to be less water in urine
26
what does the hypothalamus do?
* stimulate release of hormones into the blood
* secretes tropic hormones
* stimulates the posterior pituitary
* pupper master
27
what is the anterior pituitary controlled by?
tropic hormones
28
describe the pathway of cortisol.
* hypothalamus releases CRH which is a tropic hormone which stimulates the release of other hormones
* the anterior pituitary then releases ACTH to the adrenal cortex
* this then releases cortisol: stress
29
what is phytoestrogens?
plants posses estrongen like compounds, which can cause for vertebrates to become feminized due to too much exposure from phytoestrogens
30
what are the 4 functions of the nervous system
* recieve external and internal signals
* transmit external and internal signals
* integrate/interpret all signals
* coordinate/command an action/response to those signals
31
what are the two components of the nervous system and their function?
* CNS: brain and nerve cord
* PNS: all neurons and their projections outside the CNS
32
what is integration carried out by?
interneurons
33
what is the general structure of a neuron?
* dendrites: recieve inputs from other neurons or the environment
* nucleus
* cell body/soma: has nucleus and organelles
* nodes of ranveir: location of action potential
* axon: transmit impulses
* myelin sheath: allow saltatory/jumping conductions
* axon termini
34
what is a nerve tract?
a bundle of axons
35
what is a ganglion
a collection of neuron cell bodies
36
what is the myelin sheaths role, and what is it formed by?
* formed by glial cells
* acts as insulating material
37
where does the action potential run down and go?
runs down the azon and then it has to be relayed off to the next cells, when it reaches the axon termini
38
how are the glial cells subdivided? what is each of their functions?
* microglia: defense and savenging of the immune cells of the CNS
* astrocytes: maintenance and support
* oligiodendrocytes: insulating of neurons for electrical transmission, outside of the CNS called schwan cells, form the myelin sheath
39
is a reflex arc voluntary or involuntary?
involuntary
40
what is an effernt neuron
motor neuron
41
what were the steps in evolution related to the nervous system?
* more nerves and nerve bundles
* concentration of nerves (ganglia)- cell bodies organized
* specialization of function of cells
* more complex synaptic contacts
* trend toward cephalization (creating a brain)
42
what is cephalization?
tendency toward bundles of nerves around the head
43
what is the hindbrain
* survive
* central pattern generator (stores the pattern of neuronal connections)
44
what is the midbrain?
* router
* conector to forebrain
vision and hearing
45
what is the forebrain?
* decision maker
* center for integration of complex pathways
46
how is the PNS seperated, and what are their roles?
* sympathetic: fight or flight
* parasympathetic: rest and digest
47
what is the common neurotransmitter of the PNS?
adrenaline
48
what are the differences in duration for hormonal vs neural stimulation of fight or flight?
* neural stimulation of fight or flight is immediate and short
* hormonal stimulation of fight or flight is a longer lasting response
*
49
what is the resting membrane potential in resting neurons?
-70mV
50
is there more sodium or potassium inside or outside of the cell?
* more sodium outside
* more potassium inside
51
what is an action potential?
* if the stimulus is strong enough the neuron fires a nerve impulse, which is an action potential
* action potentials move along the axon, to cell body, to synaptic termini
52
explain the steps of an action potential.
1. reach threshold: due to small depolorizations
2. rapid depolarization: fast opening of sodium channels open
3. repolarization beginds: small opening of potasssium channels open
4. repolorization continues
5. hyperpolarizations: potassium channels are slow to close, so too much flows out, making it very negative
6. resting potential restored: sodium/potassium pump is always on
53
what does the speed of action potential conduction depend on?
* axon diameter: broader is faster, due to less resistance (in bigger one)
* myelination: myelination is faster
54
what are synapses?
junctions that control the communication between a neuron and another cell (neuron or not)
55
what is the transmitting cell called?
presynaptic cell
56
what is a recieving cell called
the post synaptic celll
57
what is acetylcholine?
* type of neurotransmitter
* one of the most widepsread
* released at neuromuscular junctions
* excitatory in brain and skeletal muscles
* inhibitory in cardiac muscles
58
what happens when the action potential reaches the synaptic termini?
releases chemical messengers (neurotransmitters)
59
what do neurotransmitters do with an action potential?
* bind receptors in the post synaptic cell membrane and trigger other changes (open ion channels, initiaye other signalling changes)
* after activating their receptors, neuro transmitters are rapidly degraded or re abosorbed by pre synaptic cell (limits duration of stimulus)
60
describe what happens in the pre and post synaptic cell?
1. AP opens voltage gated calcium channels
2. calcium influx triggers vesicles docking (exocytosis event) and neurotransmitter is released in synapse
3. neuro trans bind to post synaptic cell at receptor and these initate a response (inhibitory or excitory)
61
what can neurotransmitter signalling be stopped by?
degredation at the synapse or reuptake
62
what is sumation?
the integration of both stimulatory and inhibitory stimuli
63
what does a NT cause at an excitatory synapse?
a slight depolarization of the membrane and is called an excitatory post synaptic potential (EPSP)
64
what does a NT cause at an inhibitory synapse?
a hyper polarization of the membrane and it is called an inhibitory post synaptic potrntial (IPSP)
65
what determines if a post synaptic neuron will fire an AP>
the summation of all the EPSP and IPSP that reach the axon hillock at any time
66
what is the axon hillock
where the axon originates and where the voltage gated sodium channels are
67
what does IPSP cause?
repolarize cell slightly, make more neg
68
what does EPSP cause?
depolarize cell slightly, make more pos
69
what is learning?
the process of acquiring new info, and making new connection
70
what is memory?
process of storing info in stable neuronal connections, maintaining connections
71
what is plasticity?
ability to change synaptic connections and function properties of neurons
72
how does plasticity strengthen the communications between two neurons?
making more connections or reinforcing existing connections
73
what is the hot pepper receptor type?
heat receptor
74
what is muscle tissue responsible for?
the generation of force and motion essential for many life purposes including: locomotion, circultion, digestion and the manipulation of objects
75
what is the most abundant tissue in the vertebrae body?
muscles
76
what is the organization of muscles?
* tissue is arranged into bundles of muscle fibres
* muscle fibres are comprised of thinner threadlike structures caled myofibrils
* myofibrils are made up of individual actin (thin) and myosin filaments (thick)
77
what are the main proteins responsible for contraction of muscle fibers?
actin and myosin
78
how is force generated?
* when myosin pulls the actin polymer which causes the thick filament to slide over the thin filament
* a cross bridge forms between actin and myosin
* AP is hydrolysed, releasing enegy to the myosin head
* the resulting molecular changes in myosin cause the powerstroke
* interacting is described by slidng filament model
79
what is actin and what is myosin (think in terms of common function. symbol)
actin is the cable
myosin is the engine
80
what type of protein is myosin?
* motor protein
81
what is a motor protein?
protein that changes the shape with ATP hydrolysis to generate force
82
what are the roles of tropomyosin and troponin?
* tropomyosin: wraps around actin and blocks myosin binding sites
* troponin: regulates tropomyosin
83
what does contraction pull on?
* contraction pulls the actin
* pulls the thin filaments to the center of the sacromere
84
how are thick and thin filaments arranged
in sacromeres
85
what type of pairs do muscles usually come in?
antagonistic pairs
86
what does contraction cause for the sacromere?
shortening
87
what are the 3 types of muscle conditioning?
* atrophy: decrease in the number of myofibrils per fiber
* strength training: increase myofibrils per fiber
* endurance training: increase blood vessels and mitochondria in fibers
88
what are the 3 types of locomotion?
* hydrostatic: muscles and fluid pressure
* exoskeleton: extenal structure
* endoskeleton: internal
89
what are the 2 types of muscles?
smooth and straited
90
how can straited muscle be further divided?
cardiac and skeletal
91
what happens at the muscular junction?
* axons divide into terminals containing acetylcholine
* regions of muscle under axon terminal is folded into junctional folds to increase SA
* ach receptor is ligand gated ion channel
* calcium flow into muscle leading to the depolarization and an AP
92
describe the motor analogy of muscle contraction
* myosin is the motor, converts ATP energy into movement
* actin filaments are the tracks
* ATP is the fuel
93
what are autotrophs? Heterotrophs? it is how an organism obtains _____?
* obtains carbon
* auto: utilize CO2 as carbon source, carry out carbon fixation
* Hetero: cannot fix carbon, and must synthesize carbon compounds using organic molecules created by other organisms
94
what are phototrophs? what are chemotrophs? this is how an organism obtains __?
* obtains energy
* photo: use light as energy source
* chemo: obtain energu from organic or inorganic molecules, usually via redox reactions
95
animals are chemo or phototrophs?
chemo
96
what are the exceptions of animals that need to eat food?
* corals: have endosymbiotic relationship with microbiomes, don't do lots of their own digestions
* nudibranch: feed on cnidarians and eat using stining cells
* riftia: harvest bags of bacteria
* Tape worms: don't have gut, exterior surface absorbs food
97
what compartments does the digestive system contain?
fluid compartments: intracellular, extracellular
98
what is movement between the fluid compartments of digestive system?
movement occurs through passive diffusion, facilitated diffusion, or active transport
99
what is intracellular digestion?
* phagocytosis
* often in unicellular eukaryotes
* used by protists to engulf solid particules by the cell membrane to form internal food vacuole called phagosome
* form of endocytosis
* involved in obtaining nutrients
* can be used to remove pathogens and dead cells in immune system
100
what is the problem with intracellular digestions?
there is an increased chance of infection, therefore there was selective pressure against intracellular digestion
101
what are the benefits and tradeoffs of extracellular digestion
* digestive enzymes secreted into the environment
Benefit: decreased risk of infection
Tradeoff: nutrients can wash away
102
what is the benefit and tradeoff for blind sacs?
benefit: allowed continous contact with nutrients, not washed away
tradeoff: nutrients and waste were getting mixed up
103
what is the benefit and tradeoff for unidirectionality digestion?
* mouth and anus different holes
* earliest example of specialization
benefit: allows step wise digestion, digest more complex nutrients
tradeoff: requires specialization
104
what does chewing allow for?
increased surface area for digestion
105
what is the alimentary canal?
* contains openings at both ends
* anterior end: ingestion
* middle portion: storage and initial digestion
106
what does the complete digestive system have?
regional specialization
107
describe the parts of the stomach.
* stomach: muscular, stretchable sac, mixes and stores ingested food, control passage of food in small intestine
* gastric juice: dissolve food into liquid mixture
* protection: pepsin
* goblet cells: line the stomach and secrete mucous layer for protection
108
what are the cells of the gastric pit?
* goblet cells: secrete mucous to protect stomach
* cell X: parietal cells that secrete acid
* chief cells: secrete inactive form of pepsin to digest proteins
109
what is the major site for chemical digestion?
duodenum
110
what does increased SA allow for digestion?
slow process of digestion of complex nutrients and absorption
111
what is an enterocyte?
interstinal cell
112
where are proteins are sugars aborbed into?
directly into the blood
113
what are the four compartments of the ruminant's stomach?
* rumen: where processed mechanically and exposed to bacteria to break down cellulose
* reticulum: allows the animal to regurgitate and reprocess particulate matter
* omasum: further mechanical processing
* abosmassum: the true stomach, where digestive enzymes break down bacter as to release nutrients
113
what are the four compartments of the ruminant's stomach?
* rumen: where processed mechanically and exposed to bacteria to break down cellulose
* reticulum: allows the animal to regurgitate and reprocess particulate matter
* omasum: further mechanical processing
* abosmassum: the true stomach, where digestive enzymes break down bacter as to release nutrients
114
what is the ruminat's stomach
contain enterosymbiotic bacteria that live in the rumen and can digest cellulose
115
what are the 3 types of feeders?
* continous feeders
* opportunistic feeders: eat when food is availble
* metabolic suppressors: can temporarily reduce metabolic rate and body temp (poikilotherms)
116
what is a gastrovascular cavity?
one opening (mouth) and branches that reach all the cells of the inner layer, cells digest food, nutrients diffusue into outer layer of cells
117
what are open circulatory systems?
no distinction between blood and in the interstatial fluid
118
what is a closed circulatory system?
* cardiovascular system
* blood is confined to vessels and is seperated from tissues
* blood flow may be seperated into pulmonary (right side) and systemic circuit (left side)
* general components: heart, bessels, artieries, capillaries
119
what is the problem with an open circulatory system?
as body size increases, it becomes harder to distribute nutrients
120
what is the lymphatic system?
open system that collects overflow fluid from the capillaries back to the venous system
121
why are some vessels blue and some are red?
The arteries (red) carry oxygen and nutrients away from your heart, to your body's tissues. The veins (blue) take oxygen-poor blood back to the heart.
122
what is the pacemaker? what is its role?
* a group of pacemaker cells
* modified cardiomyocytes that have a leaky sodium channel, which causes it to underho a regular slow depolarization
* action potential spreads through gap junctions across ventricles of the heart, allows coordinated contraction
123
what is the pacemaker? what is its role?
* a group of pacemaker cells
* modified cardiomyocytes that have a leaky sodium channel, which causes it to underho a regular slow depolarization
* action potential spreads through gap junctions across ventricles of the heart, allows coordinated contraction
124
simply describe arteries, capillaries, veins, roles
artieries: blood away from the heart
capillaries: exchange
veins: blood to the heart
125
what is velocity in the veins caused by?
muscle contractions
126
what are erythrocytes?
* red blood cells
* transport oxygen
* oxygen carrying capacity is determined by the number of red blood cells in circulation
127
what are leukocytes?
* white blood cells
* monocytes, lymphocytes, defense and immunity
* neutrophils (phago), eosinophils (allergic), basephils (inflammation)
128
what are platelets?
* blood vessel repair
* not cells
* mediate blood clotting
129
what is the protein that binds oxygen?
hemoglobin
130
what is the structure of hemoglobin?
* 2 alpha
* 2 beta
* each carry heme (iron carrying)
* 4 oxygens can bind one Hb tetramer
131
what is the biggest driver for oxygen affinity?
pH
132
how have fish managed to use their anatomy to create countercurrent flow?
as blood moves to the surface of gills, the blood moving the other way can bind O2
133
what does negative pressure (created) from the diaphragm contraction do?
inflates the lungs
134
what is an immune response?
the ability to recognize foreign or dangerous macromolecules and eliminate them
135
what is a lymphocyte?
non granular white blood cells that can cross into the lymph system
136
what is an antigen?
molecule specifically reckognized as foreign or dangerous by cells of the immune system
137
what are antibodies?
highly specific immunoglobulin proteins that reckognize and bind to specific antigens
138
what are the two classes of soluble factors released during innate immune response?
* cytokines: act as an alarm, signalling breach of the barriers
* complement: enhance inflammation and attract phagocytes (patrol)
139
how does a phagocytic cell reckognize something it should eat?
* potential pathogens (mostly bacteria) contain PAMP (pathogen associated molecular pattern) which are molecules found on pathogens
* phagocytes carry PRR's (pattern recog. recep.) which will bind and reckognize PAMP
140
what is the interaction between phagocytes and potential pathogen?
* phagocytes destroy potential pathogens and keep a souvenir (anti gen)
* then they present the antigen
141
what is the role of B cells?
can produce anti bodies, or become memory cells which continue to produce anti bodies after an infection has been overcome
142
what are the similarties and differences between innate and adaptive immunity?
innate
* rapid response
* B cells: target foreign pathogens
* T cells: target aainst diseased self cells
Adaptive
* slow response
* more specific
* B cells: generate antibodies against bullies
* T cells: recognize diseased traitor cells
Similarities
* innate reports to help T cell to coordinate adaptive immunity
143
what produces anti bodies?
B cells
144
describe what happens the different times you're exposed to pathogen
* first exposure: you need to identify and fight
* 2nd time: now you know how to defend, faster recovery/defense
145
what is hypertonic and hypotonic?
hyper: more solute inside cell, water flows in (freshwater-cell gets to big/swells)
hypo: less solute inside cell, water flows out (salt water- shrinks)
146
what is osmolarity?
a property of a solution
147
what is molarity
the concen. of a solute in a solution
148
what is tonicity?
solutions affect on cell volume
149
what is osmotic pressure?
force produced by movement of water
150
compare fresh vs salt water fishes
* fresh: environment is hypotonic, fish are hypertonic to their environment, water flows in
* salt: environment is hypertonic, fish are hypotonic to their environment, water flows out
151
what are osmoconformers?
* adjust the osmolarity of the body to the environment
* can't survive in the extremes
152
what are osmoregulators?
* body maintains constant osmolarity
153
what are ionoregulators vs ionoconformers?
regulators: concen. of ions in the blood are tightly regulated
conform: allow concen. of ions in blood to very in the environment
154
what is the difference between stenohaline and euryhaline?
* steno: narrow tolerance for changing salt concen
* eury: tolerate a range of salininty
155
what are the 3 processes involved in he formation of urine?
* filtrations: passive loss of wasye
* reabsorption: active reabsorption of nutrients
* secretion: active exctretion of waste, toxins, etc
156
what is the kidney?
collection of nephrons that filter the blood and excrete wastes
157
what is the function of the loop of henle?
* to create an osmotic gradient that can be used to retain water at the collecting ducts
* relatively passive process
* the longer the loop, the greater the ability to create more concen. urine and absorb more water
158
what is the pathway of filtrate through the nephron?
* renal artery
* glomerulus in Bowman's capsule
* proximated convulated tubule: active in secretion of wastes, reaborpstion of ions
* loop of henle: establish a concen gradient in interstitium
* distal convulated tubule: monitor the filtreate and pressure, responsive to blood pressure
* collecting duct: allows water reaborspotion with ADH
* ureter to urethra out
159
what is in the filtrate? what do we not want to see therw?
in it
* urea
* excess water
* excess ions
* water
not want
* glucose
* nutrients
* blood cells
160
what controls the movement of things into and out of the filtrate?
into
* blood pressure into bowmans capsule
* active secretion
out
* making pee
* reaborption
* passive water retention
161
what hormones act on the kidney and how?
RAAS: raises blood pressure
ADH: via HPA axis, opens aquaporins in collecting ducts, allows water retention
162
what does the kidney produce in response to low blood pressure?
renin
163
what does reaborption in distal convulated tubule cause
retention of fluids, increase blood volume, increase blood pressure
164
what is parhenogenesis?
female haploid egg can spontaneously duplicate genome and produce diploid zygote q
165
what is parhenogenesis?
female haploid egg can spontaneously duplicate genome and produce diploid zygote q
166
what is budding?
offspring grows off of them
167
what chromosome determines maleness?
y
168
why are reptile sex determination messed up by humans?
it is determined by incubation temp, and sex ratios are skewed due to climate change
169
what is ovipary?
lays eggs and developmet completed
* birds
* fully formed chick hatches
170
what is ovovivpary?
* young develop within the female
* derive nutrition from yolk exclusively
* no placenta
171
what is vivipary?
* young develop within female
* derive nutrients via the mother
* have placenta
172
what type of feedback do sex hormones have, and why?
negative feedback to maintain homeostasis
173
how do you get sex specific responses?
produce different receptors
174
what is pre ovulation?
stimulate growth of the follicle
175
what do FSH and LSH do for an oocyte?
mature it (stimulates meiosis)
176
what does the egg contain?
oocyte and support cells
177
what does the corpus letuem produce?
progesterone
178
what does progesterone do?
maintain corpus luteum and uterine lining awaiting implantation
179
what is the blastula?
* population of identical cells in embryonic development
* contains inner cell mass and trophoblast
* the inner mass cells of the blastula inverts itself in a provess called gastrulation which forms 3 tissue layers
180
what are the 3 tissue layers the gastrula forms?
* endoderm: becomes most organs (inside)
* mesoderm: become muscle (middle)
* ectoderm: becomes skin and nervous system (outside)
181
what does oxytocin do for partuirition (child birth)?
triggers the strenghtening contractions due to positive feedback loop
182
what is the difference between positive and negative feedback?
Positive feedback occurs to increase the change or output: the result of a reaction is amplified to make it occur more quickly. Negative feedback occurs to reduce the change or output: the result of a reaction is reduced to bring the system back to a stable state.
183
what is pheremone detection?
* chemodetection
* signalling factors
* released into the environment
* released by one sex to lure the other
* bind to receptor on sensory euron triggering signalling pathway
*
184
what is taste and smell?
* chemosensory responses: detect volatile chemicals in the environment
* taste: sensory cell is not a neuron but a cell with microbilli, which stick out of the taste bud
* smell: receptor sits on a neuron, neuronal sensors
185
what. is magnetosensing?
* detects magnetic poles and emissions
186
what is the connection with bees and magnosensing?
* bees land on flower and disrupt magnetic field
* next bee can tell that the magnetic field has been disrupted
187
what are the light sensing cells and what do they do?
* cone and rod
* detect the electromagnetic spectrum, energize and activate neurons
188
where does the action potential leave int he eye
via the optic nerve
189
is the eye an example of irreducible complexity?
no
190
what are TRP receptors?
* heat receptors
* cell sigballing receptors
191
which receptor is sensitive to heat and cold?
* TRPA1: cold and menthol
* TRPV2: heat and hot food
192
what are homeotherms?
maintain a constant body temp and therefore respond to changes in ambient temps to maintain internal body temp
193
what. isthe central thermostate for vertebrates?
hypothalamus
194
what are four types of mechanireceptors?
* merkel's disks
* meissner's corpuscles
* ruffini endings
* pacinian corpulses
all sense different degress of touch of skin
195
what are tropic hormones
a group of hormones that stimulate other endocrine glands so as to produce their particular hormones.
196
how do you feel full?
* when adipose is full of fat, secretes the hormone leptin that goes to the brain and signals that you're full.content: stops hunger
* when colon is full: gut releases peptide yy which goes to region of brain ans stops hunger
197
what happens when your stomach is empty?
* releases hormone ghrelin, which travels to the brain and stimulates appetite
