exam 2 study guide

What does the limbic system do?

Controls arousal

What is the purpose of thalamus?

Relay center for sensory information

What is the purpose of hypothalamus?

Temperature and endocrine

If hot temperature is applied to cerebral cortex will the body temp change?

No

If hot temperature is applied to hypothalamus what happens?

There's thermal receptors

What is the purpose of pituitary gland?

Involved in hormone

What is the purpose of the pineal gland?

secretes melatonin

What is the purpose of cerebellar penducles?

Knows your body and creates motor motor plan from the frontal lobe

What is the one pathway for sensory information?

Medulla

What is the purpose of the midbrain?

Vision and auditory reflex

What is the purpose of pons?

Breathing and swallowing

What is the role of serotonergic projections?

Regulates mood, sleep cycle, motor behavior, and stress

What is the role of raphe nuclei?

Produces serotonin

What is the purpose of medulla oblongata?

Reflex center

What does the proprioceptors measure?

Body sensation, stretch of muscle, motor control

What does the proprioceptors do?

A sensory neuron wrapped around

Can change and make more sensitive to stretch

What is a sensory Cell?

Physical and chemical stimuli into neuronal signals

What makes the sensory cell positive?

Receptor proteins interacting with physical stimuli

What is a ionotropic receptor?

Ion channel; mechanoreceptor

What is metabotropic?

Affect ion channel through G protein

What is adaptation?

Diminishing response to repeated stimulation?

What is a mechanoreceptor?

responds to mechanical forces

What is a thermoreceptor?

responds to temperature changes

What is chemotaxis?

To move towards

What is the pinnae?

To catch the sound

What is the tempanic membrane?

eardrum; converts sound waves to vibrations to hear

What is the conduction of deafness?

loss of function of tympanic membrane or ossicles

What is the nerve deafness?

Damage to inner ear or hair cells; damage is also done to temporal lobe

fovea centralis

Where the cones are; detailed central vision and color perception

ciliary body

Wraps around the lens; helps lens move around different focal points

Cornea

For protection and so light can be transmitted

Iris

Absorbs or reflects light

Pupil

Controls the amount of light entering the eye

What is the macula lutea?

contains mostly cones

Ground Squirrel

1. A thermistor is placed into the hypothalamus

2. A thermistor can heat up or cool down an area, the thermistor cools down the hypothalamus

3. Metabolism increases, which burns more calories and and body temp increases

4. Hypothalamus starts to heat up, which decreases both body temp and metabolism

Bear Attack (sympathetic)

1. see a bear

2. brain goes, “oh no thats not good”

3. pre-ganglionic neurons in thoracic lumber region of spinal cord become active, firing AP, releasing PCH to post-ganglionic neuron

4. Post-ganglionic neuron receives neurotransmitters with a nicotinic receptor (ACH)

5. Post-ganglionic neuron fires and AP; releases norepinephrine, heart tissue will receive norepinephrine with adrengenic receptor (gs-coupled)

6. Norepinephrine is then released to the heart, increasing heart rate

Bear Attack (OR/AND)

7. pre-ganglionic neuron go around the post-ganglionic neuron; goes directly to adrenal medulla gland

8. Fires AP, releasing ACH into the cell

9. Adrenal Medulla cell receives ACH (nicontic receptor); releasing norepinephrine and epinephrine to blood stream (adrenaline rush)

Beer Attack (parasympathetic)

1. Interpret an event as a relaxation event

2. Brain will activate preganglionic neurons (located in brain stem)

3. Fires action potentials; goes to the ganglia (parasympathetic) close to the target organ

4. Releases ACH to the post-ganglionic neuron receives it with nicotinic ACH

5. Post-ganglionic neuron gets to threshold, fires AP; releases ACH

6. Heart tissues does NOT have nicotinic receptors; it will have muscarnuic ACH Receptors (Gi-coupled receptors)

7. This causes heart rate to go down

Olfactory Essay

1. ligand enters your nasal cavity; binds to the receptor proteins

2. GDP goes away

3. A shiny new GTP comes and binds to the alpha subunit of G protein effector (AC)

4. AC converts cAMP; cAMP binds to cynic gated ion channels

5. Both sodium and calcium enters; positively charge giving receptor potential

6. Calcium will bind to chloride ion channel; opens up

7. Chloride must be higher on the inside so chloride will leave; making receptor potential

8. Receptor potential if above threshold will cause an AP

9. Releases a neurotransmitter to the dendritic region of glomerulus mitral cell

10. Mitral cell fires action potential, then goes to the uncus

Chochea Essay

1. Basilar membrane stiff at the beginning but flexible at the end (moveable)

2. High frequency sound has higher energy; low frequency sound has low energy

• Putting low frequency sound will not move the basal membrane

• Vibrator energy takes a short cut from the upper to lower canal

• basilar membrane through the middle canal causes the membrane to deflect up

3. The stern cilia deflect and move, opening ion channel, potassium enters

4. IF a positive enters, er get a positive receptor potential, releasing neurotransmitters

5. Neurotransmitters form action potential to the brain

Vision Essay

1. Light hits rhodopsin

2. Rhodopsin binds with g-protein

3. GDP goes away

4. GTP comes on goes to the alpha subunit

5. Alpha subunit goes to PDE

6. PDE converts cGMP to GMP

7. As cGMP levels decrease the ion channels will close and get more negative; detecting hyper polarization and decrease in neurotransmitters

Vision (DARK) (10)

1. no light hits photoreceptors

2. rhodopsin is inactive

3. g-protein (transduction) is inactive

4. PDE s inactive

5. cGMP lvls stay high

6. cGMP keeps Na+ channels open

7. Na+ and some Ca+ flow into the cell

8. Cell stays positive

9. Photoreceptors release a lot of glutamate

10. Signal continues to bipolar cells

In the dark, photoreceptors are depolarized and releases a lot of glutamate

Vision (LIGHT) (11)

1. light hits rhodopsin

2. retinal changes shape

3. rhodopsin becomes activated

4. activates g-protein (transduction)

5. transduction activates PDE

6. PDE breaks down cGMP to GMP

7. cGMP levels drop

8. CGMP gated Na+ channels close

9. Less Na+ enters and cell becomes more negative (hyper polarized)

10. Photoreceptors releases less glutamate

11. Bipolar cells detect this change and signal is sent to ganglion cells which is sent to the brain

Stroke Essay

1. Blood clot stops the flow of brain to region

2. No oxygen and glucose, neurons depolarized due to loss of sodium potassium pump

3. The neurons reach threshold and produce a barrage of AP

4. These firing neurons release excitatory neurotransmitter glutamate; lack of energy in the presynaptic neuron causes glutamate transporters

5. Removes the transmitter from the cleft, to stop working (no uptake)

6. Post-synaptic neurons are bombarded with glutamate, producing a barrage of AP, an excessive amount of calcium and zinc enters the cell

7. The excessive intercellular calcium and zinc trigger cll death and neuron succumbs to exotoxcity

Basal Ganglia Direct Pathway: MOVE

1. Cortex neuron fires AP; release excitatory neurotransmitter

2. Stratum fires AP; releases excitatory neurotransmitter

3. Second striatal neuron fires; releases inhibitory neurotransmitter

4. Neuron in G int does not fire; does not release inhibitory neurotransmitter

5. Thalamic neuron is not inhibited by(relieve of IN); fires AP; releases excitatory neurotransmitter to the cortex

6. Signals brain to move

Basal Ganglia Indirect Pathway: DO NOT MOVE

1. Cortex fires AP; release ENY

2. Striatum gets excited, fires AP, release ENY

3. Second striatal neuron gets excited, fires releases INT

4. Guest gets inhibited; does NOT fire, does NOT release INT

5. Second GPext no longer inhibited to STN; STN fires and releases ENT

6. Gpint gets excited; fires; releases INT

7. Thalamus get inhibited; does not fire; does not release ENT

Direct Pathway with Parkisons’s

SN cells are dying with parkisons

1. Fires releases ENT

2. Gets more excited BUT dopamine is in a downstate

3. It fires but not as much ENT is released

4. Gets excited but not enough; fires less; releases INT but not enough

5. Get inhibited but not enough, fires too much; releases INT too much

6. Gets inhibited too much, does not fire enough, does not release enough ENT

eplipesy (essay)

1. Neurons have a dysfunctional chloride potassium pump; thus there is too much chloride

2. The extra chloride has no meaningful effect on resting membrane potential

3. Because the pump isn’t getting rid of the chloride, there would be a small ISPS

4. There would be too much fired out and thus epilepsy occurs