Physiology Exam II Study Guide Essay example

Submitted By Chelsea-Sanders
Words: 6951
Pages: 28

I.

Things we need to know by heart:
A. Blood Brain Barrier is a functional barrier between the interstitial fluid and the blood structure: 1. tight junctions promoted by astrocytes whose foot processes envelop brain capillaries and sinuses.
ONLY
lipids can enter the capillaries/sinuses. aka why you can black out with too much alcohol
2. Function:
a) To limit permeability for most molecules. Exceptions: CO2, O2, alcohol, steroids, and H2O these all go down a gradient. But anything the is lipid soluble can’t be regulated.
b) Protects brain hormones and circulating chemicals:
(1) protects CNS from chemical fluctuations
(2) prevents entry of harmful substances
(3) prevents entry of molecules that could act as NT
(Neurotransmitters)
B. Brain receives 15% of blood in body and half of the glucose consumption
C. Major functions of the brain (pg. 7 from CNS notes):

D. Know what the lobes of cortex and what they relate too. Cortex is divided into four major lobes:
1. Occipital Lobe­ carries out initial processing of visual input
a) Visual cortex
2. Temporal Lobe­ initial reception of sound sensation, taste, smell
a) Auditory cortex
1

E.

F.

G.
H.

b) Gustatory Cortex
c) Olfactory Cortex
3. Parietal Lobe­ somatosensory processing
a) Primary somatosensory cortex
4. Frontal lobe­ is responsible for: motor processing, voluntary motor activity, speaking ability, elaboration of thought
a) Primary motor cortex
Know the integration of cortical regions pathway (pg.11)
1. From the Sensory input­ relayed from afferent neuronal receptors
2. to the primary sensory areas (somatosensory, 1 visual, 1 auditory cortices)­ initial cortical processing of specific sensory input
3. to the higher sensory areas­ further elaboration and processing of specific sensory input
4. to the association areas­ integration, storage, and use of diverse sensory input for planning of purposeful action
5. to the higher motor areas­ programming of sequences of movement in context of diverse information provided
6. to the primary motor cortex­ commanding of efferent motor neurons to initiate voluntary movement
7. to the motor output­ relayed through efferent motor neurons to appropriate skeletal muscles, which carry out desired action
**Example he gave was: you see a box labeled “books” that you have to lift up >>your higher sensory areas tell you what books mean >> association area will tell you that books in a box are heavy >> your higher motor areas now knows that you need a lot of muscles cells to make it happen >> primary motor cortex gives the command >> then you perform
Know the hypothalamus functions, expect on the test him to ask something like “what five functions does the hypothalamus have?”
1. receives indirect inputs from all sensory systems
2. controls sympathetic and parasympathetic nervous system
3. sends both neural and hormonal outputs to pituitary
4. coordinates activities of the endocrine/nervous system
5. induces emotions and behavioral drives
6. coordinates voluntary and autonomic functions
7. regulates body temperature
8. coordinates circadian cycles
Cranial nerve number
X (10) Vagus is a both sensory and motor, its function is sensory and efferents to many internal organs, muscles and glands
Basic learning­ behavior­ non associative
1. Habituation­ decreased responsiveness to a repetitive stimulus [choosing to ignore] a) closure of Ca2+ channels [no response in the presynaptic cell]
b) Reduced neurotransmitter release
2

c) decrease EPSP
d) Fewer postsynaptic APs generated
e) Example he gave was that the vent always makes noise but we never notice it because we choose to ignore it
2. Sensitization­ increasing responsiveness to a noxious or intense stimulus
a) release of serotonin from interneuron
b) increases cAMP in presynaptic neuron
c) blocks K+ channels and prolongs AP­ by not repolarizing
d) Ca2+ channels are open longer­ more magic is happening
e)…