NA and NP (6) - language, memory and sleep

Question 1

What is dual innervation in regards to the visceral organs?

Answer 1

The parasympathetic and sympathetic works in opposite directions

Ex. For the heart;

• PNS; slowing, restful effect
• SNS; heart rate speeds up

Ex. For the GI system;

• PNS; Stimulatory (digestive)
• SNS; Inhibitory (digesting food is not so important when SNS is activated)

Question 2

What is an example of a cooperative effect?

Answer 2

Regulation of the external genitalia during intercourse

• PNS; dilation of blood vessels in penis to allow for erection
• SNS; drives the process of ejaculation

Question 3

What are examples of actions handled by only one branch of the ANS (either sympathetic or parasympathetic)

Answer 3

SNS; Vascular tone = blood vessels are kept in a state of partial vasoconstriction (somewhere in the middle of being constricted and dilated), regulation of blood vessel diameter is only SNS NOT PNS

PNS; the heart = at rest it has a tonic slowing effect on the heart at the level of the sinoatrial node (the pacemaker of the heart that sets the rate at which the heart contracts)

Question 4

List some examples of organs that use SNS regulation only

Answer 4

Adrenal medulla, sweat glands, arrector pili (goosebumps), muscles of hair follicles, kidneys, most blood vessels

Question 5

What is the result when renin is released from the kidneys?

Answer 5

Increased blood pressure - activatesthe production of angiotensin II (a potent vasoconstrictor)

Question 6

Where can ACh be found to be released?

Answer 6

Released by all preganglionic axons in both the PNS and SNS, as well as all postganglionic fibers in the PNS

Question 7

what are the 2 types of cholinergic receptors that bind ACh?

Answer 7

Nictinic and muscarinic

Question 8

Describe nicotinic receptors

Answer 8

Found on motor end plates (somatic NS skeletal muscle), all ganglionic neurons of both SNS and PNS, hormone producing cells of the adrenal medulla

ACh binding to nicotinic receptors is always stimulatory

Question 9

Describe muscarinic receptors

Answer 9

Found on all effector cells innervated by postganglionic cholinergic fibers (essentially all PNS target organs)

Depending on the subclass of the receptor, ACh binding to muscarinic can be either stimulatory or inhibitory

Question 10

What receptors are associated with NE?

Answer 10

Adrenergic receptors; NE is released only by postganglionic fibers of SNS

alpha and beta tyes

effects can either be stimulatory or inhibitory based on receptor subtype and organ

Question 11

What would be the result of damage to either Broca’s area or Wernickes area?

Answer 11

Broca’s; can understand language but have difficult speaking (maybe also with written language and sign language)

Wernicke’s; can speak but speech is often a ‘word salad’ and have trouble understanding language

Question 12

What is the correlation between Broca’s area and Wernicke’s area?

Answer 12

Both areas interact with basal nuclei in order to create a language implementation system

This system analyzes both incoming and outgoing word sounds and grammatical structures

Links with surrounding cortical structures that are involved in the more complex functions of concepts and ideas

Motor areas on the right side are involved in body language (gestures/tone of voice/understanding the emotional context)

Question 13

What is memory ?

Answer 13

The storage and retrieval or information

Question 14

What are 4 types of memory? Subclasses within them (if any)?

Answer 14

1) Declarative = fact based memory (words, dates, names, faces)

• Short term (working) memory - temporary (15-30s) and limited
• Long term (storage) memory - limitless capacity but can forget things with time

2) Procedural = skill based memory (playing an instrument, typing)

3) Motor = riding a bike

4) Emotional = putting emotional value on something (feeling fear when you hear what sounds like a gun)

Question 15

What are some factors that may influence what we store in our LTM?

Answer 15

• emotional state (release of NE) = we tend to remember things better if there was a strong emotionl value connected to it
• rehearsal
• association (linking and connections)

Question 16

How does permanent transfer of info to LTM occur?

Answer 16

Requires consolidation - considerable passing info from various cortical areas through the hippocampus

Hippocampus sorts them by comparing with previous recorded ones and creates associations

Associations are sent back to be stored as memory traces

Through repetition and use of mnemonic devices, this info is sent back to the hippocampus repeatedly and the hippocampus continues to strengthen the associations

Question 17

What is skill memory? What are its results?

Answer 17

Involves motor activity (physical activity) and is acquired through practice

Communication between basal nuclei and premotor cortex

Release of dopamine by the substantia nigra

Results = connections between a stimulus and a motor response

Question 18

What is an EEG and what is its function?

Answer 18

EEG = electroencephalogram

Records neural activity through continuous electical activity of neurons

Meaures voltage differences between various cortical areas and are recorded as brain waves (Hz)

Question 19

What are the 4 types of brain waves?

Answer 19

1) Alpha waves (8-13Hz); regular and rhythmic
2) Beta waves (14-30Hz); rhythmic but less regular and higher frequency
3) Theta waves (4-7Hz); more irregular
4) Delta waves (4Hz>); high amplitude, deep sleep and when RAS is suppressed

Question 20

What are 4 levels of consciousness?

Answer 20

Alertness, drowsiness (lethargy), stupor, coma

Question 21

What is the difference between a coma and deep sleep ?

Answer 21

Deep sleep = brain remains active and oxygen consumption is similar to awakened state

Coma = oxygen consumption is significantly reduced

Question 22

What is REM? NREM? what happens during REM sleep?

Answer 22

REM = rapid eye movement
NREM = non-rapid eye movement

Most dreaming usually occurs during REM sleep , usually has a higher rate of use of oxygen

Question 23

What is the hypothalamic suprachiasmatic nucleus?

Answer 23

Our biological clock (we follow a 24hr circadian rhythm)

• it inhibits the RAS so less stimulations goes to the cortex allowing us to relax and fall asleep

Question 24

What is released as we awaken from sleep?

Answer 24

orexin peptides

also a release of cortisol by adrenal cortex (however instead of the usual stress responses, cortisol release at this time increases alertness and readiness to wake up)

Question 25

What typically happens in our brain during sleep?

Answer 25

We consolidate (establish) new memories

Discard memories no longer accessed

Is restorative as most brain areas can function at a lower level and synapses can be tidied up

Question 26

What are some examples of sleep disorders?

Answer 26

Narcolepsy; sudden lapsing into sleeep from the awake state at any time of day

• hypothalamic orexins are destroyed by the immune system because the immune system attacks the peptides as if they were a foreign substance

Insomnia; chronic inability to obstain suffient sleep

Sleep apnea; temporary cessation of breathing during sleep (muscle relaxation causes an obstruction of air pathways)

• CO2 levels will build up causing one to briefly wake up to release CO2 and then fall back asleep