Lec 21: Language, Memory & Sleep Flashcards
Antagonistic Interactions
Heart Rate
GI System
Respiratory System
PNS: slows down heart rate
SNS: accelerate heart rate
PNS: ↑ secretion, motility, blood flow; ↓constrictions
SNS: ↓ gastric acid production, digestive enzyme release, gallbladder function; ↑ insulin and glucose levels
PNS: ↓ Respiratory rate
SNS: ↑ Respiratory Rate
Actions handled only by one branch of the ANS
SNS and Vascular Tone
No action for PNS
SNS is the effector of neurogenic control of vascular tone, inducing mainly vasoconstriction of small resistance arteries
Actions handled only by one branch of the ANS
PNS and Heart
At rest, has a tonic slowing effect on the heart at the level of the sinoatrial nod
SNS regulation only
adrenal medulla, sweat glands, arrector pili
muscles of hair follicles, kidneys, most blood vessels, hermoregulatory responses to heat, renin release from kidneys
Metabolic effects
(i) increases metabolic rate of body cells
(ii) raises blood glucose levels
(iii) stimulates mobilization of fats
(iv) increases mental alertness
(v) increases speed/strength of muscle contraction
Neurotransmitters and Receptors
Acetylcholine
plays a role in memory, learning, attention, arousal and involuntary muscle movement
Medical conditions associated with low acetylcholine levels include Alzheimer’s disease and myasthenia gravis
Neurotransmitters and Receptors
Nicotinic Receptors
found on all ganglionic neurons of both the SNS and PNS and the hormone- producing cells of the adrenal medulla
ACh binding to nicotinic receptors is always stimulatory
Muscarinic Receptors
On all effector cells innervated by postganglionic cholinergic fibers
Depends on the subclass of receptor as to whether the effect of ACh
binding is stimulatory or inhibitory
Norepinephrine
- Adrenergic receptors; NE is released only by postganglionic fibers of SNS
- 2 major types: alpha (α) and beta (β)
- Effects can be stimulatory or inhibitory depending on receptor subtype and organ
REMEMBER
Hypothalamus
> anterior regions are parasympathetic
posterior area is sympathetic
How are ANS and Hypothalamus related
contains centres to coordinate heart
activity, blood pressure, body temp, water balance,endocrine activity; also centres that help mediate emotions & biological drives
Language
involves almost all of the association cortex on the left side of the brain in some way
Broca-Wernicke loop is also functional in individuals who are deaf
and use sign language
Damage to Broca’s area
can understand language but have
difficulty speaking, possibly also with writing and sign language
Damage to Wernicke’s area
can speak but speech is often a “word
salad” and they have trouble understanding language as well
Paul Broca
In 1861 when autopsying brain of
a patient who could understand spoken language but could not communicate by
speaking or writing, PB identified area of
lesion.
Carl Wernicke
In 1871,CW identified area of lesion found in
brains of people who could speak but whose
speech was often incoherent, didn’t make sense.
Broca’s and Wernicke’s areas interact with ___ and function
basal nuclei in order to
create a language implementation system that analyzes both incoming and outgoing word sounds as well as grammatical structures
Right side
body language, gestures, tone of voice and emotional context of speech
Memory
- the storage and retrieval of information
- need memories so we can learn, so we can adjust behaviour based on experience
Different kinds of memory
- Declarative (fact-based) memory: names, faces, words, dates
- Procedural (skill-based) memory: playing an instrument, typing on a keyboard
- Motor memory: e.g. riding a bike
- Emotional memory: e.g. fear when you hear what sounds like a shotgun
Declarative Memory
2 stages:
* short-term (working) memory – temporary (15-30 sec) holding bin; limited to 7-8
chunks
* long-term memory (storage) – limitless capacity but can forget things with time
The Process
we may or may not choose to
transfer that to LTM – this is
influenced by:
* emotional state – helped by
release of NE
* rehearsal
* association
* and some it just happens
automatically
Consolidation
involves considerable passing information from various cortical areas through the hippocampus; the hippocampus sorts them by
comparing with previous recorded ones, creates associations and then sends them back to be stored as memory traces
Skill memory
involves motor activity and is acquired through practice; involves communication between the basal nuclei and the premotor cortex
as well as release of dopamine by the substantia nigra; results are automatic connections between a stimulus and a motor response
Mechanisms of Memory
- neuronal RNA content is altered
- dendritic spines change shape
- extracellular proteins deposited at synapses involved in LTM
- number and size of presynaptic terminals may increase
- more NT is released by presynaptic neurons
- new hippocampal neurons appea
Four Types of Brain Waves
- Alpha waves: (8-13 Hz)
- Beta waves: (14-30 Hz)
- Theta waves: (4-7 Hz)
- Delta waves: (4 Hz or less)
Alpha Waves
waves are regular and rhythmic; a brain that is “idling”
Beta Waves
waves also rhythmic but less regular and higher frequency; mentally alert, concentrating on something
Theta Waves
more irregular; common in children but rare in adults; seen sometimes when concentrating
Delta Waves
high amplitude waves characteristic of deep sleep and when RAS is suppressed (e.g. during anaesthesia); if seen in an awake
adult, are indicative of brain damage
Consciousness
encompasses perception of sensations, voluntary initiation and control of
movement, and capabilities associated with higher mental processing (memory,
logic, judgement, perseverance, and so on)
4 levels of Consciousness
- alertness
- drowsiness or lethargy
- stupor
- coma
Sleep and Sleep-Awake Cycles
Sleep and Sleep-Awake Cycles (explained)
Sleep Disorders
Narcolepsy
sudden lapsing into
sleep from the awake state at any time
of day; also extreme daytime
sleepiness; suggested to be an
autoimmune disease in which
hypothalamic orexins are destroyed by
the immune system
Sleep Disorders
Insomnia
chronic inability to obtain
sufficient sleep/sleep quality (usually 7-
8 hours for adults); can result from
anxiety, depression, overuse of
caffeine, using screens close to
bedtime
Sleep Disorders
Sleep Apnea
temporary cessation of breathing during sleep – often due to muscle relaxation and obstruction of air pathway
