Lecture 8 Flashcards

The body cannot directly utilize the chemical energy from ingested food at the cellular level.
Energy in carbon-hydrogen bonds from food must be converted to ATP (adenosine triphosphate).

Enzyme Involved: ATPase is responsible for splitting the terminal phosphate from ATP.
- Process: Hydrolysis of the terminal phosphate group releases energy.
Energy Consumption: Approximately 70% of the total energy released is degraded to heat, while the remaining energy performs work.

Creatine Phosphate (CP) System
- Vital for muscle contraction by replenishing ATP for immediate contractions.
- Supplies ATP during the first few seconds of exercise, enabling glycolysis to be initiated before ATP stores are depleted.
Glycolysis
- Involves the breakdown (lysis) of glucose molecules.
- Accomplished through glycolytic enzymes located in the cytosol of the cell.
- More complex than the CP system but produces less ATP compared to oxidative phosphorylation.
- Can occur in the absence of oxygen, allowing access to ATP without O2.
Oxidative Respiration
- Breaks down fuel in the presence of oxygen in the mitochondria, known as cellular respiration.
- Considered an aerobic process due to the presence of oxygen.
- Produces abundant ATP for extended activity without fatigue.

At rest, metabolic requirements are dominated by muscles, heart, brain, liver, and kidneys.
Resting Metabolic Rate: Approximately 3.5 mL/min/kg, termed 1 MET (metabolic equivalent).
As muscles extract oxygen from capillaries, a widening of the arterial and venous oxygen concentrations occurs (AV-O2 difference).
- The difference is influenced by both blood's oxygen carrying capacity and mitochondrial oxidative potential.

Fick Equation: Determines Rate of Oxygen Uptake (VO2)
- $VO_2 = Q imes (AV - O2)$
- Where:
- VO2 = rate of oxygen uptake
- Q = cardiac output
- AV-O2 = arteriovenous oxygen difference
VO2 is commonly measured using metabolic carts to assess changes in respiratory gases and volume.
During submaximal exercise, a linear relationship exists between cardiac output and oxygen uptake.
An increase in exercise intensity leads to greater oxygen extraction by muscles, widening the AV-O2 difference.

Definition: Electroencephalography (EEG) is a non-invasive method to record electrical brain activity through the scalp.
Historical Context: The first EEG recordings were performed by Hans Berger in the 1920s (Ince et al., Child Nerv Sys, 2020).

Records electrical activity of pyramidal neurons in the cortex by placing electrodes on the scalp.
Can detect signals from action potentials across thousands of neurons through the dipoles they create.
Typically uses EEG caps that allow recordings from the entire scalp to observe event-related potentials for specific tasks.

EEG signals can be overwhelmed by electrical activity generated by the body or environment.
Signals must pass through biological filters, reducing amplitude and spreading the signal output.
Conducting specific tasks across multiple trials helps to isolate EEG activity associated with those tasks from background noise.

Utilizes electrodes across the scalp to map brain electrical activity.
Different brain wave frequencies correspond to different states of arousal:
- Beta Waves: >13 Hz (14 – 30 Hz), associated with conscious and logical thought, focus, problem-solving, and can indicate anxiety or stress when heightened.
- Alpha Waves: 8 – 13 Hz, promote deep relaxation, found in daydreaming, and linked to anxiety when suppressed.
- Theta Waves: 4 – 7.5 Hz, associated with daydreaming, sleep, creativity, and emotional connection; linked to impulsivity when suppressed.
- Delta Waves: 1 – 3.5 Hz, slowest brain waves, prevalent in deep restorative sleep, crucial for immune system function; a lack of adequate delta waves can lead to issues in rejuvenation and severe cognitive problems.

Various brainwaves correspond to consciousness levels during different sleep stages.
Awake Stage: Predominantly low voltage, high frequency (Beta and Alpha).
Stage Rem Sleep: Low voltage, mixed frequency, characterized by rapid eye movement and muscle atonia, diminishing total time across lifespan from 8 hours at birth to about 45 minutes at age 70.

Stage I: Increased theta activity, loss of alpha, presence of vertex sharp waves.
Stage II: Features theta and delta waves, vertex sharp waves, K complexes, and sleep spindles.
Stage III: Higher voltage delta waves comprising 20-50% of background activity.
Stage IV: More than 50% delta slow waves, indicating deep sleep.

Research on Brain-Computer Interface (BCI) technology aims to adapt applications for pediatric use, particularly for neurological disabilities.
- Fundamental goals include understanding BCI technology's mechanisms for children, adapting different paradigms, and optimizing signal processing algorithms.
Transitioning BCI technology beyond laboratory settings into clinical environments is crucial.
- Investigating how children can learn and optimally use BCI technology is another focus.

Unique collaboration among researchers in neuroscience, engineering, medicine, and rehabilitation sciences.
Partnerships with: University of Calgary, Alberta Children's Hospital, University of Alberta, University of Toronto, and NCAN Centre in Albany, New York.