Topic A: Intersystem communication

What is the nervous system?

A complex, highly organised network of billions of nuerons that influences all body functions.

What is the role of the brain?

Acts as a central computer. It integrates information, selects responses, and signals organs and tissues to act

Outline the four basic functions of the nervous system

1. Sensory function → detects internal stimuli (e.g. blood acidity)

2. Integrative function → analyses and stores info; makes decisions

3. Motor function → sends signals via motor (efferent) neurons to produce responses

4. Coordination and communication → enables communication and coordination within the body and with the external environment

What is the role of the NS in exercise and extreme environments

adjusts cardiovascular, respiratory, and metabolic function → supports transition from rest to activity by increasing energy supply

List and describe the three ways the body can adjust to exercise or extreme environments

1. Nervous system

2. endocrine system

3. hormones

briefly outline the nervous system impacts

faster, brief, localised effects via nerve impulses

briefly outline the endocrine system

slower, long-lasting, widespread effects via hormones

How are hormones released

Travel via blood to regulate cells elsewhere

ROle of the spinal cord

enables info to travel between the brain and the rest of the body

What is the sympathetic nervous system

Activates fight or flight response → increase blood flow to active muscles whilst reducing blood flow to other tissues

What is the parasympathetic nervous system

Relaxes the body'; supports rest and digest functions, involved in digestion, urination, glandular secretion and conservation of energy

What are the four main parts of the brain

• brain stem

• cerebellum

• cerebrum

• diencephalon

What does the cerebellem do

governs balance, and coordinates skilled and precise movements

Explain the two connected hemispheres of the cerebrum

1. Cerebral cortex (outer layer) → consious thought + awareness of sensory stimuli (voluntary control of movement)

Explain the diencephalon and what it contains

• thalamus (motor control)

• Hypothalamus (control centre for homeostasis)

Outline the steps of intrinsic excitation of the heart:

1. sinoatrial nod

2. atrial conduction

3. atrioventricular node

4. bundle of his

5. purkinje fibres

6. ventricular contraction

Where are proprioceptor located

muscles, tendons, joints,and inner ear

role of proprioceptors

body position, muscle length, tendon tension, joint position, head position + balance, enables tasks without vision

role of chemoreceptors

detect chemical changes in mouth, nose, and blood. monitor blood levels of O2, Co2, and H+

Where are chemorectpros located

carotid bodies (neck) and aortic bodies

where are baroreceptors located

pressure sensitive receptors located int he aorta and carotid arteries

role of baroreceptors

detect changes in blood pressure via stretch of arterial walls

define homeostasis

the regulation of the body’s internal environment so it remains relatively constant within phsiological limits

Give examples of internal and externals stressors that activates a response to achieve homeostasis

Internal: low blood glucose levels e.g.

External: Heat, cold, humidity, lack of o2 e.g.

Why is a stable internal environment essential

• optimal performance

• safe and effective body function

Importance of hypothalamus

The main control centre for homeostasis

what key physiological processes does the hypothalamus control

• blood pressure

• heart rate

• thermoregulation

• osmoregulation

• appetite and food intake

what may the body do during exercise or extreme environments?

• increase/decrease metabolism to meet energy demands

• adjust cardiovascular and respiratory responses to supply oxygen

• remove metabolic by products (C02 e.g.)

• regulate body temp

Explain the process of feedback mechanisms (3 steps)

1. Receptor

2. Control centre

3. Effector

What can the SA node firing rate be influenced by

• Blood O2 and CO2 levels

• hormones (epinephrine, norepinephrine)

what does the body do when there is a high level of glucose?

pancreas secretes insulin and increases glucose transport into cells

what does the body do when there is a low level of glucose?

pancreas secret glucagon, and stimuluate glycogenolysis (glycogen → glucose), and stimulates gluconeogensis (protein/fat → glucose)

list the four ways heat can be transfered

1. conduction

2. convection

3. radiation

4. evaporation

define conduction in heat transfer

when heat moves through body tissues to the skin surface

define convection in heat transfer

heat transfer by movement

define radiation in heat transfer

heat transfer by energy waves

define evaporation in heat transfer

the form of evaporative cooling

What are the functions of blood during exercise?

Transports gases, nutrients, waste products, hormones and heat

General components of blood and functions

plasms → fluid of water + dissolved substances

platelets → ploot clotting and repair

white blood cells → immune defence

red blood cells → transport of O2 to tissues and CO2 to lungs

What does high O2 pressure in lungs lead to ?

O2 binds to haemoglobin

What does low O2 pressure in lungs lead to?

O2 released to tissues

Why is higher haemoglobin beneficial for sports performance?

Greater O2 transport

What is a common example that athletes train to support higher haemlobin production?

Higher altitude training because it stimulates EPO

What is EPO?

What is an example of athletes MISUSING increased haemoglobin production?

Removing and reinfusing blood, or synthetic EPO injections

Why does higher altitudes increase EPO?

Forces body to adapt to the lower O2 levels → increases EPO stimulation → increases haemoglobin production → improves oxygen delivery to cells

Does exercise change systolic way greater or diastolic blood pressure way better?

Systolic

Formula for cardiac output (Q)

Q=Stroke volume (SV)*Heart rate (HR)

Define stroke volume

The amount of blood pumped with each beat

Importance of healthy blood pressure

Allows efficient filling and emptying of the heart, maintains adequate blood flow to body tissues

What organs are prioritised in exercise?

Brain and heart

How do fitness levels affect stroke volume?

Trained individuals can achieve greater cardiac output, high stroke volume while maintaing a lower heart rate

Why can high blood pressure be damaging?

Forces heart to pump faster, leading to damage artery walls and increased risk of risks and heart attacks (wear and tear)

What is the AV difference?

An INDICATOR of performance: diff in O2 travelling in artery and difference in oxygen travelling in brain

Why is the AV difference best if it is high?

Indicates that the oxygen is being extracted from the heart to cells

Calculation of Max heart rate

220 minus age

How does max heart rate affect performance?

Some sports require athletes at difference fitness levels that may decrease when they grow older

What are the four main changes during long term training

Structural, functional, monitoring and recovery, health and performance

What are two structural changes in long term training?

• Increased capillary density

• Increased hypertrophy

What are five functional changes in long term training?

• lower resting heart rate

• increase stroke volume

• decrease heart rate

• lower blood pressure

• increased haematocrit

What are four monitoring and recovery importance in long term training?

• HR and RPE

• Sleep and nutrition

• Rest days

• Avoid overtraining

What are the pos impacts of long term training on health and performance?

• increased endurance

• increased VO2 max

• better exercise tolerance

• lower cariovascular risk

What is the main role of the respiratory system?

Transport of O2 in exercise

What is VO2?

Rate of oxygen taken in and used for aerobic energy

Fick equation

Vo2=Cardiac output * (arterial - venous O2 diff)

What are some adaptations in increasing VO2?

Stroke volume, blood volume, capillaries, mitochondria

Briefly explain environments of lung and atmosphere during inhalation

Air moves into lungs when intrapulmonary pressure < atmospheric pressure

What are some phenomenoms of diffusion during exercise?

Increased metabolism, steeper O2 and Co2 gradients, ventilation increases to keep alveolar P O2 high and P Co2 low → continuous breathing maintains gradients which sustains aerobic activity

Calculation for vital capacity

VC = IRV + ERV +TV

Calculation for total lung capacity

TLC = VC + RV

Why do hyperventilation occur?

When there arterial CO2 levels drop → reduced CO2 means a reduced stimulus to breath (aka rebreathing)

What are the four main roles of water in our body?

Solvent, redistribute heat, lubricant, medium for biochemical reactions of metabolism inside and outside cells

What are the results of water being an excellent solven in the body?

Transport nutrients to cells, remove waste produces and transport other metabolites produced by cells such as hormones

How can water be replaced?

Through food, drinking and metabolic processes

What are some processes in which water can be lost in the body?

Evaporation of sweat, evaporation from breathing, exretion from urine, excretion of faeces

What organs help regulate water and electrolyte balance?

Hypothalamus, pituitary, and kidneys

What hormone gets released when the body sense an under or overconsumption of water?

Antidiuretic hormone (ADH) is released

What happens when the ADH is released?

Allows kidneys to absorb and into blood stream, decreases urine and increases sensation of thirs

What is the hypothalamus’s role in regulating water balance?

Detects fluid concentration changes

What is the pituitary gland role in regulating water balance?

Releases ADH

What are the kidneys role in regulating water balance?

Adjusting water reabsorption and urine output

Why do athletes need more fluid intake?

Because they are also losing water from sweat loss due to evaporation to dissipate heat from muscle contraction

What are electrolytes?

Ions that carry an electric charge in water

How does hypernatremia occur

When there is too high concentration of sodium (low water/dehydration)

What happens when there is hyponatremia?

Low concentration of sodium (high water/overhydration)

Why is it important to intake electrolytes too and not just water?

sweating loses water and salt, but water replaces only water not salt

What are some common hydration mistake in athletes?

Drinking too much water → can lead to hyponatremia (especially in high endurance sports)

Signs of hyponatremia

Bloating, headache, nausea → can be fatal

In what factor groups are hyponatremia more common?

Endurance sports, (swimming, running e.g.), biological females and high temps

When does cardiovascular drift occur?

During prolonged steady-state aerobic exercise

What is cardiovascular drift characterised by?

Increased heart rate, decreased stroke volume, decreased mean arterial blood pressure

Causes of cardiovascular drift

Body shifts fluid, often due to sweating and vasodilation

Effects of cardiovascular drift

Heart rate increases to maintain cardiac output as stroke volume falls

Calculation for cardiac output

(heart rate * stroke volume)/1000

Define cardiovascular drift

The rise in heart rate and fall in stroke volume over time, during prolonged aerobic exercise at a steady state intensity

Where can glycogen be found in the body?

Liver and muscle

What is the difference between glycogen stored in muscles and glycogen stored in liver

Muscles feed ONLY muscles, whilst liver stores glycogen for whole body

What location does glycolysis happen

In the cytosol

Why is glycolysis so important?

It is the first step in energy production