A1.1 Inter system Communication Flashcards
what does the nervous system focus on
controlling and generating movement
what does the endocrine system focus on
helps control the body’s activities by releasing hormones
What do the endocrine and nervous system work together to do
maintaining homeostasis
Nervous system 3 main functions
Sensory function- detecting internal stimuli ex. increased blood acidity
Integrative function - analyzing sensory info and making decisions as a response
Motor Function - Take messeges around the body from the brain to the tissue/muscle
What are the three types of neurons
Sensory neurons - carry impulses from the receptor to the brain carries sensory info
Interneurons - link afferent neurons to motor neurons
Motor Neurons - carries impulses from the brain to the effector (muscle)
What is a reflex action
an automatic, rapid response to a stimulus that occurs without conscious thought, help protect the body from harm
This quick reaction is controlled by the spinal cord or lower brain centers rather than going all the way to the upper brain so that makes the reaction faster.
Afferent Nerves
information is brought from the sensory receptors to the CNS
efferent Nerves
neurons carry information away from the CNS to the muscles and glands in order to initiate an action.
What does the central nervous system include
Brain and spinal cord
CNS
Central Nervous System
PNS
peripheral nervous system
Function of the CNS
It acts as the control center, processing and interpreting sensory information sent from the PNS and coordinating the body’s response.
Role of the CNS in communication
The CNS sends instructions to the PNS to initiate actions and manage bodily functions. It is also responsible for higher functions, like thinking, memory, and decision-making. It also plays a role in coordinating reflex responses to certain stimuli.
Components of the PNS
Divided into the somatic and autonomic nervous system
Function of the PNS
connects the CNS to the rest of the body, transmitting sensory information to the CNS and carrying out the CNS commands by activating muscles and glands
Somatic nervous system
Controls voluntary movements by activating skeletal muscles.
Autonomic nervous system
Manages involuntary functions, such as heart rate and digestion
Sub divisions of the Autonomic nervous system
divided into the sympathetic (fight or flight) and parasympathetic (rest and digest) systems.
The sympathetic nervous system
Fight or flight, speeds things up and prepares the body for action
The parasympathetic nervous system
rest and digest’ functions and is the body’s ‘housekeeping system’ (Slows things down)
brainstem
connects the brain and spinal cord and is responsible for sending messages between the two structures
Cerebellum
governs balance and coordinates skilled movements
Cerebral cortex
outermost layer and is the conscious brain, allowing athletes to think, be aware of sensory stimuli and control their movements
Whats a negative feedback loop
A negative feedback loop is
basically a response from the body when conditions change from their ideal or set point and returns to this set point. Eg. you get cold and you start shivering to keep warm.
Hypothalamus
Maintains homeostasis regulates: Blood pressure
Appetite control
Heart rate and stroke volume
Respiration
Digestion, thirst and fluid balance
Sleep/wake cycles
Body temperature.
negative feedback loop temp decrease example
If the temperature decreases, the hypothalamus send messages to the organs to vasoconstrict the blood vessels to retain warmth in the core and to shiver (which is a muscle contraction and produces heat) to increase heat in the body.
The role of the parasympathetic nervous system during exercise
is to help the body recover and return to a state of balance after exertion.
It slows the heart rate, promotes relaxation, aids digestion, and conserves energy, helping the body to rest, repair, and prepare for future activity.
negative feedback loop temp increase example
If the temperature increases, the hypothalamus send messages to the organs to vasodilate the blood vessels to send blood to the peripheries (outer) of the body and to sweat to rid the body of heat.
The role of the sympathetic nervous system during exercise
to prepare the body for intense physical activity by triggering the “fight or flight” response.
It increases heart rate, redirects blood flow to muscles, releases energy stores, and boosts breathing rate - all to help the body meet the demands of exercise effectively.
Structure of the heart
The heart has 2 atria are receiving chambers (left and right) and 2 ventricles which act as the pumping chambers (left and right).
Blood goes from the right atrium into the right ventricle and is then pumped out towards the lungs for reoxygenation.
Once the blood is reoxygenated, it flows back to the left atrium and into the left ventricle where it is pumped out of the aorta and around the body.
intrinsic excitation
The heart having the ability to generate its own electrical signal which allows it to contract without any external stimulation
Electrical impulse path in the heart
The electrical impulse starts at the sinoatrial (SA) node in the right atrium.
The impulse generated spreads through the atria and reaches the atrioventricular (AV) node.
From the AV node, the impulse enters the Bundle of His This allows the impulse to reach the ventricles).
The impulse moves along the bundle of His and into the Purkinje fibers. This causes the ventricles to contract and eject the blood from the heart.
Process of sensory stimuli and body responses
A sensory stimulus is received (e.g a runner’s foot hits the ground)
The information travels along the sensory nerves to the CNS
The CNS selects the appropriate response
CNS sends message along the motor nerves to the skeletal muscles
A motor response occurs (quads contract eccentrically as the foot hits and then concentrically to propel the runner up and forward)
Proprioceptors
located in muscles tendons, joints and the inner ear.
Provide information about body position, muscle length and tension, position and movement of joints
e.g help us detect how much force to put into doing something, like lifting a spoon to your mouth versus a squat
Proprioceptors monitor..
Where our head and limbs are located and how they are moving without looking at them
The degree to which muscles are contracted
The amount of tension on tendons
The positions of joints
Chemoreceptors location
Located in neck (carotid) and heart (aorta)
Chemoreceptors function
Detect chemicals in the mouth (taste), nose (smell) and bodily fluids
e.g changes in CO2 and O2 levels in the blood and send messages to the brain to change something to maintain homeostasis
Baroreceptors location
Located in carotid and aorta arteries
Baroreceptors function
It’s sensitive to pressure so it detect changes in blood pressure (e.g feeling dizzy) and send messages to the brain to raise/lower blood pressure to maintain homeostasis
what do the endocrine glands secrete
secrete hormones directly into the blood
Steroid hormones
Steroid hormones are fat soluble and can easily pass through membranes to interact with receptors and illicit a response
e.g testosterone, oestrogen and progesterone
Non steroid hormones
Non steroid hormones are NOT fat soluble and must interact with receptors on the cell to trigger messenger chemicals within the cell that then elicit the response.
e.g adrenaline (secreted by adrenal glands) and glucagon (secreted by the pancreas)
Where is Epinephrine and Norepinephrine (adrenaline) released from
adrenal glands
Epinephrine and Norepinephrine (adrenaline) effect on the body
↑ heart rate and force of contraction
↑ the blood pumping out of the heart (↑bp) in readiness for fight or flight
↑ blood flow to heart, liver, skeletal muscles and adipose tissue
Dilate airways to the lungs
↑ blood levels of glucose and fatty acids for fuel
Norepinephrine also plays a role in
arousal, dreaming and mood regulation
where are Insulin and Glucagon produced from
pancreas
function of Insulin and Glucagon
Help regulate blood sugar levels
Insulin assists glucose entry into cells to store for later use
Glucagon helps to breakdown glycogen into glucose to increase the availability so it can be used when needed
where is Antidiuretic Hormone secreted from
pituitary gland
function of the Antidiuretic Hormone
Regulates fluid and electrolyte balance in the blood by reducing urine production (diuresis)
where is Testosterone
secreted from
testes and very small amount is the ovaries in women
function of Testosterone
Needed for the development of sperm
Helps with control and development of male reproductive hormones
Promotes development and maintenance of secondary male sex characteristics (body hair, deep voice)
Helps with bone formation (stronger bones)
Aids in muscle growth and protein synthesis
Helps produce erythropoietin, which are red blood cells that carry oxygen throughout the body
where is Oestrogen secreted from
ovaries
Oestrogen function
Promotes body growth, broadens the hip, stimulates breast development and increases fat deposition (particularly in the hips and thighs)
Promotes secondary sex characteristics (voice pitch, hair growth on body)
Increases protein anabolism, builds strong bones
Lowers blood cholesterol and helps bodies store glycogen
Insufficient oestrogen causes bones to feel stiff and not move easily
Progesterone
Female sex hormone also secreted by the ovaries
Plays a key role in the menstrual cycle and pregnancy
Oestrogen positive effects
bone, heart, muscle recovery, cartilage and synovial fluid.
Oestrogen decrease effects
Decreases in oestrogen levels in the body can negatively affect these tissues. Less synovial fluid causing joint stiffness, bone density losses causing osteoporosis, and increased inflammation. High levels (follicular and luteal phases) can cause joint laxity and increased risk of ligament damage (ACL).
Oestrogen and Glycogen Sparing
Biological females rely more on fat as a source of fuel and spare glucose when compared to biological men, especially when levels are high. This occurs both at rest and during exercise which should have influences on the types and durations of training for biological females.
Progesterone and Thermoregulation
Progesterone increases body temperature and, due to increased progesterone during the luteal phase, body temperature increases. This can affect fatigue perception and motor control in warm environments, decreasing performance in skill based sports. It also presents thermoregulatory changes as body temperature is increased.
Progesterone and Sleep Quality
Progesterone has a calming effect on the CNS. Increased levels of progesterone during the luteal phase can induce feelings of drowsiness which can help to fall asleep. The slight increase in body temperature mentioned above also help transition from wakefulness and sleep.
Menstrual Phase (Days 1-5) hormone levels and training considerations
Hormone levels: Low estrogen and progesterone.
Training considerations:
Energy levels may be lower due to fatigue or menstrual symptoms (e.g., cramps, discomfort).
Focus on low-intensity or moderate training, such as mobility work, light cardio, or technique refinement.
Proper hydration and iron intake are essential, as blood loss can reduce iron levels
Follicular Phase (Days 6-13)
Hormone levels: Estrogen rises, while progesterone remains low.
Training considerations:
High estrogen levels can improve strength, endurance, and recovery.
Ideal for high-intensity training, including strength training, interval workouts, and skill acquisition.
Reduced injury risk, as ligaments are less affected compared to the ovulatory phase.
Ovulatory Phase (Days 14-16)
Hormone levels: Estrogen peaks, and luteinizing hormone (LH) surges; progesterone begins to rise.
Training considerations:
Peak strength and power capabilities—great for testing maximum performance.
Increased injury risk: High estrogen levels can lead to ligament laxity, increasing the risk of ACL injuries. Include neuromuscular and stability exercises to reduce risk.
Luteal Phase (Days 17-28)
Hormone levels: Progesterone dominates, and estrogen decreases in the latter part of the phase.
Training considerations:
Progesterone can raise core temperature and increase perceived exertion, affecting endurance and performance and challenging temperature regulation
Prioritize steady-state cardio, moderate resistance training, and active recovery.
Focus on hydration and electrolyte balance due to increased thermoregulation demands.
General reccs for the menstrual cycle:
tracking the cycle, nutrition, rest and recovery, communication
Motor Planning
The brain (specifically the motor cortex and cerebellum) first plans the movement based on sensory information and prior experiences. It determines which muscles to activate, in what sequence, and with what intensity to achieve the intended movement.
Signal Transmission:
The nervous system sends electrical impulses (action potentials) from the brain and spinal cord through motor neurons to the muscles. These signals travel along the central nervous system (CNS) and peripheral nervous system (PNS) pathways to the muscle fibers.
Muscle Activation
When the action potential reaches the muscle fibers, it triggers the release of calcium ions within the muscle cells. This initiates the sliding filament mechanism, where actin and myosin filaments slide past each other, shortening the muscle and generating force.
Movement Control:
The nervous system regulates the force, speed, and direction of the contraction by adjusting the frequency and intensity of nerve impulses. By varying these signals, the body can produce different types of movements, like smooth and precise motions for tasks requiring fine motor skills or powerful, explosive movements for strength and speed.
Feedback and Adjustment:
Sensory receptors (such as proprioceptors in muscles and joints) provide feedback to the brain about the position, tension, and movement of the body. This feedback allows the nervous system to adjust the motor signals in real-time, helping maintain balance, refine the movement, and make adjustments for accuracy.
Neuromuscular junction
A synaptic connection between the end of a motor neuron and a skeletal muscle
