A.1 IB Sports Science HL

Sensory Function

Detecting internal stimuli, such as increase in blood acidity

Integrative Function

Analyzing (and storing some) sensory information and making decisions for responses.

Motor Function

Responding to integration decisions; in other words, motor (or efferent) neurons carry information from the brain towards the spinal cord (or from the brain and spinal cord to, for example, muscle fibres)

Central Nervous System

Made up of the brain and spinal cord. Key in maintaining a relatively stable and constant internal environment through the process of homeostasis. Regulates body functions, such as respiration and heart rate.

Peripheral Nervous System

All nerves outside the CNS. Divided into sensory (afferent) nerves, and motor (efferent) nerves.

Sensory (Afferent) Nerves

Inform the CNS about what is going on within the body and outside the body.
Example: “It is hot”

Motor (Efferent) Nerves

Responds to signals coming in from sensory division, sends information from the CNS to tissues, organs, and systems of the body.

Somatic Nervous System

Part of motor (efferent) nerves, controls voluntary movements of the skeletal muscles.

Autonomic Nervous System

Part of motor (efferent) nerves, regulates bodily functions, such as heart rate, digestion, and breathing.

Sympathetic Nervous System

Divided from autonomic nervous system, activates the fight or flight response.

Parasympathetic Nervous System

Divided from autonomic nervous system, major role in carrying out processes such as digestion, urination, glandular secretion and conservation of energy, body’s housekeeping system.

Vasodilation

The widening of blood vessels (caused by relaxation of the smooth muscle in the wall of the blood vessel.)

Vasoconstriction

The narrowing of blood vessels (caused by contraction of the smooth muscle in the wall of the blood vessel)

Brain

Consists of four major parts:
Brain Stem
Cerebellum
Cerebrum
Diencephalon

Brain Stem

Connects the brain and spinal cord, sensory and motor nerve messages pass through the brain stem and relay information in both directions between brain and spinal cord.

Cerebellum

Controls balance and coordinates skilled movements.

Cerebrum

Composed of two hemispheres that communicate with each other

Cerebral Cortex

Outermost layer of cerebrum, conscious brain, sensory stimuli awareness, voluntary muscle control.

Diencephalon

Contains the thalamus (important for motor control) and the hypothalamus (homeostasis)

Hypothalamus

Maintains homeostasis by regulating processes that affect the body’s internal environment. (Blood pressure, heart rate and stroke volume, respiration, digestion, etc.)

Pulmonary Circulation

The portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.

Systemic Circulation

The portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.

Intrinsic Excitation

Describes cardiac muscle’s unique ability to generate its own electrical signal. This allows it to pump without any external stimulation.

Sinoatrial (SA) Node

Initiates impulse for contraction; located in the wall of right atrium.

Atrioventricular (AV) Node

Once SA impulse reaches this, the aria contract. Then it conducts electrical impulse from atria to ventricles (bundle of his)

Bundle of His

Only site where electrical impulse can conduct from the atria to the ventricles.

Purkinje Fibres

Impulse travels from apex of heart towards ventricles and ventricles contract.

Proprioceptors

Provide information about body positions and movement. Aids in coordination and in deciding how much muscular effort is needed to perform a task.

Chemoreceptors

Detect the presence of and react to chemical stimulus. Detect changes in oxygen, carbon dioxide, and hydrogen ions in the blood.

Baroreceptors

Pressure sensitive nerve cells. Located in the aorta and carotid arteries. Sense changes in blood pressure. Important for maintaining blood pressure homeostasis.

Endocrine System Function

Parters with nervous system in regulating the human body and controlling response to physiological changes.

Endocrine System Structure

Uses chemical signals (hormones) released by glands or tissues to control and regulate the activity of other cells around the body.

Epinephrine & Norepinephrine

Released from adrenal medulla, increase heart rate and force of contraction, increase pumping output of the erat, prepares body for fight o flight responses, etc.

Insulin

Produced by pancreas, decreases blood sugar concentration, assist glucose entry into cells.

Glucagon

Produced by pancreas, help regulate blood sugar concentration, promotes increased breakdown of liver glycogen to glucose.

Antidiuretic Hormone (ADH)

Secreted by the pituitary gland, regulates fluid and electrolyte balance in the blood by reducing urine production.

Estrogen

Female sex hormone secreted by ovaries, promotes female characteristics, lowers blood cholesterol and helps bodies store glycogen, insufficient levels cause joints to feel stiff.

Progesterone

Female sex hormone secreted by ovaries, plays a key role in the menstrual cycle and pregnancy.

Testosterone

Male sex hormone secreted by the testes, needed for development of sperm, helps control development of male reproductive hormones, promotes development and maintenance of male secondary sex characteristics, bone formation, muscle growth, production of erythropoietin.

Steroid Hormones

Fat soluble and can easily pass through cell membranes to interact with the receptors and elicit and response. Ex: Testosterone, estrogen, and progesterone.

Non-steroid hormones

Not fat soluble, so they have to interact with receptors on the cell surface to trigger messenger chemicals inside the cell that then elicit the response. Ex: epinephrine (adrenaline) and glucagon. Faster acting.

Prostaglandis

Non steroid hormone, produced in most membranes in cells and secreted near the site of action. Example is in response to injury, prostaglandin will be secured and stimulate local swelling response.

Negative Feedback System

Increase in monitored variable is detected, invoking coordinated physiological responses (such as hormone secretion) to reduce the elevated variable.

Neural

Main source that impacts hormone secretion, signals from the nervous system. Ex: during intense exercise the sympathetic nervous system signals to the adrenal gland to release epinephrine to increase cardiovascular response.

Humoral

Main source that impacts hormone secretion, due to changes in the chemistry of the blood. Ex: when blood glucose levels rise after eating, the pancreas is stimulated to release insulin. Insulin interacts with cells to stimulate them to intake glucose. into cells and for glucose to be converted into glycogen for storage.

Hormonal

Main source that impacts hormone secretion, relay information by responding to other hormone levels. Ex: When hungry the stomach releases ghrelin which signals hypothalamus to increase appetite. Once stomach is full, it slows down gherkin release which will signal hypothalamus to decrease appetite.

Pituitary Gland

Secrets many different hormones, controlled primarily by the hypothalamus.

Gylcogenesis

Glucose → Glycogen, makes glycogen, occurs in the liver and muscle after a meal when blood glucose is high. Insulin stimulates the process.

Glycogenolysis

Glycogen → Glucose (release), occurs when blood glucose is low, stimulated by glucagon, liver releases glucose into blood, muscle uses.

Gluconeogenesis

Liver’s way of raising blood glucose during prolonged exercise. Synthesizes glucose. High levels of glucagon.

Stroke Volume

Blood per beat ejected from left ventricle, rest 60-70mL/beat untrained; 100-120mL/beat trained.

Cardiac Output

CO = HR x SV, volume of blood pumped per minute. Rest ~5L.

Blood Pressure

Force of blood on artery walls, Normal ~120/80 mmHg. Resistance training both systolic and diastolic spike due to compression.

Diastole

Heart relaxes and fills with blood.

Systole

Ventricles contact, eject blood.

Alveoli

Site of gas exchange, thin walls, large SA node, capillary network.

Main breathing muscles

Diaphragm + intercostals.

Minute Ventilation

VE = TV x RR

Tidal Volume

Amount of air per breath. 0.5L at rest, ~3L exercise.