Week 2: Systems of the Body Flashcards
What are some impt points to note about systems of the body?
- Systems are INTERCONNECTED and DEPENDENT on e/o
- For optimal everyday functioning, systems need to be ACTIVATED
- However, when systems become OVER-ACTIVATED, they can result in diseases
What are the parts of the nervous system?
Nervous system: Central nervous system + Peripheral nervous system
What are the parts of the central nervous system?
CNS: Brain + spinal cord
What are the parts of the peripheral nervous system and what are their functions?
Somatic + Autonomic nervous system
Somatic: Controls voluntary movement
Autonomic: Controls organs that operate involuntarily
What are the parts of the autonomic nervous system and what are their functions?
Sympathetic + Parasympathetic nervous system
Symp: Mobilises the body for action
Para: Maintains and restores equilibrium
What is the central nervous system?
Carries voluntary nerve impulses to skeletal muscles & skin; carries involuntary impulses to muscle & glands
What are neurotransmitters?
Chemical signals that are used by the nervous system for communication
What are the parts of the brain?
- Forebrain
- Midbrain
- Hindbrain
What are the parts of the hindbrain and what are their functions?
1) Medula: Regulates HR, BP and respiration
2) Pons: Helps control respiration
3) Cerebellum: Coordinates voluntary muscle movement & maintenance of balance & equilibrium, muscle tone & posture
What is the function of the midbrain?
Coordination of visual and auditory reflexes
What are the parts of the forebrain?
1) Cerebral cortex
2) Hypothalamus
3) Amgydala
4) Hippocampus
What are the parts of the cerebral cortex?
1) Frontal lobe
2) Parietal lobe
3) Temporal lobe
4) Occipital lobe
What is the limbic system and what is it made up of?
Limbic system: Stress & emotional responses
1) Hypothalamus
2) Amygdala
3) Hippocampus
What are the functions of the parts of the limbic system?
1) Hypothalamus: Emotional functioning, release of hormones
2) Amygdala: General arousal, threat detection
3) Hippocampus: Detection of emotionally charged memories
What happens when the SNS is activated?
Activation of SNS triggers release of catecholamines (neurotransmitter) - epinephrine and norepinephrine
How is the CNS involved in SNS activation?
SNS activation -> Release of catecholamines -> Systemic (stress-like responses) occur simultaneously
What are the systemic responses that occur during SNS activation?
- Cardiovascular: HR increases, blood vessels constrict, BP increases
- Respiratory: Respiration increases, airflow into lungs inceases
- Digestive: Digestion and urination decreases
What are the diseases involving the nervous system?
- Epilepsy
- Parkinson’s disease
- Cerebral palsy
- Multiple sclerosis
- Huntington’s disease
- Dementia/Alzheimer’s disease
- Cerebrovascular disease
- Sleep (lack of)
Dementia/Alzheimer’s disease occurs due to…
Amyloid/tau (protein) desposits in the brain
What is the endocrine system?
Made up of a number of glands that SECRETE HORMONES into the bloodstream to stimulate activity in the organs
What are the parts that make up the endocrine system?
- Pituitary glands and hypothalamus regulates endocrine system
- Adrenal glands (made up of adrenal cortex and adrenal medulla) secretes hormones implicated in stress response
What is the process of activation of the hypothalamic-pituitary-adrenal (HPA) axis?
2 pathways:
- Stress > Pituitary gland > Activates adrenal cortex in adrenal gland > Secretion of corticosteroids
- Stress > SNS > Activates adrenal medulla in adrenal gland > Secretion of catecholamines (epinephrine and norepinephrine)
What occurs when corticosteroids are secreted?
- Increase protein and fat mobilisation
- Increase access to bodily energy storage
- Inhibits antibody formation and inflammation
- Regulates sodium retention
What occurs when catecholamines are secreted?
- HR increase and heart capillaries dilate
- BP increase via vasoconstriction
- Blood is diverted to muscle tissue
- Breathing rate increase
- Digestion slows down
- Pupils of eyes dilate
What are the diseases related to the endocrine system?
- Diabetes (Type I and Type II)
What is diabetes?
Chronic inability to manufacture or properly use insulin
Comorbid w/ coronary heart disease and kidney disease
What is insulin?
A hormone that promotes absorption and metabolism of carbohydrates, fats and proteins
What is Type I diabetes?
An autoimmune disorder where the immune system erroneously destroy’s body own cells that are needed to produce insulin
What are the characteristics of Type I diabetes?
- Happens early in life (late childhood/early adolescence)
- Partly genetic in nature
What is Type II diabetes?
Insufficient insulin produced by the body
What are the characteristics of Type II diabetes?
- Typically happens after 40
- Largely lifestyle-related
What is the cardiovascular system?
1) Left ventricle contracts after receiving O2 blood from lungs
2) Contraction forces aortic valve open
3) O2 blood is pumped through aorta to body
4) Right ventricle contracts after receiving de-O2 blood
5) Contraction forces pulmonary valve open
6) De-O2 blood returns to lungs
What are the indexes of the cardiovascular system?
1) Blood pressure (BP) – Systole + Diastole
2) Pre-ejection period (PEP)
3) Cardiac output (CO)
4) Total peripheral resistance (TPR)
What is blood pressure?
Force on blood vessel walls from systolic and diastolic processes
Systole: Heart contracts to pump blood out
Diastole: Heart relaxes to take in blood
What is pre-ejection period (PEP)?
Time b/w left ventricle contraction (1) and aortic valve opening (2)
A pure measure of SNS activation
- Shorter PEP –> More activation
What is cardiac output (CO)?
Volume of blood pumped per min.
An indicator of cardiac functioning
What is total peripheral resistance (TPR)?
Vascular resistance to blood flow
An index of “stiffness” in arteries - stiff arteries, high TPR
What is cardiac efficiency?
An index of general cardiac functioning
What are the characteristics of high/low cardiac efficiency?
High cardiac efficiency:
- Short PEP: Blood is pumped quickly
- High CO: In high volumes
- Low TPR: And at low resistance
Low cardiac efficiency:
- Short/Long PEP: Blood is pumped quickly/slowly
- Low CO: In low volumes
- High TPR: And at high resistance
Besides physical fitness, what else can affect cardiac efficiency?
- Everyday experiences and stimuli can temporarily increase or decrease cardiac efficiency
- E.g. Giving a speech (challenge/threat) - high/low CE
- E.g. Anger (high CE), excitement (high CE), anxious (low CE)
What are the diseases related to the cardiovascular system?
- Atherosclerosis
- Hypertension
- Thrombosis
What is atherosclerosis?
Narrowing of arteries due to deposits of substances (mostly cholesterol) on arterial walls
What is hypertension?
Too high CO or TPR (unrelated to deposits)
What is thrombosis?
Clotting of blood vessels
-Types: Coronary/cerebral thrombosis (cardiov. system/brain)
How does the respiratory system work?
- Inspiration causes lungs to expand in the thorax, O2 enters system
- Expiration reduces volume in lungs, CO2 is eliminated from system
- The lungs are connected to the heart through the pulmonary artery and pulmonary vein
What are the diseases relating to the respiratory system?
- Viral infection
- Bacterial infection
- Pneumonia
- Tuberculosis
- Lung cancer
