Systems of the Body Flashcards
What are the key parts of a neuron and their functions?
- Cell body: source of life for the cell
- Dendrites: receive messages from other neurons
- Axon: carries messages away from the cell
- Synaptic knobs: send messages to other neurons
- Synapse: gap between neurons for signal transmission
What are the main divisions of the nervous system?
- CNS: brain and spinal cord
- PNS: somatic (controls voluntary movements) and autonomic (regulates involtunary functions such as the regulation of internal organs and smooth muscles) systems
What are the key parts of the hindbrain and midbrain, and what are their functions?
- Hindbrain:
Medulla: Receives sensory info from the heart
Pons: Links hindbrain and midbrain
Cerebellum: Coordinates voluntary muscle movements - Midbrain: Pathway for sensory and motor impulses
What are the two main sections of the forebrain, and what are their functions?
- Diencephalon:
Thalamus: Relays sensory stimuli
Hypothalamus: Regulates heart rate and blood pressure - Telencephalon: Includes the two cerebral hemispheres
What are the key parts of the limbic system and their functions?
- Amygdala: Detects threats
- Hippocampus: Stores emotional memories
- Cingulate gyrus, septum, and hypothalamus: Involved in emotional functioning
What are neurotransmitters and catecholamines?
- Neurotransmitters: Chemicals that regulate nervous system function
- Catecholamines: Epinephrine and norepinephrine promote sympathetic NS activity and are released during stress
What is the role of the spinal cord and the difference between efferent and afferent nerves?
- Spinal cord: Transmits messages between brain and body
- Efferent nerves: Carry signals from brain to muscles (e.g to produce muscle action)
- Afferent nerves: Carry sensory info from body to brain (e.g sensory information)
What does the somatic nervous system control?
The somatic nervous system controls both sensory and motor functions of the skin and muscles.
what are the two divisions of the autonomic nervous system?
The autonomic nervous system has two divisions:
1. Sympathetic nervous system: Activates the body for action (“fight or flight”).
- Parasympathetic nervous system: Relaxes the body (“rest and digest”).
What regulates the endocrine system and how does it communicate?
The endocrine system is regulated by the hypothalamus and pituitary gland and communicates through hormones like adrenaline and cortisol.
Where are the adrenal glands located, and what do they do?
The adrenal glands are located on top of each kidney. They release hormones in response to emergencies and stress.
Cortisol: Helps control swelling, but high levels over time can cause issues like high blood pressure or ulcers.
Epinephrine & Norepinephrine (adrenaline and noradrenaline): Trigger quick energy responses in the body.
What happens during sympathetic nervous system activation?
The sympathetic nervous system triggers the release of epinephrine and norepinephrine from the adrenal glands, increasing heart rate and blood pressure.
How does the HPA axis respond to stress, and what are its impacts on the body?
The HPA axis is activated during stress, leading the pituitary gland to release ACTH, which stimulates the adrenal glands to produce cortisol.
- Prolonged activation can lead to allostatic load and weaken the immune system.
Where is the thyroid gland located, and what does it do?
The thyroid gland is located in the neck and produces thyroxin, a hormone that regulates activity levels and growth.
What are hypothyroidism and hyperthyroidism?
- Hypothyroidism: Too little thyroid hormone, leading to low energy and weight gain.
- Hyperthyroidism: Too much thyroid hormone, leading to high energy, weight loss, and trouble sleeping.
Where is the pancreas located, and what does it do?
The pancreas is located below the stomach and regulates blood sugar levels by producing insulin, which helps the body absorb blood sugar.
Why does high blood sugar make it difficult to lose weight?
When blood sugar is high, the body uses glucose for energy instead of burning fat. The body only burns fat when blood sugar levels drop low enough.
What is diabetes, and what are the differences between Type I and Type II diabetes? When do they usually occur?
Diabetes occurs when the body cannot produce or use insulin properly.
- Type I diabetes: The body cannot produce insulin and is insulin-dependent.
- Type II diabetes: The body doesn’t produce enough insulin or becomes insensitive to it
What are the main functions of the mouth, stomach, small intestine, and large intestine in digestion?
- Mouth: Breaks food down with the help of salivary glands
- Stomach: Starts protein digestion by liquefying and mixing food.
- Small Intestine: Responsible for chemical breakdown and nutrient absorption.
- Large Intestine: Absorbs water and stores waste for excretion.
What role do enzymes and the esophagus play in digestion?
Enzymes break down food substances, and the esophagus pushes food to the stomach using peristalsis.
What are some common disorders of the digestive system?
- Peptic Ulcers: Sores in stomach or small intestine lining
2.Hepatitis: Inflammation of the liver (caused by viruses or alcohol)
- Cirrhosis: Liver cell death and scarring (due to alcohol or hepatitis)
How does the respiratory system function?
- The respiratory system moves air in and out of the lungs through mechanical action
- Gas exchange in the alveoli removes CO₂ and brings O₂ into the blood.
- Protective mechanisms like sneezing and coughing help maintain its function.
What can happen if the respiratory system’s function is impaired?
Impaired function can lead to respiratory conditions such as asthma, bronchitis, and emphysema.
Describe the pathway of air through the respiratory system.
Air enters through the nose/mouth, passes through the larynx, trachea, bronchial tubes, bronchioles, and finally reaches the alveoli for gas exchange.
What are some common disorders of the respiratory system?
- Asphyxia: Too little oxygen and too much CO₂, common in limited breathing spaces.
- Anoxia: Oxygen shortage, often occurring at high altitudes, causing confusion and coma.
- Hyperventilation: Rapid breathing reduces CO₂ levels, leading to dizziness and lightheadedness.
What is the function of arteries and veins in the cardiovascular system?
Arteries carry oxygenated blood from the heart to the body, while veins carry deoxygenated blood back to the heart and lungs.
How many chambers does the heart have, and what are they called?
The heart has four chambers: the left atrium, right atrium, left ventricle, and right ventricle.
What are the functions of the left and right sides of the heart?
The left side pumps oxygenated blood to the body, and the right side pumps deoxygenated blood to the lungs.
What is blood pressure?What happens to blood pressure during the systolic and diastolic phases?
- The force of blood pushing against artery walls.
- During the systolic phase, when the heart contracts, BP rises.
- During the diastolic phase, when the heart relaxes, BP is at its lowest.
What factors affect blood pressure and how do they influence it? Think of blood pressure like water flowing through a garden hose:
- Cardiac Output (Water Flow Rate):: More blood pumped = higher BP.
- Blood Volume (Amount of Water in the Hose: More blood in the body = higher BP.
- Peripheral Resistance (Hose Narrowing): Narrower arteries = higher BP.
- Elasticity (Hose Flexibility): Stiffer arteries = higher BP.
- Viscosity (Thickness of Water):Thicker blood = higher BP
What happens to diastolic blood pressure (BP) when arteries dilate?
When arteries dilate, such as in heat, diastolic BP decreases.
How does blood pressure fluctuate throughout the day?
Blood pressure follows a daily rhythm, with its lowest point during deep sleep.
What factors cause blood pressure to increase?
Blood pressure increases in response to activity, changes in posture, stress, temperature, and increased heart rate or cardiac output.
What is atherosclerosis and what causes it?
- Atherosclerosis is the buildup of cholesterol and plaques in arteries, narrowing them
- Associated with poor health habits
What is arteriosclerosis and how does it affect blood pressure?
- Arteriosclerosis is the hardening of arteries, often following atherosclerosis.
-As plaques harden, arteries lose their elasticity, leading to increased BP.
What are the consequences of atherosclerosis?
Atherosclerosis can cause 1. Angina pectoris (chest pain due to insufficient oxygen)
2. Myocardial infarction (heart attack from blocked blood supply).
What is considered high blood pressure in hypertension, specifically regarding systolic and diastolic measurements?
Systolic blood pressure ≥ 140 mmHg
Diastolic blood pressure ≥ 90 mmHg.
What is the difference between primary and secondary hypertension?
Primary hypertension has no known cause, while secondary hypertension is due to specific causes like adrenal tumors.
What are the two main components of blood?
- Formed elements
- Plasma.