Key Concepts in Cardiovascular and Respiratory Physiology

Fluid Dynamics and Capillary Exchange

Factors Affecting Capillary Fluid Shift

  • Hemorrhage: Leads to a decrease in capillary hydrostatic pressure, causing a fluid shift towards absorption from the interstitium.
  • Exercise: Increases capillary hydrostatic pressure, promoting a fluid shift towards filtration into the interstitium.
  • Malnutrition: Results in decreased plasma protein concentration (and thus decreased plasma oncotic pressure), leading to a fluid shift towards filtration.

Pressure Gradients in Capillary

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Human Body Systems and Functions

The Senses

The Sense of Sight

Components of the eye:

  • Extraocular muscles
  • Sclera
  • Choroid
  • Optic nerve
  • Crystalline lens
  • Iris
  • Cornea
  • Aqueous humor
  • Vitreous humor
  • Retina

The Sense of Hearing

Components of the ear:

  • Pinna
  • External auditory canal
  • Eardrum
  • Semicircular canals
  • Cochlea
  • Auditory nerve
  • Eustachian tube
  • Ossicles (chain of bones)

Coordination Systems

Nervous System

This system receives and transmits information rapidly by electrical impulses, through sensory neurons.

Endocrine System

This system consists of glands that secrete

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Understanding Cholesterol and Protein for Better Health

Cholesterol
Cholesterol can be synthesized by the body, absorbed by the intestine, and causes excess cardiovascular problems.
HDL cholesterol collects in the arteries and transports it to the liver. Exercise and moderate alcohol consumption increase HDL, while smoking decreases it.
Functions of Cholesterol

  • Synthesis of steroid hormones
  • Synthesis of bile acids necessary for the absorption of fats
  • Synthesis of vitamin D
  • Formation of cell membranes

Protein
A protein is considered more complete the more amino

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Body Composition, Energy Needs & Nutritional Health Factors

Body Mass Index (BMI)

Formula: BMI = Weight (kg) / Height (m)²

BMI Categories:

  • 18.5 – 24.9: Normal weight
  • 25.0 – 29.9: Overweight
  • 30.0 – 39.9: Obese
  • 40.0+: Very Obese (Morbidly Obese)

Waist Circumference & Health Risks

Measure around the smallest part of the waist.

Risk Thresholds (Waist Circumference):

  • Men: Increased risk > 94 cm; High risk > 102 cm
  • Women: Increased risk > 80 cm; High risk > 88 cm

Associated Health Risks:

  • Diabetes (Type II)
  • Non-communicable diseases (e.g., cardiovascular disease)
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Autonomic Nervous System Divisions Compared

Somatic vs. Autonomic Nervous Systems

Somatic Nervous System (SNS)

  • Single axonal pathway from CNS.
  • Thick myelin fibers.
  • Target organs: skeletal muscles.
  • Effect of neurotransmitter: excitatory.
  • Neurotransmitter at target site: always acetylcholine.
  • No ganglia present.

Autonomic Nervous System (ANS)

  • Preganglionic and ganglionic neurons.
  • Effectors are glands and involuntary muscles.
  • At least one ganglion located outside the CNS.
  • Thin or unmyelinated fibers.
  • Transmitted effect may be excitatory or inhibitory.

Shared

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Biofuels, Polymers, and Sustainable Materials

Understanding Biofuels

Biofuel is any liquid fuel produced from vegetable raw materials whose chemical characteristics can replace gasoline and diesel.

Types of Biofuels

Biodiesel

Biodiesel is a liquid synthetic biofuel obtained from natural lipids such as vegetable oils or animal fats.

Biodiesel Applications

  • Vehicles (e.g., rental cars, food transport trucks, farm machinery, commercial freight vessels like ferries, yachts, sailboats)
  • Home heating oil
  • Electricity generators (often a superior alternative
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