Cellular Physiology

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Cellular Physiology

• Nermien Waly MD, PhD
• Lecturer

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House-keeping rules

• Attendance.
• Cell phones off, please.
• Breaks and food.
• Loos!
• Questions welcomed
• any time.
• Exams and evals.

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Course objectives

• To define the word physiology (
• To be able to identify the system your drug is
  dealing with
• To be able to understand the mechanism by which
  this system is working with.
• To be aware of the possible interactions between
  different systems

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Overview

• What is physiology
• The human body (functional point of view)
• Body fluid (water)
• The cell (living units of the body)
• Control systems

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Physiology

• It is the science of explaining the physical and
  chemical factors that are responsible for the
  origin, development, and progression of life.
• Physiology can be divided into viral, bacterial,
  plant physiology and many more divisions.
• In human physiology we attempt to explain the
  specific characteristics and mechanisms of the
  human body that make it a living being.

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The human body
Leonardo Davinci vitruvian man
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Body systems

• Nervous system
• Endocrine system
• Myoskeletal system
• Cardiovascular system (CVS)
• Lymphatic system
• Respiratory system
• Digestive system
• Urinary system
• Reproductive system
• Hematopoietic system (blood)
• Immune system (RES)
• Special senses (vision hearing)

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Body water

• 60 of body weight is water
• 40 of body weight is ICF (intracellular)
• 20 of body weight is ECF (extracellular)

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ICF ECF

• Intracellular
• 
  
• 2/3rd of body water
• K, Mg, protein
• pH acidic
• Osmolarity 290

• Plasma, interstitial fluid
• 1/3rd of body water
• Na,Cl-, HCO3-
• pH alkaline
• Osmolarity 290

• Osmolarity is concentration of particles in
  solution expressed as osmole per liter
• pH is the logarithmic expression of hydrogen ion
  concentration

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The cell

• Standard cell (merely hypothetical!)
• Specialized cell neurons, muscle cells, red
  blood cells, hair cells and many others.
• Any cell is comprised mainly of cell membrane and
  intracellular organelles

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The cell membrane

• Structure lipid bilayer (phospholipids),
  protein, cell connections e.g. gap junctions.
• Functions protection, support, transport,
  cell-body and cell-cell interaction.
• Cell characteristics life, division,
  nourishment, etc..

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Cell organelles

• Nucleus
• Mitochondria
• SER and RER
• Golgi apparatus
• Ribosomes
• lysosomes

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Transport across cell membrane

• Diffusion simple or facilitated .
• Active transport primary or secondary.
  Co-transport or counter-transport. Na-K ATPase
  pump as an example of primary active transport.
• Osmosis its a water thing (

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Break (
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Simple and Facilitated diffusion
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Na-K ATPase pump

• Significance Drugs acting on this mechanism e.g.
  cardiac glycosides
• Other pumps Ca pump, H,K pump.

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Secondary active transport

• Co-transport and counter-transport.
• Significance!

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Osmosis
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Neurons as an example of specialized excitable
cells
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Membrane characteristics of excitable cells

• Excitable cells are capable of spontaneously
  firing electrical impulses e.g. nerve cells and
  cardiac myocytes
• Membrane potentials resting (RMP) and action
  potential.
• Depolarization and repolariztion

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Resting Membrane Potential

• -70 mV .
• Depolarization
• Repolarization.

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Action potential
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Cell-cell interaction/communication

• Anatomical e.g. gap and tight junctions
• Electrical nerve signals- action potentials
• Chemical neurotransmitters, hormones. The role
  of receptors.

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Control systems

• Nervous system (nerve signals/action potentials)
• Endocrine system (hormones)
• Feed back mechanism as a characterstic of control
  system.

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Thank you