A series of lectures on medical physiology

1. BASIM ZWAIN LECTURES
MEDICAL PHYSIOLOGY
CELL PHYSIOLOGY - 1
Professor Dr. Basim Zwain
Faculty of Medicine
Jabir ibn Hayyan Medical University
basimzwain@jmu.edu.iq

2. CELL PHYSIOLOGY
Plasma Membrane
The fluid mosaic model
Integral and peripheral proteins

3. CELL PHYSIOLOGY
Proteins act as:
Receptors
Enzymes
Carriers
Channels

4. Channels
CELL PHYSIOLOGY
Ungated (leak)
Voltage gated
Ligand gated
-Direct receptor channel complex
-Intracellular second messenger–gated channel
-NMDA (voltage and ligand gated)
Mechanically gated

6. CELL PHYSIOLOGY
Clinical considerations
Cystic fibrosis is an autosomal recessive disease of a
direct effect on ion channels caused by mutations in
the cystic fibrosis transmembrane regulator (CFTR)
gene, which codes for the chloride channel gated by
cAMP. Deletion of single phenylalanine molecule
prevents the channel protein from reaching the
plasma membrane. Reduction in chloride channels
results in thick mucous secretions that block airways.

7. CYSTIC FIBROSIS

8. CYSTIC FIBROSIS

9. CELL PHYSIOLOGY
Clinical considerations
Myasthenia gravis is an indirect ion channel disease
produced by an autoimmune disorder.
Autoantibodies against the AChRs lower the receptor
concentration, causing lysis of the motor endplate.
The decreased number of nicotinic AChRs results in
smaller postsynaptic responses and a tendency to
block neuromuscular transmission. Individuals with
this disease experience weakness of skeletal
muscles.

10. MYASTHENIA GRAVIS
BLEPHAROPTOSIS

11. CELL PHYSIOLOGY
Clinical considerations
Malignant hyperthermia is an autosomal dominant
condition occurs due to mutations in the ryanodine
receptor leading to an overactive receptor to
halothane and muscle relaxants such as carbachol. It
results in increased Ca2+ release, sustained muscle
contraction, extensive necrosis of muscle cells,
release of large amounts of K+, cardiac arrhythmias,
and ventricular fibrillation. High Ca2+ levels leads to
increased heat production. Treated with dantrolene,
inhibits the receptor.

13. CELL PHYSIOLOGY
Clinical considerations
Brody disease is an autosomal recessive
mutation in the ER Ca2+-ATPase, which
leads to exercise induced impairment of
skeletal muscle relaxation.
Darier disease is an autosomal dominant
skin disorder (dyskeratosis follicularis) due
to mutations in the ER Ca2+-ATPase, leads
to loss of cell adhesion.

14. BRODY DISEASE

15. DYSKERATOSIS FOLLICULARIS

16. CELL PHYSIOLOGY
Clinical considerations
X-linked congenital stationary night blindness is a
recessive disease of human retina due to mutations
in a voltage-gated Ca2+ channel, defective glutamate
release and neurotransmission. Patients have
difficulty adapting to low light situations, reduced
visual acuity, myopia, nystagmus, and strabismus
Lambert-Eaton myasthenic syndrome (LEMS) is an
autoimmune disease characterized by an increased
number of LEMS antibodies against voltage-gated
Ca2+ channels, leads to defective neurotransmission
and weakness of proximal muscles.

17. VOLTAGE-GATED CA2+ CHANNEL

19. CELL PHYSIOLOGY
Transport processes across plasma membrane:
Passive transport
Active transport

20. CELL PHYSIOLOGY
Passive transport
Diffusion
Simple diffusion
Facilitated diffusion
Osmosis
Osmolality, osmolarity, isotonic, hypotonic and
hypertonic solutions.
Filtration

22. CELL PHYSIOLOGY
Active transport
Primary active
Secondary active
Symport (cotransport)
Antiport (exchange)

23. CELL PHYSIOLOGY
CARDIAC STIMULANTS
The natural wild flower Digitalis
purpurea (foxglove) and synthetic
cardiac glycosides, including
ouabain and digitalis, inhibit the
Na+/K+-ATPase pump.