Digestive System
Purpose:
Obtain energy-containing substrates,
water, vitamins, and ions from outside
body into circulation.
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Human Digestive System: Structure and Secretion Processes, Slides of Human Resource Management
A comprehensive overview of the human digestive system, detailing its structure and the processes involved in the secretion of saliva. Topics covered include the role of various organs such as the liver, stomach, and pancreas, as well as the functions of the gastroesophageal sphincter and salivary glands. The document also discusses the composition of saliva and the process of its secretion, including the stimulation of the parasympathetic nervous system and the active transport of ions.
Typology: Slides
2012/2013
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Digestive System
Purpose:
Obtain energy-containing substrates, water, vitamins, and ions from outside body into circulation.
Gastroesophagealsphincter Liver Stomach Gallbladder Pancreas
Duodenum Descending colon Transverse colon Ascending colon Jejunum Cecum lleum Appendix
Sigmoid colon
Anus
Rectum
Mouth
- Mastication
- Moisten
- Enzymatic breakdown
Formation of saliva
- Ptyalin or α amylase
- Mucus
- Water
- Thiocyanate, proteolytic enzymes, and
antibodies.
Salivary gland containing secretory granule.
Process of saliva secretion
- Parasympathetic nervous system stimulation causes release of acetylcholine (ACH) on surface of salivary gland cells.
- ACH causes increase in membrane permeability to Ca++.
- Ca++ causes secretory vesicles to fuse with cell membrane and break open on outer surface, emptying contents into lumen of salivary gland (exocytosis).
Process, cont.
- ACH stimulation causes Na+ transport out of salivary cells by active transport (with ATP), Cl- follows passively, water moves by osmosis.
- As water containing ions and other secretions moves toward mouth, K+ actively exchanged for Na+, HCO3- actively exchanged for Cl-.
- Role of SNS--vary blood flow, esp. decrease blood flow Docsity.com