GI: Week 5 Flashcards
What fuels are used by the brain
Glucose, ketones
What fuels are used by the muscle
Glucose
Ketones (starvation)
Triacyglycerol
BCAA
What fuels are used by the liver
AA
Fatty Acids
Glucose
Alcohol
Why does the liver not use ketones as a source of fuel
Because they do not have the enzyme thiolase
What fuel are used by the kidneys
Glucose + Ketones (cortex)
Glucose (medulla)
What fuel is used by the small intestines
Ketones
Glutamine (AA)
What fuel is used by the large intestines
Short-chained fatty acids
Glutamine
Define BMR
Minimum amount of energy required to keep the body alive
What factor causes BMR to decrease
Age
What is the units for BMI
Kcal expended/hr/m^2
Where is vitamin A stored
Space of Disse
Liver
What is vitamin A needed for
Cell growth Vision Healthy Skin Reproduction Embryonic Development Maintenance of body mucous membranes Lymphocyte production
4 sources of vit A
Liver
Dairy products
Oily Fish
Margarine
What can a deficiency of vit A cause
Night blindness
Keratinising of epithelia
Impaired hearing
What is the function of via C
Synthesis of collagen, neurotransmitters
Absorption of plant-based iron
Sources of vit C
Citrus fruits
Potatoes
Green veg
What does deficiency of via C result in
Weakness
Bleeding gums
Scurvy (50-100 days without bit C)
What is the function of via B
Important in cell metabolism + energy production
What is the main bit B needed by the body
B-12
Where is vit D stored
Liver
What is vit D3
Cholecalciferol (skin produced vitamin D)
What is vitamin D2
Derived from plants
What is the role of vitamin E
Antioxidant
What happens to food in the mouth
Moistened by saliva and mechanically broken down by the temperomandibular joint
What nerve innervates the muscles controlling the temperomandibular nerve
Mandibular nerve - V3
What is the role of the buccinator during oral phase
Helps contain food against teeth surface
What nerve senses when food is moist enough to be swallowed
Linguinal nerve
What do food particles form as they are pushed to the back of the mouth
Form a trough
What muscles allow for trough formation
Intrinsic muscles of the tongue
What happens to the tongue as food is moved towards the back of the mouth
The tongue is elevated to the roof of the mouth via the mylohyoid and three glossus muscles
What two things happen to stop food entering the nasal cavity
- Soft palate is elevated to close off the nasopharynx
2. Walls of the pharynx move closer towards the soft palate
How does the pharynx prepare to recieve the bolus
- The pharynx is moved upwards + forwards by the suprahyoid, salpingopharyngeus and palatopharyngeus muscles
- Palatopharyngeal folds are brought close together by the superior constrictor muscles so only a small amount of bolus can pass through.
What happens to the auditory tube as food moves down the pharynx
The auditory tube opens due to the elevation of the pharynx and soft palate to equalise pressure in the nasopharynx and middle ear
What happens to muscles in the larynx to prevent aspiration
- The glottis closes
- Epiglottis folds over
- True vocal cords adduct to stop aspiration
- Hyoid elevates to lift pharynx and larynx further
When do the larynx and pharynx move back down
Via elastic recoil as food enters the oesophagus
How does the dorsal mesentery form
The connective tissue attaching to the gut sections and the abdominal wall narrow
How does the bile duct form
As hepatic cells penetrate the septum transversum, the connection between the liver and foregut begin to narro w
What cells are produced by the septum transversum
Haematopoietic cells
Kupffer cells
Connective Tissues
What structure gives rise to liver epithelial cells
Liver cords
Define parenchyma
A ‘bulk’ of cells
What produces the visceral peritoneum of the liver
Mesodermal cells on the surface of the liver
What are the innervation of the pharyngeal arches
5,7,9,10 (in that order)
5th - Superior laryngeal nerve
6th - Recurrent Laryngeal nerve
What muscles do the 1st pharyngeal arch develop into
All muscles innervated by the mandibular nerve (tensor tympani, mastication, digastric and myolohyoid)
What bones does the 1st pharyngeal arch develop into
Maxilla, mandible, incus and malleus
What muscles does the second arch develop into
Facial expression, stapedius, stylohyoid,
What bones does the second arch develop into
Stapes, styloid, lessor horn of hyoid cartilage
What muscles does the third arch develop into
Stylopharyngess
What bones does the third arch develop into
Body + greater horn of the hyoid cartilage
What is the fourth arch innervated by
Superior laryngeal nerve of the Vagus
What muscle does the fourth arch develop into
Cricothyroid muscle
What bones doe the fourth arch develop into
Thyroid cartilage and epiglottic cartilage
What muscle does the 6th arch develop into
All laryngeal muscles except cricothyroid
What bones does the 6th arch develop into
Cricoid cartilage, arytenoid, corniculate and cuneiform
