CTB Flashcards
List the Macronutrients
Carbohydrates
Lipids (fats)
Proteins
What are the Functions of Macronutrients in Health?
Provide us with energy
What is Malnutrition?
When a person’s diet does not provide enough nutrient (starvation) or the right balance of nutrients for good health
List the Common Micronutrients
Vitamins, Minerals
List the Common Vitamins and their Functions in Health
A - Eyesight, Growth, Immunity B - Carbohydrate, Fatty Acid, Protein metabolism, Nucleic Acid Synthesis C - Cartilage and bone D - Calcium and phosphate metabolism E - Antioxidant K - Vegetables, fruit
List the Common Minerals and Their Functions in Health
Iron - Component of Haemoglobin for O2 transport
Calcium - Bones and Teeth, Nerve, and Muscle Function
Zinc - Enzymes, Immunity
Magnesium - Metabolism, Nerve and Muscle function
Potassium - Fluid Balance, Nerve and Muscle function
What is the Theoretical Energy Content Of the Macronutrients?
Carbohydrates - 4kcal
Lipids - 9kcal
Proteins - 5kcal
What percentage energy intake do each of the Macronutrients account for?
Carbohydrates - 50 - 75%
Lipids- 15 - 30%
Proteins - 10 - 20%
What is meant by the Thermic Effect of Food?
The energy used obtaining energy from food.
- About 10% for Carbs and Lipids
- About 20% for Proteins
What is Energy Balance?
Difference in energy intake and energy expenditure + Difference in Energy Stores
What is meant by Basal Metabolism?
Energy Required to keep your body functioning at rest
Factors affecting Basal Metabolic Rate (BMR)
Size (height + weight), Body Composition, Age, Climate, Hormones, illness, Drugs, Malnutrition
Describe Carbohydrate storage
- Molecule
- Store Size
- Storage site
- Gycogen
- Small
- Liver, Muscle
Describe Lipid storage
- Molecule
- Store Size
- Storage site
- Triglycerides
- Moderate - Large (Unlimited)
- Adipose
Describe Protein storage
- Molecule
- Store Size
- Storage site
- Protein
- Moderate (Limited)
- Muscles (plus others)
What Cells is the Oesophagus lined with?
Stratified Squamous Epithelial Cells
Protection
What are the major functional differences between cilia and microvilli? 2
Cilia are motile and facilitate the transport of substances
Microvilli are non-motile and increase the surface area of the epithelium.
What is the role of tight junctions in cellular transport?
Prevent paracellular transport of molecules (water and ions). Also prevent migration of membrane proteins to allow specialised functions of surfaces to be preserved
What are Desmosomes?
A type of Cell Junction. Occurs between adjacent cells to provide strong cell-to-cell adhesion.
- Via cadherin attachment to intracellular keratin filaments in cytoskeleton.
What are Gap Junctions made up of?
Connexons, Each of which consists 6 connexin proteins
What are Tight Junctions?
What are they made up of?
Junctions between adjacent cells to separate the apical from the basolateral membranes.
Made up of Occludins and Claudins - Membrane proteins as well as associated cytoplasmic proteins. Adherens Junctions found below
What is an endocrine gland?
A gland which is involved in secreting its products directly into the bloodstream.
E.g. Thyroid gland
What is an exocrine gland?
Gland which secretes its secretions into a duct which then empties onto an epithelial surface.
E.g. Salivary glands
Difference between Stereocilia and Cilia
- Stereocilia are non-motile mechanoreceptors. Cilia are motile and facilitate fluid movement across epithelium.
- Stereocilia found in inner ear
- Cilia found in Trachea
- Both contain actin (similarity)
What Cell Types are found in the Kidney?
Where?
- Tubules - Simple Cuboidal
- Glomeruli - Simple Squamous
What is Endocrinology?
Science of the structure and function of the endocrine glands, and the diagnosis and treatment of disorders of the endocrine system.
List the Endocrine Organs
Hypothalamus, Pituitary gland, Parathyroid glands, Adrenal glands, Thyroid gland, Pancreas, Ovaries, Testes
List Main Hormones
Peptides, Amines, Steroids, Thyroid Hormones (Technically peptides)
Describe Synthesis of Peptide Hormones
Water-soluble
Transcribed - Translated on rER - Processing rER - Packaging Golgi into Secretory Vesicles - Ready for Exocytosis when stimulated.
Rapid Action - Seconds
Describe Synthesis of Steroid Hormones
Derived from Cholesterol, Are synthesised upon stimulation, no store. Lipid Soluble.
- Hydrolysis of esters and release of cholesterol - Conversion of cholesterol to pregnenolone (in the mitochondria) - Processing in smooth ER - Diffusion out of cell.
Hours to Days Action
Describe the Action of Lipid-Soluble Hormones
- Diffuse through bilayer
- Binds to and activates intracellular receptor
- Hormone-Receptor Complex Alters Gene expression
- Transcription and Protein Synthesis
- Protein alters cell’s activity
Describe the Action of Water-Soluble Hormones
- Binds cell surface Receptor (G-protein coupled receptor/Tyrosine Kinase Receptor)
- Generate/Inhibit production of signalling molecules e.g. cAMP/IP3.
What is Positive Feedback?
Output enhances original stimulus
- Coagulation cascade
- Ovulation
What is Negative Feedback?
Output reduced the original stimulus
What are the differences between Releasing Hormone, Tropic Hormone, Effector Hormone?
- Releasing Hormone - Released by hypothalamus into portal veins act upon anterior pituitary
- Tropic Hormone - Affects other endocrine glands
- Effector Hormone - Affects target cells
What is Addison’s disease (Hypoadrenalism)?
Caused by deficiencies of glucocorticoids, mineralocorticoid e.g. aldosterone, and sex hormones.
- Caused by primary defect
- Signs + Symptoms - Weight loss, weakness, postural dizziness, confusion, hyperpigmentation
- Treatment - Lifelong oral steroid replacement.
What is Cushing’s Syndrome
Clinical manifestation of excessive glucocorticoid e.g. cortisol production.