Physiology Questions Cmt Nta Leve 4

Mention the importance of endocrine system

  1. The endocrine system, like the nervous system, adjusts and correlates the activities of the various body systems, making them appropriate to the changing demands of the external and internal environment.
  2. Endocrine integration is brought about by chemical signals secreted by ductless glands and transported in the circulation to target cells.
  3. The hormones regulate metabolic processes.
  4. The term metabolism, literally meaning change, is used to refer to all the chemical and energy transformations that occur in the body.
  5. The animal organism oxidizes carbohydrates, proteins, and fats, producing principally CO2, H2O, and the energy necessary for life processes. CO2, H2O, and energy are also produced when food is burned outside the body.
  6. In the body, oxidation is not a one-step, semiexplosive reaction but a complex, slow, stepwise process called catabolism, which liberates energy in small, usable amounts. Energy can be stored in the body in the form of special energy-rich phosphate compounds and in the form of proteins, fats, and complex carbohydrates synthesized from simpler molecules.
Mention 2 Functions of hypothalamus
Control pituitary functions

Mention 2 parts of pituitary gland
-posterior pituitary
anterior pituitary gland 

Mention hormones produced by the anterior pituitary gland
-FSH,LH,prolactin,ACTH,growth hormone.

Mention hormones produced by the posterior Pituitary gland
-ADH and oxytocin

Mention function of FSH and LH
Stimulates structure within the ovaries, primary follicle, to grow toward maturity.
Each follicle contains a developing egg cell (ovum), which is released from the ovary during ovulation.
FSH stimulate the follicle to synthesize and secrete estrogen (female sex hormones Oestrogen and Progesterone) in the male, FSH stimulates the development of the seminiferous tubules of the testes and maintains spermatogenesis (sperm production) by them.

Luteinizing Hormone (LH)
Stimulates the formation and activity of the corpus luteum of the ovary.
The corpus luteum (meaning yellow body) is the tissue left behind when a follicle ruptures to release its egg during ovulation.
The corpus luteum secretes progesterone and estrogeus when stimulated by LH.

Mention function of growth hormone
It stimulates growth and division of most body cells especially that of bones and skeletal muscles.
It also regulates metabolism in many organs example, stimulates protein synthesis and break down of fats.
Stimulate growth by stimulating the liver to produce certain growth factors, which in turn accelerate amino acid transport into cells.

Mention  function of ADH
The main effect of ADH is to regulate fluid balance in the body by reducing the urine output, for instance during thirsty, hypotension and when there is high plasma osmolarity and during stress.

Mention function of ACTH
This increases the concentration of cholesterol and steroids within the adrenal cortex and the output of steroid hormones, especially cortisol.

Mention function of oxytocin
Oxytocin also stimulates contractions of the milk ducts in the breast, which move milk to the 
nipple (the let-down) in lactating women.
uterine contractions stimulate the release of oxytocin from the posterior pituitary, which, in turn, increases uterine contractions.

Mention function of prolactin
It initiates milk secretion (lactation).

Functions of hormones produced by the thyroid gland
Increase metabolic activities.

Functions of hormones produced by the parathyroid gland.

Calcium balance

  • Mention hormones produced by the adrenal gland.
  • -minerocorticoids
  • -glucocorticoids
  • -noraepinephrine
  • Mention functions of adrenaline hormone

flight and fright

  • Mention functions of aldosterone hormone

Salt balance

  • Mention functions of cortisol

functions to increase blood sugar through gluconeogenesis, to suppress the immune system, and to aid in the metabolism of fat, protein, and carbohydrates.[2] It also decreases bone formation.

  • Mention 3 functions of the kidney

regulating acid-base balance, electrolyte concentrations, extracellular fluid volume, and blood pressure

  • Mention 5 parts of the nephron

Glomerulus, Efferent arteriole, Bowman’s capsule,  Proximal convoluted tubule, Cortical collecting duct,. Distal convoluted tubule, Loop of Henle,

  • Function of loop of Henle

the loop of Henle’s main function is to create a concentration gradient in the medulla of the kidney.By means of a countercurrent multiplier system, which utilizes electrolyte pumps, the loop of Henle creates an area of high urea concentration deep in the medulla, near the papillary duct in the collecting duct system

  • Mention functions of glomerulus

Ultra filtration

  • Why are protein molecules not filtrated in the glomerulus?

Because of higher molecular weight

  • Briefly Explain filtration process  

Filtration is movement of fluids across the filtration membrane into the lumen of Bowman’s capsule as results of pressure difference

The fluid entering the nephron is called the filtrate

The filtrate in the glomerolus is similar to plasma with the exception of plasma protein Filtration takes place through the semi permeable walls of the glomerulus and glomerular capsule

The formation of filtrate depend on a pressure gradient, called the filtration pressure, which forces fluid from the glomerular capillary across the filtration membrane into the lumen of Bowman’s capsule

  • Briefly Explain secretion

Selective reabsorption takes place in the proximal convoluted tubule of the kidney

It is the process by which certain substances that are required by the body (such as glucose, amino acids, vitamins and water) that have been filtered out of the blood during ultrafiltration, are reabsorbed. As only certain substances are reabsorbed, it is known as selective reabsorption

In this way, many useful solutes (primarily glucose and amino acids), salts and water that have passed in the proximal tubule through the Bowman’s capsule, return in the circulation

These solutes are reabsorbed isotonically, in that the osmotic potential of the fluid leaving the proximal tubule is the same as that of the initial glomerular filtrate

However, glucose, amino acids, inorganic phosphate, and some other solutes are reabsorbed via secondary active transport through cotransport channels driven by the sodium gradient out of the nephron

  • Briefly explain tubular reabsorption  

As the glomerular filtrate enters the renal tubules, it flows sequentially through the successive parts of the tubule-the proximal tubule, the loop of Henle, the distal tubule, the collecting tubule, and, finally, the collecting duct-before it is excreted as urine

Along this course, some substances are selectively reabsorbed from the tubules back into the blood, whereas others are secreted from the blood into the tubular lumen

Eventually, the urine that is formed and all the substances in the urine represent the sum of three basic renal processes-glomerular filtration, tubular reabsorption, and tubular secretion-as follows:

Some substances are removed from blood through the peritubular capillary network into the distal convoluted tubule or collecting duct, by secretion mechanism

These substances are Hydrogen ions, creatinine, and drugs

Substances which are not reabsorbed after glomerular filtration and those secreted into the tubules forms the components of Urine

For many substances, reabsorption plays a much more important role than does secretion in determining the final urinary excretion rate

Secretion accounts for significant amounts of potassium ions, hydrogen ions, and a few other substances that appear in the urine

  • Define the terms metabolism, catabolism and anabolism
  • Define carbohydrate metabolism

Carbohydrate metabolism denotes the various biochemical processes responsible for the formation, breakdown and interconversion of carbohydrates in livingorganisms.

  • identify types of carbohydrates metabolism
  • Glycolysis – the oxidation metabolism of glucose molecules to obtain ATP and pyruvate[9]
  • Pyruvate from glycolysis enters the Krebs cycle, also known as the citric acid cycle, in aerobic organisms after moving through pyruvate dehydrogenase complex.[10]
  • pentose phosphate pathway, which acts in the conversion of hexoses into pentoses and in NADPH regeneration.[11] NADPH is an essential antioxidant in cells which prevents oxidative damage and acts as precursor for production of many biomolecules.
  • Glycogenesis – the conversion of excess glucose into glycogen as a cellular storage mechanism; this prevents excessive osmotic pressure buildup inside the cell
  • Glycogenolysis – the breakdown of glycogen into glucose, which provides a glucose supply for glucose-dependent tissues.
  • Gluconeogenesis – de novo synthesis of glucose molecules from simple organic compounds. Anexample in humans is the conversion of a few amino acids in cellular protein to glucose.
  • why is ATP used in glycolysis process

This reaction consumes ATP, but it acts to keep the glucose concentration low, promoting continuous transport of glucose into the cell through the plasma membrane transporters.

Synthesis and breakdown of amino acids (hence important in protein metabolism).Conversion of glycogen in  liver and muscle tissue to glucose (hence maintenance of blood glucose levels). Reaction that produces a heme precursor, necessary for formation of haemoglobin.Conversion of amino acid tryptophan to niacin.

  • Mention  roles of vitamin B3 in human metabolic processes

Utilized in carbohydrate, fat and protein metabolism.

  • Mention  roles of folate and folic acid in human metabolic processes

Metabolism of amino acids (conversion of histidine to glutamic acid).Synthesis of thymine (a distinctive component of DNA) and therefore in the formation of red blood cells

  • Mention  roles of vitamin C in human metabolic processes

Involved in the formation of collagen (major component of connective tissues). Prevents scurvy/enhances wound healing. Enhances absorption of non-haem iron in foods of plant origin (hence important in anaemia prevention). Is an antioxidant (prevents the harmful action of free radicals).

  • Mention  roles of vitamin D in human metabolic processes

Absorption and metabolism of calcium (hence formation of bones, teeth)

  • Mention  roles of vitamin E in human metabolic processes

An antioxidant, reproduction (enhances fertility), and role in haemoglobin synthesis

  • Mention  roles of vitamin K in human metabolic processes

Blood coagulation (takes part in synthesis of clotting factor ‘prothrombin’)

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