Wk13 REMEMBER

Question 0

Normal body temp 37 degrees

.4/.5 degree difference during the day

Answer 0

Dynamic equilibrium - actively seeking equilibrium. Body must put energy into this

Stress - out of homeostasis eg. Poor health, accidents)

Autonomic - without our conscious input

Question 1

Homeostasis: numerous activities geared to maintain the specific conditions needed for cell survival

Answer 1

Negative feedback in the control of body temp _ temp goes up a message is sent to say no no no come down

Question 2

Positive feedback - keeps going and going til fixed

Answer 2

Homeostasis controls the internal environment which is
The blood
The intercellular fluid
The intracellular fluid (cytosol)

Internal enviro has many homeostatic functions. Wastes etc

Question 3

Endocrine system: endo = internal

Coordinates and directs the activity of the body’s cells (along with the nervous system)

Main processes controlled by hormones: reproduction, growth and development, mobilisation of body defences against stress

Answer 3

Hormones are: secreted into bloodstream, transported to distant target tissue, affect function of target tissue cells

How are they transported: mainly by binding to plasma proteins

How is hormone secretion regulated: by negative feedback mechanisms

Question 4

Organs of Endocrine System:

• pineal gland
• hypothalamus
• pituitary gland
• thyroid gland
• parathyroid glands
• thymus gland
• adrenal gland
• pancreas
• ovary/testis

Answer 4

Pituitary gland - 9 essential hormones produced here (1 cell produces 1 hormone)

Hypothalamus -
Temp control, ions in blood, produce hormones that pass on to pituitary gland

Question 5

LEARN!!
Hormones of the hypothalamus
* Growth hormone-releasing hormone (GHRH): Target tissue-anterior pituitary cells that secrete growth hormone, response-increased growth hormone secretion

• growth hormone-inhibiting hormone (GHIH or somatostatin) target tissue-anterior pituitary cells that secrete growth hormone, response-decreased growth hormone secretion
• thyrotropin-releasing hormone (TRH) target tissue-anterior pituitary cells that’s secrete thyroid-stimulating hormone (thyrotropin), response-increased thyroid-stimulating hormone secretion
• corticotropin-releasing hormone (CRH) target tissue-anterior pituitary cells that secrete adrenal corticotropin hormone (corticotropin), response-increased adrenocorticotropic hormone secretion
• gonadotropin-releasing hormone (GnRH) target tissue-anterior pituitary cells that secrete luteinising hormone & follicle stimulating hormone, response-increased secretion of luteinising hormone & follicle stimulating hormone
  cont. …

Answer 5

• prolactin-inhibiting hormone (PIH) target tissue- anterior pituitary cells that secret prolactin, response-decreased prolactin secretion
• prolactin-releasing hormone (PRH) target tissue-anterior pituitary cells that secrete prolactin, response-increased prolactin secretion

Question 6

Effects of growth hormone (GH) NEED TO KNOW!!!

• hypothalamus secretes growth hormone-releasing hormone (GHRH) and somatostatin (GHIH)
• down through the anterior pituitary to the ‘initial stimulus’ Growth hormone which has these direct effects….

Answer 6

Left side……

• increases/stimulates the ‘physiological response’ of the [liver and other tissues]
• down to which increases/stimulates the ‘physiological response’ of [insulin-like growth factors: IGFs]
• [insulin-like growth factors] then either go
  
  1. reduces/inhibits back up to (feedback mechanism) which (inhibits GHRH release, stimulates GHIH release) OR
  2. increases/stimulates down to (indirect growth-promoting actions) which increases/stimulates [skeletal effects] and/or [extraskeletal effects].
     - [skeletal effects] increases/stimulates and the result being [increased cartilage formation and skeletal growth] which ends in GROWTH
     - [extraskeletal effects] increases/stimulates and the result being [increased protein synthesis, and cell growth and proliferation] which ends in PROTEIN METABOLISM

Question 7

The endocrine pancreas

• important not just because its endocrine function but its also a exocrine gland that’s essential for digestive processes.
• consists of patches of tissue called Islet of Langerhans which produce insulin and glucagon so important for level of glucose we maintain in our blood
• secretions go into the surrounding blood vessels and difectly into liver
• found behind the stomach, below the liver and diaphragm

Answer 7

Islet of Langerhans:
2 types of cells
à = glucagon producing cells
B = insulin producing cells

Question 8

CONT….Effects of growth hormone (GH) NEED TO KNOW!!!

• hypothalamus secretes growth hormone-releasing hormone (GHRH) and somatostatin (GHIH)
• down through the anterior pituitary to the ‘initial stimulus’ Growth hormone which has these direct effects….

Answer 8

Right side…

• increases/stimulates the ‘physiological response’ of [anti-insulin actions] which then in turn…
• increases/stimulates the ‘physiological response’ of [fat] and/or [carbohydrate metabolism]
  - [fat] increases/stimulates the result of [increased lipolysus] resulting in CARBOHYDRATE & FAT METABOLISM
  - [carbohydrate metabolism] increases/stimulates the result of [increased blood sugar and other anti-insulin effect] resulting in CARBOHYDRATE & FAT METABOLISM

Question 9

Effects of growth hormone (GH)
Hyposecretion of growth hormone =
- hypopituitary dwarfism: can also be caused by insensitivity of cell receptors to GH (in normal levels)

Answer 9

Hypersection of growth hormone =

1. in children and adolescents whose epiphyseal (or growth plates) have not yet closed, the effect of increased GH levels on long bone growth is termed GIANTISM.
2. ACROMEGALY occurs in adults who are exposed to continuously excessive levels of GH