2 - APP - Unit 3.2 - The Endocrine System Flashcards
Gland
Any tissue or organ that produces a secretion
2 types:
- Endocrine gland
- Exocrine gland
Gland - Endocrine
Organized group of tissues which uses materials from the blood or lymph to make new compounds called hormones
AKA ductless glands or glands of internal secretion (secretion are released directly in bloodstream as blood circulate through the gland)
Secretion are transported to all body areas where they have special influence on cells, tissues & organs
Gland - Exocrine
Secretion from the gland must go through a duct (tube) that carries the secretion to a body surface of organ
Expl:
- sudoriferous glands - sweat
- sebaceous glands - oil
- salivary glands
- lacrimal glands - tears
- liver
- pancreas - performs as an exocrine gland (produces pancreatic juices going through a duct into small intestines) & endocrine gland (secretes hormone insulin directly into bloodstream)
Endocrine system
Secrete hormones or chemical messengers which coordinate and direct the activities of target cells and target organs
Majors glands
- Pituitary
- Thyroid
- Parathyroid
- Adrenals
- Gonads
- Pancreas
Each gland has specific function
Any disturbance cause changes in the appearance or functioning of the body
Hormonal control - Secretion of hormones
Operates on a negative feedback system or under the control of the nervous system
Hormonal control - Secretion of hormones - Negative feedback
Occurs when there is a drop in the level of a hormone, that triggers a chain reaction of responses to increase amount of hormone in the blood
Hormonal control - Secretion of hormones - Nervous system
Controls the glands which are stimulated by nervous stimuli, as in the adrenal medulla where the gland is stimulated by the sympathetic nervous system
Expl: when frightened, adrenal medulla secretes adrenalin
Glands of body - Pituitary Gland
A tiny structure located at the base of the brain.
Known as “master gland” because of its major influence on the body’s activities.
Pituitary gland is connected to the hypothalamus by a stalk called infundibulum.
Divided into :
- Anterior pituitary
- Posterior lobe
Glands of body - Pituitary Gland - Hypothalamus
Considered as part of the nervous system
Neurons in hypothalamus produce 2 hormones, stored and secreted by posterior pituitary lobe:
- Vasopressin - converts to antidiuretic hormone (ADH) (makes you not go pee)
- Oxytocin - causes strong contractions of uterus
Glands of body - Pituitary Gland - Infundibulum
Stalk connecting Pituitary Gland and Hypothalamus
Glands of body - Pituitary Gland & Hypothalamus process
[Anterior pituitary lobe]
The hormones in the anterior pituitary are controlled by the releasing chemicals or factors produced by the hypothalamus in the brain. As pituitary are needed by the body, hypothalamus releases specific releasing factor for each hormone.
[Posterior pituitary lobe]
Consists primarily of nerve fibers & neuroglial cells that support the nerve fibers.
Hypothalamus produces Vasopressin & Oxytocin that are stored in posterior lobe and are released into the bloodstream in response to nerve impulses from the hypothalamus
Glands of body - Hormones of the pituitary gland
- Growth hormone (GH) - somatotropin
Promotes growth and development. Help fat to be used for energy, saves glucose & helps maintain blood sugar levels - Prolactin hormone (PRL)
Develops breast tissue and stimulates production of milk after childbirth (function in males unknown) - Thyroid-stimulating hormone (TSH)
Stimulates growth and secretion of thyroid gland - Adrenocorticotropic hormone (ACTH)
Stimulates growth and secretion of adrenal cortex - Follicle-stimulating hormone (FSH)
Stimulates growth of Graafian follicle and production of estrogen in females.
Stimulates production of sperm in male - Luteinizing hormone (LH)
Stimulates ovulation & formation of corpus luteum (which produces progesterone in females) - Interstitial cell-stimulating hormone (ICSH)
Necessary for production of testosterone by interstitial cells of testes in men
Glands of body - Pituitary Gland - Vasopressin
Produced by neurons in hypothalamus
Converts to antiduiretic hormone (ADH) in the bloodstream.
Maintains water balance by increasing absorption of water in kidneys.
Diuretic drugs inhibit ADH action, resulting in increase in urinary output & decrease in blood volume, so a decreasing blood pressure
Glands of body - Pituitary Gland - Oxytocin
Released during childbirth or breastfeeding - Causes strong contractions of uterus
Pitocin: synthetic form of oxytocin helps labor
Glands of body - Pituitary disorders - Hyper functioning
Often due to pituitary tumor
Hyper secretion of pituitary growth hormone.
2 conditions:
- Gigantism
- Acromegaly
Glands of body - Pituitary disorders - Hyper functioning - Gigantism
Too much growth hormone during preadolescence (child)
Overgrowth of the long bones leading to excessive body growth
“Child becomes a giant”
Most common treatment: drug therapy (inhibits GH) & radiation treatments
Glands of body - Pituitary disorders - Hyper functioning - cromegaly
Too much growth hormone during adulthood
Adults whose long bones have already matured: growth hormone attacks cartilaginous regions & bony joints.
Overdevelopment/abnormal enlargement of the bones of:
- the face - chin protrudes, lips, nose enlarge
- the hands & feet
Lethargy & severe headaches.
Most common treatment: drug therapy (inhibits GH) & radiation treatments
Glands of body - Pituitary disorders - Hypo functioning - Pituitary dwarfism
Hypo functioning during childhood.
Growth of the long bones is abnormally decreased by an inadequate production of growth hormone.
- Small size, but body normally proportioned & normal intelligence
- Physique remains juvenile & sexually immature
Treatment: early diagnosis & injection of human growth hormone. Treatment for 5 years or more.
Glands of body - Pituitary disorders - Diabetes insipidus
Drop of ADH
Causes excessive loss of water and electrolytes.
Symptom: polydypsia (excessive thirst) and polyuria (production of abnormally large volumes of dilute urine)
Diabetes
= To pass thru
3 P’s of diabetes
- Polyuria - Excessive urination
- Polydypsia - Excessive thirst
- Polyphagia - Excessive hunger
Glands of body - Thyroid & Parathyroid glands - 3 hormones
[Thyroxine (T4)]
Controls rate of metabolism, heat production & energy creation with the cells. Can speed up or slow down activities of the body.
[Triiodothyronine (T3)]
Same effect as T4
5 to 10 times more active than T4, but activity less prolonged
[Calcitonin]
Lowers calcium levels in blood and body fluids by decreasing rate of osteoclastic activity (bone resorption) and by increasing osteoblastic activity (calcium absorption by bones - builders).
Proper calcitonin secretion prevents hypercalcemia (harmful rise in blood calcium level)
Thyroid hormones contain iodine coming form diet.
Glands of body - Thyroid & Parathyroid glands - Thyroid-stimulating hormone (TSH)
Controls the production and secretion of the thyroid hormones from the thyroid gland
Glands of body - Thyroid & Parathyroid glands - Parathormone
Produced and secreted by the parathyroid glands.
Controls concentration of calcium on bloodstream
Increases calcium level in blood by increasing number and size of specialized cells based on osteoclasts responsible for breaking down bone, liberating calcium back to the bloodstream.
Glands of body - Thyroid & Parathyroid Disorders - Hyperthyroidism
Due to over activity of the thyroid gland
Too much thyroxin secreted (hyper secretion), leading to enlargement of the gland.
Most pronounced symptoms:
- Enlargement of thyroid gland (= goiter)
- Bulging of the eyeballs (=exophthalmos)
- Dilatation of the pupils
- Wide-opened eyelids
Other symptoms:
- Consuming large quantity of food but loss of body fat and weight
- feeling too hot
- fast growing rougher fingernails
- weakened muscles
- Increased blood pressure & heartbeat
- Hand tremors
- Perspiration
- Irritability
- Increased blood sugar levels and mild case of glycosuria due to liver releasing excess glucose into bloodstream
Glands of body - Thyroid & Parathyroid Disorders - Goiter
Enlargement of thyroid gland
Glands of body - Thyroid & Parathyroid Disorders - Exophthalmos
Bulging of the eyeballs
Glands of body - Thyroid & Parathyroid Disorders - Hypothyroidism
Thyroid gland does not secrete sufficient thyroxin (hypo secretion).
Symptoms:
- Low T3 & T4 levels or increased TSH blood levels
- Dry/itchy skin, dry & brittle hair
- Constipation
- Muscle cramps at night
Potential cause of adult hypothyroidism: Iodine deficiency
Major cause: Autoimmune disorder (Hashimoto’sThyroidis) that attacks the body’s thyroid gland causing an inflammation of the thyroid destroying the ability of the gland to make thyroxine.
Glands of body - Thyroid & Parathyroid Disorders - Hypothyroidism - 2 types of disorders
[Myxedema] - Adults
Swollen face, weight increase and initiative& memory failure
Treatment: daily administration of thyroid hormone replacement medication
[Cretinism] - Early infancy or childhood
Lack of mental and physical growth, resulting in mental retardation & malformation (dwarfism or cretinism).
Sexual development & physical growth of cretins do not proceeds beyond that of 7- or 8-year-old children
Glands of body - Thyroid & Parathyroid Disorders - Parathyroid glands
Regulate use of calcium and phosphorus, both involved in many blood systems
Glands of body - Thyroid & Parathyroid Disorders - Parathyroid glands - Hyper functioning
Too much parathormone
May cause increase of blood calcium, and so tendency for the calcium to crystallize in the kidney as kidney stones.
Excess amount of calcium & phosphorus withdrawn from bones, leading to eventual deformity.
So much calcium removed = bones honeycombed with cavities become so fragile walking can cause fractures
Glands of body - Thyroid & Parathyroid Disorders - Parathyroid glands - Hypo functioning
Not enough parathormone
Severly diminished calcium levels affect the normal function of the muscles and nerves.
Leads to tetany.
Glands of body - Thyroid & Parathyroid Disorders - Tetany
Presents with convulsive twitching of the muscles which may eventually lead to the death of the afflicted person due to spasms in the respiratory muscles.
Glands of body - Adrenal glands (x2)
1 gland on top of each kidney.
Each gland has 2 parts:
- cortex (outer covering)
- medulla (inner portion)
Glands of body - Adrenal glands - Hormone of the Adrenal Glands - 3 hormones secreted by adrenal cortex
- Mineralcorticoids
- Glucocorticoids
- Sex hormones
Glands of body - Adrenal glands - Hormone of the Adrenal Glands - Adrenal cortex - Mineralcorticoids
Expl: Aldosterone
Affect kidneys by speeding up sodium resorption into the bloodstream as well as increasing the potassium excretion from the blood stream.
Sodium resorption speeds up water resorption by kidneys because sodium is very hydrophilic.
Slight increase of blood pressure
Glands of body - Adrenal glands - Hormone of the Adrenal Glands - Adrenal cortex - Glucocorticoids
Expl: Cortisone & cortisol
Increase amount of glucose in blood by converting complex carbohydrates, proteins & fats into glucose within liver.
Decrease edema during inflammatory reactions & reduce pain.
Glands of body - Adrenal glands - Hormone of the Adrenal Glands - Adrenal cortex - Sex hormones
Androgenes = masculine sex hormones found in men and women
Together with hormones from gonads, bring masculine characteristics.
Some estrogens also produced by adrenal cortex
Glands of body - Adrenal glands - Hormone of the Adrenal Glands - Adrenal medulla - 2 hormones
- Epinephrine - AKA adrenaline
- Norepinephrine - AKA norepinephrine
= “fight of flight” hormones.
Powerful cardiac, respiratory & full body stimulants
Prepare body for emergency & energy expending situations.
Glands of body - Adrenal glands - Adrenal disorders - Cushing’s syndrome
Hyper secretion of the glucocorticoid hormones from adrenal cortex.
Cause: adrenal cortical tumor or prolonged use of prednisone
Symptoms:
- hirsutism (excessive hair growth)
- hyperglycemia (high blood sugar)
- high blood pressure,
- muscular weakness,
- obesity,
- poor healing of skin lesions,
- tendency to bruise easily,
- menstrual disorders in women,
Most noticeable characteristics (due to redistribution of body fat)
- rounded ‘moon’ face
- “buffalo hump”
Glands of body - Adrenal glands - Adrenal disorders - Addison’s disease
Hypo secretion of adrenal cortex
Symptoms:
- Excessive pigmentation prompting the characteristic “bronzing” skin
- Decreased blood glucose levels
- Hypoglycemia (decreased level of blood glucose)
- Hypotension = Low blood pressure (especially when standing)
- pronounced muscular weakness & fatigue
- diarrhea
- weight loss
- vomiting
- severe drop of sodium in blood and tissue fluids causing severe electrolytes imbalance
Glands of body - Gonads
= sex glands
Include:
- ovaries (female) - produce ova (=egg) and hormones estrogen and progesterone
- testes (male) - produce sperm hormone testosterone
Glands of body - Gonads - Hormones of the gonads - Estrogen
Produced by ovaries
Responsible for development of the reproductive organs & female secondary sex characteristics (as pubic and axillary hair)
Glands of body - Gonads - Hormones of the gonads - Progesterone
Produced by ovaries
Works with estrogen to build up lining of uterus for fertilized egg
Helps maintain pregnancy once implantation takes place
Glands of body - Gonads - Hormones of the gonads - Testosterone
Produced by testes
Responsible for development of the reproductive organs and male secondary sex characteristics (as beard growth & other body hair, voice deepening, musculature increase & sperm production)
Glands of body - Gonads - Gonad disorders
Disturbance in ovaries: cysts & tumors, abnormal menstruation & menopausal changes
Disturbance in testes: variety of disorder from changes in testosterone production to abnormal sperm production
Glands of body - Pancreas
Located behind the stomach
Functions as :
- exocrine gland - secretes pancreatic juices containing enzymes excreted through a duct into small intestine to aid digestion.
Combined with other digestive juives in small intestine
- endrocrine gland - involved in production of insulin and glucagon, hormones helping blood glucose levels regulation
Glands of body - Pancreas - Hormones of the pancreas (x2)
Pancreas secretes 2 hormones
- Insuline
- Glucagon
Glands of body - Pancreas - Hormones of the pancreas - Insuline
Produced by beta cells
Promotes absorption into body cells of:
- glucose - increasing it absorption helps to bring down blood glucose levels
- amino acids
- lipids
Glands of body - Pancreas - Hormones of the pancreas - Glucagon
Produced by alpha cells
Increases glucose levels in bloodstreams, by stimulating conversion of liver glycogen to glucose
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes
Caused by decreased secretion of insulin by pancreas or ineffective use of insulin.
2 main types: Type 1 & Type 2
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes - Type 1
Formerly “Juvenile diabetes”, “insulin dependent diabetes” or “diabetes melitus”
Exhibited in children & young adults
Cause: autoimmune reaction, involving genetic and viral factors destroying beta cells of the pancreas (the one producing insulin)
Symptoms - 3 P's of diabetes - Polyuria - Excessive urination - Polydypsia - Excessive thirst - Polyphagia - Excessive hunger \+ weight loss, blurred vision & possible diabetic coma
Patient with Type 1 diabetes take synthetic insulin & monitor daily blood glucose levels
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes - Insulin deficiency
Cause glucose to accumulate in bloodstream, rather than go to cells and convert into energy
Excess become too much for kidneys to reabsorb so is excreted by urine
Excretion of excess glucose REQUIRES accompanying excretion of large amounts of water
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes - Ketone bodies
Product of abnormal rate of fat oxydation happening when fat used as fuel source
Highly toxic
Most common type: acetoacetic acid.
Ketone acids accumulate in blood, promoting acidosis development, giving “sweet” acetone odor to breath and urine.
Severe acidosis my result in diabetic coma & kidney damage.
Therapy: daily insulin injections & controlled diet.
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes - Hypoglycemia/hyperglycemia
Insulin-dependant diabetes requires education in signs of:
- hypoglycemia - low blood sugar / insulin shock
- hyperglycemia - high blood sugar / diabetic coma
Glands of body - Pancreas - Hormones of the pancreas - Pancreas disorders - Diabetes - Type 2
Formerly “Adult Onset” or “Insulin Independent Diabetes”
90-95% of diabetics
Most common in:
- adults over 45
- overweight people
- individuals with immediate family member with diabetes
- certain ethnic or cultural group people
