PT100 Study > Chapter 12: Endocrine System Review and Biology > Flashcards
Chapter 12: Endocrine System Review and Biology Flashcards
dys-
bad, painful, difficult
circum-
around
epi-
above, upon
eso-
inward
eu-
good, normal
exo-
away from, outside, external
hyper-
excessive, above
hypo-
below, beneath
para-
beside, near
poly-
much, many
-al
pertaining to
-centesis
surgical puncture
-dipsia
thirst
-ectomy
excision, surgical removal
-ism
condition
-itis
inflammation
-kinesia
movement
-megaly
enlargement
-penia
deficiency
-phagia
eating, swallowing
-phasia
speech
-phobia
fear
-ptosis
drooping, prolapse
-therapy
treatment
-uria
urine
homeostasis
state of dynamic equilibrium
Hormones
usually work in pairs to maintain a healthy balance, with one acting to raise levels of other substances when needed and the other acting to lower levels when needed.
Endocrine glands
responsible for the sexual maturation of individuals from childhood to adolescence and into adulthood. Endocrine glands also play a role in the body’s ability to metabolize food and store energy.
pituitary gland
a small, round, pea-sized structure attached to the lower surface of the hypothalamus in the brain. It is commonly called the master gland because it controls all the other glands in the body. (Even so, the pituitary is controlled by the hypothalamus.)
The pituitary gland is divided into an anterior lobe and a posterior lobe.
anterior lobe
- Growth hormone (GH)
- Thyroid-stimulating hormone (TSH)
- Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- Prolactin
- Adrenocorticotropic hormone (ACTH)l.
Growth hormone (GH)
promotes the growth of body structures, such as bones.
Thyroid-stimulating hormone (TSH)
affects the growth and functioning of the thyroid gland.
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
referred to as gonadotropins because they act on the gonads—the ovaries in the female, to produce an ovum, and the testes in the male, to produce sperm.
Prolactin
acts on the mammary glands to produce milk
Adrenocorticotropic hormone (ACTH)
acts on the adrenal glands to secrete glucocorticoids, including cortisol.
posterior lobe
secretes the following two hormones
- Oxytocin
- Antidiuretic hormone (ADH)
Oxytocin
acts on the uterus to promote contractions during labor and delivery.
Antidiuretic hormone (ADH)
acts on the kidneys to increase the absorption of water.
pineal gland
sometimes referred to as the pineal body. It is shaped like a pinecone and is in the brain, above and behind the thalamus. The pineal gland produces the hormone melatonin, which influences the body’s natural circadian rhythm, or sleep-wake cycle.
melatonin
influences the body’s natural circadian rhythm
circadian rhythm
sleep-wake cycle
thyroid gland
Produces the hormones triiodothyronine and thyroxine that are responsible for growth throughout childhood and regulation of body metabolism
one of the largest endocrine glands; it is highly vascular and is in the base of the neck. It is shaped similarly to the letter H and has two lobes, one located on each side of the trachea, which are connected by a narrow band. It produces the two thyroid hormones, triiodothyronine (T3) and thyroxine (T4)
triiodothyronine (T3) and thyroxine (T4)
responsible for growth throughout childhood and regulation of body metabolism.
calcitonin
hormone responsible for regulating calcium and phosphorus levels in the blood.
parathyroid glands
four tiny glands that lie on the posterior surface of the thyroid gland, within its connective tissue. They secrete parathormone (PTH)
parathormone (PTH)
also called parathyroid hormone, which also helps regulate calcium and phosphorus levels in the blood.
adrenal glands
two triangular-shaped adrenal glands are located on top of each kidney, within the retroperitoneal cavity (behind the abdomen). They are made up of an outer layer called the adrenal cortex and an inner part called the adrenal medulla. The adrenal glands secrete several hormones:
Epinephrine
Aldosterone
Cortisol
Androgens
Epinephrine
also known as adrenaline, is released during the fight-or-flight response, the physiological reaction to a perceived threat to survival, fright, stress, or even anger. Epinephrine enables the body to respond to stressful situations by converting glycogen into glucose for quick energy, increasing the heart rate, and improving blood flow to major organs, skeletal muscles, and the brain.
Aldosterone
plays a role in regulating and maintaining the body’s water, sodium, and electrolyte balance.
Cortisol
is the body’s natural steroid and works to decrease inflammation.
Androgens
are responsible for secondary sexual characteristics in females and males.
pancreas
a long, somewhat flat organ located in the upper-left quadrant of the abdomen. It plays an active role in the digestive system as well as the endocrine system. The endocrine portion of the pancreas includes the pancreatic islets, clusters of cells also called the islets of Langerhans.
insulin
secreted by the beta cells of the pancreatic islets after food is eaten to metabolize carbohydrates and break them down into glucose. Insulin also stimulates cells to take up glucose from the blood so that it can be delivered to tissue cells for energy. As a result, blood glucose levels decrease.
glucagon
secreted by the alpha cells of the pancreatic islets, acts on the liver to convert glycogen into glucose. (Glycogen is also stored in the muscles.) Glycogen is converted into glucose to meet energy needs, such as during exercise or prolonged periods without meals.
thymus gland
consists of two symmetrical lobes located in the mediastinum (midchest area). It is proportionately larger in infants and children and shrinks as people age. The main function of the thymus gland is to produce T lymphocytes that are necessary for the immune system. It plays an active role in the immune system in childhood but gets smaller and becomes less active as a person ages.
reproductive glands
sometimes called the gonads, are the ovaries and testes
ovaries
produce an ovum during each menstrual cycle and secrete estrogen and progesterone
Estrogen
helps develop secondary sexual characteristics in the female, including breasts and pubic hair. It also plays a vital role in the menstrual cycle and is important in the prevention of osteoporosis in postmenopausal women.
Progesterone
prepares the uterus for pregnancy and helps to support the developing fetus.
testes
egg-shaped glands located in the scrotum of the male reproductive tract.
testosterone
responsible for the development of male secondary sexual characteristics during puberty, such as deepening of the voice, growth of facial and pubic hair, and increased muscle development. It is also necessary in the production of sperm.
negative feedback system
how almost all endocrine glands operate
Within the endocrine system, glands and hormones work together to maintain homeostasis in the body by utilizing a negative feedback system. The system is called negative because it works by opposites to maintain a healthy balance of certain substances in the body. Each gland produces a hormone that serves to oppose another substance. The gland may increase or decrease production of the hormone to stimulate a corresponding decrease or increase of that substance.
