Metabolic and Endocrine Anatomy Flashcards
key functions
- metabolic system governs the chemical and physical changes that take place within the body enabling it to grow and function
- metabolism involves breakdown of the body;s complex organic compounds in order to generate energy for all bodily processes
- it also generates energy for the synthesis of complex substances that form tissues and organs
- organic compounds are broken down by a process called catabolism, while anabolism is the process that combines simple molecules for tissue growth
- the overall speed at which an organism carries out its metabolic processes is termed its metabolic rate
Endocrine system overview
- consists of endocrine glands that secrete hormones that travel through the blood stream to signal specific target cells throughout the body
- hormones bind selectively to receptor sites on the surface of the receptor cells
- endocrine and nervous system both function to achieve and maintain stability of the internal environment
- the endocrine and nervous systems work together to regulate metabolism, response to stress, sexual reproduction, blood pressure, and water and salt balances
endocrine system key functions
- secreting cells send hormones through the bloodstream to signal specific target cells
- hormones diffuse into the blood and travel long distances to virtually every area of the body
- endocrine effectors consist of virtually all tissues
- regulatory effects are slow and tend to last for long periods
nervous system key functions
- neurons secrete neurotransmitters to signal nearby cells that have appropriate receptor site
- neurotransmitters are sent very short distances across a synapse
- nervous effectors are limited to muscle and glandular tissue
- regulatory effects appear rapidly and are often short lived
glands of the endocrine system
- hypothalamus
- pituitary gland
- thyroid gland
- parathyroid glands
- adrenal glands
- pancreas
- ovaries
- testes
hypothalamus
- part of the diencephalon located below the thalamus and cerebral hemisphere
- connects to the pituitary gland through the infundibular or pituitary stall
- it is responsible for regulation of the autonomic nervous system (body temperature, appetite, sweating, thirst, sexual behavior, rage, fear, blood pressure, sleep) and other endocrine glands through its impact on the pituitary gland
pituitary gland
- is normally the size of a pea and is located at the base of the brain just beneath the hypothalamus
- consists of two separate glands, the adenohypophysis (anterior) and the neurohypophysis (posterior)
- considered the most important part of the endocrine system since it releases hormones that regulate several other endocrine glands
- is influenced by factors such as seasonal changes or emotional stress
- secretes endorphins that act on the nervous system and reduce a persons sensitivity to pain
- also controls ovulation and works as a catalyst for the testes and ovaries to create sex hormones
thyroid gland
- located on the anterior and lateral surfaces of the trachea immediately, below the larynx and is shaped like a butterfly
- produces thyroxine and triiodothyronine that act to control the rate at which cells burn the fuel from food
- an increase in thyroid hormones will increase the rate of the chemical reactions within the body
parathyroid glands
- four parathyroid glands found on the posterior surface of the thyroids lateral lobes
- produce parathyroid hormone, which functions as an antagonist to calcitonin and is important for the maintenance of normal blood levels of calcium and phosphate
- increases the reabsorption of calcium and phosphate from bones to the blood
- secretion of the parathyroid hormone is stimulated by hypocalcemia and inhibited by hypercalcemia
- normal clotting, neuromuscular excitability, and cell membrane permeability are dependent on normal calcium levels
adrenal glands
- the two adrenal glands are located on top of each kidney; the outer portion called the adrenal cortex, and the inner portion is called the adrenal medulla
- the adrenal cortex and the adrenal medulla secrete different hormones
- the adrenal cortex produces corticosteroid that will regulate water and sodium balance, the body’s response to stress, the immune system, sexual development, and function and metabolism
- the adrenal medulla produces epinephrine that increases heart rate and blood pressure when there is an increase in stress
pancreas
- located in the upper left quadrant of the abdominal cavity, extending from the duodenum to the spleen
- includes both endocrine and exocrine tissues
- the islets of langerhans are the hormone-producing cells of the pancreas
- alpha cells produce glucagon and beta cells produce insulin
- these hormones work in combination to ensure a consistent level of glucose within the blood stream and properly maintain stores of energy within the body
ovaries
- provide estrogen and progesterone that contribute to regulation of the menstrual cycle and pregnancy
- estrogen is secreted by the ovarian follicles and is responsible for the development and maintenance of female sex characteristics such as breast development and the cycle of the female reproductive system
- progesterone is produced by the corpus luteum and functions to maintain the lining of the uterus at a level necessary for pregnancy
testes
- secrete androgens that regulate body changes associated with sexual development and support the production of sperm
steroid hormones (prostaglandins)
- do not circulate in the blood and instead exert their effects only where they are produced
- prostaglandins are capable of producing a wide variety of effects; some effects as it pertains to rehabilitation are related to inflammation, pain mechanisms, vasodilation, vasoconstriction, nutrient metabolism, and blood clotting
amine hormones (catecholamines)
- synthesized from chromaffin cells within the adrenal medulla
- sympathetic nervous system stimulation releases the catecholamines into the blood stream
- epinephrine has one of the largest effects on the sympathetic nervous system and creates the fight or flight response
- the target areas for epinephrine are receptor sites in the cardiovascular and metabolic systems
- other functions include increasing cardiac contraction, constriction of blood vessels, activation of glycogen breakdown, blocking of insulin secretion, increasing metabolic rate, and dilation of the airways within the lungs
peptide hormones (insulin)
- released when there is an elevation in the level of blood glucose
- the insulin produces and increase in cellular uptake of glucose for metabolism
- insulin also stimulates the skeletal muscle and liver to store the glucose and increases amino acid transport across hepatic, muscle, and adipose tissues
- insulin release affects all systems of the body with its primary goal of reducing blood glucose
hypothalamus hormones
- growth hormone releasing hormone
- growth hormone inhibiting hormone
- gonadotropin, releasing hormone
- thyrotropin-releasing hormone
- corticotropin-releasing hormone
- prolactin-releasing hormone
- prolactin-inhibitory factor: dopamine
growth hormone releasing hormone
target: pituitary gland
function: increases the release of growth hormone
regulation of secretion: central nervous system feedback, circulation levels of hormones
growth hormone-inhibiting hormone
target- pituitary gland
function: decreases the release of growth hormone
regulation of secretion: central nervous system feedback, circulation levels of hormones
gonadotropin-releasing hormone
target: pituitary gland
function: increases the release of luteinizing hormone and follicle-stimulating hormone
regulation of secretion: central nervous system feedback, circulation levels of hormones
thyrotropin-releasing hormone
target: pituitary gland
function: increases the release of thyroid stimulating hormone
regulation of secretion: central nervous system feedback, circulation levels of hormones
corticotropin-releasing hormone
target: pituitary gland
function: increases the release of adrenocorticotropic hormone
regulation of secretion: central nervous system feedback, circulation levels of hormones
prolactin-releasing hormone
target: pituitary gland
function: stimulates the release of prolactin
regulation of secretion: central nervous system feedback, circulation levels of hormones
prolactin-inhibitory factor; dopamine
target: pituitary
function: decreases the release of prolactin
regulation of secretion: central nervous system feedback, circulation levels of hormones
pituitary hormones
- growth hormones
- follicle-stimulating hormone
- luteinizing hormone
- thyroid-stimulating hormone
- adrenocorticotropic hormone
- prolactin
- oxytocin
- antidiuretic hormone
growth hormone
target: bone and muscle
function: promotes growth and development; increases the rate of protein synthesis
regulation of secretion: hypothalamus
follicle-stimulating hormone
target: ovaries and testes
function: promotes follicular development and the creation of estrogen in females; promotes spermatogenesis in males
regulation of secretion: hypothalamus
luteinizing hormone
target: ovaries and testes
function: promotes ovulation along with estrogen/progesterone synthesis from the corpus luteum in females; promotes testosterone synthesis in males
regulation of secretion: hypothalamus
thyroid-stimulating hormone
target: thyroid gland
function: increases the synthesis of thyroid hormones T3 and T4
regulation of secretion: hypothalamus
adrenocorticotropic hormone
target: adrenal cortex
function: increases cortisol synthesis (adrenal steroid)
regulation of secretion: hypothalamus
prolactin
target: mammary glands
function: allows for the process of lactation
regulation of secretion: hypothalamus
oxytocin
target: uterus and mammary glands
function: increases contraction of uterine muscles; promotes release of milk from mammary glands
regulation of secretion: nerve impulses from the hypothalamus; stretching of cervix, nipple stimulation
antidiuretic hormone
target: kidneys
function: increases water reabsorption; conserves water; increases blood pressure through stimulating contraction of muscles in small arteries
regulation of secretion: decreased water content
adrenal cortex hormones
- androgen
- aldosterone
- cortisol
androgen
target: ovaries and testes
function: increases masculinization: promotes growth of pubic hair in males and females
regulation of secretion: influenced by the hypothalamic production and release of GnRH and luteinizing hormone
aldosterone
target: kidneys
function: increases reabsorption of sodium ions by the kidneys to the blood; increases excretion of potassium ions by the kidney into the uterine
cortisol
target: gastrointestinal system
function: influences metabolism of food molecules; anti-inflammatory effect in large amounts
regulation: adrenocorticotropic hormone
adrenal medulla hormones
- epinephrine
- norepinephrine
epinephrine
target: cv and metabolic systems
function: increases heart rate and force of contraction; increases energy production; vasodilation in skeletal muscle
regulation of secretion: sympathetic impulses from the hypothalamus in stress situations
norepinephrine
target: cv and metabolic systems
function: vasoconstriction in skin, viscera, and skeletal muscles
regulation of secretion: sympathetic impulses from the hypothalamus in stress situations
ovaries hormones
- estrogen, progesterone
estrogen, progesterone
target: uterus and mammary glands
function: involved in regulation of the female reproductive system and female sexual characteristics
regulation of secretion: cyclical rise and fall of hormone levels
pancreas hormones
- glucagon
- insulin
glucagon
target: liver
function: increase blood glucose by stimulating the conversion of glycogen to glucose
regulation of secretion: hypoglycemia
insulin
target: all body systems
function: decreases blood glucose and increases the storage of fat, protein and carbohydrates
regulation: hyperglycemia
parathyroid hormone
parathromone
parathormone
target: bone, kidney, intestinal mucosa
function: increases blood calcium
regulation: hypocalcemia
testes hormone
testosterone
testosterone
target: pituitary gland
function: involved in the process of spermatogenesis
regulation: influenced by pituitary release of LH
thyroid glands
- thyroxine (T4), triiodothyronine (T3)
- calcitonin
thyroxine, triiodothyronine
target: all tissues
function: involved with normal development; increases cellular level metabolism
regulation: thyroid-stimulating hormone
calcitonin
target: plasma
function: increases calcium storage in bone; decreases blood calcium levels
regulation: hypercalcemia
