Unit 8- Endocrine system- animal biology

the ____ _____ consists of glands and tissues that secrete hormones

endocrine system

chemicals that affect other glands or tissues

hormones

hormones that are growth factors promote -

cell division and mitosis

have no ducts

secrete hormones into interstitial fluid

hormones diffuse into the bloodstream

some hormones are local hormones-not carried by blood

endocrine glands

secrete their products through ducts

exocrine glands

homeostasis requires cooperation between the ____ and ____ systems

endocrine and nervous systems

endocrine or nervous system?

secretes hormones into the blood

slower response

more prolonged response

Endocrine system

endocrine or nervous system?

transmits nerve impulses

faster response

less prolonged response

Nervous system

what prompts an endocrine gland to secrete its hormones

the blood concentration of a substance

what are the two things that the production of most hormones is controlled by

negative feedback and action of antagonistic hormones

Sensitive to either the condition it regulates or the blood level of the hormone it is producing. The effect of the response returns the body condition to normal, which provides _____ ______ to stop the stimulation of the sensor.

negative feedback

action of antagonistic hormones

insulin and glucagon

what is this an example of?

as the blood glucose level rises, the pancreas secretes insulin

negative feedback

what is this an example of?

insulin causes the liver to store glucose, and glucose is removed from the blood

negative feedback

what is this an example of?

the stimulus for insulin production is thereby inhibited

negative feedback

what is this an example of?

the pancreas stops secreting insulin

negative feedback

what is this an example of?

the effect of insulin is offset by the secretion of glucagon

an antagonistic hormone

what is this an example of?

insulin lowers the blood sugar level, while glucagon raises it

an antagonistic hormone

_____ are chemicals that can have a range of effects on target cells

hormones

what are the two chemical classes hormones fall into

peptide and steroid hormones

what are peptide hormones

peptides, proteins, glycoproteins, or modified amino acids

what are steroid hormones

same complex of four rings, but varying side chains

what are chemical signals

a means of communication between cells, body parts, or even individuals

a peptide hormone initiates a chemical signaling process after binding to its receptor; it serves as the _____ _____

first messenger

the activated receptor leads to the production of a ____ _____

second messenger

a _____ hormone can diffuse through the target cell membrane

steroid

this hormone can bind to its receptor either in the cytoplasm or the nucleus

Steroid hormone

______ are chemical signals that act between individuals of the same species

Pheromones

what are the two ways the hypothalamus can regulate the internal environment

through the autonomic nervous system and through control of the pituitary gland's secretions.

what do neurons in the hypothalamus called neurosecretory cells produce

antidiuretic hormone (ADH) and oxytocin

released from the posterior pituitary in response to increased concentration of blood (not enough water). causes increased reabsorption of water in the kidneys.

ADH- antidiuretic hormone

what is diabetes insipidus (DI)

the posterior pituitary gland does not produce enough ADH or kidneys unable to respond to ADH, leading to excessive thirst and urination.

causes uterine contractions and milk letdown during lactation. release controlled by positive feedback: the stimulus brings about an effect that increases intensity

oxytocin- posterior pituitary

what system consists of two capillary networks connected by a vein and lies between the hypothalamus and the anterior pituitary

the portal system

the hypothalamus controls the anterior pituitary by producing:

hypothalamic-releasing hormones and hypothalamic-inhibiting hormones

hypothalamic-releasing hormones

stimulates the anterior pituitary gland to release certain hormones

hypothalamic-inhibiting hormones

prevents the anterior pituitary gland from releasing certain hormones.

thyroid-stimulating hormone (TSH)

stimulates the thyroid gland to produce thyroid hormones

adrenocorticotropic hormone (ACTH)

stimulates the adrenal cortex to produce cortisol

follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

stimulate the gonads to produce gametes and sex hormones

what four pituitary hormones have target effects on other glands

thyroid-stimulating hormone (TSH)

adrenocorticotropic hormone (ACTH)

follicle-stimulating hormone (FSH)

luteinizing hormone (LH)

what three anterior pituitary hormones do not affect other glands

prolactin (PRL)

melanocyte-stimulating hormone (MSH)

growth hormone (GH)

prolactin (PRL)

stimulates the mammary glands to synthesize milk

melanocyte-stimulating hormone (MSH)

stimulates the pigment-producing melanocytes of the skin

growth hormone (GH)

stimulates bone and muscle growth and increases protein synthesis and fat metabolism

what is pituitary dwarfism

a disorder in the pituitary gland where too little growth hormone is secreted by the anterior pituitary

what is giantism

a disorder in the pituitary gland where excess growth hormone is produced during childbirth, and the individual grows very big and tall

what is acromegaly

a disorder in the pituitary gland where excess growth hormone in adulthood. long bones cannot grow, so only the hands, feet, and facial bones become large

what gland is large and located in the neck

the thyroid gland

what glands are embedded in the posterior surface of the thyroid gland

the parathyroid gland

the thyroid gland has many follicles, each a small spherical structure of thyroid cells that produce:

thyroxine (T4) and triiodothyronine (T3).

what is calcitonin

produced by the thyroid gland in response to increased blood calcium levels

causes an increase in blood calcium and a decrease in blood phosphate. increases osteoclast activity and release of calcium from bones. promotes the reabsorption of calcium by the kidneys. when blood calcium levels increase this hormone secretion is shut off.

parathyroid hormone (PTH)

hypothyroidism

thyroid gland does not produce enough thyroid hormones. failure of thyroid function in infancy or childhood results in congenital hypothyroidism. individuals are short and stocky and may be mentally impaired

Hashimoto thyroiditis

a form of hypothyroidism that occurs in adults. the immune system produces antibodies that destroy the thyroid gland

myxedema

is a group of clinical symptoms in adults not treated for hypothyroidism

goiter- a disorder of the thyroid

lack of dietary iodine makes the thyroid unable to produce sufficient T3 and T4. the thyroid gland is then constantly stimulated by TSH. the result is an enlarged thyroid gland

hyperthyroidism- a disorder of the thyroid

results from over secretion of thyroid hormones

what are the two parts of the adrenal gland that function independently

adrenal medulla and adrenal cortex

adrenal medulla

(inner portion) under the control of the nervous system

adrenal cortex

(outer portion) under the control of adrenocorticotropic hormone (ACTH), an anterior pituitary hormone

the hypothalamus initiates nerve impulses by way of the brain stem, spinal cord, and sympathetic nerves to the ____ _____

adrenal medulla

what are the two hormones that the adrenal medulla secretes

epinephrine and norepinephrine

hormones of the _____ _____ result in long-term response to stress

adrenal cortex

what are the two types of hormones in the adrenal cortex

glucocorticoids and mineralocorticoids

what are glucocorticoids

regulate carbohydrate, protein, and fat metabolism, leading to an increase in blood glucose level

what are mineralocorticoids

regulate salt and water balance, leading to increases in blood volume and blood pressure

_____ is the principle glucocorticoid hormone stimulated by ACTH

cortisol

_____ is the principal mineralocorticoid hormone that targets the kidneys

aldosterone

atrial natriuretic hormone (ANH)

produced and released by cardiac cells when atria of the heart are stretched. inhibits the release of aldosterone from adrenal cortex

Cushing’s syndrome- disorder of the pituitary gland

excess production of ACTH (usually caused by a tumor). adrenal cortex then produces excess cortisol

Addison’s disease- disorder of the adrenal gland

the most common cause of destruction of the adrenal cortex by the immune system. decreased production of mineralocorticoids can affect Na+ and K+ levels, which can adversely affect the heart.

the pancreas is composed of two types of tissue

the exocrine portion secretes digestive enzymes into the small intestine by ducts. pancreatic islets are the endocrine portion of the gland

what are the three types of endocrine islet cells

alpha cells, beta cells, and delta cells

what do alpha cells produce

glucagon

what do beta cells produce

insulin

what do delta cells produce

somatostatin

released after eating, when blood glucose level is high. stimulates uptake of glucose by cells

insulin

release before eating when glucose is low. targets liver and adipose tissue: glycogen breakdown and glucose synthesis. increase blood glucose

glucagon

also known as growth hormone inhibiting hormone. also produced by cells in the stomach and small intestine

somatostatin

diabetes mellitus

affect ability to regulate glucose metabolism

what is type 1 diabetes

insulin shortage

what is type 2 diabetes

body not responding to insulin

the ___ are the testes in males and the ovaries in females

gonads

what are gonads

endocrine glands. secretions of gonads controlled by hypothalamus and pituitary gland

what do testes produce

sperm and androgens (testosterone)

what is testosterone

responsible for male secondary sex characteristics

stimulates in oil production by oil glands

contributes to increased muscle development

what ovaries produce

eggs, estrogen, and progesterone

what is estrogen

stimulates growth of uterus and vagina

required for egg maturation

responsible for female secondary sex characteristics

what is progesterone

regulation of uterine cycle along with estrogen

what is the thymus gland

located beneath the sternum

largest and most active during childbirth

secretes thymosins, hormones involved with maturation of T lymphocytes

what is the pineal gland

located in the brain

produces melatonin, primarily at night

what is the protein hormone leptin

produced by adipose tissue

stimulates the satiety center in the hypothalamus to signal that individual has had enough to eat

it is though that leptin in obese individuals may be ineffective

what is granulocyte-macrophage colony-stimulating factor

produced by many different tissues

causes bone marrow stem cells to various types of white blood cells

what is platelet-derived growth factor

released by platelets; wound healing

what is epidermal growth factor and nerve growth factor

wound healing

what is prostaglandins

produced from arachidonate, a fatty acid

act locally; effects depend on location