Anatomy 2 Lab Practical 1 Exercise 23- Endocrine

To identify the following endocrine glands on a diagram or model

- anterior and posterior pituitary glands - thyroid and parathyroid glands - adrenal gland - pancreas - testes - ovaries

To list the hormones produced by each endocrine gland identified, and discuss the actions of each hormone identified

- anterior and posterior pituitary glands - thyroid and parathyroid glands - adrenal gland - pancreas - testes - ovaries

To differentiate among the histology of the above glands when viewed on a microscope slide

- distinguish btwn the anterior and posterior lobes - distinguish among the thyroid follicles, parafollicular cells - identify the zona glomerulosa, zona fasciculata, zona reticularis, and adrenal medulla - identify pancreatic islets

anterior lobe of pituitary gland

- has basophils and acidophils - basophils synthesize and secrete ATCH or MSH (basophils=blurry) - acidophils synthesize and secrete either prolactin or growth hormone

Hypothalamic Hormones

- hypothalamus secretes stimulating and inhibitory hormones which cause or inhibit the release of hormones from their target areas - gonadotropin- releasing hormone - thyrotropin- releasing hormone - corticotropin- releasing hormone - prolactin- releasing hormone - prolactin- inhibiting hormone - growth hormone- releasing hormone - somatostatin

Virtual Rat Endocrinology

(see handout)

Negative Feedback Loop

A feedback loop that causes a system to change in the opposite direction from which it is moving

infundibulum of pituitary gland

A narrow stalk connecting the hypothalamus to the pituitary gland (endocrine system).

adrenal gland

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

Thyroid Gland histology

Colloid- composed of thyroglobulin Follicular Cells- surround the colloid

adrenal glands hormones

Corticosteroid Hormones- important in water and electrolyte balance (Na+, K+) in the body. Also important for carbohydrate, protein, and fat metabolism, as well as stress management (the different zones secrete different types of discussed later)

Adrenal Gland layers histology

From superficial to deep: -Adrenal Gland - Zona Glomerulosa (dark purple top) - Zona Fasciculata ( lightest purple middle) - Zona reticularis (bright purple/pink bottom middle) - Medulla (light purple/blue very bottom)

thyroid gland

endocrine gland that surrounds the trachea in the neck

ovaries

female gonads

posterior pituitary gland hormones

hormones released from the posterior pituitary are synthesized (made) by the hypothalamus and flow through axons to be stored in the posterior pituitary. 1. Antidiuretic Hormone (ADH)- stimulates the reabsorption and retention of water by the kidneys. It is also known as vasopressin because it causes arterioles to constrict, which elevates blood pressure. 2. Oxytocin- stimulates the contraction of the cells of the mammary glands, resulting in the release of milk, and causes uterine contractions. External influences on hormone actions can be skin in the release of oxytocin.

Ovary Histology

identify structures from above here - follicles will be found in the cortex of the ovary

Adrenal Gland Histology

identify: - adrenal cortex: zona glomerulosa, zona fasciculata, zona reticularis - adrenal medulla

Parathyroid Gland Histology

identify: - chief cells (highlighted in blue) - oxyphil cells (the bottom, more scattered portion)

Pancreas Histology

identify: - islet cells - exocrine acini (acinar cells)

Testis Histology

identify: - seminiferous tubule - interstitial cell (Leydig cell)

Ovary Histology Parts

identify: - vesticular or Graafian follicle -antrum - ovum - primary and primordial follicles - medulla and cortex - distinguish between oocytes and follicles

Thyroid Gland histology (2)

includes: - follicular cells - colloid - parafollicular cells

Parathyroid and Thyroid Gland Histology

-attached to the posterior portion of the thyroid gland -thyroid gland and parathyroid glands -left side is parathyroid - right side is thyroid

Section of Thyroid Gland

-thyroid follicle contains all the parts - Follicular cells surround the colloid - Colloid- composed of thyroglobulin - Parafollicular cells (C cells)- in the spaces between the follicles

anterior pituitary gland hormones

1. Follicle Stimulating Hormone(FSH)- one of the gonadotropins meaning it stimulates ovaries and testes; stimulates the production of sex cells, causes ovarian follicles to mature (develop and produce egg cells), and stimulates testes to produce spermatozoa 2. Luteinizing Hormone (LH)- the other gonadotropins; stimulates ovaries to produce other hormones (progesterone and estrogen), causes the maturation of Graddfian follicles and ovulation, and stimulates testosterone production in testes 3. Thyroid Stimulating Hormone (thyrotropin) (TSH)- stimulates thyroid gland to produce thyroid hormones 4. Adrenocorticotropic Hormone (ACTH)-controls hormone production in the adrenal cortex; regulate levels of the steroid hormone cortisol, which released from the adrenal gland 5. Prolactin (PL)- stimulates mammary glands to begin the production of milk 6. Growth Hormone (GH)- aka somatotropin, promotes growth of most of the cells and tissues of the body Fresh Lettuce Actually Tastes Pretty Good

Testes hormones

1. testosterone- responsible for secondary sex characteristics such as the development of facial and body hair, the expansion of the larynx (deeper voice), and the increased muscle and bone mass seen in males. Also influences the development of penis and scrotum. Testosterone, in conjunction with FSH, aids in the production of spermatozoa. 2. inhibin- ? hormone produced and secreted by the testes and is involved in negative feedback providing regulation for testosterone production

parathyroid gland hormones

Parathyroid Hormone (PTH)- produced by Chief cells and are responsible for increasing calcium levels in the blood. This occurs by increasing calcium uptake in the intestines, increasing kidney reabsorption of calcium, and releasing calcium from bone.

Ovaries hormones

Produce two estrogens (estradiol and estrone) and progesterone - female hormones are responsible for secondary sex characteristics in women such as development of breasts, an additional subcutaneous adipose layer, and a higher voice. Also influence the development of the endometrium, cause maturation of the oocytes, and regulate the menstrual cycle. - inhibit is also secreted by the ovary and regulates the levels of estrogen and progesterone

pancreas

Regulates the level of sugar in the blood

Describe the relationship between the hypothalamus and the pituitary gland; the pituitary gland and the target gland; the target gland and the hypothalamus/pituitary (i.e. describe the nature of the feedback loops that regulate the activity of the hypothalamus, pituitary, and endocrine glands.

The hypothalamus is located in the inferior portion of the forebrain and is connected to the anterior pituitary by the hypophyseal portal system. Primary capillaries in the hypothalamus lead to the secondary capillaries in the anterior pituitary. The hypothalamus has neurons that extend into the posterior pituitary by the hypothalamohypophyseal tract, so the posterior pituitary can actually be considered an extension of the hypothalamus. The hypothalamus secretes both stimulating and inhibitory hormones that either cause the release of hormones from their target areas or prevent the release of hormones from these areas.

testes

The male gonads, which produce sperm and secrete male sex hormones.

posterior pituitary gland

also called neurohypophysis

anterior pitutary gland

also called pars distalis and adenohypophysis

Pancreas Histology (2)

another picture

parathyroid gland

any one of four endocrine glands situated above or within the thyroid gland

Negative Feedback on Thyroid

inhibitory and stimulatory affects on thyroid

anterior and posterior pituitary gland histology

know which lobe is which based on tissue

Pancreas hormones

mixed gland in that it has exocrine and endocrine function; endocrine function is secretion of hormones 1. insulin- pancreatic islets produce; lowers the blood glucose level. Produced in beta cells- stimulates the conversion of glucose to glycogen 2. glucagon- when blood glucose levels drop, glucagon converts glycogen to glucose. produced in alpha cells that occur in pancreatic islets 3. somatostatin- produced in delta cells; secreted after the ingestion of a meal and inhibits the secretion of insulin and glucagon from the pancreas

anterior and posterior lobes of pituitary gland

pars nervosa = posterior pituitary = neurohypophysis pars distalis = anterior pituitary = adenohypophysis

thyroid gland hormones

secretes three specific hormones 1. Triiodothyronine (T3)- includes 3 iodine atoms 2. Thyroxine (T4)- includes 4 iodine atoms these hormones increase basal metabolic rates, are stored in the colloid. 3. Calcitonin- decreases blood calcium levels by causing excretion of calcium by the kidneys and deposition of calcium in bone by decreasing osteoclast activity and formation. Produced by the parafollicular or C cells. calcitonin is antagonistic to parathyroid hormone.