(BIO 201) Lab Exam 1

Name the type of gland.

Endocrine gland — hormones are secreted from cells (yellow) directly into bloodstream

Name the type of gland.

Exocrine gland — duct/tubule releases hormone onto skin surface

Identify the structures.

Green — transport protein

Yellow — free hormone

Blue — bound hormone

Which process is this diagram showcasing?

Briefly explain what occurs during this process.

Down-regulation

• process by which target cells decrease number of receptors in response to prolonged exposure to a high level of hormone in blood

Which process is this diagram showcasing?

Briefly explain what occurs during this process.

Up-regulation

• process by which target cells produce a greater number of receptors in response to a temporary increase in hormone level in blood

Type of cell signaling?

Endocrine cell signaling

Type of cell signaling?

Paracine cell signaling

Type of cell signaling?

Autocrine cell signaling

Is this feedback loop negative or positive?

Negative

Name lobes A & B

A — anterior lobe

B — posterior lobe

(i) What system is displayed in this image? Function?

(ii) Identify structures A, B, and C

Hypothalamo-hypophyseal portal system

• BVs connecting hypothalamus to ant.pit.

Thesee images are showcasing individuals with which condition?

Acromegaly (overprudction of a hormone)

In this image, the poeple on the left side have which condition?

Pituitary dwwarfism

Growth Hormone — Name its 4 target tissues.

• liver

• adipose tissue

• muscle tissue

• bone & cartilage

ADH — Name its 2 target tissues.

1) kidneys

2) brain

Oxytocin — Name its 2 target tissues.

1. Mammary gland

2. Uterus

Thyroid Gland

• Location

• Anatomical structure

• Histology / Cellular structure

Location

Anatomical Structure

• R & L lobes connect at midline by isthmus

Histology/cellular structure

• Highly vascularized

• Composed of thyroid follicles (function units of gland)

• Each follicle has 2 main parts:

  • Follicular cells

    • single layer of cuboidal epithelial cells forming follicle's border

    • secretes thyroglobulin (precursor to thyroid hormone)

  • Colloid

    • Iodine‑rich, gel‑like material in follicle lumen

    • stores thyroglobulin

• Parafollicular cells

  • small clusters in b/w follicles

  • secretes calcitonin

Describe the chemical structure of thyroid hormones (T3 and T4).

How do T3/T4 differ from other monamine hormones?

T3: amino acid core bound to 3 iodine atoms

T4: amino acid core bound to 4 iodine atoms

T3/T4 are more hydrophobic than other monoamine hormones.

T or F: Both T3 and T4 are physiologically active.

True.

Parathyroid Glands

• Location

• Anatomical structure

• Histology / Cellular structure

Location

• 3-5 separate glands on posterior surface of thyroid (sits on either side of pharynx/throat)

Anatomical Structure

Histology/cellular structure

• Chief cells (AKA principal or parathyroid cells) → secrete PTH

• Oxyphil cells → eoisionophilic cells; visibly larger & less numerous than chief cells, have lots of dots

Adrenal Glands

• Location

• Anatomical structure

• Histology / Cellular structure

Location

• Sits directly on superior aspect of each kidney

Anatomical Structure

• Roughly pyramid-shaped

Histology/cellular structure

Medulla

• Medulla

  • Chromaffin cells

    • secrete Epinephrine & Norepinephrine

• Cortex

  • Zona glomerulos

    • secrete mineralcorticoid (aldosterone) 

  • Zona fasciculata

    • secrete glucocorticoid (cortisol) 

  • Zona reticularis

    • secrete androgen (DHEA) 

Which part of adrenals has typical endocrine function?

Cortex

What part of adrenals are neuroendocrine tissue?

Medulla — secretes catecholamines

Describe the anatomy/histology of thyroid gland.

Location

Anatomical Structure

Histology/cellular structure

Describe the anatomy/histology of thyroid gland.

Location

Anatomical Structure

Histology/cellular structure

Describe 3 major functions of thyroid gland.

(1) Thermoregulation + Regulation of metabolic rate

• sets basal metabolic rate (amount of E required by body at rest)

• increases rate of catabolic reactions (breaking down macromolecules)

• increasing rate of anabolic reactions (building up macromolecules)

• generates heat

(2) Promotion of growth & development

• bone & muscle growth

• NS development

(3) Synergism w/ SNS

• increases (up-regulates) production of receptors for sympathetic neurotransmitters

• consequently helps in regulation of BP & HR