BIOB33 Final Exam: Urinary, Digestive, Endocrine, Reproductive Systems

How is the hypothalamus involved in the endocrine system?

Links NS to ES

Produces ADH and oxytocin

Neurohypophysis

Posterior lobe of pituitary gland, has axons/terminals of hypothalamic neurons

Releases hormones produced by hypothalamus

Pituitary Gland

Pea-sized, base of brain

Controls many other glands, regulates growth, metabolism, reproduction

4 Groups of Hormones

Steroids, Amino acid-derived, Peptide/protein, and Eicosanoids

Steroid Hormones

Lipid-soluble derived from cholesterol

ex) cortisol, estrogen, testosterone

Amino Acid-Derived Hormones

Small molecules

ex) epinephrine, thyroxine

Peptide/Protein Hormones

Made of chains of amino acids, ranging from short (peptide) to long (protein)

ex) insulin, growth hormone, oxytocin

Eicosanoid Hormones

Group of lipids derived from fatty acids

ex) prostaglandins

Thyroid Glands

Butterfly-shaped, front of neck

Uses iodine to make thyroxine (T4) and triiodothyronine (T3)

Produces calcitonin

Thyroxine (T4)

Helps regulates metabolism, growth/development

Converted in body’s tissues to T3

Triiodothyronine (T3)

Helps regulate metabolism, body temp, heart rate, growth

Calcitonin

Reduces blood calcium levels by inhibiting bone breakdown and increasing calcium excretion through kidneys

Hypophyseal Portal System

Network of blood vessels, connects hypothalamus to anterior pituitary gland, allows for direct and rapid transport of hormones

Parathyroid Glands

4 tiny glands near/behind thyroid

Produce parathyroid hormone: increases blood calcium levels

Adrenal Cortex (superficial to deep)

Zona Glom. = Aldosterone (maintains body’s salt/water balance, blood pressure)

Zona Fasc. = Cortisol (metabolism, stress, anti-inflammatory)

Zona Reti. = DHEA (androgen/male sex hormone—early devo/puberty onset)

Adrenal Medulla

Epinephrine (triggers fight/flight— ^ heart rate/blood pressure/flow to muscles

Norepinephrine (works w/ epi, hormone + neurotransmitter)

Pancreas

Has endocrine (hormonal) and exocrine (digestive) functions

Islets of Langerhans

alpha cells = glucagon

beta cells = insulin

f cells = pancreatic polypeptide

delta cells = somatostatin

Pineal Gland

Part of epithalamus

Pinealocytes = melatonin

Kidneys

Respond to low blood pressure by releasing renin into blood

Produce calcitriol (active form of vitamin D)

EPO: bone marrow, boost RBCs

Testes

Produce testosterone

Secondary male sex characteristics, sperm production

Ovaries

Produce eggs (oocytes)

Secrete estrogen, progesterone, and testosterone

3 Types of Salivary Glands

1. Parotid

2. Sublingual

3. Submandibular

Mesenteries of Stomach

Greater Omentum

• Extends from the greater curvature of the stomach and drapes across the surface of the small intestine

Lesser Omentum

• Hepatogastric ligament

• Hepatoduodenal ligament

Gastric Pits

Small indentations in the stomach lining that lead to gastric glands, where digestive juices are produced

Regions of Small Intestine

(from stomach to colon):

Duodenum, jejunum, and ileum

Large Intestine

Thinner walls than SI, no villi in mucosa, lost of mucus cells, lymphoid nodules

Liver

4 lobes (bound by round and coronary ligaments)

Hepatocytes make bile, stored in gallbladder, secreted into duodenum to emulsify fats

• hepatocytes adjust circulating metabolites in blood

Sinusoid

Special capillaries that connecting blood vessels at periphery of lobules with central vein

Portal Triads

Groups of vessels at periphery of lobules containing blood vessels & interlobular bile duct

Follicle Stimulating Hormone

Stimulates follicle growth and egg development in ovaries/sperm in testes

Helps regulate menstrual cycle

Luteinizing Hormone

Menstrual Cycle—triggers ovulation (releases egg from ovary)

Tells testes to produce testosterone

Epididymis

Back of testicle, stores/matures sperm

Connects testicle to vas deferens

Seminal Glands

Sac-like organs that produce seminal fluid, a major component of semen

• help sperm with motility and viability

Prostate

Small gland below bladder, surrounds urethra

Produces a fluid that nourishes and carries sperm

Bulbourethral Glands

Produce pre-ejaculate

• lubricate urethra

• neutralize acidic urine

Oogenesis

Development of an immature egg cell (oogonium) into a mature ovum through cell division/maturation.

The process produces one viable egg and smaller polar bodies vs spermatogenesis which produces four viable sperm

Ovarian Cycle

Follicular phase, ovulation, luteal phase

Follicular Phase

Starts Day 1: FSH stimulate follicles in the ovary to grow (produce estrogen)

Ovulation

Around Day 14: Surge in LH triggers ovulation. A mature follicle ruptures and releases a secondary oocyte (the egg) into the fallopian tube

Luteal Phase

The ruptured follicle transforms into the corpus luteum. This structure produces hormones (progesterone) that help prepare the uterine lining for a potential fertilized egg

Mammary Glands

Apocrine cells secrete milk

Urinary System

Kidneys (nephrons), renal pelvis, ureters, bladder and urethra

Glomerulus

Bundle of capillaries

Waste products filtered from blood

Renal Corpuscle

Filtering unit, made up of glomerulus and Bowman’s capsule

Podocytes

Found in glomerulus

Have ‘foot processes’ that interlock, creating filtration slits

Urine Transport

Renal pelvis —> ureters —> bladder

Urinary Reflexes

Storage reflex: the process that prevents urination until it's appropriate, by keeping the bladder muscle relaxed and the urethral sphincters contracted

Voiding reflex: spinal reflex that involuntarily triggers urination when the bladder is full

Micturation Reflex

Neural circuit that coordinates the storage and expulsion of urine from the bladder