anatomy unit 11 endocrine and excretory systems

THE ENDOCRINE SYSTEM

The Second greatest controlling system of the human body.

Function:

Coordinates and directs the activity of the body's cells.

Organs:

Hypothalamus

Pituitary Gland

Pineal Gland

Parathyroid Glands

Thyroid

Adrenal Glands

Pancreas

Ovaries

Testes

Positive Feedback

a process in which an initial change will bring about an additional change in the same direction.

Examples:

Childbirth

Blood clotting

Negative Feedback

when a process influences the operation of the process itself in such a way as to reduce changes

Examples:

Regulating Blood Pressure

Regulating Blood Glucose Levels

Body Temperature Regulation

Hormone Regulation

Hormone

a class of regulatory biochemicals produced in specialized cells then transported by the bloodstream to other parts of the body.

Influences:

Digestion

Metabolism

Growth

Reproduction

Mood control

Target Cells

cells that have receptors for a particular hormone

target organs

organs that respond to a particular hormone

Growth Hormone-

a general metabolic hormone secreted from the pituitary gland. Plays a role in determining final body size.

Growth of skeletal muscles

Growth of long bones

Antidiuretic hormone

"against the flow of urine from the kidney" prevents excessive water loss in the urine, secreted by the pituitary gland. Travels in the blood to the kidneys. (no pee)

Aldosterone

Allows water loses and regulates the sodium ion content in the Extracellular Fluid, secreted by the adrenal glands. (pee)

Melatonin

- involved in rhythmic activities, secreted by the pineal gland.

Regulated by light/dark cycles

Calcitonin

reduces blood calcium levels by returning the calcium to the bones, secreted by the thyroid gland.

Parathyroid hormone

raises the blood calcium level by taking the calcium from the bones, secreted by the parathyroid glands.

Epinephrine and Norepinephrine

Secreted by the Adrenal glands. Together form Adrenaline. Released in response to a threat or stress. Fight or flight response.

Glucagon

raises blood glucose by taking it out of storage (liver), secreted by the pancreas.

Insulin

reduces blood glucose by telling body cells to use it, secreted by the pancreas.

ductless glands

endocrine glands that produce hormones that they release into the blood or lymph

- Endocrine glands have a very rich blood supply.

Pineal Gland

located in the brain behind the thalamus, very small and cone shaped. Somewhat a mystery; only secretes melatonin.

Pituitary Gland

approximately the size of a grape located in the brain. Master gland, controls other endocrine glands.

Thyroid Gland

located at the base of the neck, looks like a butterfly with two lobes.

Parathyroid glands

tiny masses

imbedded in the thyroid gland

at the base of the neck, two

glands in each lobe of the thyroid.

Thymus

located in the upper thorax, posterior to the sternum. Large in infants and children, gets smaller as you grow older. Helps WBCs mature

Adrenal glands

- two bean-shaped glands that curve over the top of the kidneys.

- produce essential hormones that regulate metabolism, immune response, blood pressure, stress, and sexual development

Pancreas

located close to the stomach in the abdominal cavity, is a mixed gland.

Gonads

Ovaries and Testes, overlaps with the reproductive system. Ovaries produce Estrogen and Progesterone. Testes produce Testosterone.

EXCRETORY SYSTEM

Disposes of waste and excess ions

Regulates blood volume and chemical makeup.

Provide temporary storage reservoirs for urine or serve as transportation channels to carry it from one body region to another.

Organs: Kidney, Ureter, Bladder, and Urethra

Kidney

filters blood and extracellular fluid for excess water and ions; about 12cm long and 6cm wide, located abdominal cavity in the back wall.

Renal Capsule

fibrous transparent membrane that encloses the kidney.

Renal Cortex

the outer region, found just under the renal capsule.

Medullary pyramid

triangular regions with a striped appearance. The broader bases faces toward the cortex, the tip points towards the inner region.

Renal columns

the area in between each of the medullary pyramids.

Renal Artery

the arterial supply of each kidney.

Nephrons

millions of tiny structures in each kidney, which are the structural and functional units of the kidneys. Responsible for forming urine.

Glomerulus

a knot of capillaries within the nephron. (start filtering

blood)

Renal tubule

the long tube

that makes up the greater

part of the nephron.

Produces and filters the

urine.

Bowman's Capsule

part of the renal tubule that

performs the first step

of filtration of blood.

Loop of Henle

main function is to create a concentration gradient in the medulla of the kidney.

Collecting Duct

collects urine after filtration and sends it to the ureter.

Ureter

brings urine from the kidneys to the bladder

Bladder

storage tank for urine. Normally holds approximately 500mL.

Urethra

urine exits the bladder into the urethra,which carries urine out of the body.

Electrolyte balance

the solute concentrations in the various fluid compartments, cause excess water and ions to move into the kidneys.

Acid-Base Balance

the optimum level of H+ ions that are present in the blood. We want to keep this balance, not too acidic, not too basic; just right.

Most hydrogen ions originate as by-products of cellular metabolism, which continuously adds substances to the blood.

Alkalosis

Whenever the pH of arterial blood rises above a pH of 7.45.

Acidosis

Whenever the pH of arterial blood falls below a pH of 7.35.

7.35 is not acidic from a chemical standpoint, however a pH of 7.35 represents a higher-than-optimal H+ concentration for the functioning of most body cells.

Bicarbonate buffer system

is a mixture of carbonic acid and bicarbonate ion. Helps maintain the pH of the blood.

characteristics of urine

Usually pale to deep yellow.

The normal yellow color is due to urochrome, a pigment that results from the body's destruction of hemoglobin.

The more solutes there are in the urine, the deeper the yellow its color.

Urine is sterile

Urine is slightly acidic (pH around 6)

Abnormal Urinary things

Glucose- diabetes

protein- kidney issues

WBCs and bacteria- infection

RBCs and Hemoglobin- kidney/bladder stones or infection

bile pigment- liver problems

urochrome

pigment that makes urine yellow

proximal convoluted tubule

reabsorbs most water, glucose, amino acids, and ions (like 80% of water)

Distal Convoluted Tubule

fine-tunes electrolyte/water balance (more "optional" reabsorption) under hormones like aldosterone