Bio2 Slides Exam 2

What is homeostasis?

Steady state of physiological conditions in the body

SEQ GENERAL FEEDBACK REGULATION

STIMULUS (TRIGGER) —> RECEPTOR (DETECTS CHANGE) —> CONTROL CENTER (PROCESSES INFO) —→ EFFECTOR (CARRIES OUT RESPONSE)

What is the difference between positive & negative feedback mechanisms?

Negative feedback

• Response to stimulus reduces stimulus (more common) 

Positive feedback

• Response to stimulus amplifies stimulus (less common)

Are living organisms open or closed systems?

Open systems that must exchange with their environment

For living organisms to exchange Nutrients, gases, & waste products, they must:

1. Must dissolve in aqueous solution before moving across the plasma membrane

What are Adapatations for exchange in internal exchange surfaces (increases surface area)

• Branching (Alveoli in lungs)

• Folding

• Internal fluids 

What are hormones, where are they released, and how do they function?

1. They are chemical signaling molecule messengers that allow for regulation in the body (basically allow cells to communicate w/ eachother)

2. they are secreted into the blood

3. they bind to target cells via the target cell’s specific receptors

What are receptors in cell communication? Are they used once and then replaced?

• They are Large proteins or glycoproteins on/in target cells that recognize and bind to specific hormones.

• They are Continually synthesized and degraded

In endocrine signaling, what is the type of secreting cell and the route taken to the target?

1. Endocrine cells secrete hormones into extracellular fluid 

2. Hormones diffuse into the bloodstream & reach target cells

In paracrine & autocrine signaling, what is the type of secreting cell and the route taken to the target?

1. Cells produce & secrete local regulators

2. Act over short distances → diffusion (so acts on targets quickly)

In synaptic signaling, what is the type of secreting cell and the route taken to the target?

1. Neurons produce neurotransmitters (chemicals)

2. neurotransmitters Diffuse across a short distance of the synapse

In neuroendocrine signaling, what is the type of secreting cell and the route taken to the target?

1. Neurosecretory cells secrete neurohormones

2. they diffuse from nerve cell endings into the bloodstream

What are the 4 major chemical classes of hormones and what are they made of?

1. Amine: single amino acid

2. Peptide : short chain of amino acids

3. Protein: long chain of amino acid

4. steroid: lipid with 4 fused c rings

What types of hormones are typically soluble in aqueous environments?

• amine/ peptide/ protein hormones

What type of hormrones are Soluble in lipid-rich environments?

steroid hormones

The cellular response to pathways is based on:

solubility of the hormone

Explain these components of the water soluble pathway for hormones:

• Hormone (does it enter cell?):

• Receptor (where is located?):

• G protein (Where is located, how does it change?):

• Adenlyl cyclase (what is it, where is it?):

• cAMP (where is it?)

• Protein kinases (where, and what does it allow for?)

SEQ PATHWAY FOR WATER SOLUBLE HORMONES

SEQ PATHWAY FOR LIPID SOLUBLE HORMONES

What are the main differences between water soluble hormones and lipid soluble hormones? (where effect happens & how fast)

• Water soluble hormones

  • Cause effects in the cytoplasm of target cells

  • Act faster

• Lipid soluble hormones

  • Affect gene expression of target cells (get into nucleus and causes change to DNA)

  • Act slower, but longer lasting

What are the main differences between the Endocrine System and the Exocrine System? (mechanism of secretion, pathway, function)

What is the difference between tropic & non-tropic hormones?

1. Tropic: act on another endocrine gland to stimulate the release of other hormones

2. Non-tropic: act directly on target tissue 

In vertebrate endocrine control, what is the hypothalamus (HYP), where is it located, what is it associated with, and what is its function?

The hypothalamus (HYP) has two modes of action. SEQ the one that ends with the anterior pituitary

1. HYP Releases hormones (RH) and inhibiting hormones (IH)

2. into pituitary portal vessels

3. Direct path to anterior pituitary (AP)

• Stimulate or inhibit release of specific hormones from AP

The hypothalamus (HYP) has two modes of action. SEQ the one that ends with the posterior pituitary

• produces Antidiurectic Hormone (ADH) and oxytocin (OT)

  • Produced in cell bodies

• Axons extend into posterior pituitary

• Stored in vesicles until needed

• Then released by the posterior pituitary

What are the 2 hormones released by the posterior pituitary and their target tissues?

What is the anterior pituiartary always influenced by?

The hypothalamus’s RELEASING HORMONES (RH) & sometimes INHIBITING HORMONES (IH)

THE HORMONE TRH (Thyrotropin RH) from the HYPOTHALAMUS (HYP) SHEET:

• AFFECTS WHAT ANTERIOR PITUIARY HORMONE?

• AFFECTS WHAT TARGET?

• OVERALL EFFECT

• 
  

THE HORMONE GH RH/IH (Growth Hormone RH/IH) from the HYPOTHALAMUS (HYP) SHEET:

• AFFECTS WHAT ANTERIOR PITUIARY HORMONE?

• AFFECTS WHAT TARGET?

• OVERALL EFFECT

THE HORMONE CRH from the HYPOTHALAMUS (HYP) SHEET:

• AFFECTS WHAT ANTERIOR PITUIARY HORMONE?

• AFFECTS WHAT TARGET?

• OVERALL EFFECT

THE HORMONE GnRH from the HYPOTHALAMUS (HYP) SHEET:

• AFFECTS WHAT ANTERIOR PITUIARY HORMONE?

• AFFECTS WHAT TARGET?

• OVERALL EFFECT

What is thyroid and what type of hormones does it produce?

SEQ THRYOID HORMONE (TH) SECRETION

NOTE THE MAIN DIFFERENCES BETWEEN HYPO AND HYPERTHRYOIDISM

What happens if you have hyposecretion of the growth hormone in childhood?

How do you treat hyposecretion of the growth hormone in before puberty?

What happens if you have hypersecretion of the growth hormone in childhood?

Gigantism, normal proportions

What happens if you have hypersecretion of the growth hormone in childhood?

Where are the adrenal glands located, what 2 parts is it made of, and what is its function?

Adrenal cortex- Chronic stress

adrenal medulla -acute tress

SEQ HOW THE ADRENAL CORTEX MANAGES CHRONIC STRESS

1. During chronic stress

   1. HYP secretes CRH

      1. Ant pit releases ACTH

         1. Adrenal cortex produces corticosteroids 

SEQ HOW THE ADRENAL MEDULLA MANAGES ACUTE STRESS

wHAT ARE THE 2 MAIN TYPES OF Corticosteroids (rmbr that these are released by the Adrenal cortex, which manages chronic stress)

1. Glucocorticoids —> regulate glucose metabolism  During stress → Energy for body cells 

1. Mineralocorticoids → Regulate mineral metabolism —> Aldosterone —> Regulates H20 sodium balance in the blood (when stressed, dehydrated)

Where are the parathyroid glands and what is their funftion?

What do the parathyroid glands do if your blood calcium levels are too low? (Include indirect effects as well)

SEQ GLUCOSE HOMEOSTASIS BY THE PANCREAS (PLS MENTION 2 MAIN MOLECULES PRODUCED)

What is asexual reproduction? Is there meiosis? Is there fusion of gametes?

1. Single parent produces 2 or more offspring; clones are 100% genetically identical

2. No meiosis

3. No fusion of gametes

What are the 4 methods of asexual reproduction?

1. Budding: Small part of parent’s body 

2. Fission: Parent separates into 2- equal individuals 

3. Fragmentation & regeneration

   1. Parent breaks into pieces —> Each produces missing parts

4. Parthenogenesis

Unfertilized egg (n) —> Undergoes mitosis —> Adult animal produced (n)

What are the advantages of asexual reproductiojn?

1. No mate needed

2. Rapid 

3. 100% of genes passed on

What are the two main parts of sexual reprdouction?

1. Production of gametes (meiosis)

   1. Sperm

      1. From male parent

      2. Small, flagellated & motile

   2. Egg (ovum)

      1. Female parent

      2. Large & nonmotile 

      3. Nutrients from embryo 

2. Fertilization

   1. Gametes fuse

   2. Fertliized egg = zygote (2n)

What is the major disadvatnage of sexual repro?

Only 50% of genes passed on

What are the advantage of sexual reproduction for animals?

1. Promotes genetic recombination 

2. Offspring better able to survive 

3. Easier for population to get rid of harmful alleles

What is ploidy? CC haploid vs diploid

SEQ mitosis

SEQ meiosis

What are the two functions of the male reproductive system?

• Spermatogenesis     = process of sperm production

• Deliver sperm to female reproductive tract

SEQ SPERM PATHWAY

What do the testes in the male reproductive system consist of?

1. Semineferous tubules

   1. Long & hollow tubes made up of Sertoli cells

   2. Spermatogenesis happens in here

2. Leydig cells

   1. Scattered between tubules

   2. Testosterone & other sex hormones produced here 

What is the epididymis in male reproductive system and its functions?

1. It is a coiled tube Coiled tube

2. Functions

   1. Masturation: hanges the physical structure of the sperm so they gain the ability to swim forward.

   2. Storage 

   3. Transport (-3 weeks

 Both the testes & epididmyis in the male reproductive system are located where?

In the scrotum

4 key features of the scrotum

• Suspended 

• 1-2 degrees < body temp

• Sperm production

• Longetivity

What do the vas deferens in the male reproductive system consist of, and what is there function?

• Sperm ducts (2)

• Brings sperm from scrotum to pelvic cavity 

What is a vasectomy, and what happens if you don’t get it?

1. Vasectomy (the cutting and tying off of the vas deferens)

2. If no vasectomy: the sperm can travel and empties into an ejaculatory duct

What is the ejucatlotry duct in the male reproductive system?

What is the urethra in the male reproductive system, where is it located, and what it is function

1. tube that goes Through penis

2. Urine & semen

What is the function if the penis in the male reproductive system and what does it consist of?

1. Copulatory organ 

   1. Sperm delivery 

2. Glans

   1. Most of sensory nerves

3. Foreskin

   1. Loose-fitting skin

   2. Circumcision 

What are the 3 accessory glands in the male reproductive system and their functions (fluid + location of secretion)

1. Seminal vesicles (2)

   1. Fluid made of Fructose (E) & Prostaglandins (uterine contractions that secrete into vas deferins

2. Prostate gland

   1. Fluid with citrate *nutrient) that secretes into urethra 

3. Bulbourethral glands (2)

   1. Fluid with mucus (neutralizes acidic urine) that secretes into urethra 

What is semen?

 Mixture off sperm & fluids from glands 

SEQ spermatogenesis/ sperm production

What are the components of a mture sperm cell?

What are androgens?

Male sex hormones such as testorene

SEQ HORMONAL CONTROL OF SPERM PRODUCTION