BIOL 256 SI, Molly

2/29/16

EXAM 2 REVIEW

1.)Put all your knowledge together. Collaborate with those around you to create a flow chart and/or diagram of the propagation of a signal due to your finger being stung by a bee. At the LEAST, include in your answer: the type of receptor, the mechanics of an action potential (location in the neuron, values, types of channels, and ions), the mechanics at the synapse, the pathway/tract to the brain, # of efferent neurons, type of effector receptor, and anything else you think needs to be included. This question is meant to be challenging, ask Molly if you have a question!

(You can use the next page, too)

2.)Which brain waves correspond with the following descriptions? (No repeats)

  1. Waves that occur when you are “idling”alpha
  2. Waves that occur in children but are abnormal in adultstheta
  3. Waves that occur in deep sleepdelta
  4. Waves that occur when you are awake and alertbeta

3.)Name and describe the six sensory receptors:

  1. Chemoreceptors – detect chemicals in aqueous solutions - taste
  1. Photoreceptors – detect light - retina
  1. Thermoreceptors – detect temperature change - fingers
  1. Mechanoreceptors – detect physical changes, such as pressure and gravity, by cells membrane deformation – cutaneous receptors
  2. Nociceptors – detect pain – free nerve endings
  1. Proprioceptors – detect body position – muscle spindles

4.)What is the difference between phasic and tonic receptors?

Phasic receptors fire quickly at first and fade as they adapt to the stimulus

Tonic receptors fire all at once at a constant rate until the stimulus is removed

5.)Which of the following cutaneous receptors would detect:

  1. A deep massage on your back __pacinian corpuscle___
  2. A slight breeze blowing your skin _____root hair plexus____
  3. A prick from a finger blood draw _____free nerve endings____
  4. A strong grasp on your wrist ______ruffini endings_____
  5. Running your hand over Velcro ____meissner’s corpuscles_____
  6. Holding your finger on the fountain pop dispenser ____merkel’s disks___

6.)List the five taste sensations and describe how they work. Be specific, but don’t just copy from your notes. Highlight the major differences among them.

Salty – Na+ enters the cell, causing depolarization and the release of Ca++

Sour – H+ prevents K+ from leaving inside of cell, causing depolarization and the release of Ca++

Sweet – G protein gustducin cause cascade that depolarizes cell and releases Ca++

Bitter and Umami – K+ channels close, causing depolarization and the release of Ca++

Also… G protein transducing opens Ca++ channels

7.)Describe how you interpret a scent. (Hint: it may be helpful to draw an arrow diagram)

Odorant enters nose  odorant binds to receptor  G protein produces second messenger cAMP Na+ and Ca++ channels open  depolarization  Action Potential  mitral cells carry signal to olfactory cortex, hypothalamus, amygdala, limbic system, BUT NOT THALAMUS

8.)Describe the utricle and saccule following the prompts:

  1. Where are they located?

Between the semicircular canals and the cochlea

  1. Where do they each extend into?

Saccule extends into the cochlea

Utricle extends into the semicircular canals

  1. What do they contain?

The equilibrium receptors - maculae

  1. What do they detect?

Saccule detects up and down motion

Utricle detects forward and backward motion

9.)Imagine you’re on a roller coaster and you have your eyes closed. The carts are arriving at the terminal, so they halt suddenly and your head gets thrown forward. You know that your head is tipping forward, but your eyes are closed. How does this happen? Describe it in as much detail pertaining to physiology as possible.

The otoliths in the maculae of the utricle brush the kinocilium in the direction of the hairs, which causes depolarization. An action potential is sent to the brain, which tells you that your head is moving forward.

10.)Pitch is to _____frequency______as loudness is to ______amplitude______.

11.)The cochlea is divided into three chambers. What are the chambers, what is the fluid in the chambers, and what is one main event that happens in each chamber?

Scala vestibule – perilymph – carries sound waves into the cochlea

Scala media (cochlear duct) – endolymph – contain Organ of Corti which detects sound

Scala tympani – perilymph – releases pressure through the round window

12.)Place “rod” or “cone” beside each of the following phrases:

  1. Detects colors cone
  2. Vision in dim light rod
  3. Peripheral vision rod
  4. Located in the fovea centraliscone
  5. Detects black and white rod

13.)Which of the following is true?

  1. One rod stimulates one other rod
  2. One rod stimulates multiple other cones
  3. One cone stimulates one other cone
  4. One cone stimulates multiple other cones

Does this result in distinct or blurry vision?

Distinct

14.)Describe the difference among humoral, hormonal, and neural stimulation.

Humoral – secretion from a cell in direct response to blood ion levels

Hormonal – secretion from a cell in response to other circulating hormones

Neural stimulation – sympathetic activation of hormonal release

15.)What does each of the following hormones do? (There’s a lot of them, but now you’ll have them in one place!)

  1. Follicle-stimulating Hormone (FSH)–stimulates gamete production
  1. Leutinizing Hormone (LH) – in females: triggers ovulation and promotes synthesis of estrogen/ in males: stimulates production of testosterone
  1. Prolactin (PRL) – stimulates milk production by the mammary glands
  1. Antidiuretic Hormone (ADH) – prevents dilute urine formation (makes you urinate less)
  1. Oxytocin – stimulates uterine contraction during labor, triggers milk “letdown” after birth
  2. Thyroid Hormone – increases metabolic rate and heat production
  1. Calcitonin–inhibits osteoclasts, stimulates calcium uptake (basically remember calcitonin = calcium in bones)
  2. Parathyroid Hormone (PTH) – increases blood calcium, stimulates osteoclasts (opposite calcitonin)
  3. Aldosterone – increases blood pressure, maintains sodium ion balance
  1. Cortisol – keeps blood sugar constant, maintains blood volume
  1. Glucagon – “fasting hormone”, raises blood glucose levels
  1. Insulin – “fed hormone”, lowers blood glucose levels