BIOE3100 Exam #2

Where are peptide hormones synthesized and stored?

Made in advance; stored in secretory vesicles

Where are steroid hormones synthesized and stored?

Synthesized on demand from precursors

Where are amine hormones (catecholamines) synthesized and stored?

Made in advance; stored in secretory vesicles

Where are amine hormones (thyroid) synthesized and stored?

Made in advance; precursor stored in secretory vesicles

How are peptide hormones released from parent cells?

Exocytosis

How are steroid hormones released from parent cells?

Simple diffusion

How are amine hormones (catecholamines) released from parent cells?

Exocytosis

How are amine hormones (thyroid) released from parent cells

Transport protein

How are peptide hormones transported in blood?

Dissolved in plasma

How are steroid hormones transported in blood?

Bound to carrier proteins

How are amine hormones (catecholamines) transported in blood?

Dissolved in plasma

How are amine hormones (thyroid) transported in blood?

Bound to carrier proteins

Where is the peptide hormone receptor located?

Cell membrane

Where is the steroid hormone receptor located?

Cytoplasm or nucleus; some have membrane receptors

Where is the amine hormone (catecholamines) receptor located?

Cell membrane

Where is the amine hormone (thyroid) receptor located?

Nucleus

What are hormones?

Chemical messengers that are secreted by specialized epithelial cells into the blood for transport to a distant target, where it exerts its effect at very low concentrations.

Where are all hormones secreted into?

Blood

Synergism

Combined effect is greater than the sum of individual effects

Permissiveness

Need second hormone to get full effect

Antagonism

One substance opposes the action of another

What two components are the central nervous system composed of?

Brain & spinal cord

What two components are the peripheral nervous system composed of?

Somatic & autonomic (Sympathetic & Parasympathetic) nervous systems

What are the parts of a neuron?

Myelin acts as a support and insulation for axon, made by Schwann cells and oligodendrocytes, made up of concentric layers of phospholipid

What type of signal is a graded potential?

Input signal; Depolarizing or hyperpolarizing

Where does a graded potential occur?

Dendrites and cell body

Where does an action potential occur?

Trigger zone through axon

What types of gated ion channels are involved in graded potentials?

Mechanically, chemically, or voltage-gated channels.

What types of gated ion channels are involved in action potentials?

Voltage-gated channels

What type of signal are action potentials?

Depolarizing; Regenerating conduction signal

What is the strength of graded potentials?

Depends on the initial stimulus; it can only be summed

What is the strength of action potentials?

All-or-none phenomenon; cannot be summed

What initiates the graded potential?

Entry of ions through gated channels

What initiates the action potential?

Above-threshold graded potential at the trigger zone opens ion channels

What are the 3 unique characteristics of graded potentials?

• No minimum level is required to initiate

• Two signals coming close together in time will sum

• Initial stimulus strength is indicated by the frequency of a series of action potentials

What are the 2 unique characteristics of action potentials?

• Threshold stimulus required to initiate

• Refractory period: two signals too close together in time cannot sum

What are the 4 characteristics of reflexive (implicit) memory?

1. Recall is automatic and does not require conscious attention

2. Acquired slowly through repetition

3. Includes motor skills and rules and procedures

4. Procedural memories can be demonstrated

What are the 3 characteristics of declarative (explicit) memory?

1. Recall requires conscious attention

2. Depends on higher-level thinking skills such as inference, comparison, and evaluation

3. Memories can be reported verbally

What are the 4 types of sensory receptors?

1. Chemoreceptors

2. Mechanoreceptors

3. Photoreceptors

4. Thermoreceptors

What neurotransmitter/receptor is at the neuron-target synapse for the somatic neuron pathway?

Ach/nicotinic

What neurotransmitter/receptor is at the neuron-target synapse for the autonomic neuron pathway

ACh/muscarinic or NE/alpha- or Beta-adrenergic

What is the target tissue of the somatic motor pathway?

Skeletal muscle

What is the target tissue of the autonomic motor pathway?

Smooth and cardiac muscle; some endocrine glands; some adipose tissue

What are the somatic motor pathway effects on target tissue?

Excitatory only: muscle contracts

What are the autonomic motor pathway effects on target tissue?

Excitatory or inhibitory

How many neurons are in the efferent path of the somatic motor system?

1

How many neurons are in the efferent path of the autonomic motor system?

2

What is the function of the somatic motor pathway?

Posture and movement

What is the function of the autonomic motor pathway?

Visceral function, including movement in internal organs and secretion; control of metabolism

What is the fiber arrangement of skeletal muscles?

Sarcomeres

What is the fiber arrangement of smooth muscles?

No sarcomeres

What is the fiber arrangement of cardiac muscles?

Sarcomeres

Where is the skeletal muscle located?

Attached to bones; a few sphincters close off hollow organs

Where is the smooth muscle located?

Forms walls of hollow organs and tubes; some sphincters

Where is the cardiac muscle located?

Heart muscle

What does the skeletal muscle look like under a microscope?

Striated

What does the smooth muscle look like under a microscope?

Smooth

What does the cardiacmuscle look like under a microscope?

Striated

What is the initiation of contraction for skeletal muscles?

Requires ACh from motor neuron.

• Somatic motor neuron

• Fastest

• Not graded contraction force

What is the initiation of contraction for smooth muscles?

Requires stretch, chemical signals. Can be autorhythmic

• Autonomic neurons

• Slowest

• Graded contraction force

What is the initiation of contraction for cardiac muscles?

Autorhythmic

• Autonomic neurons

• Intermediate

• Graded contraction force

What is the tissue morphology of skeletal muscles?

Multinucleate; large, cylindrical fibers

What is the tissue morphology of smooth muscles?

Uninucleate; small spindle-shaped fibers

What is the tissue morphology of cardiac muscles?

Uninucleate; shorter branching fibers

Label the (A) cornea, (B) optic nerve, (C) retina, (D) vitreous chamber, (E) lens, (F) aqueous humor, (G) sclera and (H) pupil.

In the somatic motor pathway, what is the neurocrine and receptor?

Neurocrine: Acetylcholine & Nicotinic receptor

In the parasympathetic pathway, what is the neurocrine and receptor?

Acetylcholine & Nicotinic receptor → Acetylcholine & Muscarinic receptor

In the sympathetic pathway, what is the neurocrine and receptor?

Acetylcholine & Nicotinic receptor → Norepinephrine & alpha receptor

In the adrenal sympathetic pathway, what is the neurocrine and receptor?

Epinephrine → Beta2 receptor

What is endocrinology?

The study of hormones

What are pheromones?

Specialized ectohormones that act on other organisms of the same species to elicit a physiological or behavior response

What are growth hormones?

A large group of substances that influence cell growth and division.

What are preprohormones?

Contain one or more copies of a peptide hormone, a signal sequence that directs the protein into the lumen of the rough ER, and other peptide sequences.

What is a prohormone?

As the inactive preprohormone mows through the endoplasmic reticulum, the signal sequence is removed, creating smaller, still-inactive molecule called a prohormone

What are the 3 types of hormones?

1. Peptide

2. Steroid

3. Amino-Acid Derived/Amine

Where are steroid hormones derived from?

Cholesterol

What is a trophic hormone?

Controls the release of other hormones

What is the posterior pituitary?

An extension of the brain that secretes neurohormones made in the hypothalamus

What is the anterior pituitary?

Master gland of the body. Neurohormones from the hypothalamus control the release of the anterior pituitary hormones.

What are afferent nerves?

Carry signals from the body to the brain

What are efferent nerves?

Carry signals from the brain to targets throughout the body

What is hypersecretion?

Excess hormone

What is hyposecretion?

Deficient hormone

What are neurohormones?

Specialized neurons release neurohormones into the blood.

What are the three integrating centers for endocrine control systems?

• Hypothalamic stimulation

• Anterior pituitary stimulation

• Endocrine gland stimulation

What is down-regulation?

Decreased number of receptors

What is the sympathetic branch?

Fight or Flight & metabolic homeostasis

What is the parasympathetic branch?

Rest and Digest

Which sense triggers the strongest memories and emotions?

Olfactory

What are the 5 primary taste sensations?

1. Umami

2. Sweet

3. Salty

4. Sour

5. Bitter

The loudness or intensity of a sound is related to its

amplitude

The pitch of a sound wave is related to its

frequency

Which lasts longer: Emotions or moods?

Moods

Describe the spinal cord.

• Gray matter - unmyelinated nerve cell bodies

• White matter - myelinated axons

• Meninges - 3 layered membranes

  • Dura - outer & thickest

  • Arachnoid - middle

  • Pia - inner

What is a convergent pathway?

Many presynaptic neurons provide input to influence a smaller number of postsynaptic neurons

What is a divergent pathway?

One presynaptic neuron branches to affect a larger number of postsynaptic neurons

What are the four properties of a sensory stimulus?

1. Modality

2. Location

3. Intensity

4. Duration

Where are peptide hormones derived from?

Linked amino acids

Where are amino acid derived/amine hormones derived from?

Tryptophan