PSYC 4316 Brain and Behavior: Unit 7 Flashcards

What are the differences between NT’s and hormones?

NT’s mediate rapid signaling over short distances, while hormones communicate over longer distances and longer time scales (they can control things in the body that need long-term communication such as blood osmolarity, blood sugar, metabolic rate, behaviors, sexual activity, and reproductive cycles)

What are the 4 different type of secretion of hormones and their functions?

Autocrine secretions affect the secreting cell itself; paracrine secretion affect neighboring cells; endocrine secretions are released into the bloodstream and act at distant targets; exocrine secretions are released onto the surface of the body, including the surface of the gut and other internalized structures

What are the 2 main types of glands?

Endocrine glands are organs that secrete hormones directly into the circulatory system and modulate body processes (“ductless” glands); exocrine glands secrete fluids through a duct onto the epithelial surface of the body (sweat glands and gallbladder)

What are pheromones?

Exocrine secretions produced by one animal to communicate with another and can initiate a range of physiological responses; can have uses such as attracting mates or repelling predators

What is the role of behaviors for the HY?

The HY receives input concerning the environment and the "“internal status” of the body (body temperature, fluid balance, blood pressure, and body weight) from other brain regions and from visceral afferent nerves; It integrates these incoming signals and then coordinates the stimulation of various physiological responses that help to maintain body homeostasis; The HY is responsible for the 4 F’s: Fighting, Feeding, Fleeing, and Mating

How do other cells in the HY affect the posterior pituitary?

The posterior pituitary releases 2 neurohormones: Antidiuretic hormone (ADH, vasopressin); Synthesized in supraoptic nuclei (SON) and paraventricular nuclei (PVN) in HY and transported down axons to PP where they are released into capillaries

What is the HY’s control of the anterior pituitary?

Axons of some HY cells terminate in the median eminence at the floor of the HY; These secrete 7 neurohormones that control the secretion of hormones by the AP known as the hypothalamic releasing hormones (RHs, liberins) or releasing-inhibiting hormones (RIHs, statins); capillaries within the median eminence carry blood directly to glandular secretory tissue of the AP; Once in general circulation, they are diluted and enzymatically degraded within minutes

What is the correct sequence of hormones within the HPA axis during a stress response?

Hypothalamus releases CRH, stimulating anterior pituitary to release ACTH, stimulating adrenal cortex to release cortisol.

What 3 categories of hormones are synthesized from cholesterol?

Reproductive hormones, mineralocorticoids (regulate kidney function), and glucocorticoids

What are the effects of cortisol?

CORT increases glucose metabolism, blood pressure and stimulates behavioral arousal; negative feedback on both the HY and Pit; long-term effects include hypertension, diabetes, infertility, and inhibition of growth.

What are 3 symptoms of stress that occur due to an increased sympathetic drive?

Directly increases heart rate; Increases vasoconstriction; Increases release of Epi and NE from adrenal medulla

What are the effects of the adrenal medulla?

Produces catecholamines (Epi and NE); triggers stress response or fight-or-flight response (sympathetic nervous system activation); Increased Epi and NE can cause bronchodilation, mediate smooth muscle contractions, and cause vasodilation in the muscle beds; ACTH can increase the production of Epi in addition to CORT

What are the steps for the regulation of secretion?

ACh from preganglionic fibers stimulates the release of catecholamines by increasing calcium; catecholamine release increases blood flow, whereas NE from postganglionic sympathetic nerves will decrease; adenosine reduces Ca2+ influx, thereby reducing release (inhibitory system); Catecholamines are taken up by cells that release them and stored in vesicles or are metabolized by MAO and COMT

What is the relationship between the neuroendocrine system and PTSD?

Increasing NE will increase flashbacks and panic attacks, people with PTSD have lower levels of circulating CORT, and HPA axis has become sensitized