Homeostasis, motivated behavior, and stress

Question 1

Homeostasis

Answer 1

the active process of maintaining a relatively stable, balanced internal environment.

Question 2

Motivation

Answer 2

psychological process that induces or sustains a particular behavior.

Question 3

Critical structures for motivated behavior

Answer 3

-Hypothalamus and associated pituitary gland
- Limbic system
- frontal lobe

Question 4

Regulatory behavior

Answer 4

-Behavior motivated to meet the survival needs of the animal
-Controlled by homeostatic mechanisms, which involve the hypothalamus

ex. eating, temperature and salt regulation, waste elimination

Question 5

Homeostatic Mechanism

Answer 5

Process that maintains critical body functions within a narrow, fixed range

Question 6

Nonregulatory behavior

Answer 6

-Behavior unnecessary to meet the basic survival needs of the animal
-Not controlled by homeostatic mechanisms
-Most involve the frontal lobes more than the hypothalamus
Strongly influenced by external stimuli

ex. sex, aggression

Question 7

Regulatory Function of the Hypothalamic Circuit

Answer 7

-Hypothalamus maintains homeostasis by acting on both the endocrine system and the autonomic nervous system.
-Influences behaviors selected by the limbic system

Question 8

What motivated behaviors is the hypothalmus responsible for

Answer 8

Wide range of behaviors including heart rate, feeding, and sexual behaviors

Question 9

Osmotic thirst

Answer 9

stimulated by high extracellular solute concentration.

ex. eating pizza

Question 10

Hypovolemic thirst

Answer 10

stimulated by reduced extracellular volume

ex. blood loss

Question 11

Osmosensory neurons

Answer 11

in the hypothalamus respond to changes in osmotic pressure

Question 12

Aldosterone

Answer 12

steroid hormone that is released from the adrenal gland in response to thirst signals

-stimulates the kidneys to conserve Na+, aiding water retention.

Question 13

Pituitary Gland

Answer 13

secretions control the activities of many other endocrine glands

associated with biological rhythms

Question 14

Subfornical organ

Answer 14

-sensitive to angiotensin II
-stimulation strongly elicits drinking behavior

Question 15

Posterior Pituitary

Answer 15

Neural tissue; continuation of the hypothalamus

Question 16

Anterior Pituitary

Answer 16

Glandular tissue; synthesizes various hormones

Question 17

Peptides that are released by the hypothalamus and act to increase or decrease the release of hormones from the

Answer 17

anterior pituitary

Question 18

Three Regions of the Hypothalamus

Answer 18

Lateral region
Medial region
Paraventricular region

Question 19

Vasopressin

Answer 19

aka anti-diuretic hormone
prevents urination to conserve water

Question 20

Paraventricular region of the hypothalmus

Answer 20

produce oxytocin: released during intimate moments such as nurturing behavior, hugging, or sex; known as the bonding hormone.

Question 21

Lateral Region of the hypothalmus

Answer 21

Contains nuclei and nerve tracts that connect the lower brainstem to the forebrain

Question 22

Medial Forebrain Bundle (MFB)

Answer 22

-Tract that connects structures in the brainstem with various parts of the limbic system
-Forms the activating projections from the brainstem to the basal ganglia and frontal cortex
-Dopamine-containing fibers are involved in reward and therefore contribute to many motivated behaviors

Question 23

Feedback Loops

Answer 23

Control the amount of hormone that is released
Hormones influence the hypothalamus to decrease secretion of releasing hormones

Question 24

Neural Regulation

Answer 24

Other brain regions (e.g., limbic system and frontal lobes) influence hormone release
Excitatory and inhibitory influences exerted by cognitive activity can influence neurons in the periventricular region

Question 25

Aphagia

Answer 25

-observed following lesions to the lateral hypothalamus -failure to eat

Question 26

Experiential Responses

Answer 26

Experience can alter the structure and function of hypothalamic neurons

Question 27

Endotherms

Answer 27

generate most of their own heat through internal processes

Question 28

Ectotherms

Answer 28

get most of their heat from the environment.

Question 29

Homeostatic mechanisms that regulate temperature, body fluids, and metabolism are primarily

Answer 29

negative feedback systems

Question 30

Hyperphagia

Answer 30

-overeating -produced by lesions in the ventromedial hypothalamus or the paraventricular nucleus of the hypothalamus

Question 31

Cognitive factors that contribute to eating behavior

Answer 31

1. amygdala- projects to hypothalamus 2. Inferior prefrontal cortex- receives input from olfactory bulb

Question 32

negative feedback

Answer 32

property by which some of the output of a system feeds back to reduce the effect of input signals

Question 33

Lesions in the lateral hypothalamus (LH)

Answer 33

abolish behavioral regulation, but do not affect physiological responses such as shivering.

Question 34

Intracellular compartment:

Answer 34

The fluid part of the body contained within cells

Question 35

Extracellular compartment

Answer 35

The fluid space outside of cells -The extracellular compartment, is divided between the interstitial fluid (the fluid between cells) and blood plasma (the protein-rich fluid that carries red and white blood cells).

Question 36

Ventromedial hypothalamus

Answer 36

controls female mating posture

Question 37

Water moves in and out of cells through

Answer 37

aquaporins

Question 38

Osmosis

Answer 38

passive movement of water molecules, through a semipermeable membrane, from one place to another

Question 39

Osmotic pressure

Answer 39

tendency of a solvent to move through a membrane in order to equalize the concentration of solute

Question 40

Baroreceptors in major blood vessels and the heart detect the initial drop; the heart decreases secretion of

Answer 40

atrial natriuretic peptide (ANP).

Question 41

atrial natriuretic peptide (ANP) causes

Answer 41

blood pressure to rise and water excretion to decrease

Question 42

Preoptic area of the medial hypothalamus

Answer 42

Controls copulatory behavior in males, but not sexual motivation

Question 43

Amygdala (sexual response)

Answer 43

controls sexual motivation in males and possibly in females outside of their estrous cycle

Question 44

Low road

Answer 44

sensory info -> thalamus -> directly to amygdala primes the amygdala

Question 45

High road

Answer 45

thalamus -> sensory cortex -> amygdala detailed analysis

Question 46

Primary olfactory pathway

Answer 46

-pyriform cortex -common odors -vomeronasal organ: pheromones

Question 47

______ seem to increase aggression in rats

Answer 47

androgens

Question 48

______ levels seem to impact aggression levels in humans

Answer 48

serotonin

Question 49

Hypothalamus stimulates ________ in response to stress

Answer 49

anterior pituitary

Question 50

Stress immunization

Answer 50

mild stress early in life makes one more capable of handling stress later in life

Question 51

Epigenetic regulation

Answer 51

change in expression of a gene rather than a change in the encoding region of the gene