FINAL EXAM Lecture 16 & 17 Diencephalon & Hypothalamus

Question 1

The most dorsal part of the diencephalon

It forms a caplike covering over the thalamus

Answer 1

Epithalamus

Question 2

The Epithalamus is the _______ and _________ part of the ___________.

Answer 2

Smallest

Oldest

Diencephalon

Question 3

The Epithalamus is composed of: (3)

Answer 3

1. Pineal Body
2. Habenular Nuclei
3. Caudal Commissure

Question 4

Function of the Epithalamus:

Answer 4

It is functionally and anatomically linked to the limbic system. It is involved in regulating reproductive functions (mating behavior; responsible for postpartum maternal behavior.) Melatonin, secreted by the pineal gland at night, is concerned with biological timing including sleep induction.

Question 5

Melatonin is secreted by the _______ at _______.

It is concerned with biological timing including __________ ________.

Answer 5

Pineal gland

Night

Sleep Induction

Question 6

This is located ventral to the thalamus and _______ to the hypothalamus & is only present in ________

Answer 6

Subthalamus

Lateral

Mammals

Question 7

The Subthalamus is involved in the ________ ___ _________ ____________, which selects ______ and suppreses _______ movements.

Answer 7

Generation of Rhythmic Movements

Wanted

Unwanted

Question 8

Stimulation of the ________ provides the most effective treatment for late-stage Parkinson’s disease in humans.

Answer 8

Subthalamus

Question 9

The largest component of the diencephalon

Answer 9

Thalamus

Question 10

4 Subdivisions of the Diencephalon

Answer 10

1. Epithalamus
2. Subthalamus
3. Thalamus
4. Hypothalamus

Question 11

The thalamus is:

Composed of a large number of ______. The two you should know are: ______ & _________ (and their main functions).

Answer 11

Nuclei

1. Lateral Geniculate - Vision
2. Medial Geniculate - Hearing

Question 12

The _______ serves as the great sensory receiving area (receives sensory input from all sensory pathways EXCEPT _________) and relays sensory information to the _______ ________.

Answer 12

Thalamus

Olfaction

Cerebral Cortex

Question 13

What nucleus controls circadian rhythms?

Answer 13

Suprachiasmatic Nucleus

Question 14

The most ventral part of the diencephalon

Answer 14

Hypothalamus

Question 15

While there are 4 parts to the diencephalon, from a clinical perspective, the most significant component is the ____________, since leasions of this area can cause abnormalities in _________, __________ or _________ __________.

Answer 15

Hypothalamus

Endocrine

Limbic

Autonomic Function

Question 16

Hypothalamus Function

Most important job is to maintain _________

It does this by: (3)

Answer 16

Homeostasis (the body’s status quo)

Endocrine Secretion

Autonomic Function

Emotions and Drives

Question 17

Hypothalamus

Endocrine Section - Controls _______ release by the ______ ________.

Answer 17

Hormone

Pituitary Gland

Question 18

_Hypothalamus _

Autonomic Function -

Integrates autonomic functions via ____ _____ to ______ ______ neurons located in the _____-______ and _______ ________.

Answer 18

Direction Projections

Preganglionic autonomic neurons

Brain-Stem

Spinal Cord

Question 19

_Hypothalamus _

Emotions & Drives -

It has numberous interconnections with the ______ _____ by which it generates behaviors involved in ____, ______, _____, etc.

Answer 19

Limbic system

Rage

Aggression

Escape

Question 20

3 Subdivisions of the Hypothalamus

Answer 20

Supraoptic

Tuberal

Mamillary

Question 21

The most important division in veterinary medicine, it lies above the optic chiams and contains 3 important nuclei.

_Name the division and all 3 nuclei _

Answer 21

Supraoptic Region (of the hypothalamus)

1. Supraoptic Nucleus
2. Paraventricular Nucleus
3. Suprachiasmatic Nucleus

Question 22

Supraoptic Nucleus

Contains neurons that produce antidiuretic hormone (______ or ________)

Their axons project to the ______ ________ _____ (neurohypophysis) where ____ is released and entes the blood.

Answer 22

ADH

Vasopressin

Posterior Pituitary Gland

ADH

Question 23

Paraventricular Nucleus

Contains neurons that produce premoninately _______

Answer 23

Oxytocin

Question 24

Suprachiasmatic Nucleus

Plays a role in ________ _________.

Answer 24

Circadian Rhythms

Question 25

Tuberal Region Lies directly anove the ____ \_\_\_\_\_ and contains cells that produce ________ (\_\_\_\_\_\_\_), which control various aspects of sleep. Dogs with _______ have a mutation in the _____ receptor gene.

Answer 25

Pituitary gland Orexins (Hypocretins) Narcolepsy Orexin

Question 26

Most caudal portion of the hypothalamus comprised primarily of the mamillary bodies - plays a role in \_\_\_\_\_\_\_.

Answer 26

**_Mamillary Region_** Memory

Question 27

Key Concept While there are a number of regions that comprise the hypothalamus the ________ region is by far the most important and damage to this area can result in problems with _____ (damage to _____ cells or \_\_\_\_\_), with ____ \_\_\_\_ (\_\_\_\_ _____ \_\_\_\_\_\_) and _______ regulation.

Answer 27

Supraoptic Region Urination - ADH cells or fibers Circadian Rhythms (Sleep wake cycle) Temperature Regulation

Question 28

**_Afferent Inputs to the Hypothalamus _** (Fibers coming from other brain regions) In order to maintain ______ the hypothalamus must receive inputs about the state of the body. The major inputs that convey this information include: 1. 2. 3. 4.

Answer 28

Homeostasis 1. Nucleus of Solitary Tract 2. Limbic System 3. Retina 4. Blood

Question 29

**_Afferent Inputs to the Hypothalamus_** This nucleus collects all of the visceral sensory information from the vagus nerve and sends it to the hypothalamus.

Answer 29

Nucleus of the Solitary Tract

Question 30

**_Afferent Inputs to the Hypothalamus_** Structures such as the amygdala and olfactory cortex ( Piriform lobe) project to the hypothalamus and help regulate behaviors such as eating and reproduction.

Answer 30

Limbic System via the fornix

Question 31

**_Afferent Inputs to the Hypothalamus _** \_\_\_\_\_\_\_ via direct branches of the optic nerve that go to the suprachiasmatic nucleus

Answer 31

Retina

Question 32

**_Afferent Inputs to the Hypothalamus_** ## Footnote Hypothalamus has intrinsic receptors including _______ and _____ that monitor _____ and ______ balance; In addition hypothalamic cells are sensitive to hormone concentrations and glucose levels, etc.

Answer 32

BLOOD Thermoreceptors Osmoreceptors Temperature Ionic

Question 33

Major Efferent Projections from the Hypothalamus Once the hypothalamus is aware of a problem, it fixes the problem via the following routes of communcation: 1. 2. 3. **Ultimatley, through these connections the hypothalamus can control every ____ \_\_\_\_ and can alter _____ \_\_\_\_\_, ______ \_\_\_\_\_, and ______ to maintain body homeostasis.**

Answer 33

1. Neural signals to the autonomic nervous system via projections to the brain stem vagal nuclei and to pregnanglionic nuclei in the spinal cord 2. Neural signals to the limbic system 3. Endocrine signals to/through the pituitary gland **Endocrine Gland** **Blood Pressure** **Body Temperature** **Metabolism **

Question 34

**_Pituitary Gland _** Lies beneath the _____ and is formed by ___ distinct parts: a _____ part, the \_\_\_\_\_ and a ______ component derived from _____ \_\_\_\_\_, called the \_\_\_\_\_\_\_\_\_.

Answer 34

Brain 2 Neural part, the Neurohypophysis Glandular Oral epithelium Adneohypophysis

Question 35

The hypothalamus controls the endocrine system via ____ different routes: 1. _______ by secretion of _____ products into the general circulation via the _____ of the ____ \_\_\_\_ ____ (\_\_\_\_ and \_\_\_\_\_). 2. _______ by secretion of ______ factors into the local _____ \_\_\_\_\_ ______ \_\_\_\_\_\_\_\_ (A vascular plexus that carries these factors from the base of the hypothalamus [an area known as the eminence] to the anterior pituitary). The hypothalamus thus controls _______ \_\_\_\_\_\_\_ hormone synthesis and release via the transport of these factors to the \_\_\_\_\_\_\_\_\_\_.

Answer 35

Endocrine 2 Directly, Neuroendocrine, vasculature, Posterior Pituitary Gland, AHD, Oxytocin Indirectly, Releasing, Hypophyseal Portal Venous Plexus Anterior pituitary, adenohypophysis

Question 36

The hypothalamus is connected directly to the Pituitary gland via the axons of the ______ and ______ nuclei and indirectly via the ____ \_\_\_\_\_ \_\_\_\_\_\_.

Answer 36

Supraoptic Paraventricular Hypophyseal Portal System

Question 37

Hypothalamic Functions The hyopthalamus: (1) Controls the release of at least ____ major hormones by the \_\_\_\_\_, and is involved in (2) _______ regulation, (3) control of _____ and ____ intake, (4) _______ behavior and \_\_\_\_\_\_\_\_\_, (5) control of daily cycles in _________ state and behavior, and (6) mediation of _________ response.

Answer 37

8 Hypophysis Temperature Food & Water Sexual & Reproduction Physiological Emotional

Question 38

Hypothalamus secretes ____ and ____ into the circulation which has a direct effect on the ________ \_\_\_\_\_\_\_\_.

Answer 38

Oxytocin Vasopressin (ADH) Endocrine System

Question 39

Oxytocin is Greek for

Answer 39

Rapid Birth

Question 40

**_Oxytocin_** **Is produced by:** ________ in the ________ \_\_\_\_\_\_ of the hypothalamus **Functions: acts on ____ \_\_\_\_\_ muscle to stimulate myometrial contractions and accelerates _____ (thus oxytocin or synth. derivates of oxytocin can be given to induce \_\_\_\_, eg in the mare). ** Activates ____ \_\_\_\_\_ _____ in response to suckling (induces contraction of myoepithelial cells in mammary gland). It also acts on the _________ (& nucleus accumbens) to enhance _____ between a male and female once they have mated and between a mother and her newborn.

Answer 40

Neurons, Paraventricular Nuclei Uterine Smooth Muscle Parturition Parturition Milk Letdown Reflex Amygdala Bonding

Question 41

Vasopressin ( ____ ) Produced by: ______ in the _____ \_\_\_\_ Function: to _______ \_\_\_\_\_\_ of ____ in the _____ (via collecting ducts and convoluted tubulues). Thus it decreases _____ production and ______ body water. Capillary density of the ____ \_\_\_\_\_ is ____ than any other part of the brain and ____ in blood osmolarity _____ release of ADH.

Answer 41

ADH Neurons, Supraoptic nucleus Increase, Reabsorption, Water, Kidneys Urine, Conserves Supraoptic nucleus, higher, Increases, Stimulate

Question 42

Diabetes Insipidus A disorder of _____ balance in which there is a ____ of ____ of water excretion due to a failure of production, transport or release of ______ into the blood stream from the \_\_\_\_\_\_\_\_\_\_.

Answer 42

water loss ADH (Vasopressin) Neurohypophysis

Question 43

**_Causes of Diabetes Insipidus _** \_\_\_\_\_ or ______ of _____ or \_\_\_\_\_\_\_; Commonly associated with tumors of the ______ which compress the \_\_\_\_\_\_\_\_\_.

Answer 43

Trauma Disease Pituitary Hypothalamus Adenohypophysis Neurohypophysis

Question 44

**_Diagnosis of Diabetes Insipidus_** Imagery of the _____ with a positive finding of a tumor; \_\_\_\_\_\_ deprivation test - if animal is unable to produce ______ \_\_\_\_\_\_\_ urine as a water intake is restricted.

Answer 44

Pituitary Water More Concentrated

Question 45

**_Diabetes Insipidus _** Treatment: _____ or intranasal, oral or SQ injection of \_\_\_\_\_\_\_\_

Answer 45

Surgery Desmopressin

Question 46

Hypothalamus Indirect effects on the endocrine system - Production & Release of hypothalamic ______ \_\_\_\_\_\_\_ which either stimulate or inhibit the release of hormones from the _____ \_\_\_\_\_\_ \_\_\_\_\_\_.

Answer 46

releasing factors Anterior Pituitary Gland

Question 47

\_\_\_\_\_\_\_\_\_\_\_\_\_\_ (Cushing's Disease) often accompanies tumors of the \_\_\_\_\_\_, which produce excess _________ hormone. One of the most common diseases of _____ aged and older dogs.

Answer 47

Hyperadrenocorticoidism Adenohypophysis Adrenocorticotropic Middle

Question 48

Symptoms of Hyperadrenocorticoidism (Cushing's) 1. _____ \_\_\_\_\_\_ (polyphagia - \_\_\_\_\_% show this sign) 2. ____ \_\_\_\_ ___ (usually on the sides) 3. ________ - Bloated abdomen and "potbelly" due to increase of fat in the abdomen and increased _____ size and stretching of abdominal wall (\_\_\_\_\_% have this symptom) 4. ______ \_\_\_\_\_, ________ and sometimes lameness (excess ______ causes protein breakdown leading to muscle weakness)

Answer 48

Extreme Hunger - 80-95% Poor Hair Coat Obesity Muscle Weakness, Lethargy Cortisol

Question 49

Treatment of Hyperadrenocoritcoidism (Cushing's) \_\_\_\_\_\_ to remove _____ tumor \_\_\_\_\_\_\_\_ to control tumor growth Medication - _____ or _____ - destroys the cortisol producing cells in the ______ \_\_\_\_\_\_\_

Answer 49

Surgery, Pituitary Radiation Lysodren or Mitotane Adrenal Cortex

Question 50

Hypothalamus Control of the Autonomic Nervous System: 1. _____ \_\_\_\_\_ 2. \_\_\_\_\_\_\_\_\_\_ 3. \_\_\_\_\_\_\_\_\_\_ 4. \_\_\_\_\_\_\_\_\_\_

Answer 50

Heart Rate Vasoconstriction Digestion Sweating

Question 51

What alterations have been observed in cattle with abscesses of the hypothalamus? ![]()

Answer 51

Alterations in cardiovascular function Slowing of heart rate

Question 52

The hypothalamus stimulates the ____ \_\_\_\_\_ which acts on _________ responses (e.g. Slowed heart rate)

Answer 52

Rostral Hypothalamus Parasympathetic

Question 53

The hypothalamus stimulates _____ \_\_\_\_\_ which acts on _____ responses (e.g. increased heart rate, vasoconstriction, etc.)

Answer 53

Caudal Hypothalamus Sympathetic

Question 54

The hypothalamus can control temperature regulation through the _____ and _____ hypothalamus.

Answer 54

Rostral & Caudal

Question 55

The Rostral Hypothalamus is also known as the ___ \_\_\_ \_\_\_\_\_\_ Warm blood, antipyretic substances or impulses from heat receptors can cause \_\_\_\_\_, _____ and ____ which serve to _____ body temperature. Lesions cause ______ in dogs and other species.

Answer 55

Heat Loss Center Panting Vasodilation Sweating Reduce Hyperthermia (fever)

Question 56

The caudal hypothalamus is also known as the _____ \_\_\_\_\_ \_\_\_\_\_ Cool blood, Pyrogenic substances or input from cold receptors causes _______ and \_\_\_\_\_\_, which serves to ______ body temperature. Lesions result in _____ and disturbances in _______ mechanisms.

Answer 56

Heat Conservation Center Shivering & Vasoconstriction Increase Hypothermia Sweating

Question 57

Cattle with abscesses of the pituitary gland that effect the hypothalamus are often \_\_\_\_\_\_\_\_\_\_\_.

Answer 57

Hypothermic

Question 58

Hypothalamic Functions (6) 1. 2. 3. 4. 5.

Answer 58

1. Direct effects on the Endocrine System 2. Indirect effects on the Endocrine System 3. Control of the Autonomic Nervous System 4. Temperature Regulation 5. Regulation of Food and Water Intake

Question 59

The hypothalamus controls ______ \_\_\_\_\_\_ and appetite as well as water intake. Lesions of the hypothalamus often cause abnormal ______ and \_\_\_\_\_\_\_\_.

Answer 59

Body Weight Eating & Drinking

Question 60

Lesions in the _________ Hypothalamus will cause an obese animal. ## Footnote ![]()

Answer 60

Ventromedial ![]()

Question 61

Lesions in the _______ Hypothalamus will cause anorexia. ![]()

Answer 61

Lateral ![]()