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==Introduction==

==Introduction==

The ''forebrain (proencephalon)'' is the largest part of the brain, most of which is ''[[#Cerebrum|cerebrum]]''. Other important structures found in the forebrain include the ''[[Forebrain - Anatomy & Physiology#thalamus|thalamus]]'' , the ''[[Forebrain - Anatomy & Physiology#hypothalamus|hypothalamus]]'' and the ''[[#Limbic System|limbic system]]''. The cerebrum is divided into two cerebral hemispheres connected by a mass of white matter  known as the ''corpus callosum''. Each hemisphere is split into four lobes; the ''frontal'', ''parietal'', ''occipital''  and ''temporal'' lobes. The surface of each hemisphere is made up of grey matter known as the ''cerebral cortex'' and is folded to increase the surface area available within the skull. The cortex has roles within perception, memory and all higher thought processes. Inside the cortex is the ''white matter'', within which are a number of nuclei (grey matter), known as the ''basal nuclei''. The basal nuclei receive information from the cortex to regulate skeletal movement and other higher motor functions.

The ''forebrain (proencephalon)'' is the largest part of the brain, most of which is ''cerebrum''. Other important structures found in the forebrain include the ''thalamus'' , the ''hypothalamus'' and the ''limbic system''. The cerebrum is divided into two cerebral hemispheres connected by a mass of white matter  known as the ''corpus callosum''. Each hemisphere is split into four lobes; the ''frontal'', ''parietal'', ''occipital''  and ''temporal'' lobes. The surface of each hemisphere is made up of grey matter known as the ''cerebral cortex'' and is folded to increase the surface area available within the skull. The cortex has roles within perception, memory and all higher thought processes. Inside the cortex is the ''white matter'', within which are a number of nuclei (grey matter), known as the ''basal nuclei''. The basal nuclei receive information from the cortex to regulate skeletal movement and other higher motor functions.

 

The thalamus functions to relay sensory information to the cerebral cortex and the hypothalamus, regulating visceral functions including temperature, reproductive functions, eating, sleeping and the display of emotion. The limbic system describes a collection of structures within the forebrain, including the ''amygdala'' and '' hippocampus'', also known as the 'emotional brain'. It is important in the formation of memories and in making decisions and learning.

The [[Forebrain - Anatomy & Physiology#thalamus|thalamus]] functions to relay sensory information to the [[Forebrain - Anatomy & Physiology#Cerebral Cortex|cerebral cortex]] and the [[Forebrain - Anatomy & Physiology#Hypothalamus|hypothalamus]], regulating visceral functions including temperature, reproductive functions, eating, sleeping and the display of emotion. The limbic system describes a collection of structures within the forebrain, including the ''amygdala  hippocampus'', also known as the 'emotional brain', the limbic system is important in the formation of memories and in making decisions and learning.

==Forebrain Structure and Function==

==Forebrain Structure and Function==

|-  

|-  

| Diencephalon

| Diencephalon

| [[Forebrain - Anatomy & Physiology#Thalamus|Thalamus]]

| Thalamus

| Organising sensory information

| Organising sensory information

|-  

|-  

| Diencephalon

| Diencephalon

| [[Forebrain - Anatomy & Physiology#Hypothalamus|Hypothalamus]]

| Hypothalamus

| Endocrine System, Thermoregulation

| Endocrine System, Thermoregulation

|-  

|-  

| Diencephalon

| Diencephalon

| [[Forebrain - Anatomy & Physiology#Pituitary|Pituitary]]

| Pituitary

| Endocrine System

| Endocrine System

|-  

|-  

| Telencephalon

| Telencephalon

| [[Forebrain - Anatomy & Physiology#Cerebral Cortex|Cerebral Cortex]]

| Cerebral Cortex

| Conciousness, language etc

| Conciousness, language etc

|-  

|-  

| Telencephalon

| Telencephalon

| [[Forebrain - Anatomy & Physiology#Limbic System|Limbic System]]

| Limbic System

| Memory, motivation, emotion

| Memory, motivation, emotion

|-  

|-  

| Telencephalon

| Telencephalon

| [[Forebrain - Anatomy & Physiology#Olfactory Bulb|Olfactory bulb]]

| Olfactory Bulb

| Smell

| Smell

|-

|-

|}

|}

===Thalamus===

===Thalamus===

The thalamus has many functions including; processes and relaying sensory information selectively to various parts of the cerebral cortex, translating signals to the cerebral cortex from lower centres including auditory, somatic, visceral, gustatory and visual systems and also regulating states of sleep and wakefulness. The thalamus plays a major role in regulating arousal, levels of conciousness and levels of activity.

The thalamus has many functions including processing and relaying sensory information selectively to various parts of the cerebral cortex, translating signals to the cerebral cortex from lower centres including auditory, somatic, visceral, gustatory and visual systems and also regulating states of sleep and wakefulness. The thalamus plays a major role in regulating arousal, levels of consciousness and levels of activity.

===Hypothalamus===

===Hypothalamus===

The function of the hypothalamus is mainly related to the overall regulation of the Endocrine System. For a more detailed analysis of the function of this part of the brain, please use the link: [[Hypothalamus - Anatomy & Physiology|Hypothalamus Anatomy and Physiology]].

The function of the hypothalamus is mainly related to the overall regulation of the [[:Category:Endocrine System - Anatomy & Physiology|Endocrine System]]. The hypothalamus is closely related to the [[Pituitary Gland - Anatomy & Physiology|pituitary gland]], controlling a large proportion of the activity going to it. For a more detailed analysis of the function of this part of the brain, please use the link: [[Hypothalamus - Anatomy & Physiology|Hypothalamus Anatomy and Physiology]].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*Association areas function is to produce a perception of the world, so an animal can interact effectively.

*The '''parietal''', '''temporal''', and '''occipital lobe''' - all located in the '''posterior''' part of the cortex - organize sensory information.  

The function of the pituitary is mainly related to the production of hormones as part of the Endocrine System. For further information on the pituitary gland please use this link: [[Pituitary Gland - Anatomy & Physiology|Pituitary Gland Anatomy and Physiology]].

*The '''frontal lobe''' or prefrontal association complex is involved in planning actions and movement.

The cerebral cortex is essential for memory, attention, awareness, thought, language and consciousness. The outer layers of the cerebrum are made up of grey matter. Grey matter is formed by neurons and their unmyelinated fibres. The white matter below the grey matter of the cortex is formed predominantly by myelinated axons (myelin is white in appearance). The surface of the cerebral cortex is folded in mammals; more than two thirds of the surface is within the grooves or ''"sulci"''. The cerebral cortex is connected to structures such as the thalamus and the basal ganglia, sending information to them along ''efferent'' connections and receiving information from them via ''afferent'' connections. Most sensory information is routed to the cerebral cortex via the thalamus. The cortex is commonly described as comprising three parts; sensory, motor and association areas.

'''Motor areas'''

*The motor areas are located in '''both hemispheres''' of the cortex.  

The ''motor cortex'' areas of the brain are located in both hemispheres of the cortex and are shaped like a pair of headphones stretching from ear to ear. The motor areas are related to controlling voluntary movements, especially fine movements. There are two main types of connection between the motor cortex and motor neurones found in the ventral horn of the spinal cord; the ''Pyramidal tracts'' and the ''Extrapyramidal tracts''.  

*They are shaped like a pair of headphones stretching from ear to ear.  

'''Pyramidal tract''' connections are direct with no synapses in the brain stem. Axons pass through the ventral aspect of the medulla oblongata. The '''extrapyramidal tracts''' pass through the medulla oblongata outside the ventral pyramidal tracts and have synapses within the brain stem nuclei. These synapses make it possible for signals travelling down the extrapyramidal horns to be influenced by other areas of the brain including the cerebrum.  

*The motor areas are related to the controlling voluntary movements, especially fine fragmented movements.

The pyramidal tracts are responsible for aspects of fine motor skills that require a degree of conscious thought and concentration. The extrapyramidal tracts are generally responsible for activation of larger muscle groups and often work in a coordinated manner to achieve smooth synchronous movements.

====Limbic System====

===Limbic System===

====Olfactory Bulb====

===Olfactory Bulb===

==Species Differences==

{{Learning|videos = [[Video: Transverse Section of Cerebral Hemispheres|Transverse Section of Cerebral Hemispheres potcast]]<br>[[Video: Canine orbit and sagittal section of the canine head|Canine orbit and sagittal section of the canine head potcast]]<br>[[Video: Lateral surface of the head of the dog potcast 4|Lateral surface of the head of the dog potcast 4]]<br>[[Video: Ventral surface of the brain potcast|Ventral surface of the brain potcast]]}}

[[Category:Nervous System - Anatomy & Physiology]]

[[Category:Nervous System - Anatomy & Physiology]]

[[Category:To Do - A&P]]

[[Category:A&P Done]]