Anatomy Physiology Chapter 8 The Brain Senses Waggy

Anatomy & Physiology Chapter 8: The Brain & Senses Waggy

Key Concepts n n Parts of the brain: cerebrum, diencephalon, brainstem Senses: The Eye n n Structure function

Parts of the Brain n n The brain is made up of three major sections: 1. 2. 3.

The First part of the brain: Cerebrum n Cerebrum - n Cerebral Cortex -

Cerebrum Cerebellum Cerebral Cortex

Features of the Cerebrum Gyri – • Sulci • • Central Sulcus – • Fissures – • Longitudinal Fissure – • Transverse Fissure – • Sylvian/Lateral Fissure –

Longitudinal Fissure Central Sulcus Sulci (groove) Gyri (ridge) Sylvian/Lateral Fissure Transverse Fissure

Lobes of the Brain n There are four lobes: 1. n 2. n 3. n 4. n

1. The Frontal Lobe n n The Frontal Lobe of the brain is located It plays an integral role in the following functions/actions:

Features of the Frontal Lobe • Primary Motor Cortex (Precentral Gyrus) – controls movements of the body • Broca’s Area – • Broca’s Aphasia – • Olfactory Bulb -

Primary Motor Cortex/ Precentral Gyrus Broca’s Area Orbitofrontal Cortex Olfactory Bulb

2. The Parietal Lobe n n The Parietal Lobe of the brain is located It plays a major role in the following functions/actions:

Features of the Parietal Lobe n Primary Somatosensory Cortex (Postcentral Gyrus) – n Somatosensory Association Cortex - n Primary Gustatory Cortex –

Primary Somatosensory Cortex/ Postcentral Gyrus Somatosensory Association Cortex Primary Gustatory Cortex

3. Occipital Lobe n The Occipital Lobe of the Brain is located • Function:

Features of the Occipital Lobe n Primary Visual Cortex – n Visual Association Area –

Occipital Lobe Primary Visual Cortex Visual Association Area

4. Temporal Lobe n n The Temporal Lobes are located They play an integral role in the following functions:

Features of the Temporal Lobe n Primary Auditory Cortex – n Primary Olfactory Cortex – • Wernicke’s Area – • Wernicke’s Aphasia –

Primary Auditory Cortex Wernike’s Area Primary Olfactory Cortex (Deep)

Lobes and Structures of the Brain B. A. G. F. C. D. E.

Lobes and Structures of the Brain (answers) A. Central Sulcus B. Frontal Lobe A. (groove) G. C. Sylvian/Lateral Fissure F. D. Temporal Lobe E. Transverse Fissure F. Occipital Lobe G. Parietal Lobe C. (groove) E. D. (groove)

The Second part of the brain: Diencephalon · Made of three parts · 1. · 2. · 3.

1. Thalamus “ Functions: “

2. Hypothalamus Control center of Functions:

3. Epithalamus n Function:

The third part of the brain: Brainstem n n The brainstem is the oldest, most primitive part of the brain Consists of: n 1. n 2. n 3.

1. The Medulla Oblongata Most inferior portion, functions as a conduction pathway Reflex centers for:

2. The Pons Superior to Medulla oblongata. Functions:

3. The Midbrain Small section superior to the pons. Functions:

Senses: The Eye n Accessory structures include

Conjunctiva n Transparent membrane that: n Function:

Lacrimal Apparatus n n Consists of the lacrimal gland & associated ducts Lacrimal glands

Extrinsic Eye Muscles n Function:

Structure of the Eyeball n n A slightly irregular hollow sphere with The wall of the eyeball is composed of three tunics (or layers) – The eyeball is filled with The lens separates the eyeball into sections

Fibrous Tunic of the eye wall n Forms the outermost layer of the eye and is composed of: n Opaque sclera n Clear cornea

Vascular Tunic of the eye wall n Has three regions: n n n 1. 2. 3. n 1. Choroid region: 2. Ciliary Body region: n 3. Iris region: n

Retina tunic of the eye wall n A delicate two-layered membrane: 1. Pigmented layer – n 2. Neural layer- n

Optic nerve The optic disc: n The rest of the retina is lined by photoreceptors: n Rods: n Cones:

Adaptation to light change Adaptation to bright light (going from dark to light) involves: n Adaptation to dark is the reverse

Inner Chambers Aqueous & Fluids Humor n n The posterior segment is filled with a clear gel called vitreous humor that: The anterior segment is filled with a clear liquid called Aqueous humor that: Lens

n Lens:

n Myopic eye (nearsighted) n Hyperopic eye (farsighted)

Depth Perception n Achieved by both eyes viewing the same image from slightly different angles

The End