BIOL 2134 Anatomy Unit 4

Cerebrum

Largest component of the human brain.

Cerebral cortex

Surface of the cerebrum; gray matter.

Gyrus

Ridge in the cerebral cortex.

Sulcus

Crease in the cerebral cortex.

Fissure

Deep sulcus.

Longitudinal fissure

Separates the brain into left and right hemispheres.

Central sulcus.

Pre-central Gyrus.

Post-central Gyrus.

Corpus Callosum

Communication between left and right hemispheres of the cerebrum.

Is the Corpus Callosum made of white or grey matter?

White.

Physiology of the Cerebrum

Interpretation of sensation, voluntary movement, speech, memory, intelligence and other higher functions.

Functional Areas: Motor areas

Control voluntary motor functions.

Functional Areas: Sensory areas

Provide conscious awareness of sensation.

Functional Areas: Association areas

Integrate and store information.

What is an example of a Motor Area?

Frontal lobe.

Frontal lobe

Primary motor cortex, is the location of somas of neurons that initiate voluntary muscle movement.

Broca’s area

Located in the left lobe only, is the location of somas of neurons that produce speech.

What is an example of the Sensory Area?

Parietal Lobe.

Parietal Lobe

Primary somatosensory cortex, is the location of somas of neurons involved with conscious awareness of general somatic sensory information.

Pre-central Gyrus

The pre-central gyrus is in the frontal lobe and anterior to the central sulcus. It is also the location of the primary motor cortex.

Post-central Gyrus

The post-central gyrus is in the parietal lobe and posterior to the central sulcus. It is also the location of the primary somatosensory cortex.

What is an example of the Sensory Area?

Insula Lobe.

Insula Lobe

Primary gustatory (taste) cortex, location of somas that interpret gustatory information.

Occipital Lobe

Primary visual cortex, location of somas that interpret visual information.

What is an example of a Sensory Area? (Temporal)

Temporal Lobe.

Temporal Lobe

Wernicke’s area (left only), location of somas involved with speech formation and comprehension.

Primary auditory and olfactory cortices

Location of somas that interpret auditory and olfactory information.

Are the motor and sensory cortices white matter or gray matter?

The motor and cerebral cortices are made up of gray matter – somas, dendrites, and synapses that are interpreting information and initiating action.

Left side of the body is controlled by the _______ primary motor cortex

Right.

Left side of the body is monitored by the ______ primary somatosensory cortex.

Right.

Broca’s Area

Related to speech. Motor. Allows for word expression. Left-sided only. Common target for stroke.

Wernicke’s Area

Related to speech. Sensory. Allows a word to be formed and understood. Left-sided only. Common target for stroke.

Words travel from gray matter in ______ to the cerebral white matter to ______ Area to the cerebral white matter to the muscles of the mouth.

Wernicke’s; Broca’s.

What is an example of Association Area? (Pre-frontal cortex)

Pre-frontal cortex.

Pre-frontal cortex

Complicated area, the site of learning, higher emotion, mortality, intelligence, and personality.

What is an example of Association cortex? (Pre-motor cortex)

Pre-motor Cortex.

Pre-motor Cortex

“Muscle memory”. Associations based on previous motor experiences.

What is an example of Association Area? (Parietal Lobe)

Parietal Lobe; somatosensory association area; associations based on previous sensory experiences.

What is an example of Association Area? (Occipital)

Occipital Lobe; visual association area; associations based on previous visual experiences.

What is an example of Association Area? (Temporal)

Temporal Lobe; auditory association area; stores memories of previous auditory experiences.

What part is green?

Temporal.

What part is red?

Frontal lobe.

What part is yellow?

Pariteal Lobe.

What part is orange?

Occipital.

What is highlighted?

Wenicke’s area.

What is highlighted?

Broca’s area.

Gray matter

Somas, dendrites, and synapses; cortex; where awareness occurs and action is initiated.

White matter

Myelinated axons; deep to cortex; where information is carried somewhere else; called “tracts”.

Basal Nuclei

Areas of grey matter within the white matter tracts of the cerebrum; regulate motor information to produce smooth movements; affected by Parkinson’s Disease.

Diencephalon

Enclosed by cerebral hemispheres.

Thalamus

Relay sensory impulses to the primary somatosensory cortex in the cerebrum.

Hypothalamus

Controls the visceral nervous system. Controls the limbic system (“emotional-visceral brain”). Controls the endocrine system with the pituitary gland.

Hippocampus

Long-term memories and olfactory tracts.

Fornix

White matter that connects all gray matter of the limbic system.

Epithalamus

Contains the pineal gland and choroid plexus.

Pineal gland

Releases melatonin.

Choroid Plexus

Filters blood plasma to produce cerebrospinal fluid.

Brainstem

Axons traveling between the brain and the spinal cord; mostly white matter.

Nuclei

Areas of gray matter are involved with visceral motor system; areas of gret matter within the brainstem involved with the visceral motor activity,

Midbrain

Nuclei relay information about vision and hearing.

Pons

Nuclei control breathing and dreaming.

Medulla oblongata

Where motor neurons “cross-over”. Nuclei initiate visceral motor activity, like heart rate, blood pressure, swallowing, vomiting, etc. Merges seamlessly into spinal cord.

What is highlighted?

Vermis. (Looks like a worm).

What is being shown?

Folia and arbor vitae. (They look like tree branches and leaves).

What are the functions of the Cerebellum?

1. “Fine tunes” skeletal muscle movement.

2. Controls balance.

Meninges

Specialized connective tissues that provide protection, physical stability, and shock absorption. Surround the brain and spinal cord.

Dura mater

Outermost and toughest layer of the meninges. Not attached to bone — forms epidural space.

Arachnoid mater

Middle layer of the meninges. Thinnest layer. Forms subarachnoid space where cerebrospinal fluid circulates.

Pia mater

The innermost layer of the meninges. Anchors blood vessels in place.

Transports nutrients and waste away from the CNS. Shock absorption.

Cerebrospinal Fluid (CSF).

Cerebrospinal fluid is made in the ______ of ventricles.

Chorioid plexus.

Enlarged chambers in the brain that contain cerebrospinal fluid.

Ventricles.

What is pictured?

Arachnoid Villi

______ lines the blood vessels of the central nervous system.

Astrocytes

Cerebrovascular accident (CVA)

Stroke.

One sided paralysis

Hemiplegia

Damage to speech center in left hemisphere.

Aphasia

Transient ischemic attack (TIA)

Temporary restriction of blood flow to the brain. Numbness, temporary paralysis, impaired speech.

General senses — Throughout body

Refers to temperature, pain, touch, pressure, vibration, and proprioception.

Special censes — Only in sense organs

Refers to vision, taste, hearing, balance, and smell.

Sensory receptors

The interface between the nervous system and the body.

Nociceptors

Detect the sensation of pain. Associated with free nerve endings and large receptor fields.

Thermoreceptors

Detect changes in temperature. Found in the dermis, skeletal muscles, liver, and hypothalamus.

Mechanoreceptors

Detect changes in pressure. (Touch, vibration, stretch)

Chemoreceptors

Detect change in the chemical composition of body fluids (specific molecules dissolved in fluid).

Mechanoreceptors — Tactile receptors

Provide sensations of touch, pressure, and vibrations.

Mechanoreceptors — Baroreceptors

Stretch receptors that monitor changes in the stretch of organs.

Mechanoreceptors — Proprioceptors

Monitor the position of joints, tension in the tendons and ligament, and the length of muscle fibers upon contraction. Controls the sense of body position.

What are the 5 special senses?

1. Vision

2. Gustation

3. Hearing

4. Equilibrium

5. Olfaction

Aqueous Fluid

Located in the anterior cavity, this liquid prevents collapse of the eye and is continuously replaced.

Flow of Aqueous

Ciliary body —> Pupil —> Scleral venous sinus —> Blood

Vitreous Fluid

Located in the posterior cavity, this gelatinous substance prevents collapse of the eye as well as supporting the overall shape of the eye and the position of the lens it is never replaced.

What is highlighted?

Posterior cavity

What is highlighted?

Anterior cavity

Identify the highlighted structure.

Lens.

What is highlighted?

Anterior chamber

What is highlighted?

Posterior chamber

The Fibrous Tunic

Outermost layer for protection. Contains the sclera and cornea. Diseases of this layer are painful.

The Vascular Tunic

Middle layer for nutrition. Contains the iris, ciliary body, choroid. Disease of this layer are inflammatory.