The Brain

The Meninges (D.A.P.) Dura mater - outermost layer (tough mother) Arachnoid mater - no blood vessels, in between layer (resembles a spider web) Pia mater -inner membrane, contains nerves and blood vessels to nourish cells (tender mother)

The Meninges Figure 13.25a CSF = cerebrospinal fluid

Dura mater is being peeled away in this photo.

Subdural Hematoma

THE BRAIN ANATOMICAL REGIONS o Cerebrum o Cerebellum o Brain Stem

CEREBELLUM Balance and coordination Could be involved in motor skill learning

Cerebrum - wrinkly large part of the brain, largest area in humans, higher mental function

Brain Stem - regulates visceral functions (autonomic system)

Figure 13.4

1. Cerebral Hemispheres - left and right side separated by the Corpus Callosum -connects the two hemispheres -Some functions appear “lateralized” but the right- brain, left-brain hypothesis is mostly debunked

Corpus callosum

3. Convolutions of the Brain - the wrinkles and grooves of the cerebrum Fissures = deep groove Sulcus = shallow groove Gyrus = bump / ridge

4. Fissures – separate lobes Longitudinal fissure - separate right and left sides

Transverse Fissure - separates cerebrum from cerebellum

Lateral Fissure separates the temporal lobe from the Frontal and Parietal lobes

Lissencephaly Lack of gyri and sulci

Albert Einstein’s Brain

Lobes of the Brain (general functions) 5. Frontal – reasoning, thinking, language, conscious thought 6. Parietal – touch, pain, relation of body parts (somatosensory) 7. Temporal Lobe – hearing, smell 8. Occipital – vision

Figure 13.7a LOBES OF THE BRAIN (CEREBRUM) Sulcus = groove Gyrus = raised bump Fissure = deep groove

Cerebral Cortex - thin layer of gray matter that is the outermost portion of cerebrum (the part with all the wrinkles)

Functional and Structural Areas of the Cerebral Cortex Figure 13.11a

FUNCTIONAL REGIONS A. MOTOR AREAS B. SENSORY AREAS C. ASSOCIATION

Motor Areas Primary Motor Cortex i n Parietal Lobe controls voluntary movements also has Broca's Area (speech)

Sensory Area Primary Somatosensory Cortex in parietal lobe involved in feelings and sensations = vision, hearing, smell, touch, taste

Association Areas higher levels of thinking, interpreting and analyzing information

Four fluid filled cavities, contain CSF VENTRICLES OF THE BRAIN

Cerebrospinal Fluid (CSF) - fluid that protects and supports brain

Intraventricular Hemmhorage A.k.a. “brain bleed” Baby is so premature that capillaries are too weak to hold blood, blood escapes and fills ventricles

Figure 13.4 BRAIN STEM

2. Hypothalamus – hormonal regulation of heart rate, blood pressure, body temp, hunger. Connected to pituitary gland (Endocrine System) 3. Thalamus - relay station for sensory info 1. Diencephalon (Interbrain – top of brainstem ) consists of two main parts:

4. Optic Tract / Chiasma - optic nerves cross over each other

BRAIN STEM Consists of three main parts: o PONS o MIDBRAIN (Mesencephalon) o MEDULLA OBLONGATA

5. Midbrain (Mesencephalon) – visual reflexes, eye movements; motivation 6. Pons - relay sensory information; dreams 7. Medulla – heart, respiration, blood pressure Cerebellum - balance, coordination

Corpus callosum Thalamus Hypothalamus Pineal gland

Midbrain Medulla Oblongata Pons

9. HIPPOCAMPUS The hippocampus plays a major role in memories. Neurogenesis – development of new neurons

10. The LIMBIC SYSTEM Major role in emotion and memory also includes olfactory lobes - memory, emotion, and smell are linked. Includes hippocampus, amygdala, mammilary body, and others

Spinal Cord passes down the vertebral canal, has 31 pairs of spinal nerves Cervical enlargement = supplies nerves to upper limbs (neck) Lumbar enlargement = supplies nerves to the lower limbs (lower back) FUNCTION: conducting nerve impulses, serves as a center for spinal reflexes

ASCENDING - impulses travel to the brain (sensory) DESCENDING - impulses travel to the muscles (motor)

Spinal reflexes - reflex arcs pass through the spinal cord