ch 8 organization of the brain central nervous system

What structures make up the central nervous system (CNS)?

Brain and spinal cord.

What connective tissue covers the CNS?

Meninges.

What fluid fills the space between the meninges and CNS?

Cerebrospinal fluid (CSF).

Where is CSF produced?

Choroid plexus in the brain ventricles.

How many ventricles are in the brain, and what are they called?

Four: two lateral, third, and fourth ventricles that run in the center

What are the raised ridges and deep grooves of the brain called?

Raised ridges = gyri, deep grooves = sulci.

The vertebrate brain

What are the three main functional divisions of the brain?

Prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain).

The vertebrate brain

What are the subdivisions of the prosencephalon?

Telencephalon (cerebral hemispheres) and diencephalon (thalamus, hypothalamus, epithalamus, pituitary).

The vertebrate brain

What are the subdivisions of the rhombencephalon?

Metencephalon (pons, cerebellum) and myelencephalon (medulla oblongata).

The vertebrate brain

What is the prosencephalon?

The forebrain; a primary division of the brain.

What percent of brain mass does the cerebrum make up?

~80%.

How do cerebral hemispheres control the body?

Contralaterally: left hemisphere controls right side, right hemisphere controls left side.

How do the left and right hemispheres communicate?

Corpus callosum.

What happens if the corpus callosum is damaged?

Split-brain syndrome: hemispheres cannot communicate.

Functional Regions of the Cerebrum

Name the five lobes of the cerebrum.

Frontal, parietal, temporal, occipital, insula.

Functional Regions of the Cerebrum

What separates the frontal and parietal lobes?

Central sulcus.

Functional Regions of the Cerebrum

What is the pre-central gyrus responsible for?

Primary motor cortex — voluntary movements.

Functional Regions of the Cerebrum

What is the post-central gyrus responsible for?

Somatosensory cortex — perception of stimuli.

Functions of the Cerebral Lobes

What are the functions of the frontal lobe?

Personality, reasoning, planning, higher thinking, verbal communication.

Functions of the Cerebral Lobes

What are the functions of the parietal lobe?

Muscular sensations, understanding speech, formulating words to express thoughts and emotions, interpretation of textures and shapes

Functions of the Cerebral Lobes

What are the functions of the temporal lobe?

Auditory processing, memory of auditory and visual experiences.

Functions of the Cerebral Lobes

What is the function of the occipital lobe?

Visual processing and coordination of eye movements.

Functions of the Cerebral Lobes

What is the function of the insula?

Integrates sensory information with visceral responses and memory.

Speech

What is the function of Wernicke's area?

Language comprehension/Articulate thoughts

Speech

What is the function of Broca's area?

Motor speech — articulating thoughts into spoken words.

Speech

What is aphasia?

Impairment of language function due to damage in Broca's or Wernicke's areas.

Speech

What are the characteristics of Wernicke's aphasia?

Fluent speech, but incomprehensible; impaired language; speech will be gibberish

Speech

What are the characteristics of Broca's aphasia?

Difficulty producing speech; cannot put thoughts into words

The Limbic System; The emotional brain

What is the limbic system?

Emotional brain controlling primal behaviors (fear, aggression, feeding, sex drive, goal setting).

Memory

What is the function of the amygdala?

Fear responses and emotional memory.

Memory

What is the function of the prefrontal cortex?

Problem solving, working memory, planning.

Memory

What is the function of the left inferior frontal lobe?

Mathematical calculations.

Types of Memory

What are the types of memory?

Short-term (recent events) and long-term (consolidated over sleep).

Types of Memory

What are the two types of long-term memory?

Non-declarative/implicit (skills, habits) and declarative/explicit (semantic; facts/episodic;events).

What is a common form of dementia?

Alzheimer's disease.

What is the pathology in Alzheimer's disease?

Amyloid beta ; clumps up outside of neurons causes neurons to die and form

• bore holes in the brain

What happens INSIDE the cell during Alzeimers disease

Neurofibrillary tangles caused by misform proteins known as Tau protien

(Turn into long strains that clump up and cause the cells to die from the inside

What does the forebrain diencephalon consist of?

consists of epithalamus, thalamus, hypothalamus and part of the pituitary gland

Forebrain; Diencephalon

What is the function of the thalamus?

Relay center for all senses except smell; filters sensory information.

Forebrain; Diencephalon

What is the function of the epithalamus/pineal gland?

Regulates circadian rhythms and melatonin secretion.

Forebrain; Diencephalon

What is the function of the hypothalamus?

Maintains homeostasis and contains center for emotions controls endocrine system.

=control when ur other endocrine glands are going to be secreting their own hormones

Midbrain= Mesencephalon

What is the function of the mesencephalon/midbrain?

Relay center; contains superior colliculi (visual reflexes)/ creates brainstem

Midbrain= Mesencephalon

What are the components of the brainstem?

Midbrain, pons, medulla oblongata.

Hindbrain=Rhombencephalon

What is rhombencephalon consist of?

metencephalon (cerebellum and pons)

myelencephalon (medulla oblongata)

Mentencephalon; Cerebellum

What is the function of the cerebellum?

Motor coordination, balance, posture, eye movements, swallowing, memory and emotion

What is a symptom of a cerebellar disorder?

Ataxia — poor coordination, unsteady gait, shaky eye movements.

Metencephalon; Pons

What is the function of the pons?

Connects medulla, cerebellum, and forebrain; regulates sleep, alertness, and dream states.

Metencephalon; Pons

What is the cause of locked-in syndrome?

Damage to pons; paralysis of voluntary muscles, only eye movements remain.

Myelencephalon; Medulla Oblongata

What is the function of the medulla oblongata?

Reflex center for heart rate, breathing, vasodilation/constriction.

Communication with spinal and brain

Why is damage to the medulla oblongata often fatal?

Controls vital autonomic functions (heart, respiration, blood pressure).