Unit 6.2 Anatomy - Central Nervous System

CNS is made up of

brain + spinal cord

Brain + Spinal cord are protected by

3 layers of meninges (connective tissue)

1. Dura Mater

(meninges) thick, tough layer

2. Arachnoid membrane

(meninges) thin, cobweb layer

3. Pia mater

(meninges) thin layer contains blood vessels

Cerebrospinal fluid (CSF) is between which meninge layers?

Arachnoid and Pia

CSF prevents contact from ______ and skull and maintains ___________

brain and skull

blood-brain barrier

CSF is ______, ______, _____ in 4 ventricles (spaces in brain)

produced, circulated, reabsorbed

Lateral ventricle

connects to 3rd ventricle through intraventricular foramen

Choroid Plexuses

clusters of capillaries in ventricle that secrete CSF

Arachnoid granulations

absorb the CSF into blood

Cerebrum is ____ part of brain

largest

Cerebrum is divided into 2 hemispheres and the _______ connects these.

Corpus callosum - bundle of nerve fibers

Cerebrum surface:

Gyri -

Sulci -

Fissures -

ridges

grooves

deeper grooves that divide brain portions

3 major layers of brain:

1. Cerebral cortex - ____ matter, made of ________

2. Cerebral medulla - ______ matter, made of ___________

3. Basal nuclei - ____________________

gray, cell bodies + dendrites

white, myelinated axons

islands of gray matter

4 Lobes of cerebrum:

frontal, parietal, occipital, temporal

Controls voluntary movements, reasoning/decision-making, verbal communication (broca), consequences

Frontal lobe

Central Sulcus separates ____ and ____

frontal lobe and parietal lobe

Provides sensations (pain, touch, pressure), creates a map of body’s position in space

Parietal lobe

Visual processing & memory of objects

Occipital lobe

memory, comprehension, pronounciation, smell/sound

Temporal Lobe

Separates temporal lobe from frontal lobe

Lateral sulcus

Diencephalon is the _____ region in cerebrum and includes ______, _______, ______

smallest

Thalamus, hypothalamus, pineal gland

Thalamus relays _____ impulses to ________ for processing/sorting

sensory impulses to cerebral cortex

Hypothalamus controls _____, ______, ______, _____, ______ system

temperature, metabolism, blood volume, hormones, limbic system (emotion/pleasure)

Pineal gland

part of endocrine system

Brain stem is located between cerebrum + spinal cord, includes ______, ______,______

midbrain

pons

medulla oblongata

Midbrain relays info to ____ and controls ______

cerebrum

movement/posture

Pons carries info from _______ and controls ______

one side to other

breathing

Medulla oblongata carries impulses between _____ and _____.

spinal cord and brain

(controls blood pressure, heart-rate, swallow/cough)

Cerebellum is _____ largest part of brain

2nd

Cerebellum coordinates

movements directed by cerebrum to be efficient/graceful + muscle memory

Goes from medulla oblongata to lumbar vertebrae

Spinal cord

________ is covered in meninges and 31 pairs of spinal nerves to ________

Spinal cord

relay impulses between PNS + brain

Spinal cord cross section:

butterfly of gray matter surrounded by white matter

How spinal cord sends impulses:

1. _______ recieves impulses from _____ nerves

2. Impulses pass through ______ to ______ nerves

3. _____/____ roots contain ________ that join together to create _________

1. Dorsal horns, afferent

2. Ventral hornes, efferent

3. Dorsal/ventral, nerve fibers, 2-directional spinal cord

Reflexes

preprogrammed responses that can be somatic (skeletal) or autonomic (smooth)

Reflex arc

pathway that reflexes travel

5 elements of reflex arc

receptor, sensory neurons, integration, motor neurons, effector