A&P Nervous system

Bones in the Nervous system

Vertebral column

skull

Meninges

dura mater

arachnoid mater

pia mater

Fluid

Cerebral spinal fluid

Macro structures of the nervous system

Spinal cord

Brain

Meninges

Membranes around the brain and spinal cord

offer protection to the brain and spinal cord

three distinct membranes

Subdural hematoma

blood stuck under the dura mater

burr holes or surgical removal necessary

Meningitis

Can be deadly, swelling that pushes against brain caused by infection

Dura Mater

outermost membrane that is attached to the inner periosteum of the skull

Structure of dura mater

double-layered external covering, tough, dense white fibrous CT

Contains many blood vessels and nerves

splits into two layers where it encloses the dural sinuses

Periosteal layer of the dura mater

attached to surface of the skull

Meningeal layer of the dura mater

outer covering of the brain

Arachnoid mater

middle layer between dura mater and pia mater

Arachnoid mater structure

Thin net-like membrane

beneath the arachnoid mater lies a wide space

Sub-arachnoid space

filled with cerebrospinal fluid

cushion of the brain

Pia mater

Inner layer that clings to brain surface

Pia mater structure

Very thin delicate CT

many nerves and blood vessels (nourish cells of brain and spinal cord)

dips into grooves and contours of the brain surface

Spinal cord

Dura mater NOT attached to bones of vertebrae

CSF fills the subarachnoid space and central canal

epidural space

the space between the dura mater and the bone

CSF

fills the subarachnoid space, central canal and ventricles

Ventricles

continuous with central canal of spinal cord

contains CSF

lined by ependymal cells

Choroid plexuses

Specialized capillaries in this region secrete CSF into the lateral ventricles

Two places CSF can enter

the central canal of the spinal cord

subarachnoid space of meninges

How is CSF reabsorbed into the blood stream

through arachnoid villi at the dural venous sinuses

Total volume of CSF

150 ml

1L secreted daily

Chemical protection of CSF

Regulates ions and hormones

What does a lumbar puncture measure?

CSF pressure

Cerebellum

Processes sensory input, coordinating movement output, balance and enabling nonverbal learning and memory

Reticular formation

filters information between hemispheres

Medulla

controls heartbeat and breathing

pons

controls breathing

Midbrain

Controls some motor movement and transmits auditory and visual information

Thalamus

Directs messages to the sensory recieving areas of the cortex and transmits replies to the cerebellum and medulla

Hypothalamus

directs eating, drinking and body temperature, helps govern the endocrine system and is linked to emotion and reward.

amygdala

controls emotion

Hippocampus

helps process explicit memories

Frontal lobe

enable linguistic processing, muscle movement, higher order thinking and executive functioning

motor cortex

controls voluntary movement

Broca’s area

controls speech

prefrontal cortex

enabling planning, social interactions, judgement and processing new memories

parietal lobe

registers sensory input for touch and body position

somatosensory cortex

registers and processes touch and movement sensations

temporal lobe/auditory cortex

enable language and sound processing

Wernicke’s area

interprets auditory input through the left temporal lobe

occipital lobe/visual cortex

register information from the visual field