Anatomy Exam 2

What are the functions of the nervous system?

collect information, process and evaluate information, and respond to information

What is the difference between grey matter and white matter?

grey matter is darker in color, regions of the CNS made mostly of cell bodies and axons.

white matter is lighter in color due to its myelin content, regions of the CNS made mostly of axons.

Where is grey and white matter found?

grey matter - mostly outside the brain, inside spinal cord, ganglia (cell bodies) in PNS

white matter - mostly inside the brain, outside spinal cord, nerves (axons) in PNS

What are the parts of the CNS?

the brain and spinal cord

What are the structures of the PNS?

cranial nerves, spinal nerves, ganglia, peripheral nerve endings/receptors, nerve plexuses (cervical, brachial, lumbar, sacral)

What are the four divisions of the nervous system?

somatic sensory, visceral sensory, somatic motor, autonomic motor (visceral motor)

know the parts of a neuron

What are the glia and their functions of the CNS?

astrocytes, oligodendrocytes, microglia, ependymal cells

What are the glia and their function in the PNS?

Schwann cells, satellite cells

Know the parts and connective tissue layers of a nerve.

What are the four divisions of the brain?

Cerebrum, Diencephalon, Cerebellum, and Brain Stem

Identify structures on the external and internal views of the brain

What are the lobes of the cerebrum, etc? Know the major sulci and hyri

frontal, temporal, parietal, occipital, insula lobes.

Hypothalamus

helps maintain homeostasis

Epithalamus

houses the pineal gland (endocrine gland which secrets melatonin)

Thalamus

Relays all somatosensory, visual, and auditory information (except for smell)

Brain stem (in general)

Connects cerebrum to spinal cord, start of cranial nerves, autonomic and reflex centers.

Cerebellum

fine tunes and tweaks body movements, coordinates body movements, maintain posture and equillibrium

Cerebral nuclei

Stops and regulates the intensity of voluntary movements.

Corpus Callosum

Provides the major pathway for communications between the left and right hemispheres of the brain

Broca’s area

Motor speech control

Wernicke’s area

Recognition and understanding of speech

Amygdala

Memory, decision making, and emotional response

Cingulate gyrus

Emotional response (limbic system)

Hippocampus

Memory storage (limbic system)

Primary somatosensory cortex

Receives information from somatic senses, enables conscious understanding of these

Primary motor cortex

Controls voluntary skeletal muscle activity

Primary visual cortex

Receives visual information from the retina of the eye.

Cerebrum (in general)

thinking, voluntary movement, sensory processing, memory, language, and emotions

Know the meningeal layers

dura mater - tough, outermost protective layer

arachnoid mater - middle, web-like layer

pia mater - thin, innermost layer that tightly follows the surface of the brain and spinal cord

What are the 3 layers of meninges?

Dura mater, Arachnoid mater, Pia Mater

Dura mater

outer meningeal later, thick and fibrous, strong protective sheath around the brain and spinal cord.

Arachnoid Mater

middle meningeal layer, thin, gauzy and fibrous, subarachnoid space is filled with mesh (arachnoid trabeculae)

Pia mater

deepest meningeal layer, touches the brain and spinal cord directly, conforms to the shape of underlying structures.

Know the vessels that supply the CNS with blood. Identify elements of the cerebral arterial circle.

supply the CNS with blood - internal carotid arteries, vertebral arteries

CAC: anterior cerebral arteries, anterior communicating artery, internal carotid arteries, posterior communicating arteries, posterior cerebral arteries

What are the arteries in the cerebral arterial circle?

R & L posterior cerebral arteries, R & L posterior communicating arteries, R & L internal carotid arteries, R & L anterior cerebral arteries, anterior communicating artery.

Identify the other arteries supplying blood to the brain. Where do they branch off from? Where do they travel to?

Know the parts of the ventricular system

What is CSF? What is its function?

• cerebrospinal fluid

• brain and spinal cord “float” in CSF

• resists compressive forces and cushions against trauma

• feeds brain, removes waste, and carries chemical signatures

Identify the dural venous sinuses

What is the pathway of CSF from production to the drainage via the internal jugular vein

Clinical Application: Multiple Sclerosis

autoimmune disease in which the immune system attacks myelin in the CNS

• impaired vision, muscle weakness and spasms, urinary and fecal incontinence, mood swings.

Clinical Application: Alzheimer’s Disease

a progressive neurodegenerative disease that damages and destroys neurons in the brain, most common cause of dementia

• memory loss, confusion and disorientation, difficulty thinking and making decisions, personality and behavior changes, difficulty communicating.

Clinical App: Meningitis

inflammation of the meninges, the protective membranes surrounding the brain and spinal cord

• fever, stiff neck, sensitivity to light, extreme fatigue or lethargy

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What are the functions of the spinal cord?

• sensory and motor innervation of the body

• two-way conduction (communication) pathway for signals between the body and the brain

• center for reflexes

Identify the structures of the spinal cord (including cauda equina, conus medullaris, and filum terminale)

What are the 3 layers of meninges protecting the spinal cord?

Dura mater, Arachnoid mater, Pia mater

What are the spaces associated with the 3 layers of meninges?

epidural space - between dura mater and surrounding bone

subdural space - between dura mater and arachnoid mater

subarachnoid space - between arachnoid mater and pia mater

What are the anchors for the spinal cord?

denticulate ligament - side-to-side stabilization

filum terminale - anchors the bottom of the spinal cord

Identify structures of the spinal cord

What are the 5 steps of the reflex arc?

1.) stimulus activates a sensory receptor (external or internal stimuli)

2.) nerve impulse travels through the sensory neuron to the CNS (usually to spinal cord, rarely to brain)

3.) information processed by interneurons

4.) motor nuerons send action impulse to effector

5.) effector responds to nerve impulse

What are dermatomes? Why are they important for health care professionals to know?

areas of skin that receive sensory information from one specific spinal nerve level. each dermatome corresponds to a spinal nerve level.

• we identify nerve damage, diagnose spinal injuries, perform neurological exams, etc.

How many cervical spinal nerves?

8

How many thoracic spinal nerves?

12

How many lumbar spinal nerves?

5

How many sacral spinal nerves?

5

How many coccygeal spinal nerves?

1

How are the spinal nerves numbered relative to the vertebrae?

named for the vertebrae that they exit near

Does C1 spinal nerve emerge superior or inferior to C1 vertebrae?

superior

What about the C8 spinal nerve? Since there are only 7 cervical vertebrae

emerges between C7 and T1 vertebrae

Cervical Plexus

• C1-C5

• Phrenic nerve - diaphragm (C3,C4,C5 keeps the diaphragm alive!)

• Ansa cerivcalis - C1-C3: infrahyoid muscles

Brachial Plexus

• C5-T1

• Musculocutaneous - elbow flexion (biceps brachii)

• Axillary - arm abduction (deltoid)

• Radial - elbow, wrist and finger extension

• Median - wrist/finger flexion and thumb opposition

• Ulnar - finger abduction and adduction

Roots → Trunks → Divisions → Cords → Branches (Remember To Drink Cold Beverages)

Lumbar Plexus

• L1-L4

• Femoral nerve - motor function: hip flexion and knee extension (front of thigh), sensory function: anterior/medial thigh and medial leg (knee extension)

• Obturator nerve - motor function: thigh adduction (bringing thighs together), sensory function: medial thigh

Sacral Plexus

• L4-S4

• Sciatic nerve - largest nerve in the body

• Tibial nerve - plantarflexion (points toes down)

• Common fibular nerve - dorsiflexion and foot eversion

• Pudendal nerve - supplies perineum and external urethra and anal sphincters

Identify the proximal and distal ends of the brachial plexus. (Identify the roots, trunks, branches, cords and divisions)

List the Brachial and Cervical Plexus nerves (5)

List the Lumbar and Sacral Plexus nerves (4)

What is homeostasis? How does the body monitor its own function?

steady state of body systems that living organisms maintain, it monitors its own function through negative feedback system.

What is the ANS?

general visceral motor system of the PNS

What is the function of the ANS?

involuntary control of visceral functions, regulates systems’ homeostasis, controls all of the routine functions of our physiological systems.

How is the ANS different from the somatic motor nervous system?

What are the general effects of the sympathetic nervous system

maintain homeostasis when under pressure, increase heart rate, respiration, and adrenaline, dilates pupils and slows digestion, liver releases sugars (energy into blood)

What is the sympathetic chain/trunk?

interwoven structure of preganglionic neuronal axons and ganglia

What are the general effects of the parasympathetic nervous system?

maintains homeostasis when at rest, slows respiration and heart rate after exertion, increases blood flow to digestion, constricts pupils

Effects of the sympathetic NS

Effects of the parasympathetic NS

What are some functions of the endocrine system?

Hormone secretion - directly into blood or interstitial fluid for transport throughout the body

Homeostasis Maintenance - ensure the body environments are operating within optimal functional ranges.

Where are the hormones released in the endocrine system?

Through the bloodstream

Different endocrine glands, hormone produced, and target

What is the master gland?

The hypothalamus

What is another function of the pancreas?

What are the secondary endocrine glands?