CA1 Brain

In the cranial cavity

• Sensory perceptions
• Issues moto commands
• Memory
• Reasoning
• Coordinates muscular movements
• Regulates visceral (organ) activities
• Personality

• Cerebrum (last portion to develop)
• Diencephalon (inner part)
• Brain stem (midbrain, pons and medulla oblongata)
• Cerebellum

• 2 hemispheres connected by a bridge of nerve fibers called the corpus callosum (L & R)
• The two hemispheres are separately the falx cerebri (midsagittal plane)
• Largest
• Gyri: ridges
• Sulci: shallow grooves
• Fissures: deep grooves

Primary MOTOR area

• Posterior to frontal lobe
• Primary SENSORY area

Inferior to frontal and prietal lobes

Posterior portion of cerebrum

• we still don't know much about it
• Deep
• Covered by parts of frontal, parietal and temporal lobes

• Unmyelinated cell bodies (no sheath)
• Cerebral cortex (surface/magic shell): superficial portion of the hemispheres consit of thin layer (2-5 mm thick)
• Consistd mostly of the *nerve cell bodie of nuclei (which appear gray in color)

• Beneatht he cortex
• Consists of mostly *myleinated nerve anons (has white sheath, appears white in color)

• Masses of gray matter that are located deep within the cortex of the cerebrum
• Caudate nucleus, putamen,a nd globus padillus
• *Relay states for MOTOR impulses originating in the cerebral cortex and can inhibit motor functions by searching dopamine (=movement)(NT) (Parkinsons)

Bwtween the cerebral hemispheres and above the brain stem. (Deep)

Mostly gray matter

• Thalamus
• Hypothalamus
• Limbic system
• Optic tracts
• Optic chiasma
• Infundibulum (stalk)
• Posterior pituitary gland (right behind bridge of nose)
• Pineal gland

Receives sensory impulses and channels them to appropriate regions of the cortex for interpretation.

Regulates heart rate, arterial BP, body temperature, water and electrolyte balance, controls hunger and body weight.

Controls emtions (also memory and smell)

Connects the brain and spinal cord

• Midbrain
• Pons (connects it with cerebellum)
• Medulla oblongata

Lies between the diencephalon and the pons

Separates the midbrain from the medulla oblongata

• Enlarged superior continuation of the spinal cord (lower end)
• -Olives (bundles of nerve fibers)
• -Nucleus gracilis and cuneatus (receive sensory impulses from the spinal cord)
• -"Centers" formed by nuclei

• Cardiac center: controls heart rate
• Vasomotor center: alters blood pressure by controlling dilation and constriciton of bl. vessels
• Respiratory center: regulates rate, rhythm and depth of breathing

• Located throughout the brainstem and is a network of nerve fibers connected by small nucli (spread out)
• Deals with psychological disorders - filtering issues
• Functions:
• Receives sensory impulses from the spinal cord & responds by activating the cerebral cortex into a state of wakefulness (high energy)
• "Fliters" incoming sensory impulses (passes them along or disregards them)
• Regulates and coordinates motor activities

• Old or Little Brain
• Is an error detection & correction center
• Has 2 hemisoheres
• Consists of an outer cortex (gray matter) and inner cortex(white matter) which are connected by a structure called the vermis (worm)
• Communicates with other parts of the CNS via cerebellar peduncles

*Functions: to coordinate skeletal muscle activity and maintain posture (affect behavior, what makes you you)

• 31
• Numbered superior to inferior in each spinal region (C1-C8, T1-T12, L1-L5, S1-S5 and Co1)

Between the level of L1 and L2 (conus medullaris)

As a bundle (cauda equina) through the spinal canal

By the merging of the dorsal root (sensory) and ventral root (motor)

• Meningeal (sinuvertebral) branch
• Posterior branch (dorsal ramus)
• Anterior branch (ventral branch)

• (dorsal ramus) sensory branch
• Innervates (supplies) muscles (motor) and skin of the back

• Network of cervical, lumbar and sacral ventral rami
• Spinal nerve fibers are sorted and combined into named individual nerves

• Do NOT form Plexuses, but instead travel between ribs (intercostal spaces) where they are called intercostal nerves
• They innervate (supply) intercostal and upper abdominal muscles and the skin of the throax and abdomen

• Lies deep in gthe neck and is formed by the ventral rami of C1-C4 (not the upper extremity)
• Nerves formed by the cervical plexus innervate muscles and skin of the NECK (not the face)
• *Nerve fibers fromt he ventral rami C3, 4 & 5 form the phrenic nerve which innervates the diaphragm ("C3, 4&5 keep the diaphragm alive")

• Located between the neck and axilla (arms and upper extremities)
• Formed by the ventral rami of C5-8 and T1 (nerve roots)
• It innervates the skin, joints and muscles of the shoulder, chest and upper limbs.
• Travels with the subclavian artery and its contination, the axillary artery b/t the anterior and middle scalene muscles and b/t the pectoralis minor and the upper ribs

• Musculocutaneous nerve
• Ulnar nerve
• Median nerve
• Radial nerve
• Axillary nerve
• Others:
• Lateral and medial pectoral nerves
• Dorsal scapular nerve
• Thoracodorsal nerve
• Suprascapular nerve

Innervates the coracobrachialis, biceps brachii and brachialis muscles. It ends by forming the lateral antebrachial cutaneous nerve which innervates the skin of the lateral forearm

• (pinki)
• innervates the flexor carpi ulnaris and the medial half of the flexor digitorum profundous muscles and skin of the hand (deep muscles and fingers)

innervates all of the muscles of the anterior forearm except the flexor carpi unlaris and it innervates some of the muscles and skin fo the hand (thumb action)

innervates the triceps, brachioradialis and the extensor muscles of the forearm as well as the skin of the posterior forearm and hands (back of arm)

Innervates the teres minor and deltoid and skin of the superior, lateral and posterior regions of the arm

• Formed by the ventral rami from T12, L1-5 S1-5 and the coccygeal nerves
• Everything from the waist down (iliac crest)
• The nerves formed by this plexus innervate the skin, joints and muscles of the lower abdominal wall, external gentalia, buttocks, thighs, legs and feet

• Obtuator nerve
• Femoral nerve
• Siatic nerve
• Others:
• Pudendal nerve - innervates muscles of the perineum (floor of the pelvis) and sensory from the external genitalia
• Interior gluteal nerve
• Superior gluteal nerve

Innervates the adductors muscles (except pectineus) and skin fo the medial thigh

Innervates iliacus, sartorius, pectineus and quadricepts femoris and skin of the thigh and legs

• Consists of two divisions in the posterior thigh (tibial and fibular) that innervate the hamstring muscles
• Proximal to the knee it splits into the tibial and common fibular (peroneal) nerves
• Tibial nerve innervates the posterior leg muscles and the foot
• Common fibular nerve innervates muscles of the anterior and lateral leg
• They both innervate the skin and joints of the gluteal region and lower limbs

• Regions (areas) on the skin innervated from nerve fibers that originate from a specific spinal cord level (sensory not motor)
• Sensory fibers from each spinal cord level will innervate skin of the body in a characteristic pattern that varies in size and shape from person to person