Nerves mp3 http://www.cptproton.com/ Test Muscles of the Forearm: Anterior Compartment . These muscles are primarily flexors of the wrist and fingers

Palmar aponeurosis

Flexor retinaculum

Flexor digitorum superficialis Flexor carpi ulnaris Palmaris longus Flexor carpi radialis

Medial epicondyle of humerus Table 10.11.1

Muscles of the Anterior Compartment

. These muscles are the primary toe extensors and ankle dorsiflexors

Tibia . They include the Tibialis anterior tibialis anterior, Extensor digitorum longus

extensor digitorum Extensor hallucis longus longus, extensor Fibularis tertius Superior and inferior hallucis longus, and extensor retinacula fibularis tertius . Fill in the blanks. Muscles of the Forearm: Anterior Compartment . These muscles are primarily flexors of the wrist and fingers

Palmar aponeurosis

Flexor retinaculum

Flexor digitorum superficialis Flexor carpi ulnaris Palmaris longus Flexor carpi radialis

Medial epicondyle of humerus Muscles of the Forearm: Anterior Compartment . These muscles are primarily flexors of the wrist and fingers

Palmar aponeurosis And, they all attach to…… Flexor retinaculum

Flexor digitorum superficialis Flexor carpi ulnaris Palmaris longus Flexor carpi radialis

Medial epicondyle of humerus

Muscles of the Anterior Compartment

. These muscles are the Tibia Tibialis anterior primary toe extensors Extensor digitorum longus and ankle dorsiflexors Extensor hallucis longus Fibularis tertius Superior and inferior extensor retinacula Nerves

These four guys and frontgirl Minnie Satellite create punkrock songs which are garage-y, fast, loud, and tricky. Less catchy than what most other folks would label punk, but still with very well crafted songs. Fundamentals of the and 11

Part A Nervous System

. The master controlling and communicating system of the body . Thoughts, actions, emotions . Communicate by electrical and chemical signals . Rapid, specific responses Nervous System

. Functions . Sensory input – monitoring stimuli occurring inside and outside the body . Integration – interpretation of sensory input . Motor output – response to stimuli by activating effector organs Nervous System

Sensory input

Integration

Motor output Or, Nervous System You see that your shoulder is on fire

You yell, “Ouch” look for the water

And, throw it on your shoulder Organization of the Nervous System

. (CNS) . Brain and spinal cord . Integration and command center . Peripheral nervous system (PNS) . Paired spinal and cranial nerves . Spinal nerves carry messages to and from the spinal cord . Cranial nerves carry messages to and from the brain Cranial nerves Peripheral Nervous System (PNS): Two Functional Divisions

. Sensory (afferent - arriving) division . Transmits impulses from the receptors to the CNS

. Motor (efferent - exit) division . Transmits impulses from the CNS to effector organs Sensory Division: Two Main Parts

. Sensory (somatic ( = body)) afferent fibers . Carry impulses from skin, skeletal muscles, and joints to the brain . Visceral afferent fibers . Transmit impulses from visceral organs to the brain Motor Division: Two Main Parts

. Somatic nervous system (aka, voluntary NS) . Conscious control of skeletal muscles . Autonomic nervous system (ANS) (aka, INvoluntary NS) (think of it as the automatic NS) . Regulates smooth muscle, cardiac muscle, and glands . Divisions – sympathetic and parasympathetic

Components of nervous system of Nerve Tissue

. The two principal cell types of the nervous system are: . Supporting cells – cells that surround and wrap (aka = neuroglia or glial cells) . Neurons – excitable cells that transmit electrical signals Supporting Cells: Neuroglia

. The supporting cells (neuroglia or glial cells): . Provide a supportive scaffolding for neurons . Segregate and insulate neurons . Guide young neurons to the proper connections . Promote health and growth Neuroglia or glial cells . CNS . . . Ependymal cells . Oligo-dendro-cytes . PNS . Satellite cells . Schwann cells Astro-cytes Astrocytes

Most abundant, versatile, and highly branched glial cells

They cling to neurons and their synaptic endings, and cover capillaries

Figure 11.3a Astrocytes

Figure 11.3a Astrocytes

. Functionally they: . Support and brace neurons . Anchor neurons to their nutrient supplies . Guide migration of young neurons . Control the chemical environment Microglia and Ependymal Cells

Microglia – small, ovoid cells with spiny processes. Phagocytes that monitor the health of neurons (other immune cells cannot enter CNS)

Ependymal cells – range in csf shape from squamous to columnar They line the central cavities of the brain and spinal column

Figure 11.3b, c

Oligodendrocytes: branched cells that wrap CNS nerve fibers creating an insulated cover

Myelin sheath Process of

Nerve fibers . PNS . Satellite cells . Schwann cells Satellite Cells so named because they circle like a satellite around a planet What do you call a when it’s happy?

Schwann cells (forming sheath)

Smyelin = smylin = smiling, get it? What do you call a group of brains who form a singing group at school?

A glia club Neurons (Nerve Cells)

. What do neurons use to talk to each other?

. Billions of cell phones Neurons (Nerve Cells)

. Structural units of nervous system (billions of ‘em) . Composed of a body, and . Long-lived (~100 yrs), amitotic (we know what that means, right?) and have a high metabolic rate (need lots of O2 and glucose) . Their plasma membrane functions in: . Electrical signaling . Cell-to-cell signaling during development Neurons (Nerve Cells)

Dendrites Cell body (receptive (biosynthetic center regions) and receptive region)

Nucleolus

Axon (impulse Nucleus generating Impulse and conducting direction Nissl bodies region) Axon terminals (secretory Neurilemma (one inter- region) node) Terminal branches

Nerve Cell Body (Perikaryon or Soma)

. Contains the nucleus and a Dendrites Cell body (receptive (biosynthetic center nucleolus regions) and receptive region) . Has well-developed Nissl bodies (rough ER)

. Is the focal point for the Nucleolus outgrowth of neuronal processes (embryonic)

. Contains an axon hillock – Axon cone-shaped area from Nucleus Nissl bodies which arise Axon hillock . Part of the receptive region Nerve Cell Body (Perikaryon or Soma)

. Has no centrioles (Why not?)

. Which cliche would a not use . Let’s make like a tree and leave . Let’s get the flock out of here . Let’s bounce . Let’s split Processes are

. Armlike extensions from the soma (cell body) . CNS contains cell bodies and processes . PNS contains chiefly processes (why?) . There are two types: dendrites and axons . Bundles of axons are called . Tracts in the CNS and nerves in the PNS Processes are axons and dendrites

Dendrites (receptive regions)

Axon Dendrites of Motor Neurons

Dendrites (receptive . Short, tapering, and regions) diffusely branched processes . One neuron usually has many dendrites, up to 10,000 . They are the receptive, or input, regions of the neuron . Convey info toward the cell Axons: Structure

. Slender processes of uniform diameter arising from the hillock, carrying information away from the cell . Long axons are called nerve fibers

. One leads from the big toe up the leg, past the cell body near the spinal cord, into the cord and up to the brainstem, a couple meters or more. . Usually there is only one unbranched axon per neuron . Axonal terminal – branched terminus of an axon (aka telodendria)

. ~10,000 or more terminal branches Axons: Structure

Axon (impulse Impulse generating direction Axon terminals and conducting Node of Ranvier region) (secretory region)

Schwann cell (one inter- Neurilemma node) Terminal branches

Axons are the conducting region leading to the secretory region Aka axon terminals synaptic knobs or boutons Myelin Sheath

. Whitish, fatty (protein-lipoid), segmented sheath around most long AXONS . NEVER found on dendrites Myelin Sheath and Neurilemma: Formation

. Formed by Schwann cells in the PNS

. Who does this in the CNS? Oligodendrocytes . A Schwann cell: . Envelopes an axon in a trough . Encloses the axon with its plasma membrane . Has concentric layers of membrane that make up the myelin sheath . Neurilemma – remaining nucleus and cytoplasm of a Schwann cell Myelin Sheath and Neurilemma: Formation

Schwann cell plasma membrane Schwann cell 1 A Schwann cell cytoplasm envelopes an axon.

Axon Schwann cell nucleus

2 The Schwann cell then rotates around the axon, wrapping its plasma membrane loosely around it in successive layers.

Neurilemma 3 The Schwann cell Myelin sheath cytoplasm is forced from between the membranes. The tight membrane wrappings surrounding the axon form the myelin (a) Myelination of a nerve sheath. fiber (axon) Myelin Sheath and Neurilemma: Formation

Myelin sheath

Schwann cell cytoplasm Axon

Neurilemma

(b) Cross-sectional view of a myelinated axon

(electron micrograph 24,000X) Nodes of Ranvier (Neurofibral Nodes)

. Gaps in the myelin sheath between adjacent Schwann cells Myelin Sheath

Node of Ranvier Axon Schwann cell terminals Neurilemma (one inter- (secretory node) Terminal region) branches Unmyelinated Axons

. A Schwann cell surrounds nerve fibers but coiling does not take place . Schwann cells partially enclose 15 or more axons Axons of the CNS

. Both myelinated and unmyelinated fibers are present . Myelin sheaths are formed by oligodendrocytes . Nodes of Ranvier are widely spaced . There is no neurilemma, one oli covers many axons Regions of the Brain and Spinal Cord

. – dense collections of myelinated fibers . Gray matter – mostly soma and unmyelinated fibers Neuron Classification

One nerve Two nerve

Red Blue nerve nerve Neuron Classification

. Structural: . Multipolar — three or more processes . Bipolar — two processes (1 axon and 1 ) . Unipolar — single, short process Neuron Classification

. Functional: . Sensory (afferent) — transmit impulses toward the CNS . Motor (efferent) — carry impulses away from the CNS . (association neurons) — shuttle signals through CNS pathways

Common as cars I feel that these Rare as glass eyes are just in between Bad drivers in California are Having a sixth as common as sense is cars as rare as multipolar glass eyes I feel that these neurons bipolar cells are just in between

Neuron animation