PNS and endocrine

Anatomy of the Spinal Cord-connection between the brain and brainstem to the rest of the body, 31 pairs of spinal nerves

Cross Section Anatomy- Two grooves divide spinal cord

Gray Matter

White Matter

Peripheral Nerves-Is made up of 31 pairs of spinal nerves and 12 pairs of cranial nerves

Spinal Nerves-Allow the brain and body to communicate

Cranial Nerves

Coverings

Autonomic Nervous System-branch of PNS

Endocrine System-Consists of endocrine glands located throughout the body

Hormones-chemical messengers, produced by endocrine cells, that travel in blood and influence certain cells elsewhere in the body

Hormonal Mechanism and Control

Endocrine Organs of the Brain

Hormones of Pituitary Glands

Cervical Enlargement-C4-T1-Nerves to and from upper limbs

Lumber Enlargement-T9-T12-Nerves to and from lower limbs

Conus Medularis-end of the spinal cord

Cauda Equina="horse's tail" divides into nerves that leave at lower levels

Anterior Median Fissure- deeper

Posterior median sulcus

Lateral Horns- Located on the side cell bodies of motor neurons to cardiac, and smooth muscle and glands

Anterior/Ventral Horns (Motor)- Cell bodies of motor neurons to skeletal muscle

Posterior/Dorsal horns (Sensory)- located in the back

Central Canal-center of gray matter commisure; continuous with fourth ventricle

Descending (Motor) Tracts-Impulses from brain

Ascending (Sensory) Tracts-impulses toward brain

Mixed nerves-carring both sensory and motor information

Posterior/dorsal roots- contain sensory fibers whose cell bodies are located in dorsal root ganglion

Anterior/Ventral roots-contain motor axons and conduct impulses from brain and cord to periphery

VI-Abducens-lateralrectus eye muscle abducts the eye

VII-Facial-motor to muscles of facial expression; sensory-taste

V-Trigeminal-3 branches- motor-chewing;sensory-skin of face

VIII-Vestibulocochclear-sensory-hearing and equilibrium (balance)

IV-Trochlear-superior oblique muscle of eye

IX-Glossopharyngeal-motor secretion of saliva; sensory-taste,regulation of blood pressure, and proprioception of muscles involved with swallowing

III-Oculomotor-mostly motor function-most of muscles of eye, eyelid, and pupillary constriction

X-Vagus-motor-smooth muscle contraction and relaxation, secretion of digestive fluids; heart, lungs-parasympathetic innervation; sensory from visceral organs it supplies and proprioception

II-Optic-Arises from retina of the eye and functions in vision

XI-Accessory-motor:swallowing and movements of head;sensory-proprioception

I-Olfactory-Sensory nerve that functions in sense of smell

XII-Hypoglossal-motor-movement of tongue during speech and swallowing:sensory-proprioception

Perineurium-surrounds fascicles (bundles nerve fibers)

Epineurium-surrounds entire nerve

Endoneurium-surrounds individual neuron

Sympathetic- fight or flight, E- exercise, excitement, emergency, embarrassment

Parasympathetic-daily body functions, feed or breed, D-digestion, defecation, and diuresis (Urination)

Negative Feedback-occurs when there is a drop in the level of a hormone, triggers a chain reaction of responses to increase hormones in the blood

Endocrine Glands of the Body

Pancreas-controls blood sugar levels

Insulin-decrease blood glucose

Thymosin Hormones-stimulates the development of the T-cells involved in the immune response

Adrenal Cortex-outer layer

Parathyroid Hormone (PTH)-increases blood calcium levels

Glucocorticoids or cortisol-responds to stress or injury and releases anti-inflammatory

Calcitonin-decrease blood calcium levels

Adrenal Medulla-inner layer

Thyroid Hormone(Thyroxine,T3 and T4)-control the basal metabolic rate

Epinephrine (adrenaline)-stimulates the fight or flight response

Anterior lobe-makes and releases hormones under the control of the hypothalamus

Posterior lobe-stores and secretes hormones that are made in the hypothalamus, such as antidiuretic hormone and oxytocin,and releases them to the rest of the body as necessary

Pituitary gland=master gland that signals other glands to produce their hormones when needed

Antidiuretic hormone (ADH)-regulates fluid balance by increasing body fluid volume and decreasing urine output

Hypothalamus-produces hormones that stimulates the pituitary gland

Oxytocin-stimulates contraction of the uterus during labor and milk, or ejection from alveoli

Melatonin-controls sleep cycles, alertness, and temperature

Human growth hormone (HGH)-stimulates growth during infancy and puberty

Prolactin-initiates and maintains milk secretion

Adrehocorticotopic hormone (ACTH)-stimulates the adrenal gland to release cortisol

Thyroid stimulating Hormone (TSH)- control basal metabolic rate releasing thyroxine

Luteinizing hormone (LH)-both involved with development of ovaries and testes

Melanocyte stimulating hormone (MSH)-stimulates production of melanin in the skin

Follicle stimulating hormone (FSH)-stimulates egg maturation in the ovary and release sex hormones