Human Structure & Function Final

Front 1

Autonomic Nervous System

Back 1

-Always efferent; never afferent
-functions below level of consciousness, but can be affected by higher brain function
-Sympathetic & Parasympathetic divisions
-innervates cardiac muscle, smooth muscle, and glands
-Works through reflex arc
-Maintains homeostasis of key visceral functions necessary for life

Front 2

Enteric Nervous System

Back 2

an extensive network of neurons and nerve networks located in the walls of the digestive tract

Front 3

Autonomic Nervous System (Reflex Arc)

Back 3

-Maintains HOMEOSTASIS for key VISCERAL functions necessary for life
-low blood pressure --> carotid sinus --> CN IX --> Medulla Oblongata --> ANS --> heart --> BP up

Front 4

Dual Innervation

Back 4

-actions are antagonistic in most cases
-in a few cases, they function cooperatively
-work sequentially, not at the same time

Front 5

Somatic Efferents

Back 5

-innervates skeletal muscle
-control is precise & voluntary
-one neuron between CNS & peripheral effector

Front 6

Autonomic Efferents

Back 6

-cardiac m., smooth m., & glands
-control is diffuse & involuntary
-two neurons between CNS & peripheral effectors
(autonomic ganglion w/ pre & post ganglionic fibers)

Front 7

Neurotransmitters in ANS

Back 7

-Cholinergic Neurons (Acetylcholine)
-Adrenergic Neurons

Front 8

Cholinergic Neurons

Back 8

-synthesize & release acetylcholine
-Preganglionic efferent neurons of both SNS and PNS
-Postganglionic neurons of PNS
-Some postganglionic fibers of SNS

Front 9

Adrenergic Neurons

Back 9

-synthesize & release norepinephrine
-Postganglionic neurons of SNS
-Adrenal medulla is a modified sympathetic ganglion

Front 10

Neurotransmitter Receptors in ANS

Back 10

-Cholingeric
1)Muscarinic
2)Nicotinic
-Adrenergic
1)Alpha
2)Beta

Front 11

Neurotransmitter Receptors in ANS (importance)

Back 11

-important in pharmacological & clinical practice to block or stimulate specific receptors

Front 12

Mechanisms of Signal Transduction used by Autonomic Receptors

Back 12

-Second Messengers --> used by autonomic receptors for membrane signaling mechanism
-cAMP & IP3
-Thus receptor stimulation triggers a series of intracellular molecular events within the membrane which eventually result in an end-organ response.
-These mechanisms of signal transduction use ion channels or enzyme activation-inhibition which controls the formation of second messengers.
-Messengers modify the activity of intracellular signaling pathways within the
intracellular space.

Front 13

Sympathetic vs. Parasympathetic

Back 13

-Sympathetic promotes (fight or flight)
-Parasympathetic inhibits (rest & digest)

Front 14

Parasympathetic

Back 14

-Organ specific with few branches/ divisions off of neurons
-Origin--> cranial & sacral
-Divisions of ANS
-CN III, VII, IX, & X
-S2-S4 --> innervate repro, urinary, & gastrointestinal systems

Front 15

Parasympathetic Divisions of ANS

Back 15

Nuclei in Brain Stem:
1)Ciliary ganglion (CN III) --> intrinsic eye muscles
2)Pterygopalatine ganglion (CN VII) --> lacrimal gland
3)Submandibular ganglion (CN VII) --> submandibular gland
4)Otic ganglion (CN IX) --> parotid salivary gland
5)Intramural ganglion (CN X) --> contained in walls of thoracic & abdominal cavities

Nuclei in Spinal Cord:
S2-S4 --> pelvosplanknic nerves --> innervate repro, urinary, and gastrointestinal systems

Front 16

Sympathetic Nervous System

Back 16

-T1-L2
-highly divergent --> mass effect (bllod vessels, heart, organs, etc.)
-Ganglion
1)Chain ganglion (paired) --> head, neck, thoracic cavity, limbs
2)Colateral ganglion (unpaired) --> Visceral effectors in adominopelvic cavity
3)Adrenal Medulla (paired) --> release hormones to effect many organs
4)Stellate ganglion --> when inferior cervical ganglion fuses w/ T1 of Chain Ganglion

Rami Communicantes --> connect spinal nerves to chain ganglion
1)White ramus communicans --> goes in
2)Gray ramus Communicans --> leads out

Front 17

Cutting Spinal Nerve

Back 17

Loss of ALL sensory & motor

Front 18

Thoracic Splanchnic Nerves

Back 18

names for what they innervate (ex. cardiac nerve)

Front 19

solitary nucleus

Back 19

-carry & receive visceral sensation from facial, glossopharyngeal, & vagus nerves as well as from ascending spinal tracts
-Receives primary afferent neurons related to cardiovascular, respiratory and gastrointestinal functions
-can participate in autonomic reflexes

Front 20

adequate perfusion

Back 20

-significant amount of blood flow to perform metabolic function at that time
-there is not enough blood for all organs to perform optimally at the same time

Front 21

More important to raise blood pressure or lower it?

Back 21

-much more important to raise blood pressure if it is low than to lower it if it is high

Front 22

Visceral Afferent Fibers

Back 22

-mostly visceral pain
-lie in dorsal root ganglia together with somatic sensory fibers
-or in the the sensory ganglia associated with cranial nerves (VII, IX, X). The chief visceral afferents from the heart, lungs and alimentary tract (pharynx to transverse colon) have their somae in the nodose ganglion and project via the vagus to the nucleus tractus solitarius (NTS).

Front 23

Sympathetic Characteristics

Back 23

-CNS visceral motor neurons --> lateral gray horns (T1-L2)
-PNS ganglia --> near vertebral column
-Preganglionic fibers --> short; acetylcholine
-Postganglionic fibers --> long; normally NE (sometimes NO or ACh)
-Has enlarged terminal knobs which release neurotransmitter near cell
-lots of divergence
-stimulates metabolism; increases alertness (fight or flight)

Front 24

Parasympathetic Characteristics

Back 24

-CNS visceral motr neurons --> Brain stem & S2-S4
-PNS ganglia --> intramural
-Preganglionic fibers --> long; ACh
-Postganglionic fibers --> short; ACh
-Have junction that release transmitter to special receptor surface
-little divergence; specific target
-promotes relaxation; nutrient uptake; energy storage (rest & digest)

Front 25

Referred pain

Back 25

-the phenomenon of pain perceived at a site adjacent to or at a distance from the actual site of an injury's origin
-e.g. myocardial infarction, appendicitis

Front 26

Hypothalamus

Back 26

visceral neuroendocrine response

Front 27

Gap Junctions

Back 27

-direct communication
-functional syncytium
-heart & single unit smooth muscle

Front 28

Synaptic Communication

Back 28

-presynaptic knob releases hormones --> bind to receptors on postsynaptic neuron

Front 29

Neurohormones

Back 29

-transmitted near blood vessels & travel long distances to target

Front 30

"classic" hormone

Back 30

endocrine cell releases hormone, goes into bloodstream, travels to target cell

Front 31

"local" hormones

Back 31

-cytokine: signaling molecules such as proteins, peptides, or glycoproteins used in cellular communication
-paracrine: kind of cytokine that is released by a secretory cell & effects a neighboring cell
-autocrine: cell that releases hormone is also the target cell

Front 32

Hormone Receptor

Back 32

-protein molecule to which a molecule binds strongly
-presence or absence of specific receptor determines hormonal activity

Front 33

Target Cells

Back 33

-specific cells that possess receptors needed to bind and "read"hormonal messages

Front 34

Neural vs. Endocrine Control

Back 34

Nervous System
-Secretory Cell --> Neuron
-Target Cell --> Neuron, Muscle, or Gland
-Messenger --> Neurontransmitter
-Pathway for Communication --> across synapse
-Specificity --> Receptors on postsynaptic target cells
-Time til effect --> immediate
-Duration --> brief

Endocrine Systems
-Secretory Cell --> Endocrine cells
-Target Cell --> Most cell types in body
-Messenger --> hormone
-Pathway for Communication --> via bloodstream
-Specificity --> Receptors on target cells throughout body
-Time til effect --> delayed
-Duration --> long

Front 35

Endocrines Controls

Back 35

-long term processes
-ex growth, development, & reproduction

Front 36

Hormones divided into 3 groups

Back 36

-based on chemical structure
1)Amino Acid Derivatives: hydrophillic
2)Peptide Hormones: most common
3)Lipid Derivatives

Front 37

Amino Acid & Peptide Hormones

Back 37

-Remain functional for less than an hour
-diffuse out of bloodstream & bind to receptor
-Broken down & absorbed by cells of the liver and kidneys
-Broken down by enzymes in plasma or interstitial fluid

Front 38

Thyroid & Steroid Hormones

Back 38

-Remain in circulation much longer
-Enter bloodstream (more than 99% become attached to special transport proteins)
-Bloodstream contains substantial reserves of hormones (inactive form)

Front 39

Cell Surface Receptor (plasma membrane)

Back 39

-proteins & peptides and catecholamines & eicosanoids
-generate second messengers which alter activities of other molecules

Front 40

Intracellular Receptors (cytoplasm & nucleus)

Back 40

-steroids & thyroid hormones
-alter transcriptional activity of responsive genes

Front 41

Catecholamines & Peptide Hormones

Back 41

-are not lipid soluble
-unable to penetrate plasma membrane
-Bind to receptor proteins at outer surface of plasma membrane (extracellular receptors)
-Cannot have direct effect on activities inside target cell
-Use intracellular intermediary to exert effects i.e. second messengers (cAMP, cGMP, Calcium ions)

Front 42

Amplification

Back 42

binding of a small number of hormone molecules to membrane receptors leads to thousands of second messengers in the cell & thus magnifies the effect of the hormone on its target cell

Front 43

Lipid Derivatives

Back 43

Cholesterol --> Steroids

Front 44

Eicosanoids

Back 44

-are generated by the action of phospholipases on triglycerides in which one of the fatty acids is arachidonic acid.
-have hormone-like activity

Front 45

Three Classes of Eicosanoids

Back 45

1)Prostaglandins
2)Thromboxanes
3)Leukotrienes

Front 46

Prostaglandins

Back 46

-regulate the synthesis of the cellular messenger cyclic AMP -Since cAMP is involved in many cellular processes, prostaglandins affect many cellular functions. -Some prostaglandins regulate muscle contraction during labor. -Other elevate body temperature (they produce fever), and cause inflamation and pain.

Front 47

Thromboxanes

Back 47

-are involved in the formation of blood clots, and the reduction of blood flow to the site of a blood clot.

Front 48

Leukotrienes

Back 48

-are responsible for the contraction of the smooth muscle lining the airways
-excess of leukotrienes results in, for example, asthmatic attacks, as well as allergic reaction resulting from bee stings, penicillin, etc.

Front 49

Non-Steroidal Anti-Inflammatory Drugs (NSAID)

Back 49

-such as aspirin & derivatives of ibuprofen
-inhibit cyclooxygenase activity of PGH2 Synthase (COX enzymes).
-inhibit formation of prostaglandins involved in fever, pain, & inflammation.
-inhibit blood clotting by blocking thromboxane formation in blood platelets.

Front 50

Anti-Asthma Medication

Back 50

-inhibitors of 5-Lipoxygenase, e.g., Zyflo (zileuton)
-drugs that interfere with leukotriene-receptor interactions
-eg. Singulair (montelukast) & Accolate (zafirlukast) block binding of leukotrienes to receptors on the plasma membranes of airway smooth muscle cells

Front 51

Lipid Derived & Steroid Hormones

Back 51

-lipid soluble
-able to penetrate plasma membrane
-bind to intracellular receptor proteins
-alter rate of DNA transcription in nucleus
-change patterns of protein synthesis
-directly affect metabolic activity and structure of target cell

Front 52

Amplitude Coding or "Pattern Recognition"

Back 52

-amount of hormone released
-pattern of hormone release/secretion

Front 53

Endocrine Reflexes

Back 53

-functional counterpart of neural reflexes
-controlled by negative feedback mechanisms (in most cases)

Front 54

Endocrine Reflexes can be triggered by

Back 54

1)Humeral Stimuli
2)Hormonal Stimuli
3)Neural Stimuli

Front 55

Humeral Stimuli

Back 55

-change composition of extracellular fluid

Front 56

Hormonal Stimuli

Back 56

-arrival or removal in specific hormone

Front 57

Neural Stimuli

Back 57

-arrival of neurotransmitters at neuroglandular junctions

Front 58

Down Regulation

Back 58

-presence of a hormone triggers decrease in number of hormone receptors
-when levels of a particular hormone are high, cells become less sensitive

Front 59

Up Regulation

Back 59

-absence of hormone triggers increase in number of hormone receptors
-when hormone levels are low, cells become more sensitive

Front 60

Endocrine Organs

Back 60

-encapsulated; can be removed from body in one piece
-eg pituitary, thyroid, parathyroid, thymus, adrenal galnds, pancreas

Front 61

Pineal Gland

Back 61

-astrocyte-like neuroglial cells
-neuron-like pinealocytes
-production of melatonin

Front 62

Postulated Functions of Melatonin

Back 62

-role as antioxidant
-role as immunoregulator
-role in mechanisms of learning & memory
-role in biological clock

Front 63

Corpora Arenacea/ Psammoma bodies/ brain sands

Back 63

-used to show brain displacement; show up on x-rays

Front 64

Pituitary Gland (Hypophysis)

Back 64

-Anterior Pituitary (adenohypophysis)
-Posterior Pituitary (neurohypophysis)

Front 65

Infundibulum

Back 65

-connects the hypothalamus to the pituitary gland

Front 66

Rathke's Pouch

Back 66

gives rise to the anterior pituitary

Front 67

Posterior Pituitary Hormones

Back 67

-released from, but not made in the posterior pituitary
-Neurosecretory neurons in hypothalamus --> infundibulum --> posterior pituitary

Front 68

Anterior Pituitary Hormones

Back 68

-made & released in anterior pituitary

Front 69

Neurohormones

Back 69

ADH
-decreases urine volume
-increases blood volume --> increases blood pressure
-made in supraoptic nucleus of hypothalamus

Oxytocin
-travels down hypothalamic-posterior pituitary stalk
-produces contractions in breasts for release of milk
-produces contractions during labor

Front 70

Anterior Pituitary

Back 70

-under control of hypothalmus
-has many target endocrine galnds
-not neural tissue like hypothalamus

Front 71

Hypothalamo-hypophyseal portal system

Back 71

-Primary capillary plexus --> receives hormones from hypothalamus
-Secondary capillary plexus --> surrounds anterior pituitary

Front 72

Thyroid Gland

Back 72

-stores hormones in an inactive state (not common; hormones usually made on demand)
-thyroid hormones contain iodine
-thyroglobulin --> colloid, innactive precursor to thyroid hormones

Front 73

Hypothyroidism

Back 73

-very short, underdeveloped (mentally & physically) --> cretinism in children
-metabolic rate lower in adult --> sluggish; weight gain --> mixodema

Front 74

Hyperthyroidism

Back 74

-higher than normal body temp --> calorigenic effect

Front 75

No iodine in diet

Back 75

-No T3 or T4 made --> lots of TSH & TRH --> goiter

Front 76

Parafollicular Cells

Back 76

-produce calcitonin (antagonistic to PTH
-calcitonin --> lowers body calcium (Ca from bloodstream into bones)

Front 77

High Calcium Reflex Arc

Back 77

High Ca --> detected by C-cells --> release calcitonin --> Ca into bone --> lower [Ca] in bloodstream

Front 78

Adrenal Cortex (3 layers)

Back 78

1)Zona Glomerulosa
2)Zona Folliculada
3)Zona Reticularis

Front 79

Adrenal Medulla

Back 79

Deep to 3 layers of adrenal cortex
-epinephrine/norepinephrine --> increased cardiac activity, blood pressure, & glycogen breakdown

Front 80

Zona Glomerulosa

Back 80

-outer layer
-cells shaped like balls
-mineralcorticoids (aldosterone) --> affect renal absorption of Na & water

Front 81

Zona Folliculada

Back 81

-middle layer
-glucocorticoids (cortisol) --> anti-inflammatory effects

Front 82

Zona Reticularis

Back 82

-deepest layer
-cells --> inner connecting web
-androgens --> not important in adult men

Front 83

Adrenocorticotropin Hormone (ACTH)

Back 83

Anterior pituitary --> adrenal cortex --> releases androgens & cortisol

Front 84

Aldosterone

Back 84

mineralcorticoid --> increases blood volume by osmosis

Front 85

Parathyroid Hormones

Back 85

-round chief cells embedded in thyroid gland
-PTH --> raises blood levels of Ca
-controlled by humeral response to Ca levels

Front 86

Somatotroph

Back 86

-production under control of hypothalamus
-promotes general body growth
-Liver will produce insulin like growth factors (somatomedins) --> effects bone growth

Front 87

Gonadotropins

Back 87

-Leutinizing Hormone (LH) & Follicle Stimulating Hormone (FSH)
-Stimulate ovaries in females & testes in males

Front 88

LH

Back 88

-stimulates ovaries in females --> estrogen & progesterone
-stimulates testes in males --> testosterone

Front 89

FSH

Back 89

stimulates gonads --> gamete productions (ova & sperm)

Front 90

Pancreas

Back 90

-cradled in flexture of deuodenum

Front 91

Ascinar Glands

Back 91

-produce enzymes that breakdown virtually everything

Front 92

Glucagon

Back 92

-produced by alpha cells
-catabolizes fuel stores
-increase in glucose, fatty acids, and amino acids in blood

Front 93

Insulin

Back 93

-made by beta cells
-promotes fuel storage
-lowers blood glucose levels, fatty acids, and amino acids

Front 94

Delta Cells

Back 94

-stimulated by protein rich meal
-inhibits glucagon & insulin secretion

Front 95

Pancreatic Polypeptide

Back 95

-produced by F Cells
-stimulated by protein rich meal
-acts on digestive organs such as gallbladder & pancreas

Front 96

Diabetes Mellatus

Back 96

-associated with pancreas
-affects glucose concentration in body

Front 97

Diabetes Insifidus

Back 97

-associated with ADH & paraventricular nucleus