Cva Lecture Final

- mount an immune response

- transport nutrients and metabolic breakdown products

- transport respiratory gases

- wound healing

maintenance of physiological parameters within acceptable limits

blood vessels - arteries carry blood away from heart, veins carry blood to heart

heart - muscular pumping organ

lymph vessels + nodes - recover interstitial fluids from tissues

spleen - immune and circulatory organ

blood formation

amniotes - occurs in spleen, liver, kidneys

mammals - occurs in bone marrow

single circulatory circuit where blood goes directly from heart to tissues

two circulatory circuits with the pulmonary circuit added that directs blood to the lungs from right side of heart; left side of heart carries blood to body

crucial part of circulatory development when mesenchymal cells coagulate together, expand, and link with developing blood vessels

an outgrowth of the archenteron

uses vitelline vessels to break up hepatic sinusoids and become hepatic vein and hepatic portal vein system

no heart; pulsatile ventral aorta

blood flow posterior along dorsal side of body and anterior along ventral side

hearts with four distinct chambers: atrium, conus arteriosus, sinus venosus, ventricle

dorso-ventral common cardinal vein

use a venous return system for blood flow

folded heart shifts ventricle down below atrium and to the right, giving S shaped curve

use a primitive venous system and primitive arterial system

partial division of left and right atrium that develops as a ridge to separate de/oxygenated blood streams

a phylogenetic change to the ventral aorta that bifurcates into left and right branches, producing systemic, carotid, and pulmocutaneous circuits

a phylogenetic change to the conus arteriosus that becomes divided into three separate vessels:

pulmonary artery - to the lungs

left + right systemic arches - to the body

(right systemic arch gives rise to carotid arteries)

three layers

- tunica intima: endothelium + elastin fibers

- tunica intermedia: smooth muscle

- tunica externa: collagen + elastin fibers

6 A.A. - 1 becomes spiracular artery; posterior 5 serve the gills

spiracular artery will carry blood from first collector loop through pseudobranch to carotid a.

anterior end of dorsal aorta becomes the internal carotid artery; gives branch to eye and upper face called stapedial a.

external carotid artery arises from ventral portion of first collector loop

A.A. number 6 remains connected to the aorta through the ductus arteriosus

FROGS - paired dorsal aortae (carotid duct) lost during development; ventral aorta near 3rd A.A. called common carotid

lost A.A. number 5

BIRDS - lost right systemic arch and only have the left aortic arch

posterior portion of posterior cardinal vein becomes the renal portal vein

right hepatic vein extends to produce a caudal vena cava to drain venous blood from kidneys

ventral abdominal vein drains some of blood from hind limbs directly into hepatic portal vein

posterior lymph vessels drain into large lymph sinus called cysterna chyli located dorsal to the aorta behind the diaphragm

excitable cells that generate electrical impulses that allow individual cells to stimulate other cells of body; can also stimulate tissue called effectors

central nervous system: containing brain and spinal cord

peripheral nervous system: includes all other nerves

coordination of body functions

gathering of sensory information

higher thought processes

initiation of response of stimuli

carries information toward central nervous system; may or may not be connected to afferent, specialized sensory organ

carries information away from CNS and stimulates an effector organ (efferent)

neurons within CNS that only stimulate other neurons

generalized term used to describe any organ within the body that does something when stimulated by nervous system

muscles or glands

the cell body of a neuron

cellular extensions that carry impulses toward perikaryon

cellular extensions that carry impulses away from perikaryon

two types:

myelinated: insulated by Schwann cells

unmyelinated: no insulative cells

multipolar - motor

bipolar - sensory

pseudounipolar - sensory

supportive cells of the nerous system

variety of cell types both within and outside the CNS that perform non-neuronal functions collectively called glial cells

glial cells that provide myelin sheaths for neurons in the peripheral nervous system

nerve impulses able to travel much more rapidly on dendrites/axons cause they're forced to skip rapidly from node to node using this process

perineurium - the wrapped connective tissue covering the processes

endoneurium - the individual fibers within a nerve are each wrapped with connective tissue

electrical activity that travels along cell membrane

does NOT directly pass electrical energy but stimulates a second cell to generate another impulse by releasing chemicals known as neurotransmitters

bundle of neuronal extensions (axons/dendrites) that travel through body as part of the PNS and wrapped by connective tissues to become long branching structures

collection of neuronal extensions that travel within a CNS and not wrapped by connective tissues

collection of neuronal cell bodies (perikarya) that bundle together and covered by connective tissue to form a single structure

collection of neuronal cell bodies clustered together somewhere within CNS

the simplest functional unit of the nervous system

mass of nervous tissue that occupies vertebral canal; part of CNS; gives off pair of spinal nerve between each pair of vertebrae

spinal cord:

includes perikarya and unmyelinated fibers

has an H shape in cross section with two horns (dorsal and ventral) and gray commissure

divided by grey horns into 3 regions:

dorsal column

lateral column

ventral column

carry sensory impulses to brain / body

somatic sensory: info from outside world

somatic motor: stimulate skeletal muscles

visceral sensory: info from internal viscera

visceral motor: stimulate smooth muscles of internal organs

no white/grey matter differentiation

no myelinated fibers

Muller fibers = conduct nerve impulses more rapidly to become the rapid escape response

surrounding connective tissue membranes that protect the CNS

three layers:

outer dura mater: very tough

arachnoid: contains cerebrospinal fluid within a subarachnoid space

pia mater: against brain and spinal cord

efferent only; specializes in control of inner organs without conscious intervention; includes two nerves and a ganglion

preganglionic nerve exits spinal cord, axon myelinated

postganglionic nerve enters effector, axon unmyelinated

sympathetic: governs fight or flight response

(adrenergic - uses neurotransmitters adrenaline and noradrenaline)

parasympathetic: governs functions during normal relaxed activities and is referred to as resting and digesting (cholinergic - uses acetylcholine as neurotransmitter)

convert energy from one form to anotherl always electrochemical energy of a nerve impulse

duration: length of time receptor is stimulated

intensity: frequency of firing neuron, number of neurons firing, sensitivity of firing neurons

location: where in body impulse is from

modality: touch, vision, hearing, etc

phasic: maintain resting potential when stimulated; responds with receptor potential in full

tonic: always active and depolarize at some rate whether stimulated or not; increased rate of depolarization when stimulated

occurs when repetitive stimuli is no longer perceived by brain

general sense: simple receptors throughout body

special sense: complex receptor organs with specific energy modalties (taste, vision, smell)

exteroceptors: receive sensory stimuli from outside body on the surface

visceroreceptors: receive sensory info from internal organs (thirst, hunger, nausea)

proprioceptors: sensory info about positions/movements of body

chemoreceptors

gustatory sense

mechanoreceptors

olfaction

main olfactory system

vomeronasal system

cutaneous receptors (unencapsulated and encapsulated)

proprioceptors

lateral line organs

electroreceptors

unmodified nerve endings

merkel's disks: modified epidermal cells w/ sensitivity to light touch, texture, edges, shapes

ruffini endings: tonic receptors for heavy touch, pressure, stretching in the dermis

eimer's organs: in moles only; specialized touch receptors

meissner's corpuscles: phasic receptors for light touch and texture

pacinian corpuscles: laminated phasic receptors sensitive to deep pressure, stretch, tickle, and vibration

muscle spindle organ: spindle shaped muscle fibers with nerve endings wrapped around them

golgi tendon organ: dendrites of sensory nerve entwined around cluster of encapsulated collagen fibers in tendon

lateral line system

cluster of sensory hair cells surrounded by sustentacular cells and named from the prominent trunk canal

neuromasts in isolated pits of skin called pit organs

membranous labyrinth: series of membranous chambers and ducts that contains endolymph fluid and occupies series of passageways in skull called osseus labryinth

inner ear structure that has a basilar membrane that holds this spiral organ

consists of hair cells supposed by sustentacular cells; sensory cilia embedded into gelatinous tectorial membrane

strands of connective tissue that envelope around the lens and attach to the ciliary body via connective tissues

divided into anterior/posterior chambers

anterior segment contains fluid called aqueous humor that will be resabsorbed at the canal of Schlem -when not absorbed properly, becomes glaucoma

rods + cones

rods: rhodopsin

cones: iodopsins

450 nm = blue

525 nm = green

550 nm = red