SLHS 303 Purdue Exam 1

Anatomy

The Study of the structure of organisms and the relations of their parts

Physiology

A science dealing with the functions of living organisms or their parts

Standard Anatomic Position

Standing upright on 2 feet, pinky inside and thumb outside with palms facing front, toes in front and heels in back

Ventral

farther back from the backbone of the body

Dorsal

closer to the backbone

anterior (ventral in humans)

closer to the front of the body

posterior (dorsal in humans)

closer to the back of the body

cranial

closer to the head of the body

caudal

closer to the tail of the body

external

outer surface

Internal

Inner Surface

Superficial

closer to the surface

Deep

away from the surface

Superior

upper

Inferior

Lower

Medial

Closer to the midline of the body

Lateral

Closer to the side of the body

Proximal

Closer to the trunk or the start of an extremity (hands/ legs)

Distal

Away from the trunk or the start of an extremity (hands/ legs)

Ipsilateral

Same side

Contralateral

opposite sides

Frontal/ Coronal Plane

A vertical splitting of the body into an anterior and posterior portion

Axial skeleton

vertebrae, rib cage, skull, face, and hyoid bone

Appendicular Skeleton

bones of the upper and lower limbs including the pelvic and pectoral girdles

Bone

Specialized connective tissue

Outer Surface of bone

-dense/ compact

-homogenous

inner surface of bone

-spongy/ cancellous

-porous

Cartilage

-connective tissue

-flexible and strong

-forms entire structures and lines articular surfaces/ facets of bone

3 types of cartilage

Hyaline, Elastic, Fibrous

Hyaline cartilage

-large amount of collagen

-ossifies with age

-found in articular surfaces of bones and larynx

Elastic Cartilage

-flexible

-very little ossification with age

-found in the ear (pinna) and ear canal

Fibrous Cartilage

-Toughest cartilage

-present in areas most subject to frequent stress

-vertebral discs

Joints

-high mobility= synovial

-limited mobility=cartilaginous

-no mobility= fibrous

Synovial Joints

-gliding joint

-hinge joint

-Condyloid Joint

-pivot joint

-saddle joint

-ball and socket joint

synovial fluid

fluid secretes by articular capsule which lubricates the joint cavity

articular capsule

fibrous tissue between the bones that form the joint

articular facet

-opposed ends of the bones

-covered with hyaline cartilage

Gliding joint

-articular surfaces= convex/ concave

-restricted movement but allow sliding

-between articular processes or vertebrae and larynx

Hinge Joint (door hinge)

-movement in one place

-elbow, fingers, toes

-allows movement in one plane

Condyloid Joint (open and close mouth)

-oval articular facet in elliptical cavity

-allows for all movement EXCEPT rotation

-TMJ

Pivot joint (shake head NO)

- allows rotation

-found between 1st and 2nd cervical vertebrae

Saddle Joint

- articular surfaces are saddle- shaped and at right angles to one another

-all movement EXCEPT rotation

-found in middle ear

Ball and Socket Joint

-rounded end of bone in a cup- like cavity

-ALL movement

-hip and shoulder

Basic Cell types of the Nervous System

Neurons and Glia

Neurons

cells that transmit information

Glia

-Schwann Cells (PNS)

-Oligodendrocytes (CNS)

Function of neurons

-building blocks of Nervous sys

-transmit information

-info is carried as electrical signals

Cell body (soma)

-surrounded by cell membrane

-membrane has small pores that allow certain things in and out

Dendrites

projections that gather messages and carry them TO the cell body

Axon

-carries info FROM the cell body

-can be myelinated or unmylinated

Terminal buttons

-located on axon

-contain neurotransmitters

Myelin/Myelin sheet

-white/ fatty wrapping

-formed by glia

-insulate axon and increase speed of conduction of nerve impulses along the axon

Oligodendrocytes (CNS)

Brain and spinal cord

Schwann Cells (PNS)

spinal and cranial nerves

-form myelin

Nodes of Ranvier

spaces between myelin

Synapse

-connection between neurons

-messages coming TO a neuron synapse on DENDRITIC SPINES

-messages coming FROM the neuron synapse at the TERMINAL BUTTONS

Glia

-support neuron

-insulate electrical activity moving down the axon and the synapse

-maintain fluid balance around the neuron

-transport nutrients

-repair damaged axons

Neural connective tissue

-surrounds the axon

-provides protection and nutrients for metabolic function

Endoneurium

-surrounds Schwann cells which are wrapped around 1 or more axons

-innermost tissue

Perineurium

-surrounds several sets of neurons

-incases the endoneurium

Epineurium

-surrounds several neural bundles to form nerve trunks

-outermost tissue

-encases entire nerve

Ion

-an electrically charged atom

-likes to move from high to low concentrations

Ion charges

• Chloride Ions (Cl-) are negatively charged

• Sodium (Na+) ion are positively charged

• Potassium (K+) ions are positively charged

Electrochemical gradient

• Similarly charged ions repel one another

• Oppositely charged ions attract one another

concentration gradient

-Ions move from areas of high concentration to areas of low concentration

Resting Membrane Potential of Neuron

-the voltage (charge) difference across the cell membrane when the cell is at rest

-ions of opposite charges are separated from each other

ions of opposite charges are separated from each other

a potential force exists

force of ions pulling on one another

Resting Membrane Potential

Extracellular

More Na+ and Cl-

Intracellular

-More K+ and negatively charged molecules

-results in negative charge

Electrical potential

-70mV

-due to difference in concentration of ions inside and outside the soma

How is RMP maintained

-sodium- potassium pump

-"leaky" potassium pump

Sodium- potassium pump

◦ Pumps 2K+ ions INTO cell for every 3Na+ ions it pumps OUT

◦ Net negative charge inside cell body that's why there is a negative charge in RMP

◦ Ions move against concentration gradient

"leaky" potassium pump

-Facilitated diffusion of K+ OUT of cell

Action potential at threshold

causes hundreds of VOLTAGE- GATED sodium channels to open on that part of the cell membrane

depolarization of the cell

- causes more VOLTAGE- GATED sodium channels to open in adjacent parts of the cell membrane

-begins at axon hillock

Depolarization

• Membrane potential becomes more positive

▪ From (-70mV to +40 mV)

▪ when neuron is at threshold

• Sodium channels OPEN

repolarization

▪ The return of the membrane potential to resting potential

▪ When neuron reaches threshold

• Potassium channels OPEN

• Sodium channels CLOSE

Hyperpolarization

This is seen in the overshooting region of the action potential when the potential dips even MORE NEGATIVE than the resting potential

"all or none phenomenon"

◦ Once depolarization reaches threshold the action potential occurs

• Size (strength) of action potential remains constant down the axon

Strength of stimulus is reflected in the frequency of action potentials triggered

Refractory period

• Time between adjacent action potentials

• Lasts a few milliseconds

Divided into ABSOLUTE AND RELATIVE

Absolute Refractory Period

• Comes immediately after the action potential

• Impossible to excite the cell during this period

• EVERY NEURON HAS THIS PERIOD

Relative Refractory Period

• Can trigger action potential

• Stimulus is stronger than normal

Conduction of Action Potential

Continuous and Saltatory

Continuous conduction

AP moves along entire length of axon (UNMYELINATED neurons)

Saltatory Conduction

◦ AP jumps along the axon due to MYELINATION

• Only depolarizes the parts of the axon at the Nodes of Ranvier

• Much faster than continuous conduction

Somatic System

◦ "voluntary" part of the system

◦ Responsible for observable actions

◦ Allows for sensation of environmental events at stimuli

Autonomic System

◦ "involuntary" part of the system

◦ Responsibility for life- sustaining activities and sensations

• Heart beat

• mucus production

• Moving of food through digestive system

Central Nervous System (CNS)

◦ Close to center of the body

◦ Brain

• Cerebrum

• Brainstem

• Cerebellum

◦ Spinal cord

Covering the CNS

▪ Bones of skull and vertebral column

▪ 3 layers of tissue (meninges) between bones and CNS

• Dura Mater

• Arachnoid Mater

• Pia Mater

▪ Cerebrospinal Fluid

Dura Mater

Outermost layer of the CNS protection

Arachnoid Mater

Middle layer of the CNS protection

Pia Mater

Inner layer of the CNS protection

Cerebrospinal Fluid

• In subarachnoid space

• Moistens, lubricates, and protects CNS

Peripheral Nervous System (PNS)

Spinal and cranial nerves

Spinal Nerves (PNS)

• Nerves coming out of the spinal cord to go to the body

• Below head and face

• MYELINATED by Schwann Cells in PNS

Cranial Nerves (PNS)

• Nerves coming out of the brainstem to go to head and face

• MYELINATED by Schwann Cells in PNS

Autonomic Nervous System (ANS)

-divided into Sympathetic and Parasympathetic

-Part of the PNS which supplies glands, smooth muscle, and internal organs (viscera)

Sympathetic (ANS)

▪ Thoracolumbar

• "fight of flight" response

• Helps body respond to danger or stress or cope with emergencies

▪ OUTFLOW from thoracic and lumbar spinal cord

▪ Ganglia are CLOSE to the spinal cord

Parasympathetic (ANS)

▪ craniosacral

• "rest and digest"

• Helps restore resting state of body

▪ OUTFLOW from cranial nerves and sacral spinal cord