A&P first year

Central Nervous system (CNS)

Consists of the brain and the spinal cord

Processes sensory data from inside and outside the body

Peripheral nervous system (PNS)

Consists of all neural tissue outside of the CNS

Deleivers information to the CNS

Carries motor commands to peripheral tissues/systems

Somatic Nervous system (SNS)

Carries motor information of skeletal muscle, both voluntary and involuntary

Automatic nervous system (ANS)

Provides automatic regulation of smooth muscle and cardiac muscle, and regulates glandular secretions at a subconscious level

Sympathetic division

Stimulates the body

Parasympathetic division

Relaxes the body

Afferent division

Carries sensory information from the PNS to the CNS

Effernt division

Carries motor information from the CNS to the PNS muscles and glands

Receptors

Sensory structures that detect changes and respond to stimuli

Effectors

The target organs that respond to efferent signals by doing something

Perikaryon

The cytoplasm of a neuron

Telodendria

Fine extentions of the distal axon

Schwann cells

Form a myelin sheath around peripheral axons (PNS)

Sarellite cells

Surround neuron cell bodies in the PNS to regulate the environment around neurons

Different than astrocytes

Astrocytes

Star-shaped cells that form the blood-brain barrier, provide nutrients, maintain chemical balance and offer structural support to neuroglia in the CNS

Repair damages neural tissue

Oligodendrocytes

Have processes that are in contact with cell bodies and axons of multiple neurons

Ependymal cells

Form a special type of epithelium (neuroepithelium)

Secretes cerebrospinal fluid (CSF)

Microglia

Migrate through neural tissue

Clean up cellular debris, waste products and pathogens

(CNS)

Resting potential

Transmembrane potential of a resting cell

Graded potential

A temperary localized change in resting potential, caused by a stimulus

Action potential

An electrical impulse produced by a graded potential that propagates along an axon

Synaptic activity

The release of neurotransmitters at the presynaptic membrane

Information processing

The response of the postsynaptic cell

How come a transmembrane potential even exists?

Extracellular fluid (ECF) and intracellular fluid (ICF) differ in ionic compositions (Sodium-Potassium gradieant)gradient

Cells have selectively permeable membranes

Membrane permeability varies by ion

Passive forces of PM

Chemical gradients - Concentration gradients of ions

Electrical gradients - Separate charges of positive and negative ions

Electrochemical gradient - the sum of chemical forces acting on a particular ion

Active forces on PM

Sodium-potassium exchange pump

Electrical synapses

Driect physical contact between the pre- and post-synaptic membranes.

Membranes are locked together at gap junctions and signal is always conveyed to the next cell.

Extreamly rare- only occurs in some areas of the brain

Chemical synapses

Transmit signals across a physical gap using neurotransmitters (NTs)

Excitatory NTs

Promote action potentials by depolarizing postsynaptic membranes

Inhibitory NTs

Supress action potentials by causing hyperpolarization of postsynaptic membranes

Cholinergic synapses

Releases acetylcholine (ACh) at:

Neuromuscular junctions

Many synapses in the CNS

All neuron-neuron synapses in the PNS

All neuronmuscular and neuroglandulas junctions of the ANS (parasympathetic division)

Norepinephrine

Excitatory - has action adrenergic synapse

Dopamine

Has both excitatory and inhibitory effects

Seritonin

Has effects on attention and emotional states

Gamma-aminobutyric acid (GABA)

Typically inhibitory

reduces anxiety in the CNS

Opioids

Neuromodulators that have action by inhibiting the release of substance p in pain pathways

Axoaxonic synapses

Synapses between the axons of two neurons

Presynaptic inhibition

occurs when the action of an axoaxonic synapse at a synaptic terminal decreases the amount of neurotransmitter release by the presynaptic membrane

Presynaptic facilitation

occurs when the action of an axoaxonic synase increases the amount of neurotransmitter released

Myocytes

Cells responsible for generating the contractil force of a muscle

control inlet/ outlet functions

Sphincters encercle openings to restrict/ enable movment (swallow — sphincter opens — food enters, urinary retention — sphincter closed — urine remains in the bladder)

Isotonic contractions

Muscle length changes with constant force

Isometric contractions

Muscle does not change with constant force

Titin

An elastic protein that stablilizes sarcomeres and helps restore it to length after contracting.

Hormones that increse protein synthesis

Growth hormone, testosterone

Hormone increases the rate of energy use

Thyroid hormone

Hormone potentiates muscle tissue

Epinephrine

Endomysium

Bundles the fiber
Contains capillary network
Location of the myosaetllite cells (stem cells)

Perimysium

Bundle fibers into a fascicle

Contains cappillary network

Epimysium

Bundles fascicles into a muscle

Most durable layer 

Blends into epimysium to for a tendon

Anatomical Position

Standing upright, facing forward, arms at sides, palms forward — the reference for all anatomical descriptions.

Supine Position

Lying on the back, face upward.

Prone Position

Lying on the stomach, face downward.

Etymology

Study of word origins; helps decode medical terms (e.g., "isch-" = restraint; "-emia" = blood condition).

Ischemia

Restricted blood flow to tissue

Hypoxemia

Low oxygen level in the blood ("hypo-" = below; "oxys" = oxygen; "-emia" = blood condition).

Hypoxia

Low oxygen level in tissues; causes fatigue, cyanosis, confusion.

Anoxia

Absence of oxygen supply.

Sagittal Plane

Divides the body into left and right halves (mid-sagittal = equal halves).

Coronal (Frontal) Plane

Divides body into anterior (front) and posterior (back) sections.

Transverse (Horizontal) Plane

Cuts body into superior (upper) and inferior (lower) parts.

Oblique Plane

Cuts the body at an angle other than 90 degrees.

Anterior (Ventral)

Toward the front of the body.

Posterior (Dorsal)

Toward the back of the body.

Superior (Cranial)

Toward the head or upper part.

Inferior (Caudal)

Toward the feet or lower part.

Medial

Toward the midline.

Lateral

Away from the midline.

Proximal

Closer to the point of limb attachment.

Distal

Farther from the point of limb attachment.

Superficial

Near the body surface.

Deep

Farther from the body surface.

Ipsilateral

On the same side of the body.

Contralateral

On the opposite side of the body.

Dorsolateral

Toward the back and side.

Protraction

Moving a body part forward (e.g., jaw forward).

Retraction

Moving a body part backward (e.g., jaw backward).

Flexion

Decreasing the angle of a joint.

Extension

Increasing the angle of a joint.

Abduction

Movement away from the midline.

Adduction

Movement toward the midline.

Rotation

Turning movement around a longitudinal axis.

Circumduction

Circular motion of a limb that traces a cone.

Elevation

Raising a body part (e.g., shrugging shoulders).

Depression

Lowering a body part (e.g., relaxing shoulders).

Dorsal Body Cavity

Cranial + Spinal cavities.

Ventral Body Cavity

Thoracic + Abdominopelvic cavities.

Thoracic Cavity

Contains mediastinum and left/right pleural cavities.

Abdominal Subregions

Nine-region method using mid-clavicular and trans-umbilical lines.

Axial Skeleton

Skull, ribs, vertebral column.

Appendicular Skeleton

Limbs and girdles (attachments).

Intra-individual Variation

Differences within one person (time of day, posture, diet).

Inter-individual Variation

Differences between people (age, sex, genetics, lifestyle).

Environmental Variation

Differences caused by surroundings (altitude, temperature, chemicals).

Anatomical Variation Examples

Extra rib, missing pyramidalis muscle, varied blood vessel paths.

X-inactivation

Random shutting off of one X chromosome in females → mosaic traits.

MHC Diversity

Genetic immune variation affecting mate preference ("sweaty T-shirt test").

Gut & Skin Microbiota

Microbes that affect digestion, immunity, mood ("human ecosystem").

Telomeres

Chromosome end caps that shorten with each cell division; linked to aging and cancer.

Nucleus

Label for the central part of a cell.