BIO262-exam2

Implicit memory is non-declarative or retention without remembering. This is demonstrated in procedural types of tasks and involves simple skills or conditioning. It relies on motor memory.

Explicit or declarative memory is described as the conscious effort in order to recall something or something that can be verbalized. It’s related to facts. In addition to fact memory, explicit memory can be divided into two categories: abstract and episodic memory.

The process of taking short term memories and making them long term memories is called CONSOLIDATION. Consolidation includes: newly synthesized mRNA is delivered to axons and dendrites, dendritic spines change in shape, unique extracellular proteins are deposited in the synapses engaged in LTM, presynaptic terminals increase in size and number, and more neurotransmitters are released. Consolidation occurs in the temporal lobe of the brain, particularly in the hippocampus and amygdala.

multiple muscles working together to perform a specific action

a number of muscle fibers bound together by connective tissue

bundle of muscle cells within a muscle

an individual cell in which contraction occurs

contractile fibers that contain proteins within a muscle cell

The arrangement of myofibrils within a muscle cell. It is the functional unit of contraction and where all the mechanical events occur.

Z-lines (Z disks) are structures that anchor the thin filaments and the titin of the thick filaments. They form the structural border for each sarcomere.

Thin filaments are made of actin and connected terminally at Z lines or Z disks. There are 2 thin filament-associated proteins called Tropomyosin and Troponin.

Thick filaments are made of myosin. They have the appearance of two golf clubs twisted together. The heads are the myosin proteins and the tails are the shafts of the golf club twisted together. The thick filaments are anchored to Z lines by a protein called titin.

• actin, myosin
• (tropomyosin, troponin - associated w/thin filaments)

• During contraction, myosin binds to the active sites of actin.
• Each tropomyosin molecule is blocking the binding position on actin for myosin.

calcium & ATP

I band, A band, H zone

no

The junction of an axon terminal with the motor end plate

The axon terminals of a motor neuron contain vesicles similar to the vesicles found at synaptic junctions between 2 neurons.The vesicles contain Acetylcholine.The region of the muscle fiber plasma membrane (sarcolemma) that lies directly under the terminal portion of the axon is known as the motor end plate. Nicotinic (cholinergic) receptors for skeletal muscle are found here. Acetylcholine is an excitatory neurotransmitter for muscle contraction, so it makes the cell more positive and closer to threshold.

Sarcoplasmic Reticulum (SR) forms a series of sleeve like segments around each myofibril. Transverse Tubules (T-tubules) surround each myofibril, continuous with the sarcoplasm surrounding the muscle fiber. It is the lateral sacs, or terminal cisternae, that lie along the T-tubules that will release the calcium into the sarcoplasm.

A twitch is the brief contraction of all the muscle fibers in a motor unit in response to a single action potential.

Unfused tetanus – When there are multiple stimulations resulting in increasing but wavering contraction. (Not enough frequency of stimulation for a continuous contraction).

Fused tetanus – When there is approximately 90 stimulations per second this will result in a sustained contraction (not wavering as in unfused). This gives the ability for more force production.

Tetany – maximum force a muscle fiber can produce

Tensile force (strength of a muscle contraction) depends on number of fibers contracting in unison (motor unit recruitment) AND the frequency of the stimulations.

Cardiovascular Endurance Training leads to: increased # mitochondria and an increased capillary network in muscle groups trained. Strength training leads to: increased fiber diameter (hypertrophy) due to more actin/myosin produced (more in myofibrils)

• 3 ways a muscle fiber can form ATP:
• 1) Creatine phosphate (CP)
• maximum muscle power for about 10 seconds
• ATP formed is limited by concentration of creatine in the cell (1:1)

• 2) glycolytic pathway in the cytosol (anaerobic glycolysis)
• Used briefly after CP – then will convert to aerobic IF Oxygen is available
• 2 stores of glucose for glycolysis: 1) Blood stores of glucose or 2) Glycogen stored within the muscle fiber

• 3) Oxidative phosphorylation in the mitochondria (aerobic respiration) 
• ongoing provided oxygen is present
• 36 ATP per glucose

Lactic acid changes acidity within the muscle from accumulation (end product of anaerobic respiration). It makes the environment unfavorable for energy production.

Delayed Onset Muscle Soreness (DOMS) is thought to be due to micro-trauma’s of individual muscle fibers

A muscle continues to consume increased amounts of oxygen for some time after it has ceased to contract. Heavy breathing, increased heart rate are all contributing to repaying your oxygen debt.

• Slow Oxidative (SO/IA) Fibers
• These fibers are small diameter and dark red in color from their high myoglobin content. (Myoglobin store oxygen in the muscle). SO fibers have many mitochondria, mainly use aerobic respiration, and are very resistant to fatigue. Their contractions are considered “slow”.

• Fast Oxidative-Glycolytic (FOG/IIA) Fibers
• FOG fibers are intermediate in diameter. They also have a lot of myoglobin. They have many mitochondria, use both aerobic and anaerobic (glycolysis) metabolism and are resistant to fatigue (but not as much so as the SO fibers). FOG fibers have moderate glycogen stores and their contractions are “fast”.

• Fast Glycolytic (FG/IIB) Fibers
• FG fibers are large in diameter and contain most myofibrils. They are the most powerful and have very rapid contractions. They have a low myoglobin level, few mitochondria and mainly use anaerobic (glycolysis) metabolism. They fatigue quickly and have large glycogen stores. FG contractions are the most “rapid” and “powerful” of all the muscle fiber types.

SO most resistant to fatigue

FG least resistant to fatigue

FG (fast glycolytic)

SO (slow oxidative)

• pyramidal
• extrapyramidal
• pyramidal
• extrapyramidal

It doesn’t initiate movements but it can compare actual movement with intended movement and adjust and coordinate as necessary.

• vision
• vestibular
• proprioception

intention tremor - tremors when performing voluntary motor movements

They receive inputs from all structures of the cerebral cortex and they project to the motor cortex and therefore have an influence on motor movements. For example, they inhibit antagonistic or unnecessary movements so that things happen smoothly. The basal ganglia will modify and inhibit much of the motor information being generated in association with specific movements to help “fine tune” them.

• RESTING TREMOR not intention like Cerebellar
• CHOREA sudden irregular jerky movements without purpose
• ATHETOSIS slow writhing movements

slow writhing movements

uncoordinated, wobbling gait

Parkinson’s Disease occurs in the Substantia nigra area in Caudate Nucleus when there is decreased dopamine secreted and decreased activation of the motor cortex. It results in decreased and slow movements, rigid muscles, resting tremors, hunched posture, and limited arm movement with walking.

Adrenal glands are located on the top portion of each kidney

• adrenal medulla
• -inner part of the gland
• -neural tissue
• -produces catecholamines (epi- & norepinephrine)

• adrenal cortex
• -bulk of gland (outer several layers)
• -endocrine tissue
• -produces glucocorticoids (cortisol) & mineralcorticoids

• -protein breakdown
• -increase use of glucose & triglycerides for energy
• -anti-inflammatory / help regulate pain
• -maintain BP & proper renal function

ACTH (ant. pituitary) & CRH (hypothalumus)

• 'fight or flight' response
• -increased HR & BP
• -increased blood flow to heart, liver, muscles
• -bronchodilation

sympathetic ANS - adrenal medulla of adrenal gland

released in response to acute stress

PTH released when Ca++ is low

Calcitonin released when Ca++ is high

growth hormone (GH), glucagon, insulin

• Islets of Langerhans in Pancreas
• -Alpha cells - glucagon
• -Beta cells - insulin

hypoglycemia - low blood sugar

hyperglycemia - high blood sugar

diabetes mellitus - polyphagia, polydipsia, polyuria, abundance of glucose in urine

• Type I
• -insulin dependent
• -decline in or destruction of beta cells - autoimmune
• -typ. childhood diagnosis

• Type II
• -non-insulin dependent (generally)
• -insulin resistance due to over-flooding of glucose
• -adult or childhood diagnosis
• -can be controlled w/ diet, exercise, & meds

secreted from anterior pituitary

• stimulated by: TRH, OT, VIP, seratonin
• inhibited by: dopamine

produced in hypothalamus, secreted by posterior pituitary

• OT released in response to suckling, promotes ejection of milk from the breast
• (PRL released to stimulate milk production)

cardiac output and peripheral resistance