BIOL 1103: Final Exam

Muscle

Bundle of fiber that can only stretch/contract in one direction

Which muscle components fuse to form the tendon?

The fascia, epimysium, perimysium & endomysium all extend beyond the muscle and fuse to form the tendon

Fascicle

Bundle of muscle fibres arranged in bundles within a muscle

Fascia

Outermost layer of an entire skeletal muscle

Epimysium

Layer under the fascia, wrapping together the whole muscle

Perimysium

Connective tissue layer that surrounds bundles of muscle fibers called fascicles

Myofibril

Rod-like organelle of a muscle cell

Sarcoplasm

Cytoplasm of striated muscle cells

Sarcolemma

Cell membrane of a muscle cell (myocyte)

Which organelles does muscle contain extra of?

They contain extra mitochondria and nuclei

Why do muscle cells have many mitochondria?

To provide extra energy needed for muscle contraction and movement

Endomysium

Delicate connective tissue that surrounds each individual skeletal muscle fiber

Why do muscles have many nuclei?

To support their large size and high protein production needs

Sarcoplasmic reticulum

Specialized form of the endoplasmic reticulum of muscle cells, containing high levels of calcium ions

Transverse tubules

T-tubules: tunnel-like extensions that run perpendicular to the sarcoplasmic reticulum

Myofilaments

Muscle filaments that cause contraction of the muscle (two types: thick and thin)

Sarcomere

Contractile unit of striated muscle, responsible for muscle contraction

Areas of the sarcomere

• Z line

• I band

• A band

• H zone

• M line

Z line

Dense proteins called Z discs form the Z line, which separates one sarcomere from another & holds actin in place

I band

Lighter portion of sarcomere that contains only the thin filaments

A band

Denser portion of sarcomere covering the whole length of the thick filament, including the parts overlapping with the thin filaments

H zone

Center of the A band containing only the thick filaments

M line

“Middle line” of the sarcomere, formed by supporting proteins that hold the middle of the thick filaments in the middle of the sarcomere

Thick muscle filament

Composed of several myosin molecules linked together → like “golf clubs twisted together”

Proteins in thin filaments

Actin, tropomyosin, troponin

Troponin

Protein that holds tropomyosin in place

Tropomyosin

Protein covering the myosin-binding sites on the actin molecules to prevent ineeraction when the muscle is at rest

Troponin

Protein holding the tropomyosin in place

Type of movement accomplished by a muscle depends on:

1. Type of joint

2. Orientation of muscle fibers

3. Action of other muscles

4. Muscle tension

How does orientation of fibers make muscles perform different types of movements?

The way muscle fibers are arranged relative to the tendon determines if the muscle focuses on pulling hard or far/fast

What can tension in one muscle prevent?

Movement of another muscle

Criteria used in the naming of muscles

1. Direction of muscle fibers

2. Size of the muscle

3. Shape of the muscle

4. Number of origins

5. Specific location of the muscle

6. Points of origin and insertion

7. Action

Abduction

Bone moves away from the midline

Adduction

Bone moves towards midline

Supination

Palm of hand turns upwards

Pronation

Palm of hand turns downwards

Eversion

Foot moves away from midline

Inversion

Foot moves towards midline

Plantarflexion

Pointing the foot downward away from your shin

Dorsiflexion

Bending the foot upward toward your shin

Protraction

Bone moves horizontally towards the front

Retraction

Bone moves horizontally towards the back

Elevation

Bone mvoes upwards

Depression

Bone moves downwards

“Maximus” meaning

“Largest” → ex. gluteus maximus

“Minimus” meaning

“Smallest” → ex. gluteus minimus

“Longus” meaning

“Long” → ex. adductor longus

“Brevis” meaning

“Short” → ex. adductor brevis

“Latissimus” meaning

“Widest” → ex. latissimus dorsi

“Longissimus” meaning

“Longest” → ex. longissimus capitis

“Magnus” meaning

“Large” → ex. adductor magnus

“Major” meaning

“Larger” → ex. pectoralis major

“Minor” meaning

“Smaller” → ex. pectoralis minor

“Vastus” meaning

“Huge” → ex. vastus lateralis

“Deltoid” meaning

“Triangular” → ex. deltoid

"Trapezius” meaning

“Trapezoid” → ex. trapezius

“Serratus” meaning

“Saw-toothed” → ex. serratus anterior

“Rhomboid” meaning

“Diamond-shaped” → ex. rhomboid major

“Orbicularis” meaning

“Circular” → ex. orbicularis oculi

“Pectinate” meaning

“Comblike” → ex. pectineus

“Piriformis” meaning

“Pear-shaped” → ex. piriformis

“Platys” meaning

"Flat” → ex. platysma

“Quadratus” meaning

“Square, four-sided” → ex. qudratus-femoris

“Gracilis” meaning

“Slender” → ex. gracilis

“Biceps” meaning

“Two tendon origins” → ex. biceps brachii

“Triceps” meaning

“Three tendon origins” → ex. triceps brachii

“Quadriceps” meaning

“Four tendon origins” → ex. quadriceps femoris

“Rectus” meaning

“Parallel to body’s midline” → ex. rectus abdominis

“Transverse” meaning

“Perpendicular to body’s midline” → ex. transversus abdominis

“Oblique” meaning

“Diagonal to body’s midline” → ex. external oblique

What are the five types of receptors?

• Mechnoreceptors

• Thermoreceptors

• Nociceptors

• Photoreceptors

• Chemoreceptors

Mechanoreceptors

Detects stimuli related to touch, pressure, vibration, hearing, equilibrium, and blood pressure

Thermoreceptors

Detects changes in temperature

Photoreceptors

Detects light on the retina of the eye

Nociceptors

Detects pain, usually as a result of physical or chemical damage to tissues

Chemoreceptors

Senses chemicals such as the taste in the mouth, smell in the nose, or chemicals in body fluids such as oxygen and glucose

Cutaneous sensors

Sensory receptors found in the dermis or epidermis

Proprioceptors

Sensory receptor that responds to position and movement. Found in muscles, tendons, and skin

Olfaction

The sense of smell

Olfactory receptors

Chemoreceptors found in the nasal epithelium in the nasal cavity that detect odor molecules

Describe the structure of the olfactory receptor neurons

Olfactory receptor neurons are bipolar neurons with elongated axons and dendrites

Olfactory pathway

The route by which smell (odor) information travels from your nose to your brain

What do olfactory receptors contain that detect odor molecules?

They contain cilia that pick up odours.

How do olfactory receptors communicate with olfactory nerves?

Olfactory receptors release neurotransmitters at synapses.

What do the axons of olfactory nerves unite to form?

They form the  olfactory nerve (cranial nerve I).

Where does the olfactory impulse go to be processed?

The primary olfactory area in the temporal lobe of the cerebral cortex.

Gustation

Sense of taste

Gustatory receptors

Taste receptor cells that detect chemicals in food and saliva, allowing us to perceive taste

Taste buds

Clusters of gustatory receptor cells found mostly on the tongue’s papillaeW

What is the difference between papillae and taste buds?

Papillae are bumps on the tongue that may house taste buds, while taste buds are sensory structures within papillae that detect taste.

How many gustatory cells are found in each taste bud?

4-20 gustatory cells

Basic taste sensations

Sour, sweet, salty, bitter, and umami

Gustatory pathway

The neural pathway that transmits taste signals from the tongue to the brain for conscious perception

What are the “hairs” in gustatory cells?

They are microvilli that extend from gustatory receptor cells into the taste pore to detect dissolved chemicals

Chemical process of tasting saltiness

Sodium ions enter via sodium channels in gustatory cells, causing depolarization

Chemical process of tasting sourness

Hydrogen ions enter via hydrogen channels, causing depolarization (sour)

Chemical process of tasting bitter, sweet, and umami

Chemicals that cause sweet, bitter and umami tastes fit into receptors that then cause depolarization

Which nerves do gustatory cells synapse with?

Cranial nerve VII (facial nerve), and cranial nerve IX (glossopharyngeal nerve)

Which part of the brain processes taste?

The primary gustatory area in the cerebral cortex

Are taste buds specialized for specific tastes, and how are they distributed?

Taste buds are specialized for one taste but are evenly distributed across the tongue