Anatomy and Physiology Exam 1

Nucleus

contains genetic material for the cells (DNA)

Cytoplasm

material between plasma membrane and the nucleus

Cytosol

largely water with dissolved protein, salts, sugars and other solutes

Mitochondria

two membranes create two compartments

• mitochondrial matrix

• unique DNA

• intermembrane space

Endoplasmic reticulum

Rough ER and Smooth ER

Rough ER

ribosomes attached, protein assembly and modification

Smooth ER

Synthesis of fatty acids, steroids, lipids

Modified forms in liver, kidney, muscles

Lysosomes

• Hydrolytic enzymes to degrade bacteria or old
  organelles

• Acidic interior→ acid hydrolases used to degrade

Peroxisomes

• Enzymes, catalases and oxidases, to degrade longchain fatty acids, free radicals, and toxic foreign molecules

• Generate hydrogen peroxide

Plasma membrane

separates the cell from the outside world

Extracellular environment

33% of the body water makes up the extracellular compartment

Blood plasma

mostly found inside the blood vessels and makes up 20% of the extracellular fluid

interstitial fluid:

makes up the other 80% of the extracellular fluid

Extracellular matrix

made up of collagen (provides strength), elastin (provides elasticity), and a gel-like ground substance (provides fluidity).

ground substance

composed of glycoproteins, and proteoglycans

Basal laminate or basement membrane

• mostly made up of collagen IV.

• Forms chemical bonds between the carbohydrates on the surface of cells, and the extracellular matrix

• forms a connection between the epithelial cells and the underlying connective tissue.

Transport across cell membranes: plasma membrane is ____

selectively permeable

Passive transport

substances move across cell membranes, without the input of any energy, down their concentration gradient

osmosis

passive movement of water molecules across a semi-permeable membrane from a region of lower solute concentration (more water) to a region of higher solute concentration (less water).

facilitated diffusion

carrier mediated diffusion

active transport

a cell uses energy, primarily from the breakdown of ATP, to move a substance across the membrane, i.e., against a concentration gradient

Primary active transport example

Na+/K+ pump

intercellular junctions

• tight

• adherence

• desmosomes

• gap

Membrane potential

A. Relative abundance of intracellular and extracellular ions
B. Resting membrane potential
C. The Na+/K+ pump and its role in maintaining the resting membrane potential

One of the five important functions of skeletal muscle contraction is heat production.

True

What is found in the Motor End Plate? (neuromuscular junction)

Acetylcholinesterase

Acetylcholine receptors

What is found in the Synaptic Knob (neuromuscular junction)

Synaptic vesicles filled with acetylcholine

Voltage-gated Calcium channels

Myofibrils are composed of protein filaments called

actin and myosin.

A bundle of muscle fibers is known as a

fascicle

A skeletal muscle fiber is…

multinucleated, meaning it contains many nuclei

The muscle cell membrane is called the

sarcolemma

Which connective tissue wrapping separates individual muscle fibers?

endomysium

Rising sarcoplasmic calcium levels results in….

contraction in smooth muscle fibers and skeletal muscle fibers.

The area of the muscle fiber where the actin and myosin myofilaments overlap is the

A band

During contraction, the actin myofilaments slide toward the

H zone

The distance from one Z disk to the next Z disk is called a(n)

sarcomere

In a fully contracted muscle, actin filaments ____myosin filaments, increasing overlap

slide past

In a relaxed muscle, the ends of the actin filaments overlap.

FALSE

Label the connective tissues associated with skeletal muscle.

Deep fascia

Label the connective tissues associated with skeletal muscle.

epimysium

Label the connective tissues associated with skeletal muscle.

perimysium

Label the connective tissues associated with skeletal muscle.

Endomysium

At the ends of muscles, the connective tissues merge to form a _________blank, which attaches the muscle to other structures.

tendon

All characteristics of cardiac muscle.

• Cells are short and branching.

• Cells have one or two nuclei in the center of the cell.

• They are composed of thick and thin filaments.

Label the structures of a sarcomere.

I band

Label the structures of a sarcomere.

M line

Label the structures of a sarcomere.

A band

Label the structures of a sarcomere.

Z disc

What are the events involved in smooth muscle contraction?

• Initiated by Ca²⁺ binding to intracellular calmodulin.

• Ca²⁺/calmodulin complex activates MLCK.

• Activated MLCK activates myosin ATPase.

The type of muscle tissue that would be found in the wall of the bladder is _________blank muscle tissue.

smooth

The primary neurotransmitter at the neuromuscular junction is

acetylcholine

Arrange the following in the proper order in which they occur at the postsynaptic side of a neuromuscular junction.

1. Action potential is propagated over the muscle cell membrane.

2. Depolarization of the postsynaptic membrane occurs.

3. Sodium ions move into muscle cell.

3,2,1

The area between the presynaptic nerve cell and the postsynaptic muscle cell is termed the

synaptic cleft.

Receptors on the postsynaptic cell membrane that bind neurotransmitters (like acetylcholine at the neuromuscular junction) are

ligand-gated ion channels

Label the components of skeletal muscle.

skeletal muscle

Label the components of skeletal muscle.

fascicle

Label the components of skeletal muscle.

muscle fiber

Label the components of skeletal muscle.

myofibril

Check all that are proteins of thin filaments.

actin and troponin

Which is a characteristic of skeletal muscle from the selections below?

mutinucleated

Which of the following connects muscle to bone?

tendons

The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the

transverse tubule (t-tubule)

A motor neuron transmits the effect of a nerve impulse to the muscle fiber at a _________

neuromuscular junction.

Smooth muscle is not located in the respiratory system.

false- it is found in the walls of the bronchi and bronchioles,

Label the structures of a skeletal muscle fiber.

sarcolemma

Label the structures of a skeletal muscle fiber.

openings into T-tubules

Label the structures of a skeletal muscle fiber.

sarcoplasmic reticulum

Label the structures of a skeletal muscle fiber.

nucleus

Label the structures of a skeletal muscle fiber.

myofibril

Neighboring cardiac muscle cells in the walls of heart chambers have specialized cell-to-cell contacts that electrically and mechanically link the cells together, permitting the immediate passage of muscle impulses. These cell-to-cell contacts are called _________________

intercalated discs

the specialized region of the sarcolemma that has folds and indentations to increase the membrane surface area covered by the synaptic knob is the

motor end plate

the contractile unit of a myofibril is called the

sarcomere

If you were studying the neurotransmitter released from axon terminals at a neuromuscular junction, you would be studying

acetylcholine

Match each sarcomere region with the filament(s) it contains: THICK FILAMENTS

H band and M line

Match each sarcomere region with the filament(s) it contains: THIN FILAMENTS

I band

Match each sarcomere region with the filament(s) it contains: BOTH THICK AND THIN FILAMENTS

A band

all functions of skeletal muscle tissue.

• Body movement – Skeletal muscles pull on bones to produce movement

• Maintenance of posture – Skeletal muscles stabilize the body and help maintain posture.

• Heat production – Muscle contractions generate heat to help maintain body temperature.

• Metabolic regulation – Skeletal muscle stores and uses glucose and other nutrients, contributing to metabolism.

All the muscle fibers under the control of a single motor axon are referred to as

a motor unit

Some reflex arcs (like stretch reflexes) are monosynaptic and do not involve

interneurons—the sensory neuron synapses directly with the motor neuron.

Direct motor pathways are involved in

consciously contracting skeletal muscle.

Which neuron in a sensory pathway is part of the sensory receptor?

primary

Somatosensory pathways process stimuli from

the body's surface (skin, muscles, joints, fascia) for touch, pain, temperature, and proprioception

The space containing cerebrospinal fluid is the _________.

subarachnoid

Upper motor neurons may inhibit

lower motor neurons.

Motor signals to maintain posture and balance pass through a(n) _________ pathway.

indirect

All reflexes share the property of being an

involuntary response.

The spinal cord and spinal nerves are responsible for _________, which are our quickest reactions to a stimulus.

Which portion of a reflex arc is located entirely within the central nervous system?

interneuron

The spinal cord extends from the level of the _________ to the level of the _________

foramen magnum; first lumbar vertebra

A motor command from the brain to signal muscle contraction would pass through a(n)

descending pathway

There are ____ pairs of cervical spinal nerves, but only _____ cervical vertebrae.

eight, seven

Touching a hot object with the right hand will result in withdrawal of the right hand from the object. This is an example of a(n) _________ reflex.

ipsilateral

ipsilateral reflex

an automatic body response where the stimulus and the resulting action happen on the same side of the body

contralateral reflex

an automatic response on one side of the body causes a reflex action on the opposite side; helping with balance and coordination

Water-soluble hormones bind to plasma membrane receptors, which initiate a signal transduction pathway with which of the following processes?

• First messenger hormone docking with plasma receptor

• Activated protein kinase enzymes

• Second messenger pathways including G proteins and phospholipase C

• Second messenger pathways including G proteins and adenylate cyclase

The hypothalamus controls the ___ pituitary gland through hormonal regulation, while it controls the ____ pituitary through the hypothalamohypophyseal tract.

anterior; posterior

What is the name of the narrow band of tissue connecting the right and left lobes of the thyroid gland?

isthmus

The endocrine portion of the pancreas produces

insulin and glucagon

As a result of the general stress response, blood concentrations of epinephrine

and cortisol rise

Which organ produces angiotensinogen?

Liver