Anatomy Final Part 2 Study Guide

5 functions of the muscular system

5 functions of the muscular system

Support the body, allow for movement by making bones and other body parts move, maintain constant body temperature, assist in movement of cardiovascular veins and lymph, protect internal organs and stabilizes joints

2

Perimysium

3

Endomysium

1

Epimysium

Largest to smallest:

Myofibril, muscle fiber, fascicle, actin, myosin, muscle

Muscle, fascicle, muscle fiber, myofibril, myosin, actin

Thin filament

Actin

Thick filament

Myosin

I band

Contains only thin filaments

H zone

Contains only thick filaments

A band

Contains both thin and thick filaments

Z disc

protein disc within I band that anchors thin filaments and connects adjacent myofibrils

A

Z disc

C

I band

D

A band

B

H zone

Step 1 Muscle Contraction

An influx of Ca2+ causes thick myosin filaments to form crossbridges with the thin actin filament by exposing the binding site on actin.

Step 2 Muscle Contraction

The crossbridges change shape as it pulls on filaments which slides towards the center of the sarcomere in the power stroke (the distance between the Z line decreases, shortening the muscle)

Step 3 Muscle Contraction

The crossbridges detach from the actin filament when ATP bonds to myosin head

Step 4 Muscle Contraction

Step 4: The myosin head gets ready to bond to actin again using ATP energy (the cycle is repeated on another site of the actin filament)

What two molecules does actin need to pull on myosin?

ADP and P.

Insertion

Attached to the moveable bone

Origin

It is attached to the immovable (or less moveable) bone

Flexion

Bending movement, that decreases the angle of the joint and bring the articulating bones closer together

Extension

Opposite of flexion, it increases the angle of the joint and brings articulating bones further apart

Rotation

The turning of a bone around its own long axis

Adduction

Moving a part toward the midline

Abduction

Moving a part away from the body

Circumduction

Moving a limb so that it describes a cone in space

Difference between prime mover and antagonist

Prime mover is directly responsible for producing a desired motion, antagonist is a muscle that has action opposite that of prime mover, yields to movement of prime mover.

Difference between PNS and CNS

PNS consists of cranial and spinal nerves, CNS consists of brain and spinal cord.

Difference between sensory and motor divisions of the PNS

Sensory- sends impulses from the senses to CNS. Motor- sends impulses from CNS to muscles and glands

What is cell body of neuron as compared to dendrites and axons?

Cell body contains nucleus, cytoplasm, and organelles. Dendrites and axons are processes. Dendrites brings impulses to cell body, axons send impulses away from cell body.

Astrocytes function

support and anchor neurons to surrounding capillaries

Astrocytes CNS or PNS?

CNS

Microglia function

provide immune response to central nervous system

Microglia CNS or PNS?

CNS

Ependymal cells function

secrete and circulate cerebrospinal fluid

Ependymal cells CNS or PNS?

CNS

Oligodendrocytes function

provide myelin insulation to neurons in the central nervous system

Oligodendrocytes CNS or PNS?

CNS

Satellite cells function

support and anchor neurons in the peripheral nervous system

Satellite cells CNS or PNS?

PNS

Schwann cells function

provide myelin insulation to neurons in the peripheral nervous system

Schwann cells CNS or PNS?

PNS

What are the charges of a resting neuron as compared to its extracellular environment?

Neuron intracellular space is negative, extracellular space positively charged.

Depolarization

Negative membrane potential becomes less negative, reaches zero, then becomes positive.

Depolarization ion coming into neuron

Sodium

Repolarization

Membrane potential is restored to the resting state of -70mV

Repolarization ion coming into neuron

Potassium

How does a cell get back to its resting potential (what pump kicks in)?

The sodium-potassium pump restores ion concentrations to normal.

What is the importance of Ca+2 during release of neurotransmitters?

What are the three layers of meninges from outermost to intermost?

Dura mater (thick, tough layer), arachnoid membrane (thin, cobweb-like layer), pia mater (thin layer containing lots of blood vessels)

Where is CSF produced?

choroid plexuses (in the ventricles)

What is the general path of CSF?

Through the interventricular foramina to the third ventricle, then aqueduct of the midbrain, through the midbrain, into the fourth ventricle. Through median aperture and paired lateral apertures (opening in fourth ventricle), enters subarachnoid space, central canal of spinal cord, subarachnoid space around the surface of brain and spinal cord, reabsorbed through arachnoid granulations into blood.

Gyrus of the cerebrum

ridge in the surface of the cerebrum

Sulcus of the cerebrum

groove in the surface of the cerebrum

Corpus callosum in the cerebrum

a bundle of nerve fibers that connects the two hemispheres of the cerebrum

Cerebral cortex

the most superficial layer of the brain, “gray matter,” made of cell bodies and dendrites

Cerebral medulla

middle layer of the brain, “white matter,” made of myelinated axons

Basal nuclei

deepest layer of the brain, islands of gray matter

Frontal lobe function

voluntary movements, reasoning, decision-making, memory, ability to predict consequences of actions, planning, verbal communication (specifically in Broca’s area)

Parietal lobe function

sensations (pain, temperature, touch), visual-spatial processing, body position

Occipital lobe function

visual processing (vision and memory of objects)

Temporal lobe function

memory, comprehension & pronunciation of words, sensations of smell and sound, emotional association of memories

Thalamus function

relays sensory impulses to the cerebral cortex for processing and sorting

Pineal gland function

Hypothalamus function

responsible for autonomic processes (body temperature, metabolism, blood volume), controls hormones (released by pituitary gland), part of the limbic system which regulates emotions and feelings of pleasure (thirst, hunger, sex, pain)

Midbrain function (part of brainstem)

relays information to cerebrum, controls body movements and posture

Pons function (part of brainstem)

Medulla oblongata function (part of brainstem)

transmits impulses between spinal cord and brain + controls blood pressure, heart rate, coughing, swallowing

Importance of cerebellum

responsible for coordinating movements directed by cerebrum so they are graceful and efficient (involuntary)

How many spinal nerves do you have?

31 pairs

1

Central sulcus

2

Precentral gyrus

3

Occipital lobe

4

Cerebellum

5

Cerebellum

6

Parietal lobe

7

Corpus collosum

8

Thalamus

9

Hypothalamus

1

Olfactory nerve

2

Optic nerve

3

Oculomoter nerve

4

Trochlear nerve

5

Trigeminal nerve

6

Abducens nerve

7

Facial nerve

8

Vestibulocochlear nerve

9

Glossopharyngeal nerve

10

Vagus nerve

11

Accessory nerve

12

Hypoglossal nerve

a

orbicularis oculi

b

zygomaticus

c

depressor anguli oris

d

trapezius

e

pectoralis major

f

serratus anterior

g

rectus abdominis