Midterm Study Guide
Anatomy and Physiology
BIOS252
Midterm Study Guide
Anatomy and Physiology
BIOS252
Chapter 11
A. Muscles
1. Gastrocnemius (loc
... [Show More] ation)- back portion of the lower leg, being one of the two major muscles that make up the calf.
2. Muscles that make up the Hamstrings-Biceps Femoris, Semitendinosus, and Semimembranosus
3. Tibialis(location)- largest muscle located in the anterior(front)compartment of the leg
4. Brachialis (function)- muscle in the upper arm that flexes the elbow joint.
5. Deltoid (function)- Contraction of the anterior fibers flexes and medially rotates the arm by pulling the humerus towards the clavicle. Flexion and medial rotation of the arm moves the arm anteriorly (throwing a ball underhand). The lateral fibers abduct the arm by pulling the humerus toward the acromion (reaching out to the side). Contraction of the posterior fibers extends and laterally rotates the arm by pulling the humerus toward the spine of the scapula (reaching backwards or winding up to throw a ball underhand).
Chapter 12
A. Types of myelinated fibers
• Axis cylinder forms the central core of the fiber. It consists of axoplasm covered by axolemma.
• Myelin sheath derived from Schwann cells, surrounds the axis cylinder.
• Neurolemmal sheath (sheath of Schwann) surrounds the myelin sheath. It represents the plasma membrane (basal lamina) of the Schwann cell.
• Neurolemmal sheath is necessary for regeneration of a damaged nerve.
• Endoneurium is a delicate connective tissue sheath which surrounds the neurolemmal sheath.
B. Types of unmyelinated fibers
• smaller axons of the CNS, in addition to peripheral postganglionic autonomic fibers (C fibers of skin, muscle and viscera), olfactory nerves. Non-myelinated fiber consists of a group of small axons that have invaginated separately a single Schwann cell.
Chapter 13
A. Meninges and spaces associated with them-Dura Mater, outer most layer, Arachnoid is middle and Pia is the most inner (closest to the spinal cord). Subdural space between Dura and Arachnoid mater, you find intestinal fluid here. Subarachnoid space in between arachnoid and pia, the cerebrospinal fluid within this space. Denticulate is an extension off the Pia mater (ligaments)
B. External Anatomy of the spinal cord- Medulla Oblongata is in the brain. Spinal cord stops at L2, fluid continues down.
1. Cervical Enlargement-attachments of the large nerves which supply the upper limbs (C3-T2)
2. Lumbar Enlargement-attachment to the nerves which supply the lower limbs (T11-S2)
3. Filum terminals- filament of connective tissue that extends to the lowest part of the spinal cord. Acts as an anchor to the coccygeal
4. Cauda Equina-The primary function is to send and receive messages between the lower limbs and the pelvic organs. Fan shaped, the roots of the spinal nerves after the cord ends
5. Location of Epidural space-between the dura mater and inside the bony covering of the spinal cord
6. Spinal tap-lower back (lumbar region). A needle is inserted between two lumbar bones (vertebrae) to remove a sample of cerebrospinal fluid(L3-L4)
7. Length of the spinal cord-45 cm, Spinal cord stops at L2. Terminal end of the spinal cord is the Conus Medullaris (L2).
C. Internal Anatomy of the spinal cord
1. Spinal nerves-31 total pairs, 8 pairs of cervical(C1-C8), 12 pairs of thoracic (T1 – T12), 5 pairs of lumbar (L1-L5), 5 pairs of sacral (S1-S5), 1 pair of coccygeal nerves (Co1). Carries motor, sensory, and autonomic signals between the spinal cord and the body
2. Roots-connect each spinal nerve to a segment of the spinal cord.
• Posterior Root contains only sensory axons, going to the brain.
• Root Ganglion has cell bodies, sensory neurons.
• Posterior Root only has the axons.
• Anterior Root contains axons of motor neurons, going from the brain going to effectors (muscle or glands).
3. Horns-Gray matter is divided into horns
• Posterior gray horn-contains cell bodies of interneurons and sensory neurons,
• Anterior gray horn-sympatic motor neurons,
• Lateral gray horn-regions of the spinal cord in the thoracic and upper lumbar regions
• Autonomic motor neuros, cardiac, smooth, glands.
4. Shingles- an acute, painful inflammation of the nerve ganglia, with a skin eruption often forming a girdle around the middle of the body. It is caused by the same virus as chickenpox.
5. Dermatome-Certain segments of the skin are supplied by spinal nerves that carry somatic sensory nerve impulses to the brain. Pain via skin, depending on what part of the skin you can tell which part of the spinal cord is hurt.
6. Meningitis-inflammation of the meninges caused by viral or bacterial infection and marked by intense headache and fever, sensitivity to light, and muscular rigidity, leading to convulsions, delirium, and death.
7. Intervertebral foramen- foramen between two spinal vertebrae.
D. Plexus-network of axons.
• Cervical Plexus-It starts at C3-C5(phrenic nerve, goes to the diaphragm). If you hurt C2 then you can’t breathe on your own. Phrenic nerve causes the diaphragm to contract, if it isn’t contracting then it becomes more bell shaped. Head, neck, shoulder, chest, and diaphragm.
• Brachial Plexus-shoulder and upper limbs. Median Nerve C5-T1, if it is harmed it affected the hand, causing numbness, tingling. Radial Nerve can be damaged if improper injection to the deltoid muscle, cast to tight on the arm.
• Lumbar Plexus- Abnormal wall, parts of lower limbs, and external genital. Femoral Nerve L2-L4, damage caused by stabbing, or shooting and Obturator Nerve, thigh L2-L4, damage is paralysis to the thigh.
• Sacral Plexus- Butt, Buttock, and lower limbs. Sciatic nerve, starts off at one, but then branches off at the knee in the tibia and common fibular. L4-S3 most common back pain, lower body pain, or pinched nerve. Causes from slipped discs. Damage to the common fibular nerve will cause foot drop (tippy toes, or inability to flex leg).
Topic Areas for Essay questions
1. Muscle Fatigue-Inability to maintain force of contraction, Inadequate release Ca+ from SR, Buildup of lactic and ADP, and Insufficient release of Ach and NMJ
2. Description of different muscle types
• Skeletal Muscle-Multinucleate & contains long, nonbranching cylindrical cells, Found attach to bones, Voluntary control
• Cardiac Muscle-One nucleus, Found in the heart, Involuntary control
• Smooth Muscle-One nucleus in each cell, no striations, located on the hollow organs and blood vessels, Involuntary control
3. Steps in contraction cycle-
1. Calcium binds to troponin, rotation off tropomyosin off the active site on actin
2. Cross bridging occurs between the active site on the actin and myosin head
3. Myosin head pivots toward the center of the sarcomere pulling the Z lines closer causing contraction. Release store energy, calcium pulled out
4. Cross bridging detachment, the bond remains the same until the myosin head binds with another ATP molecule (rigor mortis)
5. Myosin activation, the free myosin head splits the ATP into ADP and P, which relocks the head again for the next cycle. The cycle stops when calcium levels return to low levels.
4. Neurotransmitter removal from Synapse-Diffusion, Enzymatic degradation, Uptake into the cells
5. Contributions to Resting Membrane Potential-Unequal distribution of ion across the plasma membrane and selective permeability of neurons, most ions cannot leave the cell, Na+ and K+ pumps
6. Description of Cross-sectional anatomy of spinal cord-
• Gray commissure; crossbar, that connects the two part of gray matter
• Central canal: in the middle find cerebral fluid
• Posterior gray horn: contains cell bodies, incoming sensory neurons
• Anterior gray horn: somatic motor neurons
• Lateral gray horn: only found in thoracic area and upper lumbar region (automatic neurons)
7. Description of External anatomy of spinal cord
• Cervical enlargement C4 to T1 nerves to upper limbs
• Lumbar Enlargement T9 to T12 nerves to lower limbs
• Conus medullaris: terminal of the spinal cord
• Filum Terminate: anchor coccyx bone
• Cauda equina: roots of spinal cord [Show Less]