Afferent Sensory Receptors from interoceptors (chemo or mechano) to CNS integration. Ex- monitor oxygen or BV stretch.
Efferent Sensory Receptors–from CNS out to effector organs (down white matter motor tracts of cord). The pathway to the effector organ is made up of at least 2 motor neurons with a synapse.
Sympathetic–Speeds up (excites) and consumes energy. “Fight or flight”
Parasympathetic–Slows down (inhibits) and conserves energy. “Rest and Digest”.
Autonomic Tone–The constant balance between the two branches (sympathetic and para-)
Sympathetic Division–Trunk (vertebral chain) ganglia – serves the upper body. Prevertebral (collateral) ganglia – serves below the diaphragm.
Divergent effect–One sympathetic preganglionic fiber has many axon collaterals and may synapse with 20 or more post ganglionic neurons.
Cholinergic receptors–Parasympathetic always releases ACH. Has 3 synapses.
Adrenergic–Sympathetic always releases Norepinephrine. Has 1 synapse.
Nicotinic–Found at the preganglionic ganglia, always cholinergic. Can only excite (depolarize) synapses
What are the levels of organization?

Superior–Towards the head, or upper part of a structure

Inferior–Towards the feet, or the lowest part of a structure

Anterior/Ventral–Nearer to or at the front of the body

Posterior/Dorsal– Nearer to or at the back of the body

Medial– Nearer to the midline or the midsagittal plane

Lateral–Farther away from the body midline or midsagittal plane

Intermediate–Between two structures

Proximal –Nearer to the attachment of a limb to a trunk

Distal–Farther from the attachment of a limb to the trunk

What most likely describes the epidermis?– Epithelial tissue made up of tightly packed stratified cells. Cells are filled with keratin and linked to one another to form a tight barrier between the environment and inside of the body.
What is the most abundant cell type in the epidermis?–Keratinocytes
What best describes the dermis?– Connective tissue consisting of dispersed cells that produce and extracellular matrix of collagen fibers.
Elastic Fibers / Collagen Fibers
What best describes a role for diffusion in skin physiology?– The highly vascular dermis must supply nutrients to the vascular epidermis. The nutrients are released in the dermis and diffuse from high concentration in the dermis to the lower concentration in the epidermis
What is the order of a life cycle of a keratinocyte?
1. A stem cell in the basal layer divides and turns into a keratinocyte.
2. Continuous cell division pushes the newly made keratinocyte upward.
3. As the keratinocyte moves upward, it produces keratin that fills the cells.
4. As the keratinocyte gets closer to the surface of the body the cell dies. The organelles and nucleus are lost but the shell of the cell remains filled with keratin.
5. The dead keratinocytes are linked strongly to one another and then are eventually sloughed off into the environment.
After a keratinocyte dies can it keep making keratin? why or why not?– No, once the nucleus is degraded and the ribosomes are lost there is no way to express the genes for keratin and make the protein.
What is a keratinocyte?–The major cell type in the epidermis. Produces keratin to form the strong structural framework of the skin.
What is a stem cell?– Cells scattered in the basal layer of the epidermis that divide to give rise to keratinocytes.
Which of the following is a vital sign?
(All of the above)
– blood pressure
– pulse rate
-body temperature
Cells lose water when placed in which of the following solutions?– Hypertonic
Which of the following substances comprise over 95% of the human body?–carbon, hydrogen, oxygen, nitrogen
endoplasmic reticulum is best described as–a network of interconnected membranous chambers
Matter is composed of _____, which themselves are made up of ______.
How is molecular oxygen used by living organisms?–it is used to release energy that is stored in food.
True of false: Nucleic acids are composed of building blocks called amino acids, which have an amine and an acid group in the molecule.– false
Which of the following substances is an element?–iron
If we divide the body or any organ across the middle on the shortest axis, this would be called what type of section?–transverse